PLoS Pathogens (Jan 2013)

CD4+ T cell-derived IL-10 promotes Brucella abortus persistence via modulation of macrophage function.

  • Mariana N Xavier,
  • Maria G Winter,
  • Alanna M Spees,
  • Kim Nguyen,
  • Vidya L Atluri,
  • Teane M A Silva,
  • Andreas J Bäumler,
  • Werner Müller,
  • Renato L Santos,
  • Renée M Tsolis

DOI
https://doi.org/10.1371/journal.ppat.1003454
Journal volume & issue
Vol. 9, no. 6
p. e1003454

Abstract

Read online

Evasion of host immune responses is a prerequisite for chronic bacterial diseases; however, the underlying mechanisms are not fully understood. Here, we show that the persistent intracellular pathogen Brucella abortus prevents immune activation of macrophages by inducing CD4(+)CD25(+) T cells to produce the anti-inflammatory cytokine interleukin-10 (IL-10) early during infection. IL-10 receptor (IL-10R) blockage in macrophages resulted in significantly higher NF-kB activation as well as decreased bacterial intracellular survival associated with an inability of B. abortus to escape the late endosome compartment in vitro. Moreover, either a lack of IL-10 production by T cells or a lack of macrophage responsiveness to this cytokine resulted in an increased ability of mice to control B. abortus infection, while inducing elevated production of pro-inflammatory cytokines, which led to severe pathology in liver and spleen of infected mice. Collectively, our results suggest that early IL-10 production by CD25(+)CD4(+) T cells modulates macrophage function and contributes to an initial balance between pro-inflammatory and anti-inflammatory cytokines that is beneficial to the pathogen, thereby promoting enhanced bacterial survival and persistent infection.