Reactivity of a population of armadillo lymphocytes with an antibody to human gamma,delta T-cells.
Reactivity of lymphocytes from the nine-banded armadillo (Dasypus novemcinctus) was examined by flow cytometry using a panel of 16 commercially available fluorochrome-conjugated monoclonal antibodies raised against human or murine leukocyte antigens. The only reactivity observed was with antibody TCRdelta1, directed against a common determinant on the delta chain of the human gamma,delta T-cell receptor. Using this antibody, a distinct, bright population of lymphocytes was seen in the peripheral blood in all of 47 animals examined, accounting for 2.0-47.1% of lymphocytes (median, 10.6%). The gamma,delta-reactive lymphocyte population comprised a greater percentage of intraepithelial lymphocytes in the small intestine than in the blood; variable percentages of gamma,delta-reactive cells were also observed in the spleen, thymus, lymph nodes, and bone marrow, and in cutaneous lepromas. In armadillos with disseminated Mycobacterium leprae infection, a significantly greater percentage of circulating lymphocytes reacted with the anti-gamma,delta antibody. This is the first described reactivity of armadillo lymphocytes with a monoclonal antibody to a lymphocyte antigen, and it may offer a useful tool in disease models involving the armadillo.