J Immunol 2008,
PMID: 18209097
Lemster, Bonnie H; Michel, Joshua J; Montag, David T; Paat, John J; Studenski, Stephanie A; Newman, Anne B; Vallejo, Abbe N
Degeneration of the thymus and severe contraction of the T cell repertoire with aging suggest that immune homeostasis in old age could be mediated by distinct effectors. Therefore, receptors expressed on T cells as they undergo senescence in vitro, as well as those displayed by circulating T cells during normal chronologic aging, were examined. Monitoring of T cells driven to senescence showed de novo induction of CD56, the prototypic receptor of NK cells. Analysis of fresh T cells in peripheral blood showed an age-dependent induction of CD56. These unusual T cells expressed high levels of Bcl2, p16, and p53, and had limited, or completely lost, ability to undergo cell division, properties consistent with senescence. CD56 cross-linking without TCR ligation on CD56(+) T cells resulted in extensive protein phosphorylation, NF-kappaB activation, and Bax down-regulation. CD56 cross-linking was also sufficient to drive production of various humoral factors. These data suggest that the immunologic environment in old age is functionally distinct, rather than being a dysfunctional version of that seen at a young age. CD56(+) T cells are unique effectors capable of mediating TCR-independent immune cascades that could be harnessed to enhance protective immunity in the elderly.
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Text Mining Data
NF-kappaB ⊣ CD56: "
CD56 cross linking without TCR ligation on CD56 ( + ) T cells
resulted in extensive protein phosphorylation,
NF-kappaB activation, and Bax down-regulation
"
Bax ⊣ CD56: "
CD56 cross linking without TCR ligation on CD56 ( + ) T cells resulted in extensive protein phosphorylation, NF-kappaB activation, and Bax down-regulation
"
Manually curated Databases
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