Protective immunity to Nippostrongylus brasiliensis in the rat. Central role of the lymphocyte in worm expulsion.

Abstract

Evidence is presented to show that the expulsion of adult Nippostrongylus brasiliensis worms from the intestine of the rat requires the presence of functional lymphocytes. It has been established by previous workers that expulsion involves two steps, the first involving antibody action on the worms, and the present work shows that the second step requires the participation of lymphocytes. This conclusion comes from experiments in which the expulsion of worms already affected by step 1 (damaged worms) was examined in rats which were depleted of or restored with lymphocytes, as follows: