• Antibodies

A number of human papillomavirus (HPV) type 16 proteins have recently been identified in human cervical carcinoma cell lines using polyclonal antisera against papillomavirus gene products expressed in Escherichia coli. E7 protein has been found to be the most abundant papillomavirus protein in these cells. Here we describe apanel of monoclonal antibodies recognizing a 15K Mr non-glycosylated cytoplasmic HPV-16 E7 protein. One of the antibodies cross-reacted with HPV-18 E7 protein. Up to the present time more than 50 distinct ypes of human papillomaviruses (HPVs) have been identified. They have been found associated with a number of epithelial neoplasms: benign tumours like common warts and genital condylomas and malignant tumours like carcinomas of the skin and the uterine cervix (for review, see Gissmann, 1984; Broker & Botchan, 1986). HPV types 16 and 18 are those most commonly found in cervical carcinomas (Dfirst et al., 1983; Boshart et al., 1984). They are also present in a number of cell lines derived from these tumours and are integrated into the chromosomal DNA. Viral sequences, notably the open reading frames E6 and E7, are actively transcribed in these cells (Schwarz et al., 1985). As tissue culture systems susceptible to efficient ransformation by HPVs are not available, these cell lines serve as mode