Anti-immunoglobulin E treatment decreases worm burden and egg production in Schistosoma mansoni-infected normal and interferon gamma knockout mice.
The immunoglobulin E (IgE) response is generally considered an essential component of the host defense against parasitic helminths such as Schistosoma mansoni. In contrast, work on antischistosome vaccines suggests that interferon gamma (IFN-gamma) is the critical immune mediator for vaccine-induced immunity to the parasite. In this study, the total IgE response to a primary S. mansoni infection was suppressed by anti-IgE treatment in both normal mice and in mice with defective IFN genes (gene knockout [GKO]). Reduction of the IgE response resulted in decreased worm burden and a decrease in the number of eggs produced per worm in both normal and GKO mice. Whereas anti-IgE treatment also resulted in reduced hepatosplenomegaly, granulomas around existing schistosome eggs showed normal cellularity. Serum interleukin 4 levels fell in response to the reduction in serum IgE as well. The data suggest that IgE plays a detrimental, rather than beneficial, role for the host in schistosomiasis. Furthermore, the absence of IFN-gamma was found to be of little consequence to the host-response to adults or eggs in a primary schistosome infection.
Amiri
P
P
Department of Immunology, Genentech, Inc., South San Francisco, California 94080-4990.
Haak-Frendscho
M
M
Robbins
K
K
McKerrow
J H
JH
Stewart
T
T
Jardieu
P
P
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D007073:Immunoglobulin E / Q000502:physiology*; D007371:Interferon-gamma / Q000235:genetics / Q000502:physiology*; D015847:Interleukin-4 / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D010063:Ovum / Q000276:immunology / Q000502:physiology; D012550:Schistosoma mansoni / Q000302:isolation & purification; D012555:Schistosomiasis mansoni / Q000276:immunology* / Q000469:parasitology
D000888:Antibodies, Anti-Idiotypic; C026408:anti-IgE antibodies; D015847:Interleukin-4; D007073:Immunoglobulin E; D007371:Interferon-gamma