Journal
JOURNAL OF IMMUNOLOGY
Volume 177, Issue 11, Pages 7802-7810Publisher
AMER ASSOC IMMUNOLOGISTS
DOI: 10.4049/jimmunol.177.11.7802
Keywords
-
Categories
Funding
- Intramural NIH HHS [Z01 AG000757-10] Funding Source: Medline
Ask authors/readers for more resources
Accumulation of CD28(null)CD8(+) T cells and the defects of these cells in response to antigenic stimulation are the hallmarks of age-associated decline of T cell function. However, the mechanism of these age-associated changes is not fully understood. In this study, we report an analysis of the growth of human CD28(null) and CD28(+)CD8(+) memory T cells in response to homeostatic cytokine IL-15 in vitro. We showed that 1) there was no proliferative defect of CD28(null)CD8(+) memory T cells in response to IL-15 compared with their CD28(+) counterparts; 2) stable loss of CD28 expression occurred in those actively dividing CD28+CD8+ memory T cells responding to IL-15; 3) the loss of CD28 was in part mediated by TNF-alpha that was induced by IL-15; and 4) CCL4 (MIP-1 beta), also induced by IL-15, had a significant inhibitory effect on the growth of CD28(null) cells, which in turn down-regulated their expression of CCL4 receptor CCR5. Together, these findings, demonstrate that CD28(null)CD8(+) memory T cells proliferate normally in response to IL-15 and that IL-15 and its induced cytokines regulate the generation and growth of CD28(null)CD8(+) T cells, suggesting a possible role of IL-15 in the increase in CD28(null)CD8(+) T cells that occurs with aging.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available