ted in a loss of cell fusion,which suggests the 928 site on G2 is crucial for cell fusion and the fusion peptide is likely on G2.

Hand, foot and mouth disease (HFMD) is a common acute infectious disease among children. Enterovirus 71 (EV71) is one of the major pathogens of HFMD. The incidence of HFMD in our country is higher, the main target population of infection is infants and young children; EV71 is also the most important pathogen causing severe HFMD in children currently. HFMD was classified as notifiable communicable disease of Category C on May 2, 2008. Pathogenesis of HFMD is not yet clear, and there is no drug that can treat such virus effectively. The non-structural protein 3D in EV71, is one of the important targets for the development of anti-EV71 virus drugs, which catalyzes the replication and transcription of the viral genome. This review provides a summary of the structure and function of EV71 3D, which can provide reference for the development of antiviral drugs.

Objective： ：To investigatetheeffectofsalidroside(SAL)onthephenotype of dendritic cells (DCs) and the antitumor ability of cytotoxic T lymphocytes (CTL). Methods： ：Lewis lung cancer cell line 3LL, wild type (WT) C57BL/6 mice and TLR4-/- C57BL/6 mice were chosen for this study. Mice bone marrow derived DC precursor cells were obtained to differentiate into immature DCs, which were harvested on the sixth day of culture. CD11c+ DCs were obtained by magnetic beads screening, and further divided into PBS group, SAL group and lipopolysaccharide (LPS) group.After being cultured for 48 h, the effects of SAL on surface molecules and phagocytosis of DCs as well as the efffect of TLR4 pathway on the killing effect of T cells were detected by Fow cytometry. Results： ： Compared with PBS group, expressions of DC surface molecules CD80, CD86 and MHC Ⅱ significantly increased (all P<0.05), phagocytosis significantly decreased (P<0.05), and TLR4 expression level significantly increased (P<0.01) in SAL group; Compared with WT group, after being treated with SAL or LPS, the expressions of DC surface molecules CD80, CD86 and MHC Ⅱ decreased significantly in TLR4-/- group (all P<0.05); ComparedwithPBSgroup,theactivatedCTLinSALgroupexhibited a significantly elevated killing effect against lung cancer 3LLcells (P<0.05). Conclusion：SAL can induce DC maturation by regulating TLR4, thus improving the killing ability of T cells.

Objective: To sequence the 3′UTR of enterovirus 71 strains, investigate its foundation and impact in virulence by constructing a 3′UTR-replaced recombinant cDNA infectious clone. Methods: Viral RNA of EV-A71 isolated viruses were extracted, and the nucleotide analysis was performed after sequencing. The 3′UTR of a full-length infectious clone of SDLY107 strain was replaced by its corresponding part of SDLY1 strain, and then the recombinant virus was constructed and identified. Results: The nine isolated strains were classified into sub-genotype C4a of enterovirus (EV)-A71 by analysis, and nucleotide sequence homology for 3′UTR were 94%-100%. 3′UTR of EV-A71 strains may be associated with its pathogenicity. Identification of the rescued virus by sequencing and indirect immunofluorescence confirmed the successful construction of infectious recombinant virus. Conclusions Sequence analysis indicated that the 3′UTR may be involved in the pathogenicity of EV-A71. The recombinant virus SDLY107(1-3′UTR) was rescued successfully. Our study may provide evidence for further research on the influence of 3′UTR on the virulence of enterovirus 71.

Developing universal CARs with improved flexible targeting and controllable activities is urgently needed. While several studies have suggested the potential of CD16a in tandem with monoclonal antibodies to construct universal CAR-T cells, the weak affinity between them is one of the limiting factors for efficacy. Herein, we systematically investigated the impact of Fcγ receptor (FcγR) affinity on CAR-T cells properties by constructing universal CARs using Fcγ receptors with different affinities for IgG1 antibodies, namely CD16a, CD32a, and CD64. We demonstrated that the activities of these universal CAR-T cells on tumor cells could be redirected and regulated by IgG1 antibodies. In xenografted mice, 64CAR chimeric Jurkat cells with the highest affinity showed significant antitumor effects in combination with herceptin in the HER2 low expression U251 MG model. However, in the CD20 high expression Raji model, 64CAR caused excessive activation of CAR-T cells, which resulted in cytokine release syndrome (CRS) and the decline of antitumor activity, and 32CAR with a moderate affinity brought the best efficacy. Our work extended the knowledge about FcγR-based universal CAR-T cells and suggested that only the FcγRCAR with an appropriate affinity can offer the optimal antitumor advantages of CAR-T cells.