Mice genetically deficient in immunoglobulin E are more permissive hosts than wild-type mice to a primary, but not secondary, infection with the filarial nematode Brugia malayi.
Primary and secondary murine and human infections with Brugia malayi are characterized by substantial increases in levels of immunoglobulin E (IgE). To investigate whether this is necessary for worm clearance, IgE(-/-) mice were subjected to primary- and secondary-infection protocols. Following a primary infection, IgE(-/-) mice displayed a profound deficit in their ability to clear an intraperitoneal injection of L3 infective-stage larvae in comparison to wild-type counterparts and maintained substantial worm burdens as late as 10 weeks postinfection. Although viable adult parasites were recovered at this late time point from IgE(-/-) mice, the majority of the mice remained free of microfilariae. IgE(-/-) cohorts subjected to a secondary-infection protocol were able to clear the challenge inoculation in an accelerated manner, with kinetics similar to that observed in the wild-type animals. Analysis of the humoral response in IgE(-/-) mice following infection demonstrates a defect in IgG1 and IgG2a production, in addition to the expected lack of IgE. The IgG1 deficiency is no longer evident following a secondary infection. These data imply that deficiencies other than IgE production (i.e., IgG1 production) deficiency may be responsible for the increased permissiveness of IgE(-/-) mice as hosts following infection with B. malayi.
Spencer
L A
LA
Department of Pathology, University of Connecticut Health Center, Farmington, Connecticut 06030-3105, USA.
Porte
P
P
Zetoff
C
C
Rajan
T V
TV
D000818:Animals; D017178:Brugia malayi; D005368:Filariasis / Q000276:immunology*; D007073:Immunoglobulin E / Q000172:deficiency*; D007074:Immunoglobulin G / Q000096:biosynthesis / Q000145:classification; D051379:Mice; D008807:Mice, Inbred BALB C; D018512:Parasitemia / Q000276:immunology; D010529:Peritoneal Cavity / Q000166:cytology
D007074:Immunoglobulin G; D007073:Immunoglobulin E