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- Nayanar, Sangeetha K., et al.
(författare)
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Intracellular Toll-Like Receptors Modulate Adaptive Immune Responses in Head and Neck Cancer
- 2023
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Ingår i: Viral Immunology. - 0882-8245 .- 1557-8976. ; 36:10, s. 659-668
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Tidskriftsartikel (refereegranskat)abstract
- The percentage of head and neck cancer (HNC) positive for human papillomavirus (HPV) is unknown in most parts of India. How toll-like receptors (TLRs) affect the adaptive immune response in HNC is also mainly unknown. We here assessed the expressions of HPV DNA, p16, inflammation, and TLRs in oral squamous cell carcinoma (OC) and oropharyngeal squamous cell carcinoma (OPC). Patients with OC (n = 31) and OPC (n = 41), diagnosed during 2017-2018 at the Malabar Cancer Centre (tertiary cancer center), Kerala, India, were included in the study. Immunohistochemistry was performed on tumor specimens against p16, TLR3, TLR7, TLR8, TLR9, CD4, and CD8. Quantitate polymerase chain reaction for 14 high-risk HPVs (HPV16/18/31/33/35/39/45/51/52/56/58/59/66/68) was performed. Seven out of 31 OC (22.6%) were p16+ but only 3.2% (1/31) of OC were positive for HPV DNA. While 24.4% (10/41) of OPC were p16+, HPV DNA was found in only one P16+ OPC and in no P16− OPC. TLR3, TLR7, TLR8, and TLR9 were expressed both in OC and in OPC. The expression of TLR7 was significantly higher in OPC compared with OC. TLR8 expression was correlated with and TLR7 tended to be correlated with the inflammatory score in OPC (r = 0.56, p < 0.05 and r = 0.52, p = 0.08, respectively). In conclusion, the role of HPV in OC and OPC is minor, and p16 constitutes a poor biomarker for HPV positivity in Kerala, India. Intracellular TLRs are correlated with the degree of inflammation in OPC but not in OC and may potentially constitute a medical target in the therapy of HNC in the future.
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- Nelson, B. R., et al.
(författare)
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Immune Evasion Strategies Used by Zika Virus to Infect the Fetal Eye and Brain
- 2020
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Ingår i: Viral Immunology. - : Mary Ann Liebert Inc. - 0882-8245 .- 1557-8976.
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Tidskriftsartikel (refereegranskat)abstract
- Zika virus (ZIKV) is a mosquito-transmitted flavivirus that caused a public health emergency in the Americas when an outbreak in Brazil became linked to congenital microcephaly. Understanding how ZIKV could evade the innate immune defenses of the mother, placenta, and fetus has become central to determining how the virus can traffic into the fetal brain. ZIKV, like other flaviviruses, evades host innate immune responses by leveraging viral proteins and other processes that occur during viral replication to allow spread to the placenta. Within the placenta, there are diverse cell types with coreceptors for ZIKV entry, creating an opportunity for the virus to establish a reservoir for replication and infect the fetus. The fetal brain is vulnerable to ZIKV, particularly during the first trimester, when it is beginning a dynamic process, to form highly complex and specialized regions orchestrated by neuroprogenitor cells. In this review, we provide a conceptual framework to understand the different routes for viral trafficking into the fetal brain and the eye, which are most likely to occur early and later in pregnancy. Based on the injury profile in human and nonhuman primates, ZIKV entry into the fetal brain likely occurs across both the blood/cerebrospinal fluid barrier in the choroid plexus and the blood/brain barrier. ZIKV can also enter the eye by trafficking across the blood/retinal barrier. Ultimately, the efficient escape of innate immune defenses by ZIKV is a key factor leading to viral infection. However, the host immune response against ZIKV can lead to injury and perturbations in developmental programs that drive cellular division, migration, and brain growth. The combined effect of innate immune evasion to facilitate viral propagation and the maternal/placental/fetal immune response to control the infection will determine the extent to which ZIKV can injure the fetal brain.
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- 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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| 6. |
- 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
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Ingår i: Viral immunology. - : MARY ANN LIEBERT, INC. - 0882-8245 .- 1557-8976.
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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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| 7. |
- 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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