Effects of T mitogens on in vivo antibody production to a T-dependent antigen in lines of mice genetically selected for high or low in vitro responsiveness to PHA.

Summary The influence of genes which regulate the in vitro T-cell proliferative response to T mitogen upon in vivo antibody production to a T-dependent antigen was studied in two lines of mice genetically selected for a high or a low in vitro lymphocyte response to phytohaemagglutinin (PHA). Kinetics of agglutinin production to increasing doses of sheep erythrocytes was similar in the two lines, except for the titres of mercapto-ethanol-resistant antibodies, which were slightly lower in the low-responder line. Treatment with mitogen prior to immunization modified the antibody response in the two lines differently. This finding would indicate that the genes which regulate in vitro stimulation of T cells by PHA also control in vivo activation of T-cell subsets involved in immunoresponsiveness.