Abstract
The IL-7 receptor alpha (IL-7Rα) is the high affinity receptor for IL-7 which is essential for T cell homeostasis. We recently reported an age-associated expansion of human effector memory (EM) CD8 + T cells expressing IL-7Rα low (IL-7Rα low), which could be detrimental to hosts by occupying " immunological space" We investigated the potential mechanisms for this phenomenon, focusing on cytomegalovirus (CMV) infection and INF-α. In the elderly (age≥65), CMV infection was associated with a decreased frequency of naïve CD8 + T cells as well as with an increased frequency of total EM and IL-7Rα low EM CD8 + T cells. However, in the young (age≤40), this viral infection was associated only with an increased frequency of IL-7Rα low EM CD8 + T cells. There was no association found between CMV immune status and plasma levels of IFN-α. In CMV-infected young and elderly people, INF-α levels had no correlation with the frequency of IL-7Rα low EM CD8 + T cells although this cytokine levels correlated with the frequency of IL-7Rα low CD45RA + EM CD8 + T cells in CMV-uninfected elderly people. Our findings suggest that the effect of CMV infection on the frequency of CD8 + T cell subsets may begin with IL-7Rα low EM CD8 + T cells and spread to other subsets with aging. Also, IFN-α could be associated with the expansion of IL-7Rα low CD45RA + EM CD8 + T cells in the CMV-uninfected elderly.
Original language | English |
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Pages (from-to) | 332-335 |
Number of pages | 4 |
Journal | Cytokine |
Volume | 58 |
Issue number | 3 |
DOIs | |
State | Published - Jun 2012 |
Bibliographical note
Funding Information:We thank Ms. Amy Shelton, Ms. Laurie Kramer and Yale Center for Clinical Investigation (UL1 RR024139) for assisting in the recruitment of human subjects. This work was supported in part by grants from the National Institutes of Health (AG028069, AG030834 to I.K.). Insoo Kang is a participant in the World Class University Program of Republic of Korea.
Keywords
- Aging
- CD8 T cells
- Cytomegalovirus (CMV)
- Human
- IL-7