Alexander Jeff, Mendy Jason, Vang Lo, Avanzini Jenny B, Garduno Fermin, Manayani Darly J, Ishioka Glenn, Farness Peggy, Ping Li-Hua, Swanstrom Ronald, Parks Robert, Liao Hua-Xin, Haynes Barton F, Montefiori David C, LaBranche Celia, Smith Jonathan, Gurwith Marc, Mayall Tim
PaxVax Inc, San Diego, California, United States of America.
PLoS One. 2013 Dec 3;8(12):e82380. doi: 10.1371/journal.pone.0082380. eCollection 2013.
There is a well-acknowledged need for an effective AIDS vaccine that protects against HIV-1 infection or limits in vivo viral replication. The objective of these studies is to develop a replication-competent, vaccine vector based on the adenovirus serotype 4 (Ad4) virus expressing HIV-1 envelope (Env) 1086 clade C glycoprotein. Ad4 recombinant vectors expressing Env gp160 (Ad4Env160), Env gp140 (Ad4Env140), and Env gp120 (Ad4Env120) were evaluated.
The recombinant Ad4 vectors were generated with a full deletion of the E3 region of Ad4 to accommodate the env gene sequences. The vaccine candidates were assessed in vitro following infection of A549 cells for Env-specific protein expression and for posttranslational transport to the cell surface as monitored by the binding of broadly neutralizing antibodies (bNAbs). The capacity of the Ad4Env vaccines to induce humoral immunity was evaluated in rabbits for Env gp140 and V1V2-specific binding antibodies, and HIV-1 pseudovirus neutralization. Mice immunized with the Ad4Env160 vaccine were assessed for IFNγ T cell responses specific for overlapping Env peptide sets.
Robust Env protein expression was confirmed by western blot analysis and recognition of cell surface Env gp160 by multiple bNAbs. Ad4Env vaccines induced humoral immune responses in rabbits that recognized Env 1086 gp140 and V1V2 polypeptide sequences derived from 1086 clade C, A244 clade AE, and gp70 V1V2 CASE A2 clade B fusion protein. The immune sera efficiently neutralized tier 1 clade C pseudovirus MW965.26 and neutralized the homologous and heterologous tier 2 pseudoviruses to a lesser extent. Env-specific T cell responses were also induced in mice following Ad4Env160 vector immunization.
The Ad4Env vaccine vectors express high levels of Env glycoprotein and induce both Env-specific humoral and cellular immunity thus supporting further development of this new Ad4 HIV-1 Env vaccine platform in Phase 1 clinical trials.
人们普遍认识到需要一种有效的艾滋病疫苗来预防HIV-1感染或限制体内病毒复制。这些研究的目的是开发一种基于腺病毒血清型4（Ad4）病毒的具有复制能力的疫苗载体，该载体表达HIV-1包膜（Env）1086 C亚型糖蛋白。对表达Env gp160（Ad4Env160）、Env gp140（Ad4Env140）和Env gp120（Ad4Env120）的Ad4重组载体进行了评估。
构建重组Ad4载体时完全缺失Ad4的E3区域，以容纳env基因序列。在感染A549细胞后，对候选疫苗进行体外评估，以检测Env特异性蛋白表达以及通过广泛中和抗体（bNAbs）结合监测的翻译后转运至细胞表面的情况。在兔中评估Ad4Env疫苗诱导体液免疫的能力，检测Env gp140和V1V2特异性结合抗体以及HIV-1假病毒中和情况。对用Ad4Env160疫苗免疫的小鼠评估针对重叠Env肽组的IFNγ T细胞反应。
通过蛋白质印迹分析证实了强大的Env蛋白表达，并且多种bNAbs识别细胞表面的Env gp160。Ad4Env疫苗在兔中诱导了体液免疫反应，这些反应识别源自1086 C亚型、A244 AE亚型的Env 1086 gp140和V1V2多肽序列以及gp70 V1V2 CASE A2 B亚型融合蛋白。免疫血清有效中和了1级C亚型假病毒MW965.26，并在较小程度上中和了同源和异源2级假病毒。Ad4Env160载体免疫小鼠后也诱导了Env特异性T细胞反应。
Ad4Env疫苗载体表达高水平的Env糖蛋白，并诱导Env特异性体液免疫和细胞免疫，因此支持这一新型Ad4 HIV-1 Env疫苗平台在1期临床试验中的进一步开发。
