The Common Gamma Chain Cytokines Interleukin (IL)-2 and IL-7 Indirectly Modulate Blood Fluke Development via Effects on CD4+ T Cells

J Infect Dis. 2006 Dec 1;194(11):1609-16. doi: 10.1086/508896. Epub 2006 Oct 23.

Abstract

The human pathogen Schistosoma mansoni exhibits a highly evolved and intricate relationship with its host, evading immune destruction while co-opting CD4(+) T cell-driven mechanisms to facilitate parasite development and egg excretion. Because the common gamma ( gamma (c)) chain cytokine interleukin (IL)-7 is also implicated in modulating schistosome development, we investigated whether this effect is mediated indirectly through the essential role that IL-7 plays in CD4(+) T cell growth and survival. We demonstrate that attenuated schistosome development in the absence of IL-7 results from dysregulated T cell homeostasis and not from disruption of direct interactions between schistosomes and IL-7. We also identify an indirect role that another gamma (c) chain cytokine plays in schistosome development, demonstrating that IL-2 expression by CD4(+) T cells is essential for normal parasite development. Thus, cytokines critical for CD4(+) T cell survival and function can mediate indirect but potent effects on developing schistosomes and underscore the importance of CD4(+) T cells in facilitating schistosome development.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adoptive Transfer
  • Animals
  • CD4-Positive T-Lymphocytes / immunology*
  • Homeostasis
  • Interleukin-2 / immunology*
  • Interleukin-7 / immunology*
  • Liver / parasitology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Morphogenesis
  • Parasite Egg Count
  • Receptors, Interleukin-2 / genetics
  • Receptors, Interleukin-7 / genetics
  • Schistosoma mansoni / growth & development*
  • Schistosoma mansoni / immunology
  • Schistosomiasis mansoni / immunology*
  • Schistosomiasis mansoni / parasitology*

Substances

  • Interleukin-2
  • Interleukin-7
  • Receptors, Interleukin-2
  • Receptors, Interleukin-7