EFFECT OF DIETARY VITAMIN-E AND SELENIUM DEFICIENCY ON CHICKEN SPLENOCYTE PROLIFERATION AND CELL-SURFACE MARKER EXPRESSION

Beginning at hatching, chicks were fed a Basal diet, without vitamin E or selenium (Se) or the same diet supplemented with vitamin E (100 IU /kg) and Se (0.2 ppm). The effect of these treatments on the expressio n of cell surface markers (CT-1a, CD3, CD4, CD8, sIgs, and Ia) definin g specific thymocyte and peripheral blood leukocyte (PBL) subpopulatio ns were examined using flow cytometric analyses. In parallel studies t he effect of the dietary deficiencies on splenocyte proliferative resp onses to ConA or PHA stimulation was examined. The mean expression of CD3 and CT-1a per cell was increased while CD8 and CD4 expression was decreased on thymocytes from chicks fed the Basal diet. The proportion of double negative (CD4(-),CD8(+)) thymocytes and single positive CD8 (+) thymocytes was significantly decreased while single positive CD4() and double positive (CD4(+),CD8(+)) thymocytes were significantly in creased by the dietary vitamin E and Se deficiencies. The dietary defi ciencies resulted in a decreased proportion of peripheral T cells and specifically decreased the number of CD4(+) PBL. The proliferative res ponse to both ConA and PHA was impaired by the vitamin E and Se dietar y deficiencies. The proliferative response could be fully reconstitute d but only after vitamin E and Se supplementation for periods longer t han 1 week. Plasma SeGSHpx and alpha-tocopherol levels paralleled the mitogen responsiveness observed. These results support the conclusion that vitamin E and Se deficiencies may affect both the maturation of s pecific lymphocyte subpopulations and the functional and proliferative capabilities of the peripheral lymphocytes.