•Functional antibody response differs between AA and Caucasian HIV+ individuals.•AA and Caucasian HIV+ groups have similar inflammatory marker profiles.•Pre-immunization gene profiles might play a ...role in pneumococcal vaccine response.
Both HIV positivity and African American (AA) ethnicity are associated with increased incidence of invasive pneumococcal disease (IPD). Poor immune response to pneumococcal polysaccharide-based vaccines may contribute to the race related increased frequency of IPD in African American HIV positive individuals.
Caucasian and AA HIV-infected (HIV+) individuals 40–65 years old with CD4+ T cells/µl (CD4) >200 on antiretroviral therapy (ART) received either the 13-valent pneumococcal conjugate vaccine (PCV) followed by the 23-valent pneumococcal polysaccharide vaccine (PPV) or PPV only. Serum IgG, IgM and opsonophagocytic antibody responses to serotypes 14 and 23F as well as serum IgG and opsonophagocytic antibody responses to serotype 19A were measured pre- and post-vaccination. We measured serum markers of inflammation in all participants and performed single cell gene expression profiling at the baseline by HD Biomark in Caucasians and African Americans.
There were no significant differences in pre-immunization inflammatory markers or post-vaccination IgG and IgM concentrations between Caucasian and African American participants. However, we found significantly lower opsonophagocytic activity in response to serotypes 14 and 19A in the AA group compared to the Caucasian group. There was no association between inflammatory markers and immune response to vaccination, however we found extensive biomodal variation in gene expression levels in single IgM+ memory B cells. Differentially expressed genes may be related to differences in the immune response between ethnic groups.
Distinct racial differences were found in the functional immune response following either PPV and/or PCV/PPV immunization in HIV-positive adults, although these differences were serotype dependent. Decreased ability to respond to vaccination may in part explain racial disparities in pneumococcal disease epidemiology.
ClinicalTrials.gov ID: NCT03039491.
Abstract Background Advanced age and human immunodeficiency virus (HIV) infection are associated with increased pneumococcal disease risk. The impact of these factors on cellular responses to ...vaccination is unknown. Methods HIV-infected (HIV+) individuals 50–65 years old with CD4+ T cells/μl (CD4) >200 on antiretroviral therapy (ART) ≥1 year received either the 13-valent pneumococcal conjugate vaccine followed by the 23-valent pneumococcal polysaccharide vaccine (PCV/PPV) or PPV only. HIV-uninfected (HIV−) controls received PCV/PPV. Phenotype distribution and surface expression of complement receptor CD21 and tumor necrosis factor superfamily receptors (TNFRs) were compared on serotype-specific B cells postvaccination. Results Postvaccination serotype-specific B cell percentages were significantly lower in HIV+ PCV/PPV compared to PPV groups, but similar between HIV+ or HIV− PCV/PPV groups. Transmembrane activator and calcium-modulating cyclophilin ligand interactor (TACI)+ serotype-specific B cell percentages were significantly decreased in HIV+ PCV/PPV compared to PPV groups. CD21+ serotype-specific B cells were significantly higher in HIV− compared to HIV+ PCV/PPV groups. Conclusions An initial dose of PCV reduced the frequency, but not phenotype distribution, of serotype-specific B cells and also lowered TACI expression in aging HIV+ subjects postvaccination with PPV. These findings suggest that PCV does not enhance cellular responses to revaccination with PPV.
Highlights • We studied the B cell response of healthy individuals vaccinated with PPV-23. • PPS-specific B cells were identified by flow cytometry pre- and post-vaccination. • PPS-specific B cells ...were CD19+ CD20+ CD3− CD27+ IgM+ CD43+ CD5+/− CD70−. • B cells share same phenotype as recently described putative human B1 cells
The phenotype of B cells responsible for the production of anti-pneumococcal polysaccharide Ab has been unclear. Although individuals that respond poorly to the 23-valent pneumococcal polysaccharide ...(PPS) vaccine, Pneumovax, such as children <2 y, the asplenic, and a subset of common variable immunodeficiency patients, are profoundly deficient or lack IgM memory cells (CD27(+)IgM(+)), they are also deficient in the switched memory (CD27(+)IgM(-)) compartment. Direct characterization of PPS-specific B cells has not been performed. In this study, we labeled PPS14 and PPS23F with fluorescent markers. Fluorescently labeled PPS were used in FACSAria flow cytometry to characterize the phenotype of PPS-specific B cells obtained from 18 young adults pre- and postimmunization with Pneumovax. The labeled PPS were capable of inhibiting binding of Ab to the native PPS. Similarly, the native PPS were able to inhibit binding of PPS-specific B cells in a flow cytometric assay demonstrating specificity and functionality. Phenotypic analysis of unselected B cells, pre- and postimmunization, demonstrated a predominance of naive CD27(-)IgM(+) cells accounting for 61.5% of B cells. Likewise, the PPS-specific B cells obtained preimmunization consisted primarily of naive, CD27(-) B cells, 55.4-63.8%. In contrast, the PPS-specific B cells obtained postimmunization were predominantly IgM memory cells displaying the CD27(+)IgM(+), 54.2% for PPS14 and 66% for PPS23F, significantly higher than both unselected B cells and PPS-specific B cells. There was no significant difference in switched memory B cell populations (CD27(+)IgM(-)) between groups. These results suggest a dominant role of IgM memory cells in the immune response to pneumococcal polysaccharides.
Abstract
Objective.
Clostridium difficle-associated infection (CDI) is usually treated with antibiotics; nevertheless, the infection has a high relapse rate. Case series and case reports using fecal ...microbiota transplant (FMT) for CDI show promising results. However, there are no large studies to provide evidence for the efficacy of this therapy. The aim of this pooled patient data meta-analysis was to determine the efficacy of FMT in CDI.
Methods.
We performed a literature search for FMT for CDI or pseudomembranous colitis. Individual patient data were obtained from each study. The primary endpoint was to assess the rate of diarrhea resolution. Secondary endpoints were to identify variables associated with treatment failure and side effects of therapy.
Results.
A total of 289 patients from 25 published articles who received FMT for CDI were included in the pooled data analysis. FMT had an overall success rate of 91.2%. On univariate analysis, shorter duration of symptoms before FMT (< 60 days) and gastroduodenal route of fecal instillation were associated with treatment failure. On multivariate regression analysis, shorter duration of symptoms (< 60 days) before the FMT (OR= 11.08; p = 0.0009) was associated with treatment failure. Reported adverse events following FMT were irritable bowel syndrome (n = 1), symptoms of mild enteritis (n = 3), and suspected peritonitis following the procedure (n = 1).
Conclusion.
FMT is a safe and effective treatment option for CDI. Shorter duration of symptoms (< 60 days) before administering FMT is associated with treatment failure.
Members of the Tumor Necrosis Factor (TNF)-superfamily have speculated roles in the response against T-independent type II antigens (TI-II) including pneumococcal polysaccharides (PPS). Dysregulation ...in their expression is associated with an enhanced risk for pneumococcal disease in neonates but their expression in other high-risk populations including HIV-positive individuals remains to be elucidated.
To investigate signals that contribute towards PPS-response and identify potential anomalies that may account for diminished serological response in HIV-positive individuals post Pneumovax (PPV23) immunization.
Markers of inflammation, C-reactive protein (CRP), IL-6, sCD27 and sCD30, were assessed in HIV-positive and -negative individuals as potential predictors of PPV23 response. Serum levels of B cell activating factor (BAFF), transmembrane activator and calcium-modulator and cytophilin ligand interactor (TACI), B cell maturation antigen (BCMA) and B cell expression of BAFF-R, TACI, BCMA, CD40 and CD21 were assessed in total (unselected) and PPS23F (antigen)-specific B cells of PPV23 immunized HIV-positive and -negative individuals.
CRP, sCD27, sCD30 and BAFF were significantly elevated in the serum of HIV-positive individuals but did not adversely affect PPV23 response. Assessment of PPS-specific B cells revealed enhanced TACI and reduced BAFF-R expression compared to unselected B cells in HIV-positive and -negative individuals. Surface TACI was similar but soluble TACI was significantly lower in HIV-positive compared to HIV-negative individuals.
Current studies highlight a potential role for TACI in PPV23 response based on its enhanced expression on PPS-specific B cells. Although surface levels of TACI were similar, diminished soluble TACI (sTACI) in HIV-positive compared to HIV-negative individuals could potentially decrease BAFF responsiveness and Ig response. A better understanding of the role of TNF receptors could contribute to the design of improved pneumococcal vaccines.
ClinicalTrials.gov NCT02515240.
Due to distinct immunological limitations, both infants and elderly individuals are highly susceptible to Streptococcus pneumoniae. Routine immunization of children with the conjugate vaccine over ...the past decade has substantially reduced incidence of vaccine-serotype related invasive pneumococcal disease in both vaccinated and unvaccinated persons of all ages. However, disease burden remains high in the elderly despite the effects of herd protection and recommended use of polysaccharide vaccine in this population for over 30 years. An increase in drug resistance and incidence of infections caused by non-vaccine serotypes emphasize the need to improve current vaccination strategies. Recent efforts to identify age-associated defects in vaccine response and the use of conjugate vaccine and potential alternatives in adults are discussed.
The phenotype of B cells that respond to vaccination with the purified pneumococcal polysaccharide (PPS) has been a topic of debate. We have recently identified the phenotype of cells from healthy ...young volunteers as CD27 + IgM + B cells. However, the PPS-responding B-cell population has not yet been identified in high-risk populations, such as elderly individuals. Previous studies have shown that elderly individuals have a lower percentage of immunoglobulin M memory B cells than healthy young adults. In this study, we directly characterized the phenotype of PPS-specific B cells before and after vaccination with PPS vaccine (PPV) in elderly adults, using fluorescently labeled PPS14 and PPS23F. In contrast to our observations in healthy young volunteers, the PPS-responding B-cell population consisted primarily of switched memory (CD27 + IgM - ) B cells. In concurrence with these findings, postvaccination immunoglobulin M concentrations were not significantly increased in this population, and the opsonophagocytic response was decreased, compared with that in young adults. These findings identify a significant shift in the phenotype of the B-cell population in response to PPV among elderly individuals.
Streptococcus pneumoniae is a leading cause of morbidity and mortality in both developed and developing countries. The current pneumococcal polysaccharide (PPS) vaccine is highly effective in young ...adults; however, vaccine efficacy is dramatically decreased in the elderly population. We hypothesized that the decreased vaccine efficacy in the elderly results from altered variable gene family usage. We have characterized the immunoglobulin G gene usage of the antibody response to PPS4 and PPS14 in 20 young and 20 elderly adults. The variable heavy (Vsubscript H) gene repertoire of human peripheral B cells was amplified by using PCR. A total of 364 heavy chain sequences with specificity for PPS4 and 305 heavy chain sequences for PPS14 were analyzed from young adults. In addition, a total of 325 sequences for PPS4 and 291 sequences for PPS14 were obtained from elderly adults. Complete sequence identity, somatic mutation frequencies, and Vsubscript H gene usage was determined in response to PPS4 and PPS14. In all volunteers, the immune response to both polysaccharides consisted predominantly of heavy chains belonging to the Vsubscript H3 gene family. There were significant differences in the variable gene repertoire between young and elderly adults. Somatic mutation occurred more frequently in sequences derived from young compared to elderly derived sequences. With aging, a loss of oligoclonality was noted in response to PPS4 and PPS14 compared to young adults. The observed differences in Vsubscript H repertoire, somatic mutation, and loss of oligoclonality may contribute to decreased vaccine efficacy in the elderly.
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