Concanavalin A and the production of bovine leukemia virus antigen in short-term lymphocyte cultures.

The influence of the mitogen concanavalin A (Con A) on the production of bovine leukemia virus (BLV) antigen in short-term lymphocyte cultures was determined by means of a single radial immunodiffusion test. Con A did not affect viral antigen production in peripheral blood lymphocytes from 60% of both experimentally and naturally infected cattle. Antigen production was stimulated by Con A in lymphocytes from 28% of the cattle, but it was inhibited in lymphocytes from 12%. Similar results were also obtained with lymphocytes from both blood and lymph nodes from 10 cattle with lymphosarcoma and from 10 clinically normal cattle with histologically normal lymph nodes. In sheep and goats, Con A had no effect on lymphocytes from 50%, stimulated BLV production in 43%, and inhibited BLV production in 7%. These results indicated that lymphocytes should be cultured with and without Con A to identify every BLV-infected animal.