Plasmodium berghei: the in vitro immune response.

Abstract Following primary in vitro Stimulation by Plasmodium berghei , IgM titers by the indirect fluorescent antibody test (IFAT) were negative in in vitro reconstituted syngeneic mouse spleen cultures containing T cells and macrophages, or B cells and macrophages, or macrophages alone, but IgM titers of 1:20 were obtained from cultures containing B cells, T cells, and macrophages. IFAT IgG titers were negative for cultures with T cells and macrophages together, or macrophages alone, but rose to 1:40 with cultures containing B cells and macrophages and 1,80 with cultures of B cells, T cells, and macrophages together. After a second in vitro challenge, IgM and IgG titers were similar to the stimulated cultures from immunized mice; the IgM titer reached only 1:20 but the IgG titer rose to 1:160. Total immunoglobulin was higher in the cultures from immunized mice than from in vitro primed cultures.