The Decrease in Number and Change in Phenotype of Mucosal‐Associated Invariant T cells in the Elderly and Differences in Men and Women of Reproductive Age

Abstract

Mucosal-associated invariant T (MAIT) cells are innate-like T cells comprising up to 10% of the peripheral blood T cells in humans. During ontogeny, MAIT cells can first be detected in the cord blood in low amounts, but rise steadily after birth. In this population-based study, we show that their counts continue to increase, reaching maximal levels (4.5% of CD3 + cells, 65 cells/ll) in the third and fourth decenniums. At this age, the amounts of MAIT cells exhibit the highest interindividual variability. The values then dramatically decline; subjects 80 years old and older have on average 10 times less MAIT cells, both absolutely and as a percentage among CD3 + T cells, than subjects in fertile age. The senescence of MAIT cells is associated with decreased CD8/double negative (DN) ratio. Finally, we observed significantly higher amounts of MAIT cells in women of reproductive age than in men of the same age. Our data suggest that further studies aimed at elucidating a role of MAIT cells in human pathologies must recruit age-and gender-matched controls.

Mucosal-associated invariant T cell alterations in obese and type 2 diabetic patients

“…Mucosal-associated invariant T cell alterations in obese and type 2 diabetic patients 1 Figure 1B), comparable to previous reports (22)(23)(24)(25). Compared with controls, the frequency of circulating MAIT cells in patients was significantly lower.…”

Human Mucosa-Associated Invariant T Cells Accumulate in Colon Adenocarcinomas but Produce Reduced Amounts of IFN-γ

“…Circulating MAIT cell frequencies have been shown to decrease with increasing age, at least in healthy subjects (36,37), but we could not document such an effect in the colon from this middle-aged and elderly patient material. In contrast to our results of higher MAIT cell frequencies in males, one of the latter studies (36) found no sex difference in circulating MAIT cell frequencies at the ages 50 y and above. The differences between these studies and the present results may be related to differences between the large intestine and the blood, as well as different ethnic populations.…”

Mucosal-associated invariant T cells from induced pluripotent stem cells: A novel approach for modeling human diseases

“…This corresponds to the expansion and maturation of MAIT cells by commensal microflora colonizing after birth. The highest number of MAIT cells in PBMC is observed in adults aged 30-50 years, notably in females of reproductive age [30] . MAIT cells, especially CD8 + MAIT cells as the most abundant subset, decrease drastically with age, implying an association with waning immunity in the elderly [22,30] .…”

“…The highest number of MAIT cells in PBMC is observed in adults aged 30-50 years, notably in females of reproductive age [30] . MAIT cells, especially CD8 + MAIT cells as the most abundant subset, decrease drastically with age, implying an association with waning immunity in the elderly [22,30] . The diseases in which a potential implication of MAIT cells has been reported are summarized in Table 1.…”