Decline and Restoration of Antibody-Forming Capacity in Aging Beagle Dogs

[摘要] The production of antibody to coliphage was studied in young (1 1/2 years) and old (7 to 11 years) beagles. In five old dogs given a single injection of T2 coliphage three of them showed a severe deficiency of antibody-forming capacity as compared to five young controls. When three injections of T2 or T4 coliphage were given in 5 days, 15 old dogs produced the same amount of antibody as did 15 young control dogs. Thus, antibody-forming capacity was restored to aging dogs by giving multiple injections of antigens. The relative serum titer to the cross-reacting antigen, T4 coliphage, was equal in young and old dogs given T2 coliphage. Our results are interpreted in accord with the Antigen Selection Hypothesis (33). They showed that one of the age-associated losses in antibody-forming capacity results from a decline in the proliferative activity of antigen-stimulated cells because the proliferative state can be maintained by repeated injections of antigen. We also concluded that the precursor cells suffer no loss with age in sensitivity to antigenic stimulation because there is no relative increase in the fraction of cross-reacting antibody.

[学科分类] 生物科学（综合）