A new genetic marker of human T lymphoid cells detected by a xenogenic monoclonal antibody.

Abstract

SummaryA hybrid cell line R3/41‐10 was produced by fusing a mouse myeloma line with spleen cells from CBA/H mice which had previously been immunized with human peripheral blood lymphocytes (PBL) obtained from a single donor. Hybrid secreting antibodies to lymphocyte antigens were detected by assaying the culture supernatant for antibody binding to the donor PBL. Those lymphocytes binding more than ten times the background were cloned in soft agar and transferred to micro‐culture plates (Limbro). Antibodies from some wells lost their binding activity. Antibodies from other clones, although retaining their binding capacity, were multispecific in cytotoxicity experiments, killing all the lympoid cells from a panel of normal donors; yet a third kind gave specific limited reactions. Supernatants from clones R3/41‐10 and R3/41‐13 gave concordant cytotoxic reactions killing 20‐40% of the PBL. There was no cytotoxicity of Ig+ cells (B cells). Lymphocytes from seven out of fourteen normal donors reacted with the antibody. The specificity of the antibody produced by clone R3/41‐10 was confirmed by absorption studies.The monoclonal antibodies (Mc+b) described in this communication are shown to react with a subpopulation of T lymphocytes of some individuals and not others, suggesting that they are detecting a polymorphic system of alloantigens like the Ly system in the mouse, provisionally designated HT‐Ly. l.