Activation of human T cells by neuraminidase-galactose oxidase-treated erythrocytes involving CD2 (T11) and its complementary structure.

Human T lymphocyte proliferation induced by neuraminidase-galactose oxidase (NAGO)-treated autologous erythrocytes (HENAGO) plus polyethylene glycol (PEG) has previously been shown to be independent of accessory cells. Here, we show that the response to HENAGO + PEG was accompanied by interleukin 2 (IL-2) release and was inhibited by anti-IL-2 and anti-IL-2 receptor antibodies. HENAGO alone initiated DNA synthesis together with phorbol ester (12-O-tetradecanoyl-phorbol-13-acetate; TPA). To elucidate the nature of the stimulatory signals NAGO-treated sheep erythrocytes (SENAGO) were used in additional experiments. In parallel to the superior rosetting capacity of SE compared to HE. SENAGO were by themselves stimulatory, and the response was further enhanced by PEG or TPA. Antibody L180/1, specific for the T11 (CD2) target structure (T11TS) on SE, homologous to the human CD2 ligand LFA-3, abolished the response to SENAGO alone or when combined with PEG or TPA. The results suggest that ENAGO induce T-cell response through CD2-LFA-3-T11TS interaction, and via other surface antigens bound by the oxidatively induced aldehyde groups on ENAGO.