PROTECTIVE CAPACITIES OF FRACTIONATED IMMUNE THORACIC-DUCT LYMPHOCYTES AGAINST NIPPOSTRONGYLUS-BRASILIENSIS

Thoracic duct lymphocytes (TDL) obtained from rats either on the tenth day of a primary infection (Day 10 TDL) or 1 or 5 weeks after a tertiary infection (hyperimmune TDL) with Nippostrongylus brasiliensis were fractionated into cells lacking (sIg-) or bearing (sIg+) surface immunoglobulin by a rosetting procedure. The abilities of unfractionated TDL, of the two subpopulations, and of the reconstituted cells to confer protection against the parasite were examined. The effector cells which cause worm expulsion were found only in (sIg-) cells from Day 10 TDL and also predominantly in (sIg-) cells from hyperimmune TDL. However, a small but significant degree of protection was conferred by (sIg+) cells from hyperimmune TDL. These results suggest that the mechanisms involved in worm expulsion are regulated by (sIg-) cells but that (sIg+) cells from hyperimmune rats can also contribute to the mechanisms of worm expulsion. © 1978.