Cytokine-dependent inflammatory cell recruitment patterns in the peritoneal cavity of mice exposed to the parasitic nematode Brugia malayi

Abstract.

Mice exposed intraperitoneally to either adult or first larval stage (microfilaria) of the human nematode parasite Brugia malayi display polarized cytokine responses. We have used this model to investigate the impact of altered cytokine profiles on inflammatory cell recruitment patterns in vivo. Here we demonstrate that Th2-inducing adult parasites drive the recruitment of eosinophils and macrophages after implant into the murine peritoneal cavity whereas Th1-inducing microfilaria do not. The underlying mechanism of recruitment was further defined by use of mice deficient in the key Th2 cytokines IL-4 or IL5 and mice that lack T cells (nude mice). Recruitment dynamics differed in IL-4 and IL-5 deficient mice, showing reduced or absent eosinophilia. These data emphasize the pivotal role of these cytokines in shaping the cellular profile of inflammatory responses. Surprisingly, the absence of T cells failed to influence inflammatory cell recruitment indicating that recruitment signals are provided by other cell types.