Abnormal expression of galactosyl(alpha 1-->3) galactose epitopes in squamous cells of the uterine cervix infected by human papillomavirus.

This study describes the presence of alpha-galactosyl epitopes on 12 cervical biopsy samples with features of human papillomavirus infection (HPV) and different stages of cervical intraepithelial neoplasia. An avidin-biotin-peroxidase assay with a monoclonal antibody recognizing gal(alpha 1-->3)gal residues was strongly positive in 5 of 12 cases. None of the controls stained (p = 0.02). Immunostaining was intense in the areas with the highest viral load (koilocytes and keratinocytes) and absent in malignant foci. Immunostaining was also absent in normal exo- and endocervical epithelium of 12 controls with no features of HPV infection. A faint background staining in cases and controls was evident, but similar. These initial findings suggest that alpha-galactosyl epitopes are expressed in cervical squamous cells infected with HPV, turning them vulnerable to lysis by natural anti-alpha-galactosyl antibodies.