BOLA CLASS-I POLYMORPHISM AND IN-VITRO IMMUNE-RESPONSE TO M-BOVIS-ANTIGENS

From a sample of 119 Friesian calves, serologically typed for BoLA cla ss I, 47 subjects were chosen expressing 9 different MHC types (A6, A6 .9, A10, All, A14, A15, A30, W16, M103) with the same age and reared i n the same farm conditions. The animals were s.c. injected with a wate r in oil suspension of killed M. bovis and the treatment was repeated two days later. Before the treatment and 21 days later, calves were bl ed and on PBM peripheral blood mononuclear leucocytes) were performed the following tests: 1. Lymphocyte Stimulation with bovine and avian P PDs (Purified protein derivative of Mycobacterium bovis and Mycobacter ium, respectively). 2. Phagocytic activity towards M. bovis. 3. Class II molecules expression on cell surface. 4. Percentage of leucocyte po pulations and subpopulations. In the in vitro Lymphocyte Stimulation t est, all the animals and classes were responders. Animals bearing A10 BoLA class I presented c.p.m. (counts per minute) and index values hig her than the other cattle; these values were significantly positively related both to bovine and avian PPDs (P < .01). By variance analysis A14 BoLA type showed a slight positive significant correlation with mo re efficient phagocytic activity. BoLA class I type did not seem to si gnificantly affect percentage of class II positive cells and leucocyte percentages on PBM.