INDUCTION OF IGE ANTIBODY RESPONSE IN MICE BY CONTINUOUS ADMINISTRATION OF EXCRETORY/SECRETORY PRODUCTS OF THE NEMATODE NIPPOSTRONGYLUS BRASILIENSIS

IgE-inducing potential of excretory/secretory products (ES) of the nematode Nippostrongylus brasiliensis was examined in mice immunized with ES without use of adjuvant. Repeated i.p. injections or continuous i.p. or s.c. infusion of ES induced significant increases in total serum IgE. Continuous i.p. or s.c. infusion of ES also induced ES-specific IgE antibody, while repeated i.p. injections did not. IL-4 production was increased by ex vivo stimulation with ES of mesenteric lymph node cells from repeatedly immunized mice.On the other hand, continuous intraduodenal infusion of ES induced neither total nor specific IgE responses. These results suggest that continuously secreted ES from the nematode are relevant for the up-regulation of IL-4 and IgE responses, although additional factor (s) may be necessary for the uptake of ES across the intestinal mucosal barrier.