EXPRESSION OF HUMAN PAPILLOMAVIRUS TYPE-16-E7 PROTEIN BY RECOMBINANT BACULOVIRUS AND USE FOR THE DETECTION OF E7-ANTIBODIES IN SERA FROM CERVICAL-CARCINOMA PATIENTS

Although the presence of serum antibodies against the human papillomav irus type 16 (HPV-16) E7 protein has been linked with cervical cancer, currently available assays detect antibodies in only ca. 40% of carci noma patients. The dependence of these serological assays on synthetic target antigens which present only linear epitopes may be a limiting factor. In order to produce a more realistic target antigen for use in serological assays, we have expressed the HPV-16 E7 protein in insect cells using a recombinant baculovirus vector. Two major E7 forms of c a. 18kDa and 16kDa were produced and characterised. The 16kDa componen t was shown to be truncated at the N-terminus. A radioimmunoprecipitat ion assay was developed for the detection of anti-E7 antibodies in hum an sera. This assay showed a marked increase in detection rate compare d with a western blotting method based on bacterially derived E7 fusio n proteins.