Lymphocyte abnormalities in Aleutian disease virus infection of mink: decreased T lymphocyte responses and increased B lymphocyte levels in persistent viral infection.

Persistence of virus and a marked hypergammaglobulinemia are consistent features observed in mink with Aleutian disease virus infection. These events may result from altered lymphocyte function in infected mink. To test this possibility we determined the ability of lymphocytes from infected mink to respond to phytolectins (PHA and Con A), and a specific antigen (KLH) in a lymphocyte transformation test and quantitated the number of lymphocytes bearing surface immunoglobulin. Infected mink had a significantly lower response than normal mink to PHA and Con A (P less than 0.025), and the difference in the responses increased progressively with time post-infection. Infected mink immunized with KLH also had a decreased ability to respond to this antigen when compared to normal immunized mink (P less than 0.001). The number of lymphocytes bearing surface immunoglobulin was significantly elevated in three of 10 mink infected for 10 weeks, and in all of seven mink infected 32 weeks (P less than 0.001).