Antibody production in Syphacia obvelata infected mice.

Antibody response to Syphacia obvelata infection was observed in AKR/J mice by ELISA. Experimental infection with the pinworm eggs showed the presence of specific IgG against S. obvelata somatic antigens at 12 days postinfection, and that it increased steadily thereafter. Sera of S. obvelata-infected mice showed cross-reactivity with somatic antigens of other Syphacia species such as S. mesocriceti and S. muris, but not with Aspiculuris asiatica. Western blotting of S. obvelata antigen with sera of S. obvelata-infected mice showed a corresponding increase in the number of bands during the course of infection. Infected mice showed significantly higher antibody production to sheep red blood cells than the uninfected control mice. Thus, S. obvelata infection is shown to alter the humoral response to nonparasitic antigenic stimuli. These observations indicate that infection by helminths, which apparently do not produce clinical symptoms, might modulate the immune system of the host and, therefore, affect experimental results.