Differential Antibody Response against Conformational and Linear Epitopes of the L1 Proteins from Human Papillomavirus Types 1618 Is Observed in Vaccinated Women or with Uterine Cervical Lesions

Abstract

Abstract Antibodies against the Human Papillomavirus (HPV) L1 protein are associated with past infections and related to the evolution of the disease, whereas antibodies against L1 Virus-Like Particles (VLPs) are used to follow the neutralizing antibody response in vaccinated women. In this study, serum antibodies against conformational (VLPs) and linear epitopes of HPV1618 L1 protein were assessed to distinguish HPV-vaccinated women from those naturally infected or those with uterine cervical lesions. The VLPs-1618 were generated in baculovirus, and L1 proteins were obtained from denatured VLPs. Serum antibodies against VLPs and L1 proteins were evaluated by ELISA. The ELISA-VLPs and ELISA-L1 1618 assays were validated with a vaccinated women group by ROC analysis and the regression analysis to distinguish the different populations of female patients. The anti-VLPs-1618 and anti-L1-1618 antibodies effectively detect vaccinated women (AUC 1.00.79, and 0.940.84, respectively). The regression analysis showed that anti-VLPs-1618 and anti-L1-1618 antibodies were associated with the vaccinated group (OR 2.11 10816.50 and 536.049.2, respectively). However, only the anti-L1-16 antibodies were associated with the high-grade lesions and cervical cancer (CIN3CC) group (OR 12.18). In conclusion, our results suggest that anti-VLPs-1618 antibodies are effective and type-specific to detect HPV-vaccinated women, but anti-L1-16 antibodies better differentiate the CIN3CC group. However, a larger population study is needed to validate these results.