title: The relationship of cytomegalovirus (CMV) infection with circulatory IFN-α levels and IL-7 receptor α expression on CD8+ T cells in human aging.
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.
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520, USA.
authors.forename: Won-Woo
authors.initials: WW
authors.lastname: Lee
authors.forename: Min Sun
authors.initials: MS
authors.lastname: Shin
authors.forename: Youna
authors.initials: Y
authors.lastname: Kang
authors.forename: Naeun
authors.initials: N
authors.lastname: Lee
authors.forename: Sangchun
authors.initials: S
authors.lastname: Jeon
authors.forename: Insoo
authors.initials: I
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood*; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism*; D003586:Cytomegalovirus Infections / Q000097:blood* / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D016898:Interferon-alpha / Q000097:blood*; D053722:Receptors, Interleukin-17 / Q000097:blood*
chemical_list: D016898:Interferon-alpha; D053722:Receptors, Interleukin-17