Immunological sequelae of Trichinella spiralis infection in mice: effect on the antibody responses to sheep erythrocytes and Japanse B encephalitis virus.

Immunosuppression of the antibody response to Japanese B encephalitis (JBE) virus and sheep erythrocytes (SRBC) was observed in mice infected with Trichinella spiralis. This suppression was paralleled by the presence of fewer antibody-forming cells to SRBC in the spleens of parasitized mice. Both primary and secondary complement-fixing antibody responses to JBE virus were suppressed, but the development of immunological memory was not affected. Parasitized mice demonstrated a normal blastogenic response to phytohemagglutinin and normal serum clearance rate of injected (125)I-labeled immunoglobulin G(2b), although the size of the extravascular fluid compartment was significantly increased. The data presented here and in previous reports suggest that sequential antigenic competition is a possible explanation for the humoral immunosuppression to heterologous antigens caused by T. spiralis infection.