Cell mediated and humoral immunity in experimental Plasmodium berghei infection

Adoptive passive transfer of immunity to Plasmodium berghei infection has been investigated in an inbred strain of Swiss mice. The mice were made hyperimmune by repeated passage of 10(3) parasites and subsequent therapy with an antimalarial drug. Immune sera and cells obtained from thymus, spleen and peritoneal exudate were transferred to normal animals which were subsequently challenged with standard doses of P. berghei. It was observed that: (a) immune serum in high doses (0.5 ml/mouse) enhanced parasitaemia; when used in smaller doses (0.1 ml/mouse), it afforded a considerable degree of protection; (b) viable immune lymphocytes obtained from thymus and lymph node afforded protection; (c) the mixed population of cells obtained from spleens of immunized mice, as well as peritoneal exudate, protected mice against challenge inoculum; (d) glutaraldehyde-treated spleen cells and material obtained after freezing and thawing the same number of spleen cells, macrophages and lymph node also afforded protection. These findings confirm that, under these experimental conditions, immunity against P. berghei is mediated through (i) specific antibody which is dose-dependent, (ii) cell-mediated immunity and (iii) effective response to processed antigen.