Factors affecting mitogenic response of turkey lymphocytes

The objective of the present study was to determine the parameters and conditions for measuring mitogenic response of turkey whole blood and spleen lymphocytes that may be useful in studying cellular immunity of turkeys. Heparinized whole blood or spleen was collected from normal turkeys. The mitogenic assay of whole blood lymphocytes was examined by different combinations of blood dilution (1:10 to 1:80), concanavalin A (Con A) concentration (0 to 320 g/ml), and serum of different species added. The mitogenic assay of spleen lymphocytes was examined by different combinations of spleen cell concentration (I x 10(6) to I x 10(7) cells/ml). Con A concentration (0 to 25 mug/ml), and serum of different species added. The effect of age Oil the mitogenic response of turkey whole blood cells and spleen cells to Con A was also examined, Both turkey Serum and fetal bovine serum enhanced the Counts per minute (CPM) readings of the whole blood assay. The presence of fetal bovine Serum produced higher stimulation index (SI) than the presence of turkey serum. In the presence of fetal bovine serum, the highest CPM and SI for the whole blood assay were observed with blood dilution at 1:40 and Con A concentration of 40 mug/ml. The highest CPM and SI for the spleen cell assay were observed using turkey serum and Coil A concentration of 12.5 mug/ml. Spleen cell concentrations for the highest CPM were 5 x 10(6) and I x 10(7) cells/ml whereas those for the highest Sl were 2.5 x 10(6) and 5 x 10(6) cells/ml. The mitogenic responses of both whole blood assay and spleen cell assay varied among turkeys of different ages. The results indicated that addition of fetal bovine serum is better for the mitogenic response of turkey whole blood lymphocytes and addition of turkey Serum is better for the mitogenic response Of turkey spleen lymphocytes. In the presence of appropriate serum, the greatest mitogenic response of turkey lymphocyte to Con A could be obtained by checkerboard tests of whole blood dilutions, spleen cell concentration, or Con A concentration.