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Surface markers of cloned human T cells with helper or suppressor activity on pokeweed mitogen-driven B cell differentiation

✍ Scribed by Maria Cristina Mingari; Giovanni Melioli; Alessandro Moretta; Giuseppe Pantaleo; Lorenzo Moretta


Publisher
John Wiley and Sons
Year
1982
Tongue
English
Weight
445 KB
Volume
12
Category
Article
ISSN
0014-2980

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✦ Synopsis


Abstract

Human spleen T cells stimulated with pokeweed mitogen (PWM) were cloned under limiting conditions in microculture systems using interleukin 2 and irradiated autologous cells. Clones were screened for helper or suppressor activity on PWM‐dependent B cell differentiation by adding cell aliquots to either isolated B cells and PWM or to mixtures of T and B cells and PWM. Out of 97 clones tested, 14 promoted intense B cell differentiation, as assessed by measurements of secreted IgG, and 6 strongly inhibited B cell maturation induced by spleen T cells.

All the selected clones maintained their original activity after shortterm clonal expansion; in addition, a similar (helper or suppressor) effect was detected when the total number of plasma cells per well was evaluated. Suppressor clones had no cytolytic activity on autologous T and B cell blasts, K562 cells or antibody‐coated L 1210 mouse cells. Nine helper and 6 suppressor clones were analyzed for a battery of surface markers. All the clones were E rosette‐positive and expressed HLA‐DR (Ia) antigens. Fcμ eptor was present on a single helper clone, whereas Fcγ receptor was expressed on a suppressor clone only. All but two clones expressed the OKT4^+^/ OKT8^−^, a single suppressor clone was OKT8^+^/OKT4^−^, whereas coexpression of OKT4 and OKT8 antigens was detected in one helper clone. Thus, the claim that helper T cells are OKT4+/OKT8^−^ and suppressor T cells are OKT4^−^/OKT8^+^ is not supported by the analysis of their phenotype at the clonal level.