Construction, screening and immunogenicity of the recombinant poxvirus vaccine rVTTδTK-RBD against SARS-CoV-2 / 细胞与分子免疫学杂志

Objective To construct a recombinant poxvirus vector vaccine, rVTTδTK-RBD, and to evaluate its safety and immunogenicity. Methods The receptor-binding domain (RBD) gene was synthesized with reference to the gene sequence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was inserted into the polyclonal site of the self-constructed recombinant plasmid pSTKE, to construct the recombinant poxvirus shuttle vector pSTKE-RBD. This was then transfected into BHK-21 cells pre-infected with the vaccinia virus Tiantan strain (VTT). The recombinant poxvirus rVTTδTK-RBD was successfully obtained after several rounds of fluorescence phage screening. The effect of rVTTδTK-RBD on the body mass of BALB/c mice was detected after immunizing mice by intra-nasal vaccination. The levels of specific and neutralizing antibodies produced by rVTTδTK-RBD on BALB/c mice were analyzed after immunizing mice intramuscularly. The effect of rVTTδTK-RBD on T cell subsets in BALB/c mice was detected by flow cytometry. Results Through homologous recombination, enhanced green fluorescent protein (EGFP) screening marker, and multiple rounds of fluorescent phosphorescence phage screening, a recombinant poxvirus rVTTδTK-RBD, expressing RBD with deletions in the thymidine kinase (TK) gene, was successfully obtained, which was validated by PCR. The in vivo experiments on BALB/c mice showed that rVTTδTK-RBD was highly immunogenic against SARS-CoV-2 and significantly reduced toxicity to the body compared to the parental strain VTT. Conclusion The recombinant poxvirus vaccine rVTTδTK-RBD against SARS-CoV-2 is successfully constructed and obtained, with its safety and immunogenicity confirmed through various experiments.

Preparation and identification of Env-pseudotyped subtype B HIV-1 / 军事医学

Objective To prepare the Env-pseudotyped subtype B HIV-1 with enhanced green fluorescent protein ( EG-FP) gene,explore HIV-1 infection mechanisms and develop feasible methods of identification .Methods The Env-pseudo-typed viruses were packaged in HEK293T cells by cotransfection, and the reporter gene and P24 protein were detected by PCR, Western blot and ELISA .Reporter gene amplification , viral titration assay and a single round of infection assay were performed after the env-pseudotyped viruses infected HIV-1 permissive cell .Results and Conclusion A generation and identification method of the pseudotyped HIV-1 was established . The Env-pseudotyped subtype B HIV-1 has been prepared, which is able to infect SupT1 and TZM-bl cells through infection assay .