Production of hybrids of mouse myeloma cells and protozoa which express parasite antigens.

Mouse myeloma cells were fused with blood stage forms of the rodent malaria parasite Plasmodium chabaudi and with promastigotes of Leishmania donovani, the causative agent of kala-azar in man. The fusion was carried out by polyethylene glycol treatment. The parasites provided the enzyme which enabled the hybrids to grow in selective medium containing aminopterin. Clones of parasite-myeloma hybrids grown in continuous culture for up to 5 months expressed parasite antigen and induced anti-parasite antibodies in mice.