Increased vitamin D is associated with decline of naïve, but accumulation of effector, CD8 T cells during early aging.
Given the protective roles of 25-hydroxyvitamin D (25[OH]D or vitamin D) in musculoskeletal health and the potential beneficial effects of vitamin D supplementation in reducing the risk of various chronic diseases, intensive repletion of vitamin D has been widely advocated. Of note, CD8 T cells have the highest levels of the vitamin D receptor compared with other major immune cells. The effects of vitamin D on CD8 T cells during aging, however, remain unclear. This study determined the relationship between vitamin D levels and CD8 T-cell status in 34 healthy female subjects (all >60 years old). The CD8 T cell phenotype was defined by the surface expression of CD28 and CD95. The low-25(OH)D serum groups (≤30 ng/ml) had higher percentages of CD28+CD95-CD8+(naïve) T cells and lower percentages of CD28+CD95+CD8+(effector) T cells. By contrast, subjects with high levels of 25(OH)D had very low percentages of naïve CD8 T cells but very high percentages of effector CD8 T cells. There was a significant inverse correlation between 25(OH)D levels and the frequency of naïve CD8 T cells. The results show that higher levels of vitamin D are correlated with decreased frequencies of naïve CD8 T cells during early aging, suggesting that higher levels of 25(OH)D accelerate CD8 T-cell senescence. These results warrant the further evaluation of the effects of vitamin D supplementation in immune aging.
University of Alabama at Birmingham, Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
Yong Gil
YG
Hwang
University of Alabama at Birmingham, Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
Hui-Chen
HC
Hsu
University of Alabama at Birmingham, Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
Fei-Chu
FC
Lim
University of Alabama at Birmingham, Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
Qi
Q
Wu
University of Alabama at Birmingham, Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
PingAr
P
Yang
Department of Human Studies, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
Gordon
G
Fisher
Department of Human Studies, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
Gary R
GR
Hunter
University of Alabama at Birmingham, Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA ; Birmingham VA Medical Center, Birmingham, AL, 35233, USA.
John D
JD
Mountz
human; immunosenescence; naïve CD8; vitamin D