Adoptive transfer of resistance to Plasmodium berghei with spleen cells and serum from Fansidar-cured mice.

The ability of splenic leukocytes or serum to transfer immunity to Plasmodium berghei was studied in C57BL/6 mice. Splenic leukocytes or serum was removed from mice which had been inoculated previously 1 to 4 or 5 times with P. berghei and cured 1 to 4 or 5 times with Fansidar (pyrimethamine plus sulfadoxine) and transferred to syngeneic recipients 1 or 2 days before parasite challenge. Partial protection was observed in recipients of immune serum or unfractionated splenic leukocytes. Significantly more protection was observed in recipients of preparations from immune mice enriched for immunoglobulin-positive (B-lymphocyte) cells or B-lymphocyte plus immunoglobulin-negative (T-lymphocyte) cells than in recipients of preparations enriched for T-lymphocytes. Recipients of B- or B+T-lymphocyte-enriched spleen cells from immune mice had significantly longer survival times than did recipients of T-lymphocyte-enriched spleen cells and recipients of spleen cells from normal mice. Transferred immunity lasted less than 2 months and did not protect recipients against death induced by the malarial parasite. The ability of splenic leukocytes to transfer resistance to recipients was independent of the number of times donors were inoculated with P. berghei and cured with Fansidar.