Design and immunogenicity assessment of HIV-1 virus-like particles as a candidate vaccine

Zhang, XiZhen; Wang, XiaoDan; Zhao, DongHai; Meng, XiangYu; Zhao, XingHong; Yu, XiangHui; Kong, Wei

HIV-1 VLPs possess a complex structure based on viral gag proteins that self-assemble into particular structures analogous in size and morphology to immature HIV-1 particles. As non-infectious, replication-deficient particles, VLPs are much safer compared to traditional vaccines made by chemically inactivated or attenuated live viruses. The different forms of VLPs have distinct properties [7] [8] [9] [10] . Only enveloped VLPs display full-length proteins with proper folding on their surface and closely mimic native envelope trimeric structures [7, 11, 12] . The immune system responds well to particular antigens that are similar to immature HIV-1 viruses [13] . VLPs antigens are processed and present antigens through the major histocompatibility (MHC) class II pathway as well as the MHC class I endogenous pathway, inducing both CD4-and CD8-T-cell-mediated immune responses [14] [15] [16] . Therefore, VLPs can effectively induce both humoral and cellular immune reactions. It is also widely accepted that a rational vaccine design should have the potential to block the initial step of infection. In this respect, VLP-based vaccines are a promising type of recombinant protein vaccine.