Expression of CD1d in Human Scalp Skin and Hair Follicles: Hair Cycle Related Alterations

The study investigated the expression of CD1d, an antigen-presenting molecule, in human scalp skin and hair follicles, particularly focusing on its presence during different hair cycle phases. CD1d was found to be strongly expressed in the epidermis, pilosebaceous units, and eccrine glands of the scalp skin, with notable expression in basal and granular keratinocytes. In hair follicles, CD1d expression varied with the hair cycle, increasing during the anagen phase and decreasing during the catagen and telogen phases. These findings suggested that CD1d might play a role in scalp skin immunology and protection against lipid antigen-rich microbes, and raised the possibility that keratinocytes in anagen hair follicles could present lipid antigens to natural killer T cells. This research provided insights that could inform new strategies for managing hair-related disorders.