Characterization of human T8+ suppressor and contrasuppressor cells, separated by the lectin <em>Vicia villosa</em>.

The helper function of human T4⁺ cells acting on autologous B cells, in the presence of monocytce-enriched cells (MEC), has been studied using the hapten--carrier conjugate DNP--streptococcal antigen (DNP-SA). The antibody response can be suppressed by T8⁺ cells, but selection of a Vicia villosa lectin-non-adherent (T8VV^-) subset enhances the suppresor function. The T8 Vicia villosa lectin-adherent (T8VV⁺) cells are not suppressive, rather they inhibit the T8VV^- cell suppressor function. Sequential reconstitution studies suggest that the target of both T8VV^- suppressor-cell and T8VV⁺ contrasuppressor activity is the T4 helper-inducer cell. This was established after the separation of T4⁺ cells into Leu 8^- helper- and Leu 8⁺ suppressor-inducer cells. Activation of T8VV^- and T8VV⁺ cells with antigen before reconstitution with fresh lymphocytes and MEC suggests that T8VV^- suppressor activity is antigen specific, whereas T8VV⁺ cell contrasuppressor function is non-specific. We suggest that the human T8⁺ cells are functionally heterogeneous and consist not only of suppressor and cytotoxic cells but also contrasuppressor cells. [ABSTRACT FROM AUTHOR]