In vitro responses of spleen cells from Trichinella spiralis-infected mice.

The in vitro cellular immune responses of spleen cells from mice infected with Trichinella spiralis and immunized with BCG have been investigated. ICR/CD-1 mice were originally infected with 200 T. spiralis larvae 22 days prior to infection with 4 X 10(6) viable or heat-killed mycobacteria. Analysis of the splenic cell populations indicated that significant increases in adherent cells (macrophages) were noted only in groups previously infected with the nematode; the concentration of non-adherent cells (lymphocytes) did not vary insignificantly among any of the experimental groups. Assay of blast cell transformation and 3H-thymidine incorporation demonstrated the ability of T. spiralis infection to potentiate in vitro cellular immune reactions. These findings support earlier in vivo studies concerning nematode-induced immunopotentiation of delayed-type hypersensitivity reactions, and provide additional evidence that infection with this nematode enhances the immune capabilities of both stimulated lymphocytes and nonspecific phagocytic cells.