Immunophenotypic analysis of the transformation zone of human cervix.

The immunocompetent cell population of the cervical transformation zone of 18 uteri removed for noncervical disease, has been investigated with monoclonal antibodies. The panel included Leu 2a, 3a, 4, 14, and IL II receptor for lymphocytes and T cell subsets, Leu 7 for NK cells, Leu M5, Leu 10, HLA-DR, DRC 1 for dendritic cells, and Leu 6 for Langerhans' cells (LC). In ectocervical epithelium HLA-DR, Leu 6 and Leu 10 antibodies identified subpopulations of dendritic cells which differed in number and in topographic distribution. Furthermore, a strong HLA-DR epithelial positivity was constantly observed in endocervical columnar cells as well as in keratinocytes of squamous metaplasia. Leu 2a+ cells (T suppressor/cytotoxic) prevailed in the stromal and epithelial compartments of ecto/endocervix; in 6 cases, however, Leu 3a+ cells (T helper/inducer) represented the main T cell subset in the ectocervical stroma. B lymphocytes were occasionally noticed in the subepithelial stroma while NK and DRC-1 cells were never observed. Finally, only few lymphocytes displayed a positivity for IL II receptor. This study suggests that several phenotypes of intraepithelial dendritic cells are present in the transformation zone and that endocervical columnar cells and keratinocytes of squamous metaplasia express HLA-DR products; the latter finding may be related to the presence of intraepithelial and stromal T lymphocytes.