Systemic administration of a potent mouse monoclonal antibody provides multisite protection against HPV16 infection

Although preventive vaccines for Human Papillomaviruses (HPV) are available, a definitive cure for the viral infection itself is currently lacking. There is a sizable population that remains inaccessible to HPV vaccination due to reasons such as high costs or lack of availability of the vaccines. Therefore, there remains a significant population susceptible to HPV infection. Persistent multisite infections with high-risk HPV types can cause cancer at several different anatomic sites.Especially HPV16 is a key etiologic factor for cervical, other ano-genital and oropharyngeal cancers. Therefore, it is imperative to develop pharmaceutical interventions for the treatment of viral infections. In this study, a panel of 9 neutralizing antibodies was screened using the hybridoma technique, with 20F6 being identified as the representative antibody. The purified 20F6 exhibited an IC₅₀ of 0.0011 μg/ml against HPV16, demonstrating potent viral inhibitory activity. Moreover, it displayed cross-neutralizing efficacy towards other Alphapapillom 9 subtypes including HPV31, HPV33, HPV52, and HPV58 with respective IC₅₀ values of 2.0 μg/ml, 7.3 μg/ml, 1.7 μg/ml, and 3.0 μg/ml. 20F6 recognizes the linear epitope MSLW, the first four amino-acids located at the very N-terminus of the HPV16 L1 protein. Administration of 20F6, 24 h prior to and following HPV16 pseudo-virion (PSV) challenge, conferred protection against infection in mice at doses as low as 1 mg/kg. Following intraperitoneal administration of 20F6, neutralizing antibodies were consistently detected at both oral and vaginal sites, indicating that prophylactic systemic administration of 20F6 may confer efficient protection against multiple susceptible mucosal sites.