Age-related changes in localization of injected radiolabelled lymphocytes in the lymph nodes of antigen-stimulated mice
Inchley, C.J.; Micklem, H.S.; Barrett, J.; Hunter, J.; Minty, C.
Clinical and Experimental Immunology 26(2): 286-294
1976
ISSN/ISBN: 0009-9104 PMID: 991459 Document Number: 104449
The localization of i.v. injected syngeneic lymph node cells, radiolabeled with 51Cr or 75Se-L-selenomethionine, was studied in male CBA/H mice aged between 3-30 mo. The following results were obtained. Localization of cells from young adult donors was greater in the subcutaneous lymph nodes of old than of young recipients, the main increase being between 15-17 mo. of age. Increases in lymph node wt and DNA-synthesis were also seen at this time; the rise in cell localization was significant even when calculated per unit of tissue wt. Splenic localization declined slightly with age or, like the liver, showed no significant change. Local antigenic stimulation by a single injection of sheep erythrocytes into 1 front footpad 24 h before lymph node cell injection, resulted in increased localization in the regional lymph nodes of 3-17 mo. old, but rarely of 24-20 mo. old mice. No consistent differences in localization were observed between lymph node cells from 4 mo. and 25 mo. old donors. Both age-related and antigen-related increases in cell localization were at least partly attributable to an enhanced rate of entry of lymphocytes from the blood to the lymph nodes. Although the changes underlying the decline in antigen-related localization of cells in old recipients still have to be clarified, the defective immune responses of old mice probably result partly from this decline.