Identification of Subpopulations of Mononuclear Cells in Cutaneous Infiltrates I. Differentiation Between B Cells, T Cells, and Histiocytes

Abstract

Differentiation between bone marrow-derived lymphocytes (B cells), thymus-derived lymphocytes (T cells), and histiocytes has been achieved in tissue sections through utilization of known differences in cell membrane receptors.Sheep erythrocytes (E) were coated with either IgG or IgM antibody (A) to form IgG or IgM EA. IgM EA was incubated with mouse complement (C) to form IgM EAC. Cryosections were layered with 1gM EAC, 1gM EA, or lgG EA, and subpopulations of mononuclear cells could be distinguished from one another by the adherence or nonadherence of these reagents.B cells bound 1gM EAC, but not 1gM EA or 1gG EA; histiocytes bound 1gM EAC and 1gG EA, but not 1gM EA; and T cells failed to bind any of these reagents. B cells were identified in a cutaneous leukemic infiltrate in a patient with B cell leukemia. Histiocytes were identified infiltrating the dermis and epidermis in a graft -versus- host reaction. A dermal lymphocytic infiltrate in a squamous cell carcinoma lesion did not bind IgG EA or 1gM EAC. The remainder of the fresh tissue from this lesion was finely minced and filtered through a glass wool column. The lymphocytes in the filtrate were positive for human thymic lymphocyte antigen, establishing their T cell identity.It is therefore possible to distinguish between B cells, T cells, and histiocytes in skin lesions, this method should be valuable in the investigation of cutaneous mononuclear infiltrates through identification of effector cells