AIDS Institute, Department of Microbiology, State Key Laboratory of Emerging Infectious Diseases, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, People's Republic of China.
Department of Veterinary Medicine, Foshan University, Foshan, People's Republic of China.
J Virol. 2022 Apr 13;96(7):e0216121. doi: 10.1128/jvi.02161-21. Epub 2022 Mar 17.
Vaccine-induced protective T cell immunity is necessary for HIV-1 functional cure. We previously reported that rhesus PD1-Gag-based DNA vaccination sustained simian-human immunodeficiency virus (SHIV) suppression by inducing effector-memory CD8 T cells. Here, we investigated a human PD1-Gag-based DNA vaccine, namely, ICVAX, for clinical translation. PD1-based dendritic cell targeting and mosaic antigenic designs were combined to generate the ICVAX by fusing the human soluble PD1 domain with a bivalent HIV-1 Gag-p41 mosaic antigen. The mosaic antigen was cross-reactive with patients infected with B, CRF07/08_BC, and CRF01_AE variants. In mice, ICVAX elicited stronger, broader, and more polyfunctional T cell responses than mosaic Gag-p41 alone, and suppressed EcoHIV infection more efficiently. In macaques, ICVAX elicited polyfunctional effector-memory T cell responses that targeted multiple nonoverlapping epitopes of the Gag-p41 antigen. Furthermore, ICVAX manufactured following good manufacturing practices proved potent immunogenicity in macaques after biannual homologous vaccination, warranting clinical evaluation of ICVAX as an immunotherapy against HIV-1. This study presents that ICVAX, a PD1-based DNA vaccine against HIV-1, could induce broad and polyfunctional T cell responses against different HIV-1 subtypes. ICVAX encodes a recombinant antigen consisting of the human soluble PD1 domain fused with two mosaic Gag-p41 antigens. The mosaic antigens cover more than 500 HIV-1 strains circulating in China including the subtypes B/B', CRF01_AE, and CRF07/08_BC. In mice, ICVAX elicited stronger, broader, and more polyfunctional T cell responses, with better EcoHIV suppression than the nontargeting mosaic Gag-p41 DNA vaccine. Moreover, both lab-generated and GMP-grade ICVAX also elicited strong polyfunctional effector-memory T cell responses in rhesus macaques with good immunogenicity against multiple nonoverlapping epitopes of the Gag-p41 antigen. This study therefore highlights the great potential to translate the PD1-based DNA vaccine approach into clinical use, and opens up new avenues for alternative HIV-1 vaccine design for HIV-1 preventive and functional cure.
疫苗诱导的保护性 T 细胞免疫对于实现 HIV-1 功能性治愈是必要的。我们之前报道过,基于恒河猴 PD1-Gag 的 DNA 疫苗通过诱导效应记忆 CD8 T 细胞,持续抑制猿猴-人免疫缺陷病毒(SHIV)。在此,我们研究了一种基于人 PD1-Gag 的 DNA 疫苗,即 ICVAX,以进行临床转化。通过将人可溶性 PD1 结构域与二价 HIV-1 Gag-p41 嵌合抗原融合,将 PD1 靶向树突状细胞和嵌合抗原设计结合在一起,生成了 ICVAX。嵌合抗原与感染 B、CRF07/08_BC 和 CRF01_AE 变异株的患者发生交叉反应。在小鼠中,ICVAX 引发的 T 细胞反应比单独的嵌合 Gag-p41 更强、更广、更具多功能性,并且更有效地抑制了 EcoHIV 感染。在食蟹猴中,ICVAX 引发了针对 Gag-p41 抗原多个非重叠表位的多反应性效应记忆 T 细胞反应。此外,按照良好生产规范制造的 ICVAX 在食蟹猴中进行了每半年一次的同源接种后,证明具有强大的免疫原性,这为 ICVAX 作为 HIV-1 免疫疗法的临床评估提供了依据。本研究表明,基于 PD1 的 HIV-1 DNA 疫苗 ICVAX 可以诱导针对不同 HIV-1 亚型的广泛和多功能性 T 细胞反应。ICVAX 编码一种重组抗原,由与人可溶性 PD1 结构域融合的两个嵌合 Gag-p41 抗原组成。嵌合抗原涵盖了中国流行的 500 多种 HIV-1 株,包括亚型 B/B'、CRF01_AE 和 CRF07/08_BC。在小鼠中,ICVAX 引发的 T 细胞反应比非靶向嵌合 Gag-p41 DNA 疫苗更强、更广、更具多功能性,并且对 EcoHIV 的抑制作用更好。此外,实验室生产和 GMP 级别的 ICVAX 也在食蟹猴中引发了针对 Gag-p41 抗原多个非重叠表位的强烈多反应性效应记忆 T 细胞反应,具有良好的免疫原性。因此,本研究突出了将基于 PD1 的 DNA 疫苗方法转化为临床应用的巨大潜力,并为 HIV-1 预防性和功能性治愈的替代 HIV-1 疫苗设计开辟了新途径。