Interleukin 5 (IL-5) is not required for expression of a Th2 response or host resistance mechanisms during murine schistosomiasis mansoni but does play a role in development of IL-4-producing non-T, non-B cells.
During schistosomiasis, interleukin-5 (IL-5)-dependent eosinophil responses have been implicated in immunopathology, resistance to superinfection, synergistic interactions with chemotherapeutic agents, and the inductive phase of the egg-induced Th2 response. We examined these issues in IL-5-deficient (IL-5(-/-)) mice. IL-5(-/-) and wild-type (WT) mice were indistinguishable in terms of susceptibility to primary infections and the ability to resist secondary infections. Moreover, hepatic pathology was similar in both strains apart from a relative lack of eosinophils and, during chronic infection, a significantly larger mast cell component in the granulomas of IL-5(-/-) mice. Splenocyte cytokine production in response to soluble egg antigen (SEA) or anti-CD3 revealed no significant differences except for heightened tumor necrosis factor alpha production by cells from chronically infected IL-5(-/-) mice compared to WT animals. In contrast, ionomycin-stimulated non-B, non-T (NBNT) cells from IL-5(-/-) mice produced significantly smaller IL-4 amounts than did NBNT cells from WT animals. This difference was not apparent following plate-bound anti-immunoglobulin E or SEA stimulation. The absence of IL-5 failed to affect the induction of Th2 responses in naive mice. Peritoneal exudate cells recovered from egg-injected IL-5(-/-) or WT mice produced equivalent levels of IL-4 following restimulation with SEA or anti-CD3.
Brunet
L R
LR
Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
Sabin
E A
EA
Cheever
A W
AW
Kopf
M A
MA
Pearce
E J
EJ
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D001700:Biomphalaria; D007113:Immunity, Innate / Q000276:immunology; D015847:Interleukin-4 / Q000096:biosynthesis*; D015848:Interleukin-5 / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D012555:Schistosomiasis mansoni / Q000276:immunology*; D015163:Superinfection / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology*
D015848:Interleukin-5; D015847:Interleukin-4