Gender-dependent frequency of unconventional T cells in a healthy adult Caucasian population: A combinational study of invariant NKT cells, γδ T cells, and mucosa-associated invariant T cells.

This study tested the hypothesis of gender bias in frequency of unconventional T cells. Unconventional T cells exist as minor subsets of T cells in peripheral blood. Despite their low number, they play a crucial role in various immune-mediated diseases such as inflammation, autoimmunity, allergy, and cancer. Gender-based frequency of these cells altogether on large number of healthy individuals are unestablished creating hurdles to manifest association with various immune-mediated pathologic conditions. In this study, we used a multicolor flow cytometric panel to identify iNKT cells, γδ T cells, and MAIT cells altogether in the peripheral blood samples of 93 healthy adult males and 109 healthy adult females from the Caucasian population. The results revealed iNKT cell median value (% T cells) in females was higher: 0.114% ranging from 0.011 to 3.84%, than males: 0.076% (p value 0.0292), ranging from 0.007 to 0.816% and found to be negatively correlated with age in females (p value 0.0047). However, γδ T cell median value in males was higher: 2.52% ranging from 0.31 to 16.09%, than females: 1.79% (p value 0.0155), ranging from 0.078 to 12.49% and each gender was negatively correlated with age (male p value 0.0003 and female p value 0.0007). MAIT cell median values were 3.04% ranging from 0.11 to 10.75% in males and 2.67% ranging from 0.2 to 18.36% in females. MAIT cells did not show any statistically significant difference between genders and found to be negatively correlated with age (p value < 0.0001). Our results could be used for further gender-wise investigations of various pathologic conditions such as cancer and their prognosis, autoimmune diseases, allergies, and their pathogenicity.