Effects of protein-calorie restriction on the immune response to skin allografts in the rat.
Academic Article
Overview
abstract
The effect of protein depletion on immune responsiveness was examined using a skin allograft model. Protein depletion was induced in adult Fischer (F344) male rats by the ad libitum provision of a 5% protein diet. Total serum protein, total body weight, total body nitrogen, and total body lipid were all markedly decreased in these rats. Skin from control-fed Brown Norway (BN) male rats was grafted to the middorsal region of control and protein-depleted F344 rats. BN skin allografts survived significantly longer on protein-depleted recipients (13.3 days) than on controls (8.5 days). Splenic lymphoid cells from skin grafted F344 rats were assayed for cytotoxicity against BN and F344 lymphoid cells in a 51Cr release assay. At effector to target ratios of 50:, 100:, and 200:1, spleen cells from control rats exhibited greater than 35% allospecific cytotoxicity 8 days after grafting. Spleen cells from protein-depleted rats exhibited no greater than 10% cytotoxicity from 6 to 15 days after grafting. A depression of cytotoxicity by protein depletion was also observed in rats immunized by i.p. injection of BN spleen cells. Heat-inactivated sera from skin grafted F344 rats were assayed against BN and F344 lymphoid cells in a complement-dependent trypan blue exclusion assay. Cytotoxic alloantibodies were measurable in both control and protein-depleted rats 9 days after grafting, but were of significantly lower titer in the protein-depleted group. The results indicate that both humoral and cell-mediated immune responses to alloantigens are impaired by protein-calorie malnutrition.
