Prevalence of antibodies against a cyclic peptide mimicking the FG loop of the human papillomavirus type 16 capsid among Tunisian women
Abstract Background In the past decades, several studies have identified cervical cancer is the second most common cancer in women worldwide and leading causes of death in developing countries. High-risk types of human papillomavirus (HR-HPV), mainly type 16, are the sexually transmitted agents etiologically linked to cervical cancer. The present epidemiological study aimed to investigate the efficacy of enzyme linked immunosorbent assay (ELISA) and assessed host humoral immune response against the oncogenic HPV-16 infection using the cyclic synthetic peptide mimicking the FG loop of the major L1 capsid protein of the HPV-16 among Tunisian women. Methods The antibody responses against synthetic peptides mimicking the FG loop of the HPV l6 major capsid protein L1 in sera and cervical secretions among 179 Tunisian women were assessed by ELISA. HPV infection was examined by a polymerase chain reaction-based method. Results The frequency of systemic antibodies, in contrast to HPV-16 DNA prevalence, was higher in women with low-grade squamous intraepithelial lesions (LGSIL) than in women with high-grade squamous intraepithelial lesions (HGSIL) (43.7% versus 14.8%; P=0.04). Compared to women from the general population, systemic IgG response frequency was significantly higher among legal sex workers (25.5%; P=0.002) and women with LGSIL (43.7%; P=0.001). In addition, systemic IgA and local IgG responses were higher, only among legal sex workers (P=0.002 and P=0.001 respectively). Conclusions Overall, the frequency of HPV DNA detection was significantly higher among women with HGSIL. We did not observe a positive IgG response in women with a positive HPV-16 infection, suggesting that the anti-peptide antibodies are protective and confirm that the FG loop contains neutralizing epitopes. This could have implications for future monitoring of women to predict clinical outcome and for the design of synthetic peptide-based vaccine.