Several epidemiologic studies have identified infection with oncogenic type human papillomavirus (HPV) as a necessary cause of cervical cancer. More than 99% of cervical cancers contain genes of """"""""high risk"""""""" HPVs, of which there are at least 15 different types. Our goal is to eliminate HPV-related cancer through the development of a single vaccine that is protective against all oncogenic HPV types. The two HPV capsid proteins, L1 and L2, are both independent protective antigens. Vaccination with HPV L1 virus-like particles (VLP) induces neutralizing antibodies and protection in patients with strong type restriction. Broad protection against the >15 known oncogenic HPVs is necessary for the eventual cessation of cytologic screening and eradication of cervical cancer. Broad protection may require an expensive highly multivalent L1 VLP vaccine, but current commercial clinical studies utilize VLPs from only two oncogenic types. We propose L2 as a single conserved protective antigen. Protection in animal models is mediated by L2 neutralizing antibodies which also cross-neutralize diverse HPV genotypes. Vaccination of cattle with bovine papillomavirus type 4 (BPV4) L2 11-200 protects against BPV4 challenge on the soft palate. Furthermore, vaccination of rabbits with HPV16 L2 11-200 protects against both cutaneous infection with cottontail rabbit papillomavirus (CRPV) and mucosal challenge with rabbit oral papillomavirus (ROPV). Thus, vaccination with L2 11-200 produced in bacteria protects against both the homologous virus type as well as evolutionarily distant heterologous types supporting the possibility of an L2-based pan-oncogenic HPV vaccine. Unlike currently available L1 VLP vaccines, a single L2-based antigen produced in E. coli is inexpensive to produce. As such, a pan-oncogenic HPV type that is less costly to produce would have its greatest impact in underserved areas in the US and in developing nations. The Rapid Access to Preventive Intervention Development (RAPID, NCI) program is producing GMP-grade HPV 16 L2 11-200 for this proposed clinical trial. HYPOTHESIS 1: Vaccination of patients with HPV16 L2 11-200 polypeptide is safe with or without adjuvant.
Specific Aim #1 : To evaluate whether vaccination using GMP grade HPV16 L2 11-200 with and without adjuvant is safe in healthy women. HYPOTHESIS 2: The HPV16 L2 11-200 polypeptide is immunogenic in patients and formulation with adjuvant enhances its immunogenicity.
Specific Aim #2 : To determine which formulation and minimal dose of GMP grade HPV16 11-200 polypeptide with adjuvant induces the maximal titers of neutralizing antibody and also the spectrum of HPV types neutralized by sera of patients vaccinated with the optimal formulation of GMP grade HPV16 11-200 polypeptide. HYPOTHESIS 3: Transudation of L2-specific HPV neutralizing antibody into the genital tract is the relevant correlate of protection.
Specific Aim #3 : To determine whether passive transfer of mice with L2-specific human IgG or IgM will confer protection from vaginal challenge of mice with HPV pseudovirion and determine the minimal neutralizing antibody titer for protection.
Several clinical and molecular epidemiologic studies have identified infection with oncogenic type human papillomavirus (HPV) as a necessary cause of cervical cancer. Unlike currently available L1 VLP vaccines, vaccination with L2 11-200 produced in bacteria protects against both the homologous virus type as well as evolutionarily distant heterologous types, supporting the possibility of an L2-based pan-oncogenic HPV vaccine. Furthermore, it is known that HPV type distribution is markedly different throughout the world and a pan-oncogenic L2 HPV vaccine, that is substantially cheaper to produce in E. coli, may have a substantial global impact, particularly in developing nations and low resource settings where 80% of cervical cancer occurs.
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