Transfer of immunity to Nematospiroides dubius: co-operation between lymphoid cells and antibodies in mediating worm expulsion.

The effect of transferring immune serum (IS) and immune mesenteric lymph node cells (IMLNC) either alone or in combination was studied in NIH mice infected with partially radiation attenuated (5 krad) N. dubius. It was demonstrated that immunity to N. dubius could be transferred with IS and with IMLNC. However, considerably greater protection was transferred to recipient mice when they received both IS + IMLNC. Animals treated in this way had fewer worms than either of the other groups from as early as day 9 onwards, suggesting that a substantial proportion of the worms in mice given IS + IMLNC was retained in the intestinal tissues. The few surviving worms which completed the tissue phase of their development were then rejected by the fourth week of infection. Dose response data showed that as few as 1 x 10(7) IMLNC could cause a significant reduction in worm numbers when given in combination with IS. These experiments indicate that both antibodies (IS) and sensitized lymphoid cells (IMLNC) are required for effective resistance to N. dubius.