A Role for Eosinophils in the Intestinal Immunity against Infective Ascaris suum Larvae
Peritoneal leukocytes, serum, and peritoneal fluid from Ascaris suum-infected or noninfected mice were studied using 51Cr release and larval mobility to determine if they had in vitro cytotoxicity for A. suum infective larvae. Mouse serum or peritoneal fluid from infected and non-infected mice was added to leukocyte-larvae cultures to determine their effect on leukocyte damage to larvae. Leukocytes from A. suum infected mice were cytotoxic for A. suum larvae in the presence of serum from infected or noninfected mice but only serum from infected mice produced larval cytotoxicity independent of leukocytes or in the presence of leukocytes from noninfected mice. Mouse peritoneal fluid from infected or noninfected mice was found to damage larvae independent of leucocytes. Cytotoxic activity was blocked when serum or peritoneal fluid was heat-inactivated suggesting complement as the damaging agent.