Lysis of CD3 hybridoma targets by cloned human CD4 lymphocytes.

UCHT1, a CD3-producing hybridoma, is lysed by cloned human T cells of both CD4 and CD8 phenotypes. The lysis is specific for the CD3 receptor and is mediated by 90% or more of all T cells from blood, without evidence for a subset of CD4 T cells incapable of cytotoxicity. CD4 clones characterized as 'helper' cells by in vitro help for specific antibody production by B cells also lysed CD3 targets. Varicella zoster virus (VZV) super-infected B lymphoblasts were lysed by three of six VZV-specific T-cell clones and 1 Cl-specific T-cell clones lysed 1 Cl hybridoma targets. Resting B cells (from tonsil) coated with CD3 antibody were lysed by CD4 clones. The data suggest that the majority of clonable CD4+ T cells lyse target cells recognized via CD3 or through the antigen receptor.