Deteriorating pneumococcal-specific B-cell memory in minimally symptomatic African children with HIV infection

J Infect Dis. 2011 Aug 15;204(4):534-43. doi: 10.1093/infdis/jir316.

Abstract

Invasive pneumococcal disease is a leading cause of human immunodeficiency virus (HIV)-associated mortality in sub-Saharan African children. Defective T-cell-mediated immunity partially explains this high disease burden, but there is an increased risk of invasive pneumococcal disease even in the context of a relatively preserved percentage of CD4 cells. We hypothesized that impaired B-cell immunity to this pathogen further amplifies the immune defect. We report a shift in the B-cell compartment toward an apoptosis-prone phenotype evident early in HIV disease progression. We show that, although healthy HIV-uninfected and minimally symptomatic HIV-infected children have similar numbers of isotype-switched memory B cells, numbers of pneumococcal protein antigen-specific memory B cells were lower in HIV-infected than in HIV-uninfected children. Our data implicate defective naturally acquired B-cell pneumococcal immunity in invasive pneumococcal disease causation in HIV-infected children and highlight the need to study the functionality and duration of immune memory to novel pneumococcal protein vaccine candidates in order to optimize their effectiveness in this population.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • B-Lymphocytes / physiology*
  • CD4 Lymphocyte Count
  • CD4-Positive T-Lymphocytes / physiology
  • CD40 Ligand / genetics
  • CD40 Ligand / metabolism
  • Carrier State
  • Child
  • Child, Preschool
  • Enzyme-Linked Immunospot Assay
  • Female
  • HIV Infections / complications
  • HIV Infections / epidemiology*
  • HIV Infections / immunology*
  • Humans
  • Immunoglobulin Class Switching
  • Immunoglobulin G
  • Immunoglobulin M
  • Immunologic Memory / physiology*
  • Infant
  • Malawi / epidemiology
  • Male
  • Pneumococcal Infections / etiology
  • Pneumococcal Infections / immunology
  • Streptococcus pneumoniae / immunology*

Substances

  • Immunoglobulin G
  • Immunoglobulin M
  • CD40 Ligand