Unusual pattern of surface marker expression on peripheral lymphocytes from aged humans suggestive of a population of less differentiated cells.
Monoclonal antibodies were used to detect the surface antigens T3, T4, T8, and T10 on the peripheral blood lymphocytes of 26 aged (14 female and 12 male, mean age 89) and 28 young (14 female and 14 male, mean age 29) subjects. In the aged subjects, independent of the sex of the donor, the sum of the percent or absolute number of T4- and T8-positive cells was significantly greater than the number of T3-positive cells (p less than 0.001). There was also a significant increase in the percent and absolute number of cells positive for the T10 antigen with age (p less than 0.01). Analysis of individual cell surface markers revealed that the percent and absolute number of T3-positive cells was decreased only in old females, with no difference between old males and the young donors. The expression of T4 was not affected by age or sex, but both the percent and absolute number of T8-positive cells were decreased in females relative to males, with no effect due to age. These findings are consistent with the presence of a population of peripheral T cells in advanced age with a thymocyte-like pattern of surface marker expression. This conclusion is supported by previous work showing a less differentiated pattern of LDH isoenzyme distribution in the T cells of persons of advanced age.
D000328:Adult; D000368:Aged; D000375:Aging; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface / Q000032:analysis* / Q000276:immunology; D002454:Cell Differentiation; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012727:Sex Characteristics; D013601:T-Lymphocytes / Q000145:classification* / Q000166:cytology / Q000276:immunology
D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface