Responses of B-cells to mitogens and antigen in mice receiving isogenic splenocytes from animals treated with Trichinella extract.

Splenocytes of C57BL/6J mice injected with a Trichinella spiralis larval extract for 7 consecutive days were transferred in two doses into isogenic, immunocompetent mice. On the 3rd day, some recipients were immunized with 10(9) sheep red blood cells and others were killed to investigate blastogenic response of their splenocytes to concanavalin A (Con A), Escherichia coli lipopolysaccharide (LPS), and Mycobacterium's purified protein derivative (PPD). On the 8th day of immunization, the corresponding mice were killed to study rosette-forming cells (RFC) and direct and indirect plaque-forming cells (D- and I-PFC) in their spleens. Transfer of 10(6) cells depressed the Con A reactivity and the number of RFC and 1-PFC, but increased the PPD reactivity and the number of D-PFC in the recipients, as compared to control mice receiving splenocytes from donors injected with a saline solution. Ten million cells inhibited only the Con A reactivity, but enhanced the number of LPS- and PPD-responding cells and of D-PFC in the recipients over the controls. Inoculation of cells from mice injected with bovine serum albumin did not reproduce the same effects. Splenocytes of mice treated with T. spiralis extract simultaneously inhibit and enhance diverse functions of the immune system. Stimulation is exerted on IgG antibody production and appears to be mediated by suppressor T-cells. Stimulation is exerted mainly on IgM antibody formation. Depression seems to be antigen-specific; it is partially compensated by the concurrent suppression, and it is probably a result of macrophage activation.