[Use of OKT3 monoclonal antibodies and anti-TAC for the quantitative evaluation of interleukin-2].

OKT3 (10-100 pg/ml) still induces IL-2 responsiveness, while being unable to induce IL-2 production and lymphocyte proliferation, unless exogenous IL-2 is added. This property has been used in order to evaluate and quantify the IL-2 on various cell culture supernatants. Peripheral blood mononuclear cells (MNC) or T cells purified from blood units have been incubated with various concentrations of OKT3 and used as cell target for the quantitation of putative IL-2 containing media. The anti-TAC monoclonal antibody has also been used as internal control in the assay. The procedure suggested seems to be reliable and simpler than the method, currently employed in the IL-2 assay; MNC or T-cells treated with OKT3 proliferate in response to exogenous IL-2 and do not if the anti-TAC monoclonal antibody is previously added. Results are presented and discussed.