Objective:To establish an antibody expression system to reduce the antibody-dependent enhancement (ADE) effect of target antibody.Methods:Site-directed mutagenesis was used to mutate the 234 and 235 sites of the Fc region of the mammalian cell antibody expression vector-L234A and L235A to establish the antibody expression vector pFRT-IgG1κ-FcM. An antibody Wt-WNV with significant ADE effect obtained in previous work was selected and expressed by the pFRT-IgG1κ-FcM system to obtain mutant antibody FcM-WNV. The binding ability of FcM-WNV to target antigen West Nile virus envelope protein-DⅢ (WNV E-DⅢ) was detected by ELISA, and the its binding ability to human high-affinity IgG Fc receptor hFcγRⅠ (hCD64 ) was analyzed by flow cytometry. The neutralizing activity of FcM-WNV in vitro was detected by pseudovirus infection of host cells (BHK21 and K562). Results:The expression levels of FcM-WNV and Wt-WNV were comparable, and FcM-WNV could recognize and bind to WNVE-DIII in a concentration-dependent manner. Compared with Wt-WNV, the binding ability of FcM-WNV to hCD64 was significantly weakened, showing a significant decrease in fluorescence intensity. Consistent with the previous experimental results, Wt-WNV at a concentration of 5 μg/ml significantly enhanced the infection of K562 by WNV pseudovirus, while FcM-WNV at a concentration of 5 μg/ml could effectively block pseudovirus infection in both K562 and BHK21 cells.Conclusions:The established antibody expression system can effectively reduce the ADE effect of the target antibody.

[Objective] To summarize the diagnosis and treatment of Antopol Goldman lesion (AGL) in clinical practice. [Methods] Clinical data and diagnosis and treatment process of one AGL case treated in our hospital were retrospectively analyzed, and relevant literature was reviewed. [Results] The patient presented with painless gross hematuria and right-sided lower back pain.Imaging examination suggested swelling of the right kidney, blood accumulation in the right calyx, renal pelvis and lower ureter, blood clot in the bladder, and multiple small stones in the left kidney.After multidisciplinary consultation, close imaging follow-up, interventional and flexible ureterdscope examination, tumors of hematological diseases, renal hematuria, arteriovenous fistula and collection system were excluded.After conservative treatment, the patient gradually recovered.During the follow-up of 1 year, no hematuria or low back pain recurred. [Conclusion] There is no clear diagnostic standard for AGL.Diagnosis relies on imaging, interventional methods and ureteroscopy.It is necessary to exclude other diseases and adopt conservative treatment.

Ebola viruses belong to the Filoviridae family,which is highly contagious and likely to cause a variety of symptoms,including severe haemorrhagic fever in humans and primates,with a case fatality rate of up to 90%.Niemann-Pick C1(NPC1)protein is an important receptor expressed in the endosomal membrane of host cells during Ebola virus infection,and its interaction with the glycoprotein(GP)cleaved by cathepsin of Ebola virus is a key link in the viral infection host,mediating the fusion of the viral envelope and endosomal membrane before releasing the viral genome to the host cell.Recent years have seen some small molecule inhibitors and monoclonal antibody gene therapy drugs devel-oped by using NPC1 protein as a target of broad-spectrum anti-filovirus drugs.This article introduces the structure of NPC1 and its role in Ebola virus infection,and summarizes small molecule inhibitors,monoclonal antibody drugs and gene therapy drugs targeting NPC1.

Objective:To establish an in vivo infection model of West Nile virus (WNV) pseudovirus and evaluate the neutralizing activity of antibody WNV-XH1.Methods:A stable cell line that can package the WNV pseudovirus was established in the early stage to prepare the pseudovirus supernatant. The supernatant was concentrated and infected BHK21 cells to detect the titer of the pseudovirus. After intraperitoneal injection of the pseudovirus into C57BL/J mice, bioluminescence imaging was performed to observe the infection status of the pseudovirus in the mice. After simultaneous infection, blood was collected and ELISA was used to detect NS1 levels in mouse serum. The in vivo functional activity of antibody WNV-XH1 was evaluated using the established mouse infection model.Results:Fluorescence was detected in C57BL/J mice infected with WNV pseudovirus, and the NS1 levels in the peripheral blood serum of mice infected with pseudovirus were significantly higher than those of non infected mice (1.453±0.09vs0.305±0.018). After intravenous administration of WNV-XH1 antibody before the attack, the fluorescence signal in the mice decreased and the serum NS1 level decreased (0.384±0.015).Conclusions:A successful in vivo infection model of WNV pseudovirus was established, and it was confirmed that the antibody WNV-XH1 had a protective effect against WNV pseudovirus infection in vivo.

Objective:To establish an in vivo infection model of H5N1 pseudovirus and to detect the neutralizing activity of FHA3 antibody using this model. Methods:Based on the sequence information of hemagglutinin (HA) and neuraminidase (NA) of A/Anhui/1/2005/H5N1 strain, two recombinant plasmids of pcDNA3.1-HA5 and pcDNA3.1-NA1 were constructed. The two plasmids and plasmid pNL4-3.Luc.R-E- were co-transfected into 293T cells to prepare H5N1 pseudovirus supernatant. The morphology of pseudovirus particles in the supernatant was observed by electron microscopy. MDCK cells were infected with the pseudovirus supernatant and the virus titer was detected. BALB/c mice were injected with the pseudovirus supernatant by intraperitoneal injection and subjected to bioluminescence imaging at 2, 5, 8, and 12 d after infection to detect the pseudovirus infection in vivo. The functional activity of FHA3 antibody in vivo was evaluated using the established mouse infection model. Results:The recombinant plasmids pcDNA3.1-HA5 and pcDNA3.1-NA1 were correctly constructed and could be used to prepare pseudovirus supernatants of high titer by co-transfecting 293T cells with the plasmid pNL4-3.Luc.R-E-. The virus particles were round under electron microscope. H5N1 pseudovirus-infected mice exhibits strong fluorescence signals, which were attenuated by FHA3 treatment before challenge.Conclusions:The in vivo infection model of H5N1 pseudovirus was successfully constructed and FHA3 antibody was proved to be protective against the pseudovirus infection.

OBJECTIVE: To investigate the chemical constituents from the leaves of Jatropha curcas and evaluate their inhibition on lipopolysaccharide (LPS)-activated BV-2 microglia cells. METHODS: The n-BuOH extract of the leaves of J. curcas was isolated by macroporous adsorption resin, silica gel, ODS, column chromatography and semi-preparative HPLC. The structures of the compounds were identified by MS, NMR, ECD, and other spectroscopic methods. In addition, anti-neuroinflammatory effects of isolated compounds were evaluated by measuring the production of nitric oxide (NO) in over-activated BV-2 cells. RESULTS: Seventeen compounds, including (7R,8S)-crataegifin A-4-O-β-D-glucopyranoside ( 1), (8R,8'R)-arctigenin ( 2), arctigenin-4'-O-β-D-glucopyranoside ( 3), (-)-syringaresinol ( 4), syringaresinol-4'-O-β-D-glucopyranoside ( 5), (-)-pinoresinol ( 6), pinoresinol-4'-O-β-D-glucopyranoside ( 7), buddlenol D ( 8), (2R,3R)-dihydroquercetin ( 9), (2S,3S)-epicatechin ( 10), (2R,3S)-catechin ( 11), isovitexin ( 12), naringenin-7-O-β-D-glucopyranoside ( 13), chamaejasmin ( 14), neochamaejasmin B ( 15), isoneochamaejasmin A ( 16), and tomentin-5-O-β-D-glucopyranoside ( 17) were isolated and identified. Compounds 2, 4 and 8 significantly inhibited the release of NO in BV-2 microglia activated by LPS, with IC₅₀ values of 18.34, 29.33 and 26.30 μmol/L, respectively. CONCLUSION Compound 1 is a novel compound, and compounds 2, 3, 8, 14- 17 are isolated from Jatropha genus for the first time. In addition, the lignans significantly inhibited NO release and the inhibitory activity was decreased after glycosylation.

Objective:To prepare and identify a broad-spectrum antibody FHA3 targeting influenza A virus hemagglutinin (HA).Methods:According to the single-chain antibody fragment (scFv) sequence, the heavy chain (VH) and light chain (VL) variable regions of FHA3 were amplified by PCR and a recombinant plasmid pFRT-IgG1κ-FHA3 was constructed by linking the expression vector pFRT-IgG1κ. FHA3 was expressed in the ExpiCHO system and purified by affinity purification. The binding activity of FHA3 to influenza A virus HA was detected by ELISA. The neutralizing activity of FHA3 was detected in vitro by infecting host cells with pseudovirus. Results:SDS-PAGE showed that high-purity FHA3 was obtained. FHA3 could bind to H1N1 HA, H2N2 HA, H3N2 HA, H5N1 HA, H7N9 HA and H9N2 HA in a concentration-dependent manner. FHA3 had good neutralizing activity in vitro that was it could effectively block the invasion of H5N1 and H7N9 pseudoviruses into target cells at a low concentration of 5 μg/ml and H1N1 pseudovirus at 0.012 5 μg/ml. Conclusions:A broad spectrum antibody targeting HA protein of influenza A virus with neutralizing activity in vitro was obtained.

Objective:To prepare and identify a functional antibody FNA1 targeting the neuraminidase (NA) of influenza A virus N1 subtype.Methods:According to single-chain antibody fragment (scFv) sequence, the heavy chain and light chain variable region sequences of FNA1 were synthesized, and the recombinant expression plasmid pFRT-IgG1κ-FNA1 was constructed by linking the expression vector pFRT-IgG1κ. The FNA1 antibody was expressed in ExpiCHO cells and purified using affinity purification technique. The binding ability of FNA1 to the target proteins, influenza A virus N1 subtype NA antigens, was detected by ELISA. Flow cytometry was performed to analyze the binding ability of FNA1 to the NA antigens expressed on the surface of cell membrane. The in vitro activity of FNA1 against NA was evaluated by infecting 293T cells with pseudovirus. Results:Protein electrophoresis showed that FNA1 with high purity was obtained. FNA1 specifically recognized and bound to N1 subtype NA antigens in a concentration-dependent manner. FNA1 could effectively block NA activity by binding to N1 subtype NA protein expressed on the surface of cell membrane, thus inhibiting the release of packaged pseudovirus from cell surface and further inhibiting target cell infection.Conclusions:An antibody FNA1 targeting influenza A virus N1 subtype NA with in vitro functional activity was obtained.

Colorectal cancer(CRC)ranks the third in incidence and mortality rate among human tumors. Tumor relapse,me?tastasis and drug resistance remain the main obstacle to the success of CRC treatments. Compared to traditional chemotherapy ,target therapy seems to treat tumors in more precise and rational fashion with good response and often less toxic side-effect. Although target agents provide hope for more effective therapy,recent clinical studies have shown only modest benefit from target therapy similar to tra?ditional chemotherapy. Primary and secondary resistance to target agents is still observed and contributes to CRC treatment failure. The review summarizes research progress in the mechanism of drug resistance to target therapy in CRC treatment.

5-Fluorouracil(5-FU)has been widely used to treat gastrointestinal,head,neck,chest and ovarian malignant tu-mors since 1957. As an analogue of pyrimidine,5-FU plays anti-cancer roles by inhibiting thymioylate synthase and integrating its me-tabolites into DNA and RNA. Although 5-FU is one of the first-line therapeutic compounds for gastrointestinal malignant tumor as a sin-gle drug or in combination with other drugs,its effectiveness is hindered by its low efficiency,which may be due to chemotherapy re-sistance. 5-FU chemotherapy resistance may stem from enzyme abnormality,genetic abnormality and tumor microenvironment. In this paper,we make a review about 5-FU actions and the mechanisms underlying chemotherapy resistance.