Studies in vitro on the reaction of peritoneal exudate cells from mice immune to infection with Nematospiroides dubius with the infective third stage larvae of this parasite.

The results of the present study show that peritoneal exudate cells from mice immune to infection with Nematospiroides dubius are able in vitro to damage the third stage infective larvae as measured by a loss in infectivity. The ability of these cells to function in the absence of specific antibody seems to be related to the presence of trypsin labile factors on their surfaces. Lymphocytes from immune mice are also able to damage the larvae. The suggestion is made that 'activated' macrophages may play an important role in immunity to this infection.