Acute starvation in mice reduces the number of T cells and suppresses the development of T-celll-mediated immunity

Experiments were performed to determine the effect of starvation on T-cell mediated host defences. In mice starved for 72 hr, the number of thymocytes fell by 98%, spleen cells by 82% and peripheral blood cells by 44%. By 7 days after the end of starvation, values had returned to within 50% of baseline. The percentage of L3T4 and Lyt-2 antigen bearing cells fell in the thymus, but the percentage of Thy-1.2-positive cells did not change. Starvation decreased the percentage of lymphocytes in peripheral blood but increased the percentage of granulocytes. During starvation, the cellularity in thymuses, spleens and peripheral blood was preserved in adrenalectomized mice compared to normal or sham-adrenalectomized mice. Confirming previous results of ours, starved mice were resistant to i.v. challenge with Listeria monocytogenes immediately after starvation. However, when starved mice were immunized with a sublethal dose of Listeria immediately after starvation and challenged 3-4 weeks later, they were less resistant to Listeria than fed, immunized mice. Similarly, spleen cells of starved, immunized mice had a reduced capacity to transfer immunity passively to non-immune mice. Increasing the immunizing dose of Listeria in starved mice increased the level of immunity that developed. These data indicate that starved mice have a marked reduction in T-cell cellularity, possibly related to corticosteroid production during the stress of starvation. Although starved mice were relatively resistant to Listeria immediately after starvation, they had a reduced capacity to develop T-cell mediated immunity to Listeria. This deficiency could be partly overcome by increasing the immunizing dose of Listeria.