title: Variation of lymphocyte classes and their PHA-P reactivity with age.
abstract: Absolute and relative values of lymphocyte classes in peripheral blood of 19 to 80 year-old, apparently healthy donors were determined simultaneously by means of the cytocentrifuge method. Lymphocytes were classed as cells which formed rosettes with neuraminidase-treated sheep erythrocytes (T cells), as cells which bound C3b-loaded zymosan particles (B cells), or those which showed both characteristics (doubly marked cells = D cells). Cells which exhibited none of the above characteristics were classed as O cells. The reproducible absolute valued of T, B, D, and O cells showed a statistically significant decline with age, similarly to a decline in the total lymphocyte counts. The relative values in per cent, however, remained constant over the whole age spectrum. In 1 hour experiments, the acid phosphatase activity of non-stimulated and of PHA-P-stimulated cells decreased with age, the latter, however, less than did the controls. Therefore, the stimulating effect increased significantly. When cells were stimulated for a period of 4 hours, the stimulating effect decreased with age, indicating an age-dependent loss of longer lasting reactivity to PHA-P controlled by acid phosphatase activity.
mesh_terms: D000135:Acid Phosphatase / Q000097:blood; D000328:Adult; D000368:Aged; D000375:Aging; D001402:B-Lymphocytes / Q000276:immunology; D003165:Complement System Proteins; D006801:Humans; D037102:Lectins / Q000494:pharmacology; D008214:Lymphocytes / Q000201:enzymology / Q000276:immunology; D008875:Middle Aged; D009439:Neuraminidase; D013601:T-Lymphocytes / Q000276:immunology; D015054:Zymosan
chemical_list: D037102:Lectins; D003165:Complement System Proteins; D015054:Zymosan; D000135:Acid Phosphatase; D009439:Neuraminidase