Distribution of major histocompatibility antigens in normal skin

Abstract

The distribution of major histocompatibility antigens HLA-A,B,C (HLA), .beta.2-microglobulin (.beta.2m), and Ia-like antigens (HLA-DR; Ia) in normal human skin was studied in frozen tissue sections by a 4-step immunoperoxidase method and an avidin-biotin method employing monoclonal antibodies. HLA and .beta.2m were present on the basal and spinous keratinocytes of the epidermis, on the outer root sheath epithelium in the infundibulum of the hair follicle, and on the excretory sebaceous duct epithelium. Ia-positive dendritic cells were found in the epidermis and hair follicles, but they were more frequent in the infundibulum and isthums of the hair follicle than in its inferior portion or in the epidermis. In the straight eccrine duct, HLA and .beta.2m-positivity was most evident in its lower portion. In the superficial duct, there was a less intense staining using the 4-step procedure, but when an avidin-biotin method was used, the difference was less apparent. The acrosyringial epithelium was markedly Ia-positive with decreasing intensity of staining as the duct penetrated the dermis. No HLA or Ia antigens were identified in eccrine glands and apocrine glands. Eccrine glands were slightly .beta.2m-positive. HLA and .beta.2m were uniformly present in non-dilated and dilated intrademal apocrine ducts.