| 1. |
- Amoudruz, Petra, et al.
(author)
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Impaired Toll-like receptor 2 signaling in monocytes from 5-year-old allergic children
- 2009
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In: Clinical and Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 155:3, s. 387-394
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Journal article (peer-reviewed)abstract
- The relative composition of the two major monocytic subsets CD14+CD16− and CD14+CD16+ is altered in some allergic diseases. These two subsets display different patterns of Toll-like receptor levels, which could have implications for activation of innate immunity leading to reduced immunoglobulin E-specific adaptive immune responses. This study aimed to investigate if allergic status at the age of 5 years is linked to differences in monocytic subset composition and their Toll-like receptor levels, and further, to determine if Toll-like receptor regulation and cytokine production upon microbial stimuli is influenced by the allergic phenotype. Peripheral blood mononuclear cells from 5-year-old allergic and non-allergic children were stimulated in vitro with lipopolysaccharide and peptidoglycan. Cells were analysed with flow cytometry for expression of CD14, Toll-like receptors 2 and 4 and p38-mitogen-activated protein kinase (MAPK). The release of cytokines and chemokines [tumour necrosis factor, interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-12p70] into culture supernatants was measured with cytometric bead array. For unstimulated cells there were no differences in frequency of the monocytic subsets or their Toll-like receptor levels between allergic and non-allergic children. However, monocytes from allergic children had a significantly lower up-regulation of Toll-like receptor 2 upon peptidoglycan stimulation. Further, monocytes from allergic children had a higher spontaneous production of IL-6, but there were no differences between the two groups regarding p38-MAPK activity or cytokine and chemokine production upon stimulation. The allergic subjects in this study have a monocytic population that seems to display a hyporesponsive state as implicated by impaired regulation of Toll-like receptor 2 upon peptidoglycan stimulation.
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| 2. |
- Bemark, Mats, 1967, et al.
(author)
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A glycosylation-dependent CD45RB epitope defines previously unacknowledged CD27(-)IgM(high) B cell subpopulations enriched in young children and after hematopoietic stem cell transplantation
- 2013
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In: Clinical Immunology. - : Elsevier BV. - 1521-6616 .- 1521-7035. ; 149:3, s. 421-431
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Journal article (peer-reviewed)abstract
- The immune system is dysfunctional for years after hematopoietic stem cell transplantation (HSCT). A potential cause is an intrinsic B cell deficiency. In a cohort of pediatric HSCT patients few CD27(+) B cells formed after transplantation with the number of CD27(+)IgM(high) cells more affected than class-switched ones. A previously unacknowledged population of CD27(-)IgM(high) cells made up the majority of B cells and this population was also enlarged in healthy children compared to adults. Only a minority of these CD27(-)IgM(high) B cells expressed markers typical for transitional B cells, and the non-transitional CD27(-)IgM(high) cells could be further divided into subpopulations based on their ability to extrude the dye Rhodamine 123 and their expression of CD45RB(MEM55), a glycosylation-dependent epitope. Thus, we define several novel human CD27(-)IgM(high) B cell subpopulations in blood, all of which are present in higher frequencies and numbers in young children and after HSCT than in adults.
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| 3. |
- Carvalho-Queiroz, Claudia, et al.
(author)
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Associations between EBV and CMV Seropositivity, Early Exposures, and Gut Microbiota in a Prospective Birth Cohort : A 10-Year Follow-up
- 2016
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In: Frontiers in Pediatrics. - : Frontiers Media SA. - 2296-2360. ; 4
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Journal article (peer-reviewed)abstract
- Early-life infections with persistent Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are delayed in affluent countries, probably due to alterations in early environmental exposures, such as maternal age, siblings, and day-care attendance. We have previously reported that the timing of EBV and CMV contraction is related both to allergic sensitization and changes in functional competence of immune cells, while the presence/absence of lactobacilli [Lactobacillus (L.) casei, L. paracasei, and L. rhamnosus] or Staphylococcus (S.) aureus in feces is related to the risk for allergy. Here, we used the same prospective longitudinal birth cohort of children to investigate early-life environmental exposures and their influence on EBV and CMV contraction over time. Since gut microbes also belong to this category of early exposures, we investigated their association with herpesvirus contraction. Our results show that these two viruses are acquired with different kinetics and that EBV and CMV seroprevalence at 10 years of age was 47 and 57%, respectively. We also observed that a delayed EBV or CMV infection was associated with older maternal age [time ratio (TR) 1.14, 95% confidence interval (CI) 1.07-1.21, P-adj < 0.001 and TR 1.09, CI 1.03-1.16, P-adj = 0.008, respectively]. Further, we present the novel finding that S. aureus colonization reduced the time to CMV acquisition (TR 0.21, CI 0.06-0.78, = 0.02). Together, these findings suggest that there is a relationship between timing of herpesvirus acquisition and early-life immune modulating exposures, which interestingly also includes the early infant gut microbiota.
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| 4. |
- Johansson, Maria A, et al.
(author)
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Early-Life Gut Bacteria Associate with IL-4-, IL-10- and IFN-γ Production at Two Years of Age
- 2012
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:11, s. e49315-(9 pp)
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Journal article (peer-reviewed)abstract
- Microbial exposure early in life influences immune maturation and potentially also the development of immune-mediated disease. Here we studied early-life gut colonization in relation to cytokine responses at two years of age. Fecal samples were collected from infants during the first two months of life. DNA was extracted from the fecal samples and Bifidobacterium (B.) adolescentis, B. breve, B. bifidum, a group of lactobacilli (L. casei, L. paracasei and L. rhamnosus) as well as Staphylococcus (S.) aureus were detected with real time PCR. Peripheral mononuclear cells were stimulated with phytohaemagglutinin (PHA) and numbers of IL-4-, IL-10- and IFN-γ secreting cells were evaluated using ELISpot. We further stimulated peripheral blood mononuclear cells with bacterial supernatants in vitro and assessed the IL-4-, IL-10- and IFN-γ inducing capacity by flow cytometry and ELISA. Early S. aureus colonization associated with higher numbers of IL-4- (p = 0.022) and IL-10 (p = 0.016) producing cells at two years of age. In contrast to colonization with S. aureus alone, co-colonization with lactobacilli associated with suppression of IL-4- (p = 0.004), IL-10- (p = 0.004) and IFN-γ (p = 0.034) secreting cells. In vitro stimulations of mononuclear cells with bacterial supernatants supported a suppressive role of L. rhamnosus GG on S. aureus-induced cytokine responses. We demonstrate that the early gut colonization pattern associates with the PHA-induced cytokine profile at two years of age and our in vitro findings support that specific bacterial species influence the T helper cell subsets. This suggests that dysbiosis in the early microbiota may modulate the risk of developing inflammatory conditions like allergy.
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| 5. |
- Laestadius, Åsa, et al.
(author)
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Altered proportions of circulating CXCR5+helper T cells do not dampen influenza vaccine responses in children with rheumatic disease
- 2019
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In: Vaccine. - : Elsevier BV. - 0264-410X .- 1873-2518. ; 37:28, s. 3685-3693
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Journal article (peer-reviewed)abstract
- Biological therapy options for the treatment of rheumatic disease target molecules that can affect the cross-talk between innate and adaptive immune responses upon vaccination. Influenza vaccination in children with rheumatic disease has been recommended, but there are only sparse data on the quality of vaccine responses from pediatric patients treated with biological therapy. We conducted an influenza vaccine study over 3 consecutive seasons where the antibody response to TIV was evaluated in children with PRD (n = 78), including both non-treated (n = 17) and treated (with methotrexate, TNF-inhibitors with or without methotrexate, or IL-inhibitors, n = 61) children as well as healthy age-matched controls (n = 24). Peripheral B cells, T and NK cell populations, as well as CXCR5+ (follicular) helper T cells (T-FH) and chemokines involved in antibody responses were assessed prior to immunization in the same cohort. Data on disease duration, therapy and data on previous influenza vaccinations were retrieved. The proportion of circulating T-FH cells were significantly lower in non-treated children with PRD compared to treated patients and healthy controls. The significantly lower proportion of T-FH cells was mirrored by a marked significant increase in CXCL13 serum level, the ligand for CXCR5, with higher levels in non-treated children with PRD compared to treated patients and healthy controls. However, the proportion of T-FH cells or CXCL13 level at the time of vaccination was not a predictor of the antibody response to TIV in this cohort of children. Children with PRD had an overall similar response to TIV as healthy children. Although not significant, children treated with TNF-inhibitors differed as a few children remained seronegative towards H3N2- and influenza B viruses after immunization. Our data show that children with PRD respond to TIV as healthy children. Furthermore, plasma CXCL13 levels did not correlate to the proportion of T-FH cells in blood prior to immunisation, or to antibody responses following immunization.
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| 6. |
- Lasaviciute, Gintare, et al.
(author)
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Deficits in the IgG+ memory B‐cell recovery after anthracycline treatment is confined to the spleen of rhesus macaques
- 2020
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In: Clinical & Translational Immunology (CTI). - : Wiley. - 2050-0068. ; 9:7
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Journal article (peer-reviewed)abstract
- Objectives. Loss of vaccine-induced antibodies (Abs) after chemotherapy against paediatric acute lymphoblastic leukaemia (ALL) is common and often necessitates re-immunisation after cessation of treatment. Even so, some ALL survivors fail to mount or to maintain protective Abs. Germinal centres (GCs) are clusters of proliferating B cells in follicles of secondary lymphoid tissues (SLTs) formed during adaptive immune responses and the origins of long-lived memory B and plasma cells that are the source of Abs. Furthermore, productive GC reactions depend on T follicular helper (TFH) cells. To understand why chemotherapy induces deficits in Ab responses, we examined how SLTs were affected by chemotherapy. Methods. Rhesus macaques were infused with either three cycles of the anthracycline doxorubicin or saline, followed by immunisation with a de novo and booster antigen. Spleen and lymph nodes were removed, and memory B, bulk T and TFH cells were examined. Results. Despite adequate GC morphology, a diminished memory and IgG+ B-cell population along with diminished total and booster vaccine-specific IgGproducing memory B cells were noted in the spleens of macaques with past doxorubicin exposure compared to the saline-treated controls (P < 0.05). Intact bulk T and TFH cells were found in the SLTs of treated macaques, which displayed higher CD40L upregulation capacity by their splenic CXCR5+ helper T cells (P < 0.01). In contrast to the spleen, the immune cell populations studied were comparable between the lymph nodes of both saline- and doxorubicin-treated macaques. Conclusion. Our findings suggest that the splenic memory B-cell subset, compared to its lymph node counterpart, is more severely altered by anthracycline treatment.
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| 7. |
- Lasaviciute, Gintare, et al.
(author)
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Epstein-Barr Virus, but Not Cytomegalovirus, Latency Accelerates the Decay of Childhood Measles and Rubella Vaccine Responses-A 10-Year Follow-up of a Swedish Birth Cohort
- 2017
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In: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 8
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Journal article (peer-reviewed)abstract
- Background: Epstein-Barr virus (EBV) and cytomegalovirus (CMV) are ubiquitous and persistent herpesviruses commonly acquired during childhood. Both viruses have a significant impact on the immune system, especially through mediating the establishment of cellular immunity, which keeps these viruses under control for life. Far less is known about how these viruses influence B-cell responses. Objectives: To evaluate the impact of latent EBV and CMV infection on rubella- and measles-specific antibody responses as well as on the B-cell compartment in a prospective birth cohort followed during the first 10 years of life. Methods: IgG titers against rubella and measles vaccines were measured in plasma obtained from the same donors at 2, 5, and 10 years of age. Peripheral B-cell subsets were evaluated ex vivo at 2 and 5 years of age. Factors related to optimal B-cell responses including IL-21 and CXCL13 levels in plasma were measured at all-time points. Results: EBV carriage in the absence of CMV associated with an accelerated decline of rubella and measles-specific IgG levels (p = 0.003 and p = 0.019, respectively, linear mixed model analysis), while CMV carriage in the absence of EBV associated with delayed IgG decay over time for rubella (p = 0.034). At 5 years of age, EBV but not CMV latency associated with a lower percentage of plasmablasts, but higher IL-21 levels in the circulation. Conclusion: Our findings suggest that EBV carriage in the absence of CMV influences the B-cell compartment and the dynamics of antibody responses over time during steady state in the otherwise healthy host.
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| 8. |
- Lasaviciute, Gintare, 1990-, et al.
(author)
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Human Bone Marrow Mesenchymal Stromal Cell-Derived CXCL12, IL-6 and GDF-15 and Their Capacity to Support IgG-Secreting Cells in Culture Are Divergently Affected by Doxorubicin
- 2021
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In: Hemato. - : MDPI AG. - 2673-6357. ; 2:1, s. 154-166
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Journal article (peer-reviewed)abstract
- Various subsets of bone marrow mesenchymal stromal cells (BM MSCs), including fibroblasts, endothelial, fat and reticular cells, are implicated in the regulation of the hematopoietic microenvironment and the survival of long-lived antibody-secreting cells (ASCs). Nowadays it is widely acknowledged that vaccine-induced protective antibody levels are diminished in adults and children that are treated for hematological cancers. A reason behind this could be damage to the BM MSC niche leading to a diminished pool of ASCs. To this end, we asked whether cell cytotoxic treatment alters the capacity of human BM MSCs to support the survival of ASCs. To investigate how chemotherapy affects soluble factors related to the ASC niche, we profiled a large number of cytokines and chemokines from in vitro-expanded MSCs from healthy donors or children who were undergoing therapy for acute lymphoblastic leukemia (ALL), following exposure to a widely used anthracycline called doxorubicin (Doxo). In addition, we asked if the observed changes in the measured soluble factors after Doxo exposure impacted the ability of the BM niche to support humoral immunity by co-culturing Doxo-exposed BM MSCs with in vitro-differentiated ASCs from healthy blood donors, and selective neutralization of cytokines. Our in vitro results imply that Doxo-induced alterations in BM MSC-derived interleukin 6 (IL-6), CXCL12 and growth and differentiation factor 15 (GDF-15) are not sufficient to disintegrate the support of IgG-producing ASCs by the BM MSC niche, and that serological memory loss may arise during later stages of ALL therapy.
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| 9. |
- Saghafian-Hedengren, Shanie, et al.
(author)
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Early-life EBV infection protects against persistent IgE sensitization.
- 2010
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In: The Journal of allergy and clinical immunology. - : Elsevier BV. - 1097-6825 .- 0091-6749. ; 125:2, s. 433-8
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Journal article (peer-reviewed)abstract
- BACKGROUND: Infection with EBV has previously been implicated in influencing allergic disorders, but its precise role remains contradictory. The timing of primary infection may contribute to the discrepancies. OBJECTIVE: This study aimed at investigating whether the time-point of primary EBV infection during childhood could be of importance in modulating the risk of developing IgE sensitization. METHODS: A total of 219 Swedish infants were followed prospectively to 5 years of age with clinical examinations, skin prick testing, specific IgE analyses, and determination of serostatus against EBV. RESULTS: After analysis of the children's EBV serostatus, we found that 5-year-olds who were infected with EBV before the age of 2 years were at a significantly lower risk of being persistently IgE-sensitized-that is, sensitized at both 2 and 5 years of age (adjusted odds ratio, 0.34; 95% CI, 0.12-0.94). In contrast, contraction of EBV after 2 years of age was highly associated with late-onset IgE sensitization (adjusted odds ratio, 4.64; 95% CI, 1.57-13.69). Persistently sensitized 5-year-olds had higher specific-IgE levels than children with late-onset IgE sensitization (P < .01). CONCLUSION: Our data support the value of early-life microbial exposure for protection against the development of IgE sensitization and underscore the proximate postnatal years as an important period during which EBV could contribute to an allergo-protective immune profile.
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| 10. |
- Saghafian-Hedengren, Shanie, et al.
(author)
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Epstein-Barr Virus Co-infection in Children Boosts Cytomegalovirus-induced Differentiation of Natural Killer Cells
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Other publication (other academic/artistic)abstract
- During childhood, infections with cytomegalovirus (CMV) and Epstein-Barr virus (EBV) can occur in close temporal proximity. Active as well as latent CMV infection is associated with enlarged subsets of differentiated NK- and cytotoxic T cells. How EBV infection may influence CMV-driven immune differentiation is not known. Here we found that EBV co-infection selectively influenced the NK-cell compartment of CMV-seropositive (CMV+) children. Co-infected children had significantly higher proportions of peripheral-blood NKG2C+ NK cells than CMV+EBV– children. Ex vivo NK-cell degranulation after target cell stimulation and plasma IL-15 levels were significantly higher in CMV+ children. EBV co-infection related with the highest levels of plasma IL-15 and IL-12p70. Remarkably, in vitro EBV infection of peripheral blood mononuclear cells (PBMC) from EBV–CMV+ children increased NKG2C+ NK-cell proportions. A similar tendency was seen in co-cultures of PBMC with EBV+ lymphoblastoid B-cell lines (LCL) and IL-15. Following K562 challenge, NKG2C+ NK cells excelled in regards to degranulation and production of IFN-g, regardless of previous co-culture with LCL. Taken together, our data suggest that herpesvirus interplay during childhood could contribute to an in vivo environment supporting differentiation and maintenance of distinct NK-cell populations. This viral imprint may affect subsequent immune responses through altered distributions of effector cells.
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