Immunological Functions of Human T-Lymphoid Cell Line (Molt)

Abstract

Recently much attention has been given to the classification of leukemia according to B-and T-cell origins. Wilson and Nossal (1) indicated that acute lymphoblastic leukemia (ALL) t might be a leukemia of T cells and chronic lymphatic leukemia (CLL) might be that of B cells. Since Iwakata and Grace (2) succeeded in the permanent culture of a hematopoietic cell line from the peripheral blood of a patient with acute myelogenous leukemia, many cell lines were successfully established. These cell lines produced immunoglobulins (3), and had receptors for complement and antigen-antibody complex. The cells showed clumps floating in the media. The presence of surface-bound immunoglobulins (4-6) and of receptors for complement (7,8) and antigen-antibody complex on the membranes (8, 9) were considered to be markers for B lymphocytes.Recently, Minowada et al. (10,11) succeeded in the establishment of the lymphoid cell lines (called MOLT and SOMMER) from the peripheral blood of patients with ALL. MOLT cells did not have immunoglobulins on the surface, nor receptors for antigen-antibody complex, but bound sheep red blood cells (SRBC) to form rosettes. None of the B-cell lines so far established bound SRBC. SOMMER T cells had similar characteristics to MOLT cells although the percentage of rosette formation was lower. The formation of spontaneous rosettes with SRBC in humans was considered to be a marker for T cells (6, 12). MOLT and SOMMER cells do not form clumps in the media. Furthermore, it has been shown that cytotoxicity of rabbit anti-MOLT serum was absorbed with fresh human thymocytes, but not with human B cells or liver (unpublished observation). We have recently shown that MOLT cells have antigenic determinants shared with human brain (13). Shared antigenic determinants between thymocyte and brain have been reported in the rat and mouse (14, 15). As Minowada and Moore have shown (11), rabbit anti-MOLT sera specifically killed cells from most of the patients with ALL, but did not kill cells from most of the patients with CLL.