| 1. |
- Ansari, Abdul W., et al.
(författare)
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Brief Report: Diminished Coinhibitory Molecule 2B4 Expression Is Associated With Preserved iNKT Cell Phenotype in HIV Long-Term Nonprogressors
- 2020
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Ingår i: Journal of Acquired Immune Deficiency Syndromes. - : LIPPINCOTT WILLIAMS & WILKINS. - 1525-4135 .- 1944-7884. ; 85:1, s. 73-78
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Tidskriftsartikel (refereegranskat)abstract
- Background: We have previously shown an association of elevated coinhibitory molecule 2B4 expression with iNKT cells alterations in HIV disease. Herein, we show a comparative analysis of 2B4 expression on iNKT cells of HIV long-term nonprogressors (LTNPs) and progressors. Methods: Antiretroviral therapy-naive HIV-seropositive individuals (progressors, n = 16) and LTNPs (n = 10) were recruited for this study. We used multicolor flow cytometry on frozen peripheral blood mononuclear cells to determine iNKT subset frequencies, the levels of coinhibitory 2B4 expression, and intracellular interferon-gamma (IFN-gamma) production. CD1d tetramer was used to characterize iNKT cells. Results: We report significantly lower level of 2B4 expression on bulk LTNPs iNKT cells and on their CD4 subsets compared with HIV progressors. Furthermore, the iNKT cells from LTNPs produced higher amount of IFN-gamma than HIV progressors as detected by intracellular cytokine staining. Interestingly, the frequency of 2B4(+)iNKT cells of progressors but not LTNPs significantly correlates with CD4 T-cell count, HIV viral load, and IFN-gamma(+)production by iNKT cells. Conclusion: Our results suggest that in addition to suppressed HIV replication, diminished 2B4 expression and associated coinhibitory signaling, and substantial production of IFN-gamma could contribute to preserved iNKT cell phenotype in LTNPs.
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| 2. |
- Barathan, Muttiah, et al.
(författare)
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CD8+T cells of chronic HCV-infected patients express multiple negative immune checkpoints following stimulation with HCV peptides
- 2017
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Ingår i: Cellular Immunology. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0008-8749 .- 1090-2163. ; 313
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis C virus (HCV)-specific CD4+ and CD8+ T cells are key to successful viral clearance in HCV disease. Accumulation of exhausted HCV-specific T cells during chronic infection results in considerable loss of protective functional immune responses. The role of T-cell exhaustion in chronic HCV disease remains poorly understood. Here, we studied the frequency of HCV peptide-stimulated T cells expressing negative immune checkpoints (PD-1, CTLA-4, TRAIL, TIM-3 and BTLA) by flow cytometry, and measured the levels of Th1/Th2/Th17 cytokines secreted by T cells by a commercial Multi-Analyte ELISArray (TM) following in vitro stimulation of T cells using HCV peptides and phytohemagglutinin (PHA). HCV peptide stimulated CD4+ and CD8+ T cells of chronic HCV (CHC) patients showed significant increase of CTLA-4. Furthermore, HCV peptide-stimulated CD4+ T cells of CHC patients also displayed relatively higher levels of PD-1 and TRAIL, whereas TIM-3 was up-regulated on HCV peptide-stimulated CD8+ T cells. Whereas the levels of IL-10 and TGF-beta 1 were significantly increased, the levels of pro-inflammatory cytokines IL-2, TNF-alpha, IL-17A and IL-6 were markedly decreased in the T cell cultures of CHC patients. Chronic HCV infection results in functional exhaustion of CD4+ and CD8+ T cells likely contributing to viral persistence. (C) 2016 Elsevier Inc. All rights reserved.
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| 3. |
- Barathan, Muttiah, et al.
(författare)
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Chronic hepatitis C virus infection triggers spontaneous differential expression of biosignatures associated with T cell exhaustion and apoptosis signaling in peripheral blood mononucleocytes
- 2015
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Ingår i: Apoptosis (London). - : Springer Verlag (Germany). - 1360-8185 .- 1573-675X. ; 20:4, s. 466-480
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Tidskriftsartikel (refereegranskat)abstract
- Persistent hepatitis C virus (HCV) infection appears to trigger the onset of immune exhaustion to potentially assist viral persistence in the host, eventually leading to hepatocellular carcinoma. The role of HCV on the spontaneous expression of markers suggestive of immune exhaustion and spontaneous apoptosis in immune cells of chronic HCV (CHC) disease largely remain elusive. We investigated the peripheral blood mononuclear cells of CHC patients to determine the spontaneous recruitment of cellular reactive oxygen species (cROS), immunoregulatory and exhaustion markers relative to healthy controls. Using a commercial QuantiGenePlex(A (R)) 2.0 assay, we determined the spontaneous expression profile of 80 different pro- and anti-apoptotic genes in persistent HCV disease. Onset of spontaneous apoptosis significantly correlated with the up-regulation of cROS, indoleamine 2,3-dioxygenase (IDO), cyclooxygenase-2/prostaglandin H synthase (COX-2/PGHS), Foxp3, Dtx1, Blimp1, Lag3 and Cd160. Besides, spontaneous differential surface protein expression suggestive of T cell inhibition viz., TRAIL, TIM-3, PD-1 and BTLA on CD4+ and CD8+ T cells, and CTLA-4 on CD4+ T cells was also evident. Increased up-regulation of Tnf, Tp73, Casp14, Tnfrsf11b, Bik and Birc8 was observed, whereas FasLG, Fas, Ripk2, Casp3, Dapk1, Tnfrsf21, and Cflar were moderately up-regulated in HCV-infected subjects. Our observation suggests the spontaneous onset of apoptosis signaling and T cell exhaustion in chronic HCV disease.
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| 4. |
- Barathan, Muttiah, et al.
(författare)
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Hepatitis C virus infection contributes to impregnation of markers of immune inhibition : potential preludes underlying viral latency and persistence
- 2014
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Ingår i: BMC Infectious Diseases. - : Springer Nature. - 1471-2334. ; 14:Suppl 3
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundHepatitis C virus (HCV) represents one of the persistent viral infections afflicting humankind, and a significant proportion of chronic HCV disease progresses over time through liver fibrosis, cirrhosis and hepatocellular carcinoma (HCC). One potential mechanism underlying the chronic disease is believed to be viral escape from immune surveillance via upregulation of inhibitory molecules on immune cells by HCV. We investigated the diverse expression of various inhibitory molecules in PBMCs of healthy non-HCV controls and chronically HCV infected patients.MethodsThe expression of inhibitory molecules on PBMCs was investigated in chronic HCV infected patients relative to healthy non-HCV controls using standard immunological and molecular methods. The serum levels of indoleamine 2, 3 deoxygenase (IDO) and cyclooxygenase-2 (COX-2) were also investigated.ResultsThe gene expression profile of chronically HCV infected patients was significantly different from control individuals. Our results showed upregulation of TIM-3 (p≤0.01), PD-1 (p≤0.01), FOXP-3 (p≤0.01), BLIMP-1 (p≤0.01), CD160 (p≤0.01), CTLA-4 (p≤0.01), TRAIL (p≤0.01), BTLA (p≤0.01) and LAG-3 (p≤0.01) with fold change of 1.3, 0.4, 14.6, 0.87, 6.6, 0.4, 14.7, 10.9 and 2.5 respectively in chronically HCV infected patients. The plasma IDO and COX-2 levels were significantly higher (p=0.001) in chronically HCV infected subjects relative to healthy control.ConclusionThe upregulation of inhibitory molecules on PBMCs in chronically HCV infected patients suggest the contribution of these molecules to immune cells impairment in HCV infection. Viral persistence and eventual progression following potential evasion of the host immune armory via viral impregnation of inhibitory immune biosignatures in HCV disease pathogenesis warrants further elucidation.
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| 5. |
- Barathan, Muttiah, et al.
(författare)
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Increased frequency of late-senescent T cells lacking CD127 in chronic hepatitis C disease
- 2015
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Ingår i: European Journal of Clinical Investigation. - : Wiley. - 0014-2972 .- 1365-2362. ; 45:5, s. 466-474
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundHepatitis C virus (HCV) causes persistent disease in similar to 85% of infected individuals, where the viral replication appears to be tightly controlled by HCV-specific CD8+ T cells. Accumulation of senescent T cells during infection results in considerable loss of functional HCV-specific immune responses. Materials and methodsWe characterized the distinct T-cell phenotypes based on the expression of costimulatory molecules CD28 and CD27, senescence markers PD-1 and CD57, chronic immune activation markers CD38 and HLA-DR, and survival marker CD127 (IL-7R) by flow cytometry following activation of T cells using HCV peptides and phytohemagglutinin. ResultsHCV-specific CD4+ and CD8+ T cells from chronic HCV (CHC) patients showed increased expression of PD-1. Furthermore, virus-specific CD4+ T cells of CHC-infected subjects displayed relatively increased expression of HLA-DR and CD38 relative to HCV-specific CD8+ T cells. The CD4+ and CD8+ T cells from HCV-infected individuals showed significant increase of late-differentiated T cells suggestive of immunosenescence. In addition, we found that the plasma viral loads positively correlated with the levels of CD57 and PD-1 expressed on T cells. ConclusionsChronic HCV infection results in increased turnover of late-senescent T cells that lack survival potentials, possibly contributing to viral persistence. Our findings challenge the prominence of senescent T-cell phenotypes in clinical hepatitis C infection.
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| 6. |
- Barathan, Muttiah, et al.
(författare)
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Peripheral loss of CD8(+)CD161(++)TCRV7 center dot 2(+) mucosal-associated invariant T cells in chronic hepatitis C virus-infected patients
- 2016
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Ingår i: European Journal of Clinical Investigation. - : WILEY-BLACKWELL. - 0014-2972 .- 1365-2362. ; 46:2, s. 170-180
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMucosal-associated invariant T (MAIT) cells play an important role in innate host defence. MAIT cells appear to undergo exhaustion and are functionally weakened in chronic viral infections. However, their role in chronic hepatitis C virus (HCV) infection remains unclear. Materials and methodsWe investigated the frequency of CD8(+)CD161(++)TCR V7.2(+) MAIT cells in a cross-sectional cohort of chronic HCV-infected patients (n = 25) and healthy controls (n = 25). Peripheral blood mononuclear cells were investigated for circulating MAIT cell frequency, liver-homing (CCR5 and CD103), biomarkers of immune exhaustion (PD-1, TIM-3 and CTLA-4), chronic immune activation (CD38 and HLA-DR), and immunosenescence (CD57) by flow cytometry. ResultsThe frequency of MAIT cells was significantly decreased, and increased signs of immune exhaustion and chronic immune activation were clearly evident on MAIT cells of HCV-infected patients. Decrease of CCR5 on circulating MAIT cells is suggestive of their peripheral loss in chronic HCV-infected patients. MAIT cells also showed significantly increased levels of HLA-DR, CD38, PD-1, TIM-3 and CTLA-4, besides CD57 in chronic HCV disease. ConclusionsImmune exhaustion and senescence of CD8(+)CD161(++)TCR V7.2(+) MAIT cells could contribute to diminished innate defence attributes likely facilitating viral persistence and HCV disease progression.
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| 7. |
- Larsson, Marie, et al.
(författare)
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Molecular signatures of T-cell inhibition in HIV-1 infection
- 2013
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Ingår i: Retrovirology. - : BioMed Central. - 1742-4690. ; 10:1
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Forskningsöversikt (refereegranskat)abstract
- Cellular immune responses play a crucial role in the control of viral replication in HIV-infected individuals. However, the virus succeeds in exploiting the immune system to its advantage and therefore, the host ultimately fails to control the virus leading to development of terminal AIDS. The virus adopts numerous evasion mechanisms to hijack the host immune system. We and others recently described the expression of inhibitory molecules on T cells as a contributing factor for suboptimal T-cell responses in HIV infection both in vitro and in vivo. The expression of these molecules that negatively impacts the normal functions of the host immune armory and the underlying signaling pathways associated with their enhanced expression need to be discussed. Targets to restrain the expression of these molecular markers of immune inhibition is likely to contribute to development of therapeutic interventions that augment the functionality of host immune cells leading to improved immune control of HIV infection. In this review, we focus on the functions of inhibitory molecules that are expressed or secreted following HIV infection such as BTLA, CTLA-4, CD160, IDO, KLRG1, LAG-3, LILRB1, PD-1, TRAIL, TIM-3, and regulatory cytokines, and highlight their significance in immune inhibition. We also highlight the ensemble of transcriptional factors such as BATF, BLIMP-1/PRDM1, FoxP3, DTX1 and molecular pathways that facilitate the recruitment and differentiation of suppressor T cells in response to HIV infection.
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| 8. |
- Preeyaa, Sathappan U., et al.
(författare)
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Peripheral Follicular T Helper Cells and Mucosal-Associated Invariant T Cells Represent Activated Phenotypes During the Febrile Phase of Acute Dengue Virus Infection
- 2020
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Ingår i: Viral immunology. - : MARY ANN LIEBERT, INC. - 0882-8245 .- 1557-8976. ; 33:9, s. 610-615
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Tidskriftsartikel (refereegranskat)abstract
- Peripheral follicular helper T (pTfh) cells represent specialized CD4(+)T cells that help B cells to secrete antibodies. Dengue infection appears to cause immune activation in a wide array of immune cells. Herein, we investigated the signatures of immune activation of circulating Tfh cells and mucosal-associated invariant T (MAIT) cells in adult subjects with confirmed acute clinical dengue virus (DENV) infection by multiparametric flow cytometry. The acute DENV infection induced a significant expansion and activation of pTfh cells and circulating MAIT cells during acute febrile infection. We found a higher frequency of activated PD-1(+)Tfh cells and CD38(+)pTfh cells in clinical DENV infection. We also found similar activated and expanding phenotypes of MAIT cells in the patients tested. The numbers of activated pTfh cells and circulating MAIT cells were higher in dengue patients relative to healthy controls. We concluded that pTfh cells and circulating MAIT cells represent activated phenotypes in acute DENV infection.
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| 9. |
- Saeidi, Alireza, et al.
(författare)
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Attrition of TCR Va7.2+CD161++ MAIT Cells in HIV-Tuberculosis Co-Infection Is Associated with Elevated Levels of PD-1 Expression
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 10:4, s. e0124659-
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Tidskriftsartikel (refereegranskat)abstract
- Mucosal-associated invariant T (MAIT) cells are evolutionarily conserved antimicrobial MR1-restricted CD8+ T cells co-expressing the semi-invariant TCR V alpha 7.2, and are numerous in the blood and mucosal tissues of humans. MAIT cells appear to undergo exhaustion in chronic viral infections. However, their role in human immunodeficiency virus type 1 (HIV1) mono-infection and HIV/tuberculosis (TB) co-infection have seldom been elaborately investigated. We conducted a cross-sectional study to investigate the frequencies and phenotypes of CD161++ CD8+ T cells among anti-retroviral therapy (ART)/anti-TB therapy (ATT) treatment-naive HIV/TB co-infected, ART/TB treated HIV/TB co-infected, ART naive HIV-infected, ART-treated HIV-infected patients, and HIV negative healthy controls (HCs) by flow cytometry. Our data revealed that the frequency of MAIT cells was severely depleted in HIV mono-and HIV/TB co-infections. Further, PD-1 expression on MAIT cells was significantly increased in HIV mono-and HIV-TB co-infected patients. The frequency of MAIT cells did not show any significant increase despite the initiation of ART and/or ATT. Majority of the MAIT cells in HCs showed a significant increase in CCR6 expression as compared to HIV/TB co-infections. No marked difference was seen with expressions of chemokine co-receptor CCR5 and CD103 among the study groups. Decrease of CCR6 expression appears to explain why HIV-infected patients display weakened mucosal immune responses.
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| 10. |
- Saeidi, Alireza, et al.
(författare)
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Concurrent loss of co-stimulatory molecules and functional cytokine secretion attributes leads to proliferative senescence of CD8(+) T cells in HIV/TB co-infection
- 2015
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Ingår i: Cellular Immunology. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0008-8749 .- 1090-2163. ; 297:1, s. 19-32
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Tidskriftsartikel (refereegranskat)abstract
- The role of T-cell immunosenescence and functional CD8(+) T-cell responses in HIV/TB co-infection is unclear. We examined and correlated surrogate markers of HIV disease progression with immune activation, immunosenescence and differentiation using T-cell pools of HIV/TB co-infected, HIV-infected and healthy controls. Our investigations showed increased plasma viremia and reduced CD4/CD8 T-cell ratio in HIV/TB co-infected subjects relative to HIV-infected, and also a closer association with changes in the expression of CD38, a cyclic ADP ribose hydrolase and CD57, which were consistently expressed on late-senescent CD8(+) T cells. Up-regulation of CD57 and CD38 were directly proportional to lack of co-stimulatory markers on CD8(+) T cells, besides diminished expression of CD127 (IL-7R alpha) on CD57(+)CD4(+) T cells. Notably, intracellular IFN-gamma, perforin and granzyme B levels in HIV-specific CD8(+) T cells of HIV/TB co-infected subjects were diminished. Intracellular CD57 levels in HIV gag p24-specific CD8(+) T cells were significantly increased in HIV/TB co-infection. We suggest that HIV-TB co-infection contributes to senescence associated with chronic immune activation, which could be due to functional insufficiency of CD8(+) T cells. (C) 2015 Elsevier Inc. All rights reserved.
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| 11. |
- Saeidi, Alireza, et al.
(författare)
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Functional role of mucosal-associated invariant T cells in HIV infection
- 2016
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Ingår i: Journal of Leukocyte Biology. - : FEDERATION AMER SOC EXP BIOL. - 0741-5400 .- 1938-3673. ; 100:2, s. 305-314
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Forskningsöversikt (refereegranskat)abstract
- MAIT cells represent an evolutionarily conserved, MR1-restricted, innate-like cell subset that express high levels of CD161; have a canonical semi-invariant TCR iV alpha 7.2; and may have an important role in mucosal immunity against various bacterial and fungal pathogens. Mature MAIT cells are CD161(hi)PLZF(hi)IL-18R alpha(+)iV alpha 7.2(+)gamma delta-CD3(+)CD8(+) T cells and occur in the peripheral blood, liver, and mucosa of humans. MAIT cells are activated by a metabolic precursor of riboflavin synthesis presented by MR1 and, therefore, respond to many bacteria and some fungi. Despite their broad antibacterial properties, their functional role in persistent viral infections is poorly understood. Although there is an increasing line of evidence portraying the depletion of MAIT cells in HIV disease, the magnitude and the potential mechanisms underlying such depletion remain unclear. Recent studies suggest that MAIT cells are vulnerable to immune exhaustion as a consequence of HIV and hepatitis C virus infections and HIV/tuberculosis coinfections. HIV infection also appears to cause functional depletion of MAIT cells resulting from abnormal expression of T-bet and EOMES, and effective ART is unable to completely salvage functional MAIT cell loss. Depletion and exhaustion of peripheral MAIT cells may affect mucosal immunity and could increase susceptibility to opportunistic infections during HIV infection. Here, we review some of the important mechanisms associated with depletion and functional loss of MAIT cells and also suggest potential immunotherapeutic strategies to restore MAIT cell functions, including the use of IL-7 to restore effector functions in HIV disease.
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| 12. |
- Saeidi, Alireza, et al.
(författare)
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Regulation of CD8+T-cell cytotoxicity in HIV-1 infection
- 2015
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Ingår i: Cellular Immunology. - : ACADEMIC PRESS INC ELSEVIER SCIENCE. - 0008-8749 .- 1090-2163. ; 298:1-2, s. 126-133
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Forskningsöversikt (refereegranskat)abstract
- Understanding the mechanisms involved in cellular immune responses against control of human immunodeficiency virus (HIV) infection is key to development of effective immunotherapeutic strategies against viral proliferation. Clear insights into the regulation of cytotoxic CD8+ T cells is crucial to development of effective immunotherapeutic strategies due to their unique ability to eliminate virus-infected cells during the course of infection. Here, we reviewed the roles of transcription factors, co-inhibitory molecules and regulatory cytokines following HIV infection and their potential significance in regulating the cytotoxic potentials of CD8+ T cells. (C) 2015 Elsevier Inc. All rights reserved.
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| 13. |
- Selvavinayagam, Sivaprakasam T., et al.
(författare)
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Clinical characteristics and novel mutations of omicron subvariant XBB in Tamil Nadu, India - a cohort study
- 2023
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Ingår i: The Lancet Regional Health - Southeast Asia. - : ELSEVIER. - 2772-3682. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Background Despite the continued vaccination efforts, there had been a surge in breakthrough infections, and the emergence of the B.1.1.529 omicron variant of SARS-CoV-2 in India. There is a paucity of information globally on the role of newer XBB variants in community transmission. Here, we investigated the mutational patterns among hospitalised patients infected with the XBB omicron sub-variant, and checked if there was any association between the rise in the number of COVID-19 cases and the observed novel mutations in Tamil Nadu, India. Methods Nasopharyngeal and oropharyngeal swabs, collected from symptomatic and asymptomatic COVID-19 patients were subjected to real-time PCR followed by Next Generation Sequencing (NGS) to rule out the ambiguity of mutations in viruses isolated from the patients (n = 98). Using the phylogenetic association, the mutational patterns were used to corroborate clinico-demographic characteristics and disease severity among the patients. Findings Overall, we identified 43 mutations in the S gene across 98 sequences, of which two were novel mutations (A27S and T747I) that have not been reported previously with XBB sub-variants in the available literature. Additionally, the XBB sequences from our cohort had more mutations than omicron B.1.1.529. The phylogenetic analysis comprising six major branches clearly showed convergent evolution of XBB. Our data suggests that age, and underlying conditions (e.g., diabetes, hypertension, and cardiovascular disease) or secondary complications confers increased susceptibility to infection rather than vaccination status or prior exposure. Many vaccinated individuals showed evidence of a breakthrough infection, with XBB.3 being the predominant variant identified in the study population. Interpretation Our study indicates that the XBB variant is highly evasive from available vaccines and may be more transmissible, and potentially could emerge as the 'next' predominant variant, which likely could overwhelm the existing variants of SARS-CoV-2 omicron variants.Funding National Health Mission (India), SIDA SARC, VINNMER (Sweden), ORIP/NIH (USA).Copyright (c) 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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| 14. |
- Selvavinayagam, Sivaprakasam T., et al.
(författare)
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Emergence of SARS-CoV-2 omicron variant JN.1 in Tamil Nadu, India - Clinical characteristics and novel mutations
- 2024
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Ingår i: Scientific Reports. - : NATURE PORTFOLIO. - 2045-2322. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- In December 2023, we observed a notable shift in the COVID-19 landscape, when JN.1 omicron emerged as the predominant SARS-CoV-2 variant with a 95% incidence. We characterized the clinical profile, and genetic changes in JN.1, an emerging SARS-CoV-2 variant of interest. Whole genome sequencing was performed on SARS-CoV-2 positive clinical specimens, followed by sequence analysis. Mutations within the spike protein sequences were analysed and compared with the previously reported lineages and sub-lineages, to identify the potential impact of the unique mutations on protein structure and possible alterations in the functionality. Several unique and dynamic mutations were identified herein. Molecular docking analysis showed changes in the binding affinity, and key interacting residues of wild-type and mutated structures with key host cell receptors of SARS-CoV-2 entry viz., ACE2, CD147, CD209L and AXL. Our data provides key insights on the emergence of newer variants and highlights the necessity for robust and sustained global genomic surveillance of SARS-CoV-2.
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| 15. |
- Selvavinayagam, Sivaprakasam T., et al.
(författare)
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Evolution of the Omicron B.1.1.529 Sars-Cov-2 and its Variants in Tamil Nadu, India – a State-Wide Prospective Longitudinal Genomic Surveillance
- 2023
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: The emergence of the omicron SARS-CoV-2 variant beholding many mutations, especially in the spike (S) protein severely threatens global health. With an aim to understand the mutational pattern of the variant and its genetic interrelationship in the Indian population, here we prospectively followed the viral evolution and transmission between December 2021 and March 2023 in Tamil Nadu.Methods: A total of 11526 nasopharyngeal and oropharyngeal swabs (6431 males, 5095 females including 603 children) collected from across the 38 districts of Tamil Nadu were subjected to WGS. Of the 10663 samples (92.5%) positive for omicron variants, 1688 were sequenced at the State Public Health Laboratory. We longitudinally studied the evolutionary dynamics of the different omicron variants, starting from the first detected case (B.1.1.529) to the recently reported recombinant XBB variants by sequencing the S gene and by performing phylo-geographic and molecular modeling analyses.Findings: Administration of a booster dose was associated with reduced risk of hospitalization and death. BA.1 sub-variants and BA.2.75 were associated with increased risk of severe disease, whereas BA.1 and BA.2 were associated with increased risk of death. High quality WGS data from 150 samples revealed six major omicron clusters and several other sub-clusters. Seven variants in the same BA lineages with different divergences in the S protein were noticed. Of the 5009 mutations detected, the highest was seen in the receptor-binding domain (RBD) followed by the N-terminal domain (NTD) in varying proportions among the different omicron lineages. Importantly, the mutations were observed in the sub-domain (SD1/2) furin cleavage site, fusion peptide (FP), and the heptapeptide repeat sequence (HR1) regions. Notably, unique mutations Y473I, P479F, C480F, V483T, E484C, G485T, P491G, L492K, S494M, Y495C, and G496Q were detected in BA.2.43 whereas A475Q and T478S occurred in the RBD domain of the BA.2.43 variant. The XBB variant showed 41 different mutations between the HR1 and HR2 domains of the S2 subunit. Molecular modeling using BA.2 lineage as a template for seven divergent proteins showed that BA.2.12.1, BA.4 and BA.5 exhibited strong binding affinity towards ACE2.Interpretation: The high frequency of mutations in the RBD highlights the wider distribution of vaccine escape-variants that would impact the structural and functional attributes of the omicron variant in the population. Further, our work provides key insights on the evolutionary pattern leading to the identification of seven divergent variants of omicron in Tamil Nadu, India.
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| 16. |
- Selvavinayagam, Sivaprakasam T., et al.
(författare)
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Genomic surveillance of omicron B.1.1.529 SARS‐CoV‐2 and its variants between December 2021 and March 2023 in Tamil Nadu, India—A state‐wide prospective longitudinal study
- 2024
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Ingår i: Journal of Medical Virology. - : John Wiley & Sons. - 0146-6615 .- 1096-9071. ; 96:2
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Tidskriftsartikel (refereegranskat)abstract
- A state-wide prospective longitudinal investigation of the genomic surveillance of the omicron B.1.1.529 SARS-CoV-2 variant and its sublineages in Tamil Nadu, India, was conducted between December 2021 and March 2023. The study aimed to elucidate their mutational patterns and their genetic interrelationship in the Indian population. The study identified several unique mutations at different time-points, which likely could attribute to the changing disease characteristics, transmission, and pathogenicity attributes of omicron variants. The study found that the omicron variant is highly competent in its mutating potentials, and that it continues to evolve in the general population, likely escaping from natural as well as vaccine-induced immune responses. Our findings suggest that continuous surveillance of viral variants at the global scenario is warranted to undertake intervention measures against potentially precarious SARS-CoV-2 variants and their evolution.
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| 17. |
- Selvavinayagam, Sivaprakasam T, et al.
(författare)
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Plasma CXCL8 and MCP-1 as biomarkers of latent tuberculosis infection
- 2023
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- BackgroundEarly detection of latent tuberculosis infection (LTBI) is critical to TB elimination in the current WHO vision of End Tuberculosis Strategy.Methods We investigated whether detecting plasma cytokines could aid in diagnosing LTBI across household contacts (HHCs) positive for IGRA, HHCs negative for IGRA, and healthy controls. We also measured the plasma cytokines using a commercial Bio-Plex Pro Human Cytokine 17-plex assay.ResultsIncreased plasma CXCL8 and decreased MCP-1, TNF-α, and IFN-γ were associated with LTBI. Regression analysis showed that a combination of CXCL8 and MCP-1 increased the risk of LTBI among HHCs to 14-fold.ConclusionsWe postulated that CXCL8 and MCP-1 could be the surrogate biomarkers of LTBI, especially in resource-limited settings.
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| 18. |
- Selvavinayagam, Sivaprakasam T, et al.
(författare)
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Plasma CXCL8 and MCP-1 as surrogate plasma biomarkers of latent tuberculosis infection among household contacts-A cross-sectional study
- 2023
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Ingår i: PLOS Global Public Health. - : Public Library of Science (PLoS). - 2767-3375. ; 3:11
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Tidskriftsartikel (refereegranskat)abstract
- Early detection of latent tuberculosis infection (LTBI) is critical to TB elimination in the current WHO vision of End Tuberculosis Strategy. The study investigates whether detecting plasma cytokines could aid in diagnosing LTBI across household contacts (HHCs) positive for IGRA, HHCs negative for IGRA, and healthy controls. The plasma cytokines were measured using a commercial Bio-Plex Pro Human Cytokine 17-plex assay. Increased plasma CXCL8 and decreased MCP-1, TNF-a, and IFN-? were associated with LTBI. Regression analysis showed that a combination of CXCL8 and MCP-1 increased the risk of LTBI among HHCs to 14-fold. Our study suggests that CXCL-8 and MCP-1 could serve as the surrogate biomarkers of LTBI, particularly in resource-limited settings. Further laboratory investigations are warranted before extrapolating CXCL8 and MCP-1 for their usefulness as surrogate biomarkers of LTBI in resource-limited settings.
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| 19. |
- Selvavinayagam, Sivaprakasam T., et al.
(författare)
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Platelet-Large Cell Ratio and Erythrocyte Sedimentation Rate are Surrogate Predictors of Latent Tuberculosis Infection
- 2024
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Aims: Prompt detection and treatment of latent tuberculosis infection (LTBI) holds the key to global TB elimination. The lack of an established test for predicting LTBI poses a substantial challenge in disease management. Here, we identified the biochemical and hematological markers of LTBI, and correlated their usefulness to discriminate LTBI from healthy controls. Main Methods: We conducted a cross-sectional investigation and correlated the various biochemical and hematological markers for detecting LTBI among household contacts (HHCs) of TB infection. Our study included 90 individuals – 30 healthy controls, 30 interferon-gamma release assay (IGRA) positive HHCs, and 30 IGRA-negative HHCs. Biomarkers were measured using designated auto analyzers. Key Findings: ESR, MPV, D-dimer, P-LCR, and PDW were significantly higher among LTBI subjects. ESR, PDW, and P-LCR were markedly associated with LTBI. Multivariate analysis showed that either ESR or P-LCR greater than their respective predetermined cut-off values showed higher odds of developing LTBI. Our study demonstrated that ESR and P-LCR are good surrogate markers for diagnosing LTBI. Also, significantly low ferritin in females and MCHC in males belonging to the HHC/IGRA-ve were observed. Significance: The ESR and P-LCR could aid in predicting LTBI among HHCs. Further, the low serum ferritin is associated with TB resisters.
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| 20. |
- Shankar, Esaki M., et al.
(författare)
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Asymptomatic SARS-CoV-2 infection: is it all about being refractile to innate immune sensing of viral spare-parts?-Clues from exotic animal reservoirs
- 2021
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Ingår i: Pathogens and Disease. - : OXFORD UNIV PRESS. - 2049-632X. ; 79:1
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Tidskriftsartikel (refereegranskat)abstract
- A vast proportion of coronavirus disease 2019 (COVID-19) individuals remain asymptomatic and can shed severe acute respiratory syndrome (SARS-CoV) type 2 virus to transmit the infection, which also explains the exponential increase in the number of COVID-19 cases globally. Furthermore, the rate of recovery from clinical COVID-19 in certain pockets of the globe is surprisingly high. Based on published reports and available literature, here, we speculated a few immunovirological mechanisms as to why a vast majority of individuals remain asymptomatic similar to exotic animal (bats and pangolins) reservoirs that remain refractile to disease development despite carrying a huge load of diverse insidious viral species, and whether such evolutionary advantage would unveil therapeutic strategies against COVID-19 infection in humans. Understanding the unique mechanisms that exotic animal species employ to achieve viral control, as well as inflammatory regulation, appears to hold key clues to the development of therapeutic versatility against COVID-19.
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| 21. |
- Shankar, Esaki M., et al.
(författare)
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HIV-Mycobacterium tuberculosis co-infection: a `danger-couplemodel of disease pathogenesis
- 2014
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Ingår i: PATHOGENS AND DISEASE. - : Wiley / Blackwell Publishing Ltd. - 2049-632X. ; 70:2, s. 110-118
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Forskningsöversikt (refereegranskat)abstract
- Tuberculosis (TB) and human immunodeficiency virus (HIV) infection interfere and impact the pathogenesis phenomena of each other. Owing to atypical clinical presentations and diagnostic complications, HIV/TB co-infection continues to be a menace for healthcare providers. Although the increased access to highly active antiretroviral therapy (HAART) has led to a reduction in HIV-associated opportunistic infections and mortality, the concurrent management of HIV/TB co-infection remains a challenge owing to adverse effects, complex drug interactions, overlapping toxicities and tuberculosis -associated immune reconstitution inflammatory syndrome. Several hypotheses have been put forward for the exacerbation of tuberculosis by HIV and vice versa supported by immunological studies. Discussion on the mechanisms produced by infectious cofactors with impact on disease pathology could shed light on how to design potential interventions that could decelerate disease progression. With no vaccine for HIV and lack of an effective vaccine for tuberculosis, it is essential to design strategies against HIV–TB co-infection.
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| 22. |
- Shankar, Esaki M., et al.
(författare)
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Understanding Immune Senescence, Exhaustion, and Immune Activation in HIV–Tuberculosis Coinfection
- 2017
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Ingår i: Handbook of Immunosenescence: Basic Understanding and Clinical Implications. - Cham : Springer. - 9783319645971 ; , s. 1-15
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Bokkapitel (refereegranskat)abstract
- Human immunodeficiency virus (HIV) and tuberculosis (TB) coinfection accounts for high rates of global morbidity and mortality. Although the pathogeneses of HIV and Mycobacterium tuberculosis (MTB) infections are different, the coexistence of both the agents will lead to accentuated disease progression in the host. Expression of markers associated with chronic immune activation, exhaustion, and immunosenescence on pathogen-specific CD4+ and CD8+ T cells have been associated with suboptimal immune responses in HIV–TB coinfection. The effect of chronic immune activation, exhaustion, and immunosenescence also appears to extend across distinct sets of immune cells, and hence a wider understanding of the mechanistic aspects underlying these phenomena is urgently required to necessitate the expansion of immune cells with improved functions in HIV–TB coinfection. Furthermore, strategies to cause attrition of immunosenescence and immune activation appear to stem from an improved understanding of senescence signaling.
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| 23. |
- Tan, Hong-Yien, et al.
(författare)
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Mucosal-Associated Invariant T Cells: Diplomatic Front-Runners in the Fight against Hepatitis B Virus Infection
- 2021
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Ingår i: Critical Reviews in Immunology. - : BEGELL HOUSE INC. - 1040-8401 .- 2162-6472. ; 41:5, s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- Mucosal-associated invariant T (MAIT) cells are a unique subset of innate-like T cells that bridge between innate and adaptive immunity. MALT cells act like a biliary firewall protecting the epithelial lining of the liver against pathogenic intruders. MAIT1 and MAIT17 subsets respond rapidly to pathogenic presence both in the liver as well as in the peripheral circulation. In addition to chronic hepatitis B virus (HBV) infection, MAIT cells also appear to serve as potential therapeutic targets in several other chronic ailments. Evidence indicates that MAIT cells have tissue repair functions also paving way for fibrotic changes during chronic HBV infection. Observations also suggest that HBV-hepatitis delta virus (HDV) co-infection disease progression is closely associated with loss of MAIT cells. Furthermore, reduction in the number of hepatic MAIT cells in patients with cirrhotic non-alcoholic fatty liver disease and HBV-associated primary liver cancer has also been reported. Given their concrete role against HBV disease progression, and has also become evident that the tumor microenvironment can cause functional impairment of MAIT cells. Here, we reviewed the protective and the pathological role of MAIT cells in chronic HBV infection and certain other related medical conditions based on the understanding that an optimal functioning of the MAIT cell arsenal is key to a "host-friendly" immune defense against HBV disease progression.
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| 24. |
- Velu, Vijayakumar, et al.
(författare)
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Role of PD-1 co-inhibitory pathway in HIV infection and potential therapeutic options
- 2015
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Ingår i: Retrovirology. - : BioMed Central. - 1742-4690. ; 12:14
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Forskningsöversikt (refereegranskat)abstract
- Virus-specific CD8(+) T cells play an important role in controlling viral infections including human immunodeficiency virus (HIV) infection. However, during chronic HIV infection, virus-specific CD8(+) T cells undergo functional exhaustion, lose effector functions and fail to control viral infection. HIV-specific CD8(+) T cells expressing high levels of co-inhibitory molecule programmed death-1 (PD-1) during the chronic infection and are characterized by lower proliferation, cytokine production, and cytotoxic abilities. Although, antiretroviral therapy has resulted in dramatic decline in HIV replication, there is no effective treatment currently available to eradicate viral reservoirs or restore virus-specific T or B-cell functions thatmay complement ART in order to eliminate the virus. In recent years, studies in mice and non-human primate models of HIV infection demonstrated the functional exhaustion of virus-specific T and B cells could be reversed by blockade of interaction between PD-1 and its cognate ligands (PD-L1 and PD-L2). In this review, we discuss recent advances in our understanding of PD-1 pathway in HIV/ SIV infection and discuss the beneficial effects of PD-1 blockade during chronic HIV/SIV infection and its potential role as immunotherapy for HIV/AIDS.
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| 25. |
- Vignesh, Ramachandran, et al.
(författare)
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Tuberculosis-Associated Immune Reconstitution Inflammatory Syndrome-An Extempore Game of Misfiring with Defense Arsenals
- 2023
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Ingår i: Pathogens. - : MDPI. - 2076-0817. ; 12:2
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Forskningsöversikt (refereegranskat)abstract
- The lethal combination involving TB and HIV, known as "syndemic" diseases, synergistically act upon one another to magnify the disease burden. Individuals on anti-retroviral therapy (ART) are at risk of developing TB-associated immune reconstitution inflammatory syndrome (TB-IRIS). The underlying inflammatory complication includes the rapid restoration of immune responses following ART, eventually leading to exaggerated inflammatory responses to MTB antigens. TB-IRIS continues to be a cause of morbidity and mortality among HIV/TB coinfected patients initiating ART, and although a significant quantum of knowledge has been acquired on the pathogenesis of IRIS, the underlying pathomechanisms and identification of a sensitive and specific diagnostic marker still remain a grey area of investigation. Here, we reviewed the latest research developments into IRIS immunopathogenesis, and outlined the modalities to prevent and manage strategies for better clinical and diagnostic outcomes for IRIS.
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| 26. |
- Vimali, Jaisheela, et al.
(författare)
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Chronic Viral Infection Compromises the Quality of Circulating Mucosal-Associated Invariant T Cells and Follicular T Helper Cells via Expression of Inhibitory Receptors
- 2024
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Ingår i: FRONTIERS IN BIOSCIENCE-LANDMARK. - : IMR PRESS. - 2768-6701. ; 29:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: Chronic viral infection results in impaired immune responses rendering viral persistence. Here, we compared the quality of T-cell responses among chronic hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV)-infected individuals by examining the levels of expression of selected immune activation and exhaustion molecules on circulating MAIT cells and Tfh cells. Methods: Cytokines were measured using a commercial Bio-plex Pro Human Cytokine Grp I Panel 17-plex kit (BioRad, Hercules, CA, USA). Inflammation was assessed by measuring an array of plasma cytokines, and phenotypic alterations in CD4(+) T cells including circulating Tfh cells, CD8(+) T cells, and TCR iV alpha 7.2(+) MAIT cells in chronic HBV, HCV, and HIV-infected patients and healthy controls. The cells were characterized based on markers pertaining to immune activation (CD69, ICOS, and CD27) proliferation (Ki67), cytokine production (TNF-alpha, IFN-gamma) and exhaustion (PD-1). The cytokine levels and T cell phenotypes together with cell markers were correlated with surrogate markers of disease progression. Results: The activation marker CD69 was significantly increased in CD4(+hi) T cells, while CD8(+) MAIT cells producing IFN-gamma were significantly increased in chronic HBV, HCV and HIV infections. Six cell phenotypes, viz., TNF-alpha(+)CD4(+lo) T cells, CD69(+)CD8(+) T cells, CD69(+)CD4(+) MAIT cells, PD-1(+)CD4(+hi) T cells, PD-1(+)CD8(+) T cells, and Ki67(+)CD4(+) MAIT cells, were independently associated with decelerating the plasma viral load (PVL). TNF-alpha levels showed a positive correlation with increase in cytokine levels and decrease in PVL. Conclusion: Chronic viral infection negatively impacts the quality of peripheral MAIT cells and Tfh cells via differential expression of both activating and inhibitory receptors.
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| 27. |
- Vimali, Jaisheela, et al.
(författare)
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Chronic viral infection compromises the quality of circulating mucosal-invariant T cells and follicular T helper cells via expression of both activating and inhibitory receptors
- 2023
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Chronic viral infection results in impaired immune responses rendering viral persistence. Here, we investigated the role of immune activation and compared the quality of T-cell responses in chronic HBV, HCV, and HIV infections. Cytokines were measured using a commercial Bio-plex Pro Human Cytokine Grp I Panel 17-plex kit (BioRad, Hercules, CA, USA). Inflammation was assessed by measuring an array of plasma cytokines, and peripheral CD4+ T cells including circulating Tfh cells, CD8+ T cells, and TCR iVα7.2+ MAIT cells in chronic HBV, HCV, and HIV-infected patients and healthy controls. The cells were characterized based markers pertaining to immune activation (CD69, ICOS, and CD27) proliferation (Ki67), cytokine production (TNF-α, IFN-γ) and exhaustion (PD-1). The cytokine levels and T cell phenotypes together with cell markers were correlated with surrogate markers of disease progression. The activation marker CD69 was significantly increased in CD4+ hi T cells, while CD8+ MAIT cells expressing IFN-γ were significantly increased in chronic HBV, HCV and HIV infections. Six cell phenotypes, viz., TNF-α+CD4+ lo T cells, CD69+CD8+ T cells, CD69+CD4+ MAIT cells, PD-1+CD4+ hi T cells, PD-1+CD8+ T cells, Ki67+CD4+ MAIT cells were independently associated with decelerating the plasma viral load (PVL). TNF-α levels showed a positive correlation with increase in cytokine levels and decrease in PVL. Chronic viral infection negatively impacts the quality of peripheral MAIT cells and TFH cells via expression of both activating and inhibitory receptors.
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| 28. |
- Vimali, Jaisheela, et al.
(författare)
-
HIV-HPgV Co-Infected Individuals Display Functional MAIT and Follicular T Cells Irrespective of PD-1 Expression
- 2023
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Human Pegivirus (HPgV) appears to alter the clinical outcome of HIV disease by modulating T-cell homeostasis, chemokine/cytokine production, as well as by reducing T-cell activation, and proliferation to limit HIV replication. Here, we evaluated if HPgV had any ‘favorable’ impact on the quantity and quality of T cells in HIV-infected individuals. T-cell subsets such as CD4lo, CD4hi, and CD8+ T cells, CD4+ MAIT cells, CD8+ MAIT cells, follicular helper T cells (Tfh), and follicular cytotoxic T cells (Tfc) were characterized based on the expression of markers associated with immune activation (CD69, ICOS), proliferation (ki67), cytokine production (TNF-α, IFN-γ), and exhaustion (PD-1). HIV+HPgV+ individuals had lower plasma liver transaminase SGOT and GGT (biliary) than those who were HPgV-. HIV/HPgV co-infection was significantly associated with increased absolute CD4+ T-cell counts. HIV+HPgV+ and HIV+HPgV- individuals had highly activated T-cell subsets with high expression of CD69 and ICOS on bulk CD4+ and CD8+ T cells, CD4+ MAIT cells, CD8+ MAIT cells and CXCR5+CD4+ T cells and CXCR5+CD8+ T cells as compared to healthy controls. Irrespective of activation markers these cells also expressed higher levels of PD-1 on CD4+ T and CD8+ T cells and their counterparts. However, exploring their functionality based on the mitogen stimulation demonstrated higher levels of cytokine production by CD4+ MAIT and CD8+ MAIT cells as compared to healthy controls. Decrease in absolute CD4+ T cell counts correlated positively with intracellular IFN-γ levels by CD4lo T cells, whereas increase of the same correlated inversely with TNF-α in the CD4lo T cells of HIV+HPgV+ individuals. Together, we found that HIV/HPgV co-infected individuals display functional CD4+ and CD8+ MAIT, Tfh and Tfc cells irrespective of PD-1 expression.
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| 29. |
- Vimali, Jaisheela, et al.
(författare)
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Human Immunodeficiency Virus-Human Pegivirus Coinfected Individuals Display Functional Mucosal-Associated Invariant T Cells and Follicular T Cells Irrespective of PD-1 Expression
- 2024
-
Ingår i: Viral immunology. - : MARY ANN LIEBERT, INC. - 0882-8245 .- 1557-8976.
-
Tidskriftsartikel (refereegranskat)abstract
- Human pegivirus (HPgV) appears to alter the prognosis of HIV disease by modulating T cell homeostasis, chemokine/cytokine production, and T cell activation. In this study, we evaluated if HPgV had any 'favorable' impact on the quantity and quality of T cells in HIV-infected individuals. T cell subsets such as CD4lo, CD4hi, and CD8+ T cells, CD4+ MAIT cells, CD8+ MAIT cells, follicular helper T (TFH) cells, and follicular cytotoxic T (TFC) cells were characterized based on the expression of markers associated with immune activation (CD69, ICOS), proliferation (ki67), cytokine production (TNF-alpha, IFN-gamma), and exhaustion (PD-1). HIV+HPgV+ individuals had lower transaminase SGOT (liver) and GGT (biliary) in the plasma than those who were HPgV-. HIV/HPgV coinfection was significantly associated with increased absolute CD4+ T cell counts. HIV+HPgV+ and HIV+HPgV- individuals had highly activated T cell subsets with high expression of CD69 and ICOS on bulk CD4+ and CD8+ T cells, CD4+ MAIT cells, CD8+ MAIT cells, and CXCR5+CD4+ T cells and CXCR5+CD8+ T cells compared with healthy controls. Irrespective of immune activation markers, these cells also displayed higher levels of PD-1 on CD4+ T and CD8+ T cells . Exploring effector functionality based on mitogen stimulation demonstrated increased cytokine production by CD4+ MAIT and CD8+ MAIT cells. Decrease in absolute CD4+ T cell counts correlated positively with intracellular IFN-gamma levels by CD4lo T cells, whereas increase of the same correlated negatively with TNF-alpha in the CD4lo T cells of HIV+HPgV+ individuals. HIV/HPgV coinfected individuals display functional CD4+ and CD8+ MAIT, TFH, and TFC cells irrespective of PD-1 expression.
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| 30. |
- Vimali, Jaisheela, et al.
(författare)
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Plasma interleukin-7 correlation with human immunodeficiency virus RNA and CD4+T cell counts, and interleukin-5 with circulating hepatitis B virus DNA may have implications in viral control
- 2022
-
Ingår i: Frontiers in Medicine. - : Frontiers Media SA. - 2296-858X. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Chronic viral infections represent a leading cause of global morbidity and mortality. Chronic HBV, HCV, and HIV infections result in cytokine perturbations that may hold key implications in understanding the complex disease mechanisms driving virus persistence and/or resolution. Here, we determined the levels of various plasma cytokines using a commercial Bio-Plex Luminex cytokine array in chronic HBV (n = 30), HCV (n = 15), and HIV (n = 40) infections and correlated with corresponding plasma viral loads (PVLs) and liver parameters. We observed differential perturbations in cytokine profiles among the study groups. The cytokines levels positively correlated with PVL and liver transaminases. The monocyte-derived cytokines viz., MIP-1 beta, IL-8, and TNF-alpha, and Th2 cytokines like IL-4, IL-5, and IL-13 showed a better correlation with liver enzymes as compared to their corresponding PVLs. Our investigation also identified two cytokines viz., IL-5 and IL-7 that inversely correlated with HBV DNA and HIV PVLs, respectively. Regression analysis adjusted for age showed that every increase of IL-5 by one unit was associated with a reduction in HBV PVL by log(10) 0.4, whereas, every elevation by a unit of IL-7 was associated with decreased HIV PVL by log(10) 2.5. We also found that IL-7 levels correlated positively with absolute CD4+ T cell counts in HIV-infected patients. We concluded that plasma IL-5 and IL-7 may likely have a key role on viral control in HBV and HIV infections, respectively. A noteworthy increase in cytokines appears to bear protective and pathological significance, and indeed is reflective of the hosts versatile immune armory against viral persistence.
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| 31. |
- Vimali, Jaisheela, et al.
(författare)
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Surrogate Biomarkers of Disease Progression in Human Pegivirus Seropositive Human Immunodeficiency Virus-Infected Individuals
- 2023
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Ingår i: Viral immunology. - : MARY ANN LIEBERT, INC. - 0882-8245 .- 1557-8976. ; 36:1, s. 55-62
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Tidskriftsartikel (refereegranskat)abstract
- Scientific observations indicate that an actively prevailing systemic condition could alleviate the pathology of another disease. Human pegivirus (HPgV), a highly ubiquitous flavivirus is believed to be associated with slow human immunodeficiency virus (HIV) disease progression, and has seldom been linked to hepatic pathology. In this study, we investigated whether HPgV seropositivity had any impact on surrogate markers of HIV disease progression in a cohort of HIV-infected HPgV seropositive (n = 28) and seronegative (n = 12) individuals who were prospectively evaluated for absolute CD4+ T cell counts, plasma viral load (PVL), liver enzymes, and plasma cytokine levels. The HIV PVL was relatively lower in HPgV seropositive than in HPgV seronegative HIV-infected subjects. Clinical markers of hepatic injury were significantly low among HPgV seropositive HIV-infected participants. HPgV seropositive individuals showed significantly higher levels of interleukin-7 (IL-7), and although not significant, the levels of IL-6 were lower among HPgV seropositive subjects. Spearman correlation analysis showed that the absolute CD4+T cell count was inversely correlated with HIV PVL. Exposure to HPgV appears to have a positive prognostic impact on the levels of surrogate biomarkers of HIV disease progression.
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| 32. |
- Wong, Sui-Weng, et al.
(författare)
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Chronic inflammation involves CCL11 and IL-13 to facilitate the development of liver cirrhosis and fibrosis in chronic hepatitis B virus infection
- 2021
-
Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : TAYLOR & FRANCIS LTD. - 0036-5513 .- 1502-7686. ; 81:2, s. 147-159
-
Tidskriftsartikel (refereegranskat)abstract
- The pathogenesis involving non-alcoholic fatty liver disease (NAFLD) in the context of chronic HBV (CHB) virus infection requires to be understood for developing improved modalities of diagnosis and treatment. We retrospectively investigated the association between NAFLD and CHB virus infection in the context of liver fibrosis. Among the 522 consecutive CHB patients who underwent transient elastography between years 2013 and 2016, we studied 455 subjects in the current investigation. Controlled attenuation parameter (CAP) and liver stiffness measurement (LSM) scores were generally higher in patients with steatosis and fibrosis or cirrhosis. Antiviral treatment had significantly reduced the hepatitis B virus (HBV) viral load. Other liver function markers showed a significant positive correlation with both CAP and LSM scores. Plasma IL-13 was independently associated with increased CAP score where every increase of 1 unit of IL-13 was associated with an increase in CAP score by 0.98 unit. CCL11 was independently associated with LSM with every increase of CCL11 by a unit that, in turn, was associated with an increase of LSM score. We found that there was a high concurrence of NAFLD among patients with CHB virus infection. The presence of metabolic syndrome and chronic inflammation in CHB virus-infected patients were two independent factors that led to the progression of liver cirrhosis, with IL-13 playing the key role in linking the metabolic with the inflammatory components.
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| 33. |
- Yong, Yean K., et al.
(författare)
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Decrease of CD69 levels on TCR V7.2(+)CD4(+) innate-like lymphocytes is associated with impaired cytotoxic functions in chronic hepatitis B virus-infected patients
- 2017
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Ingår i: Innate Immunity. - : SAGE PUBLICATIONS LTD. - 1753-4259 .- 1753-4267. ; 23:5, s. 459-467
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Tidskriftsartikel (refereegranskat)abstract
- Hepatitis B virus (HBV) infection is a major cause of chronic liver disease that may progress to liver cirrhosis and hepatocellular carcinoma. Host immune responses represent the key determinants of HBV clearance or persistence. Here, we investigated the role of the early activation marker, CD69 and effector cytokines, granzyme B (GrB) and IFN- in the exhaustion of innate-like TCR V7.2(+)CD4(+)T cells, in 15 individuals with chronic HBV (CHB) infection where six were HBV DNA(+) and nine were HBV DNA(-). The percentage of cytokine-producing T cells and MAIT cells were significantly perturbed in HBV patients relative to healthy controls (HCs). The intracellular expression of GrB and IFN- was significantly reduced in MAIT cells derived from HBV-infected patients as compared to HCs, and the levels correlated with the percentage and levels [mean fluorescence intensity (MFI)] of CD69 expression. The total expression of CD69 (iMFI) was lower in CHB patients as compared to HCs. The frequency of CD69(+) cells correlated with the levels of cytokine expression (MFI), particularly in CHB patients as compared to HCs. In summary, the polyfunctionality of peripheral T cells was significantly reduced among CHB patients, especially in the TCR V7.2(+)CD4(+)T cells, and the levels of cytokine expression correlated with functional cytokine levels.
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| 34. |
- Yong, Yean Kong, et al.
(författare)
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Dengue Infection - Recent Advances in Disease Pathogenesis in the Era of COVID-19
- 2022
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 13
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Forskningsöversikt (refereegranskat)abstract
- The dynamics of host-virus interactions, and impairment of the hosts immune surveillance by dengue virus (DENV) serotypes largely remain ambiguous. Several experimental and preclinical studies have demonstrated how the virus brings about severe disease by activating immune cells and other key elements of the inflammatory cascade. Plasmablasts are activated during primary and secondary infections, and play a determinative role in severe dengue. The cross-reactivity of DENV immune responses with other flaviviruses can have implications both for cross-protection and severity of disease. The consequences of a cross-reactivity between DENV and anti-SARS-CoV-2 responses are highly relevant in endemic areas. Here, we review the latest progress in the understanding of dengue immunopathogenesis and provide suggestions to the development of target strategies against dengue.
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| 35. |
- Yong, Yean K., et al.
(författare)
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Hyper-Expression of PD-1 Is Associated with the Levels of Exhausted and Dysfunctional Phenotypes of Circulating CD161(++)TCR iV alpha 7.2(+) Mucosal-Associated Invariant T Cells in Chronic Hepatitis B Virus Infection
- 2018
-
Ingår i: Frontiers in Immunology. - : FRONTIERS MEDIA SA. - 1664-3224. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Mucosal-associated invariant T (MAIT) cells, defined as CD161(++) TCR iV alpha 7.2(+) T cells, play an important role in the innate defense against bacterial infections, and their functionality is impaired in chronic viral infections. Here, we investigated the frequency and functional role of MAIT cells in chronic hepatitis B virus (HBV) infection. The peripheral CD3(+)CD161(++)TCR iV alpha 7.2(+) MAIT cells in chronic HBV-infected patients and healthy controls were phenotypically characterized based on CD57, PD-1, TIM-3, and CTLA-4, as well as HLA-DR and CD38 expression. The frequency of MAIT cells was significantly decreased among chronic HBV-infected individuals as compared to controls. Expression of CD57, PD-1, CTLA-4, as well as HLA-DR and CD38 on MAIT cells was significantly elevated in chronic HBV-infected individuals relative to controls. The percentage of T cell receptor (TCR) iVa7.2+ CD161(+) MAIT cells did not correlate with HBV viral load but inversely with HLA-DR on CD4(+) T cells and MAIT cells and with CD57 on CD8(+) T cells suggesting that decrease of MAIT cells may not be attributed to direct infection by HBV but driven by HBV-induced chronic immune activation. The percentage and expression levels of PD-1 as well as CTLA-4 on MAIT cells inversely correlated with plasma HBV-DNA levels, which may suggest either a role for MAIT cells in the control of HBV infection or the effect of HBV replication in the liver on MAIT cell phenotype. We report that decrease of TCR iV alpha 7.2(+) MAIT cells in the peripheral blood and their functions were seemingly impaired in chronic HBV-infected patients likely because of the increased expression of PD-1.
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| 36. |
- Yong, Yean K., et al.
(författare)
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Immune Biomarkers for Diagnosis and Treatment Monitoring of Tuberculosis : Current Developments and Future Prospects
- 2019
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Ingår i: Frontiers in Microbiology. - : Frontiers Media S.A.. - 1664-302X. ; 10
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Forskningsöversikt (refereegranskat)abstract
- Tuberculosis (TB) treatment monitoring is paramount to clinical decision-making and the host biomarkers appears to play a significant role. The currently available diagnostic technology for TB detection is inadequate. Although GeneXpert detects total DNA present in the sample regardless live or dead bacilli present in clinical samples, all the commercial tests available thus far have low sensitivity. Humoral responses against Mycobacterium tuberculosis (Mtb) antigens are generally low, which precludes the use of serological tests for TB diagnosis, prognosis, and treatment monitoring. Mtb-specific CD4(+) T cells correlate with Mtb antigen/bacilli burden and hence might serve as good biomarkers for monitoring treatment progress. Omics-based techniques are capable of providing a more holistic picture for disease mechanisms and are more accurate in predicting TB disease outcomes. The current review aims to discuss some of the recent advances on TB biomarkers, particularly host biomarkers that have the potential to diagnose and differentiate active TB and LTBI as well as their use in disease prognosis and treatment monitoring.
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