Monoclonal antibodies generated against activated B-cells: unexpected specific reactivity to T-cells

Monoclonal antibodies (Mabs) were produced aginst (C57B1/6 "nude" lymphoblast cells. They are IgG2a and do not react with mouse serum proteins. Five Mabs were characterixed functional by immunohistochemistry and immunofluorescence in spleen, lymph nodes and Peyer's patches from nude and normal mice, an anormal mouse thymus. Two Mabs reacted with containing B-cells as indicared by immunoperoxidase staining, another recognized T- and B-cell sites and two specifically stained T lymphocyte-containing areas. Immunofluorescence studies confirmed the sites identified above by immunohistochemistry