B cells enhance antigen-specific CD4 T cell priming and prevent bacteria dissemination following Chlamydia muridarum genital tract infection

PLoS Pathog. 2013 Oct;9(10):e1003707. doi: 10.1371/journal.ppat.1003707. Epub 2013 Oct 31.

Abstract

B cells can contribute to acquired immunity against intracellular bacteria, but do not usually participate in primary clearance. Here, we examined the endogenous CD4 T cell response to genital infection with Chlamydia muridarum using MHC class-II tetramers. Chlamydia-specific CD4 T cells expanded rapidly and persisted as a stable memory pool for several months after infection. While most lymph node Chlamydia-specific CD4 T cells expressed T-bet, a small percentage co-expressed Foxp3, and RORγt-expressing T cells were enriched within the reproductive tract. Local Chlamydia-specific CD4 T cell priming was markedly reduced in mice lacking B cells, and bacteria were able to disseminate to the peritoneal cavity, initiating a cellular infiltrate and ascites. However, bacterial dissemination also coincided with elevated systemic Chlamydia-specific CD4 T cell responses and resolution of primary infection. Together, these data reveal heterogeneity in pathogen-specific CD4 T cell responses within the genital tract and an unexpected requirement for B cells in regulating local T cell activation and bacterial dissemination during genital infection.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • B-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / pathology
  • Chlamydia Infections / immunology*
  • Chlamydia Infections / pathology
  • Chlamydia muridarum / immunology*
  • Female
  • Forkhead Transcription Factors / immunology
  • HeLa Cells
  • Humans
  • Immunity, Cellular*
  • Male
  • Mice
  • Nuclear Receptor Subfamily 1, Group F, Member 3 / immunology
  • Reproductive Tract Infections / immunology*
  • Reproductive Tract Infections / microbiology
  • Reproductive Tract Infections / pathology

Substances

  • Forkhead Transcription Factors
  • Foxp3 protein, mouse
  • Nuclear Receptor Subfamily 1, Group F, Member 3