DEVELOPMENTAL-CHANGES AND FUNCTIONAL-PROPERTIES OF HUMAN-MEMORY T-CELL SUBPOPULATIONS DEFINED BY CD60 EXPRESSION

The present study was undertaken to examine developmental changes of T cells expressing CD60 and their functional properties. Three-color im munofluorescence analysis revealed that the CD60 antigen was preferent ially expressed on a proportion of memory (CD45RO(+)) CD4(+) T cells, but less on memory CD8(+) T cells, while this antigen is undetectable in naive (CD45RO(-)) T cells. A frequency of memory CD4(+) T cells exp ressing CD60 in the peripheral blood was negligible in newborns and gr adually increased with advancing age. CD60(+) memory CD4(+) T cells sh owed stronger proliferative responses to PPD and produced higher level s of IL-4 and IL-10 than CD60(-) ones, whereas production of IL-2 and IFN-gamma was similarly found in both cell subpopulations. In addition , it was shown that efficient helper activity for Ig production by B c ells was predominated in CD60(+) memory CD4(+) T cells. These results suggest that CD60 may be primarily expressed on the functionally diffe rentiated memory effector cells among circulating CD45RO(+) CD4(+) T c ells. (C) 1998 Academic Press.