Schistosoma mansoni egg-induced early IL-4 production is dependent upon IL-5 and eosinophils.
The initial immune response to Schistosoma mansoni eggs presumably results in IL-4 production, as schistosome eggs are strong Th2-inducing antigens and the differentiation of antigen-specific Th2 cells is largely dependent on the presence of IL-4 during priming of naive Th cells. Consistent with this concept, intraperitoneal injection of mice with schistosome eggs results in an upregulation of IL-4 production by peritoneal exudate cells (PECs) within 12 h. Egg-induced IL-4 is rapidly bound by its receptor, suggesting that this cytokine is utilized by a cell type present at the site of antigen deposition or is complexed to soluble receptor. The peak of early IL-4 production is accompanied by a local eosinophilia and the apparent disappearance of mast cells. Studies utilizing either IL-4, IL-5, or mast cell-deficient mice indicate that the eosinophilia is dependent on mast cells and IL-5 and independent of IL-4. Strikingly, egg-induced IL-4 production is absent in animals lacking the early peritoneal eosinophilia. Immunocytochemical analysis of PEC following egg injection indicates that the eosinophils themselves make IL-4. These data strongly suggest that egg-induced IL-5 plays an essential role in recruiting eosinophils to the site of antigen deposition and that it is these eosinophils that then directly produce early IL-4.
Sabin
E A
EA
Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853-6401, USA.
Kopf
M A
MA
Pearce
E J
EJ
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D004802:Eosinophilia; D004804:Eosinophils / Q000276:immunology* / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism*; D015848:Interleukin-5 / Q000378:metabolism*; D008407:Mast Cells / Q000276:immunology; D051379:Mice; D018448:Models, Immunological; D010063:Ovum / Q000276:immunology*; D010529:Peritoneal Cavity / Q000166:cytology; D018123:Receptors, Interleukin / Q000378:metabolism; D019948:Receptors, Interleukin-4; D012550:Schistosoma mansoni / Q000276:immunology*; D013997:Time Factors; D015854:Up-Regulation
D015703:Antigens, CD; D015848:Interleukin-5; D018123:Receptors, Interleukin; D019948:Receptors, Interleukin-4; D015847:Interleukin-4