Differential regulation of HLA-DQ expression by keratinocytes and Langerhans cells in normal and premalignant cervical epithelium.

Keratinocytes in normal ectocervix did not express major histocompatibility complex class II molecules. In low-grade intraepithelial lesions expression was confined to HLA-DR, while in high-grade disease there was expression of HLA-DR and occasional expression of HLA-DQ. HLA-DR was expressed constitutively on the majority of Langerhans cells. In contrast, few Langerhans cells expressed HLA-DQ in normal cervix, but there was a steady upregulation of the proportion expressing HLA-DQ which paralleled the severity of disease. There was no direct correlation between human papillomavirus 16 and the expression of major histocompatibility complex class II by keratinocytes and Langerhans cells. Significant upregulation of HLA-DQ by Langerhans cells is observed in high-grade intraepithelial cervical lesions, suggesting antigen-presenting cell activation in papillomavirus-related premalignant disease.