The Sézary syndrome: a malignant proliferation of helper T cells.

Functional and phenotypic comparison of human T cell leukemia/lymphoma virus positive adult T cell leukemia with human T cell leukemia/lymphoma virus negative Sézary leukemia, and their distinction using anti-Tac. Monoclonal antibody identifying the human receptor for T cell growth factor.

“…In the present study, six of the nine HTLV antibody-negative Sezary T cell leukemic populations function as helper cells when co-cultured with normal B cells in the presence of PWM. This observation is in accord with our previous report that some, but not all, Sezary T cell leukemic populations are dedicated to helper interactions with B lymphocytes, which facilitates B cell proliferation, maturation, and immunoglobulin synthesis (1). Our initial observation has been confirmed by other workers (31) studying similar cell populations, although two cases of a Sezary leukemia functioning as a suppressor cell have been reported (32,33).…”

“…The PWM-activated in vitro biosynthesis system was also used to determine whether the neoplastic T cells manifested helper activity when co-cultured with rigorously T celldepleted B cells from normal individuals. The approach takes advantage ofthe fact that PWM stimulation ofimmunoglobulin synthesis has an absolute requirement for helper T cells (1,28,29). When normal B cells were co-cultured with either autologous or allogeneic normal T cells and PWM, they matured into immunoglobulin synthesizing and secreting cells (Fig.…”

“…The cells were analyzed by using immunofluorescence and FACS analysis with monoclonal antibodies by a slight modification of a procedure described previously (26 Assays for helper or suppressor cell activity. The methods used to test for immunoglobulin biosynthesis and for helper and suppressor activity using the PWM-driven immunoglobulin biosynthesis system have been described in detail previously (1,2,27,28). PWM-stimulated B cells in the absence of T cells produce very small amounts of immunoglobulin (1,28,29 were used in these co-culture studies.…”

“…The methods used to test for immunoglobulin biosynthesis and for helper and suppressor activity using the PWM-driven immunoglobulin biosynthesis system have been described in detail previously (1,2,27,28). PWM-stimulated B cells in the absence of T cells produce very small amounts of immunoglobulin (1,28,29 were used in these co-culture studies. The immunoglobulin synthesis in these co-cultures was compared with that predicted from the determinations of the immunoglobulin synthesis by the PWM-stimulated indicator population and leukemic cell populations when cultured alone.…”

“…Leukemic T cells from humans frequently represent expansions of a single clone of T cells that may retain a single immunoregulatory function. The examination of such neoplastic T cells and their soluble products in functional assays has provided valuable insights into the regulatory network of cells that control the human immune response in general and control B cell maturation and immunoglobulin production in particular (1)(2)(3). Furthermore, the use of monoclonal antibodies to T cell surface antigens has permitted useful correlations between cell function and phenotype (4)(5)(6)(7)(8)(9).…”