Sensitization of human lymphocytes in vitro. Kinetics and specificity of the response to hemocyanins.

In vitro primary sensitization of human peripheral blood T-cells to hemocyanins was detected during a 12-14 day culture period with antigen (KLH or HCH)-pulsed macrophages. Primed T-cells proliferate in secondary culture (2-3 days) when restimulated with antigen presented by macrophages. The kinetics of primary sensitization and secondary responsiveness are interrelated and are dependent on the antigen doses employed. Antigen-induced proliferation of cells sensitized in vitro is identical to proliferation of T-cells from immunized donors in terms of antigen specificity and the clonal nature of the response to antigen. Through the use of thymidine suicide techniques, distinct populations of cells responding to KLH or HCH can be demonstrated using cells from actively immunized donors or cells that have been sensitized in vitro to both hemocyanins.