Immune mechanisms to Ascaris suum in inbred guinea-pigs. I. Passive transfer of immunity by cells or serum.

Syngeneic Strain 2 guinea-pigs which received seven s.c. injections of infective eggs of Ascaris suum were shown to harbour less larvae in their lungs than control animals after mesenteric vein challenge with 10,000 infective larvae of A. suum. Serum and cell preparations harvested from these animals were able to transfer protective immunity to normal recipients to varying degrees. Significant protection with serum preparations was obtained with immune IgG2, IgE + IgG1 and whole immune serum. Best protection with cell preparations was obtained with a pool of cells from the mesenteric, hepatic (retropancreatic), and mediastinal nodes of immune animals. Cells from the hepatic nodes of immune animals were more effective than cells from the mediastinal and mesenteric nodes. Immune spleen cells enhanced, rather than reduced, the degree of the infection. Cells or serum preparations from normal animals were not capable of transferring portective immunity to normal recipients.