Human T-cell lymphoma with suppressor effects on the mixed lymphocyte reaction (MLR). II. Functional in vitro lymphocyte analysis.

The results of lymphocyte functional studies performed with the peripheral blood mononuclear cells (MNCs) of patient Wa with a non-Sezary T-ceIl leukemia are described. The aggressive clinical course and the distinctive histologic, cytochemical, and cytogenetic features of this T-cell lymphoproliferative disorder are detailed in an accompanying report. Immunologic marker analysis revealed that 76% of the Wa MNC fraction formed rosettes with sheep erythrocytes (E-rosettes), and on histologic examination, 95% of the E-rosettes contained neoplastic lymphocytes; 10% of the MNCs formed EAC rosettes; and 1 3% showed SIg positivity by immunofluorescence. In vitro mitogenic responses of Wa cells measured by 3H-thymidine incorporation were extremely low. and responses to candida and streptococcal antigens were absent. Although a normal percentage of B cells was evident in the Wa MNC fraction, no Ig synthesis occurred in either pokeweed mitogen (PWM) stimulated or unstimulated cultures. In coculture experiments with control MNCs from two normal individuals, the Wa cells exhibited no suppressor or helper effects on the normal PWMstimulated lg synthesis. Importantly however, the Wa cells demonstrated suppressor effects on the normal mixed lymphocyte reaction (MLR) occurring between populations of allogeneic MNCs from two normal donors. The degree of MIR suppression increased with the presence of