Bacteria-immune system interactions. XII. Effects of aging on Balb/c mice responsiveness to Salmonella typhimurium

Age-associated changes in reactivity to bacteria were tested at several levels. At the level of bacteria binding to lymphocytes, there were no significant differences between young and old mice, however the lymphocytes from adults bound less bacteria than the other age groups. Similarly, the lymphocytes from spleens of adult mice were less efficient in killing bacteria than all the other age groups. The lymphocytes of young mice had higher and longer range reactivity than the ones from old mice. Bacterial stimulation did not produce significant levels of thymidine incorporation in any of the age groups tested.