Gambhira Ratish, Jagu Subhashini, Karanam Balasubramanyam, Gravitt Patti E, Culp Timothy D, Christensen Neil D, Roden Richard B S
Department of Pathology, Johns Hopkins School of Medicine, 1550 Orleans Street, Baltimore, MD 21231, USA.
J Virol. 2007 Nov;81(21):11585-92. doi: 10.1128/JVI.01577-07. Epub 2007 Aug 22.
Current L1 virus-like particle (VLP) vaccines provide type-restricted protection against a small subset of the human papillomavirus (HPV) genotypes associated with cervical cancer, necessitating continued cytologic screening of vaccinees. Cervical cancer is most problematic in countries that lack the resources for screening or highly multivalent HPV VLP vaccines, suggesting the need for a low-cost, broadly protective vaccinogen. Here, N-terminal L2 polypeptides comprising residues 1 to 88 or 11 to 200 derived from HPV16, bovine papillomavirus type 1 (BPV1), or cottontail rabbit papillomavirus (CRPV) were produced in bacteria. Rabbits were immunized with these N-terminal L2 polypeptides and concurrently challenged with CRPV and rabbit oral papillomavirus (ROPV). Vaccination with either N-terminal L2 polypeptides of CRPV effectively protected rabbits from CRPV challenge but not from papillomas induced by cutaneous challenge with CRPV genomic DNA. Furthermore, papillomas induced by CRPV genomic DNA deficient for L2 expression grew at the same rate as those induced by wild-type CRPV genomic DNA, further suggesting that the L2 polypeptide vaccines lack therapeutic activity. Neutralizing serum antibody titers of >15 correlated with protection (P < 0.001), a finding consistent with neutralizing antibody-mediated protection. Surprisingly, a remarkable degree of protection against heterologous papillomavirus types was observed after vaccination with N-terminal L2 polypeptides. Notably, vaccination with HPV16 L2 11-200 protected against cutaneous and mucosal challenge with CRPV and ROPV, respectively, papillomaviruses that are evolutionarily divergent from HPV16. Further, vaccination with HPV16 L2 11-200 generates broadly cross-neutralizing serum antibody, suggesting the potential of L2 as a second-generation preventive HPV vaccine antigen.
目前的L1病毒样颗粒(VLP)疫苗仅对一小部分与宫颈癌相关的人乳头瘤病毒(HPV)基因型提供型特异性保护,因此仍需对接种疫苗者继续进行细胞学筛查。在缺乏筛查资源或高价多价HPV VLP疫苗的国家,宫颈癌问题最为突出,这表明需要一种低成本、具有广泛保护作用的疫苗原。在此,我们在细菌中表达了包含源自HPV16、1型牛乳头瘤病毒(BPV1)或棉尾兔乳头瘤病毒(CRPV)的1至88位或11至200位残基的N端L2多肽。用这些N端L2多肽免疫兔子,并同时用CRPV和兔口腔乳头瘤病毒(ROPV)进行攻击。用CRPV的任一N端L2多肽进行疫苗接种可有效保护兔子免受CRPV攻击,但不能保护其免受CRPV基因组DNA皮肤攻击诱导的乳头瘤。此外,缺乏L2表达的CRPV基因组DNA诱导的乳头瘤与野生型CRPV基因组DNA诱导的乳头瘤生长速度相同,这进一步表明L2多肽疫苗缺乏治疗活性。中和血清抗体滴度>15与保护作用相关(P<0.001),这一发现与中和抗体介导的保护作用一致。令人惊讶的是,在用N端L2多肽接种疫苗后,观察到对异源乳头瘤病毒类型有显著程度的保护作用。值得注意的是,用HPV16 L2 11 - 200接种疫苗分别可保护免受CRPV和ROPV的皮肤和粘膜攻击,这两种乳头瘤病毒在进化上与HPV16不同。此外,用HPV16 L2 11 - 200接种疫苗可产生广泛的交叉中和血清抗体,这表明L2作为第二代预防性HPV疫苗抗原具有潜力。