The relationship of cytomegalovirus (CMV) infection with circulatory IFN-? levels and IL-7 receptor ? expression on CD8+ T cells in human aging.

ABSTRACT: The IL-7 receptor alpha (IL-7R?) 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-7R? low (IL-7R?(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-?. 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-7R?(low) EM CD8(+) T cells. However, in the young (age ? 40), this viral infection was associated only with an increased frequency of IL-7R?(low) EM CD8(+) T cells. There was no association found between CMV immune status and plasma levels of IFN-?. In CMV-infected young and elderly people, INF-? levels had no correlation with the frequency of IL-7R?(low) EM CD8(+) T cells although this cytokine levels correlated with the frequency of IL-7R?(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-7R?(low) EM CD8(+) T cells and spread to other subsets with aging. Also, IFN-? could be associated with the expansion of IL-7R?(low) CD45RA(+) EM CD8(+) T cells in the CMV-uninfected elderly.

SUBMITTER: Lee WW 

PROVIDER: S-EPMC3340433 | biostudies-literature | 2012 Jun

REPOSITORIES: biostudies-literature