Immunofluorescent studies of human cervical epithelia in vivo and in vitro using antibodies against specific keratin components.

The human cervix consists of a vaginal ectocervix covered by stratified squamous epithelium and a uterine endocervix lined by simple mucous secreting epithelium. In this study, changes in keratin polypeptide composition in ectocervical and endocervical epithelia in vivo and in vitro have been investigated. Immunofluorescent studies wer done using a polyclonal antibody raised against a 40 kd keratin polypeptide (anti-40 kd) and a monoclonal antibody (LE61) which recognizes a keratin polypeptide of simple epithelia. In sections of ectocervix, anti-40 kd staining was restricted to the basal layer of the epithelium. In sections of endocervix all epithelial cells were positively stained by anti-40 kd and LE61. Regions of squamous metaplasia were negative for LE61 and weakly positive for anti-40 kd. Cultured ectocervical epithelial cells were negative for LE61 but some cells around the periphery of colonies were positive using anti-40 kd. Cultured endocervical epithelial cells stained positively with LE61 and anti-40 kd. Both antibodies stained a cytoplasmic filamentous network and double staining revealed a codistribution of the labelled filaments. After around 14 days in culture endocervical epithelial cells underwent a morphological change and assumed a keratinocyte appearance suggesting an in vitro equivalent of squamous metaplasia. However, such cells retain their LE61 antigenicity.