Restoration of impaired immune functions in aging animals. III. Effect of mercaptoethanol in enhancing the reduced primary antibody responsiveness in vivo.

The enhancing effect of 2-ME on the primary antibody forming capacity of young and old mice from 5 strains and hybrids was investigated by assessing the number of hemolytic antibody-forming spleen cells in response to sheep RBC stimulation. The following results were obtained: (1) the optimum dose of 2-ME is 4 micrograms per mouse; (2) the best time to administer 2-ME is just prior to, or at the same time as, antigen is given; (3) 2-ME can enhance response to suboptimum and optimum, but not supra-optimum doses of antigen; (4) 2-ME is effective in enhancing the primary antibody forming capacity of both young and old mice, with one exception, but the enhancement of old mice was greater than that of young mice (80% vs. 20%). The exception was old C57Bl mice, in which 2-ME was ineffective; (5) the level of primary antibody forming capacity of old mice can be restored to that of young mice by treating them with 3--4 weekly injections of 2-ME at a dose of 4 micrograms per injection.