Two monoclonal antibodies (DLy-1 and DLy-6) directed against canine lymphocytes.

: Two murine monoclonal antibodies directed against canine lymphocytes are described. DLy-1, raised against puppy thymocytes, and DLy-6, raised against bronchoalveolar lymphocytes, both react with most lymphocytes in peripheral blood, thoracic duct lymph, and bronchoalveolar lavage fluids. DLy-1 also recognizes monocytes and granulocytes. However, it is not reactive with erythrocytes, megakaryocytes, or platelets. Expression of DLy-1 antigen on thymocytes ranged from 5--30%. The distribution of DLy-6 antigens seems to be confined to lymphoid cells. Ten to 60% puppy thymocytes were positive. Interestingly, lymphoblasts formed in response to stimulation with mitogens or alloantigens lacked DLy-6 in contrast to DLy-1 cell surface antigen expression.