1.Expression and in vitro activity of a neutralizing antibody against West Nile virus that reduces antibody-dependent enhancement
Xiangjun HAO ; Nan CHEN ; Wanlu ZHU ; Jing WANG ; Guojiang CHEN ; Chunxia QIAO ; Xinying LI ; Beifen SHEN ; Jiannan FENG ; Lihui CHAI ; He XIAO
Chinese Journal of Microbiology and Immunology 2024;44(1):44-49
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.
2.Establishment and evaluation of a neutralizing antibody detection model for West Nile virus pseudovirus
Wanlu ZHU ; Nan CHEN ; Xiangjun HAO ; Junjuan FENG ; Xing LU ; Jing WANG ; Guojiang CHEN ; Chunxia QIAO ; Xinying LI ; Chenghua LIU ; Beifen SHEN ; Jiannan FENG ; Jun ZHANG ; He XIAO
Chinese Journal of Experimental and Clinical Virology 2024;38(2):188-192
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.
3.Effect of laparoscopic fundoplication for proton pump inhibitor dependent gastroesophageal reflux disease: a 10-year follow-up report of 160 cases in a single center
Zhiwei HU ; Jimin WU ; Meng LI ; Jiannan LIU ; Changrong DENG ; Xiulan ZHAN ; Tao JI ; Feng WANG ; Shurui TIAN ; Yu ZHANG ; Dong CHEN
Chinese Journal of General Surgery 2024;39(6):423-429
Objective:To explore the long-term efficacy of laparoscopic fundoplication for proton pump inhibitor dependent gastroesophageal reflux disease (GERD).Method:Clinical data of proton pump inhibitor dependent GERD patients who underwent fundoplication at the Rocket Force Characteristic Medical Center from Jan to Jun 2012 were analyzed, including GERD symptom score, subjective symptom relief rate, PPI discontinuation rate and surgical satisfaction, as well as recurrence and complications.Result:A total of 160 GERD patients were included in this study, with 64% of patients having respiratory symptoms. Nissen and Toupet fundoplication were performed in 43 and 117 cases, respectively, with a follow-up time of (127±3) months. The postoperative GERD symptom scores of the patients were significantly lower than before treatment (all P<0.001); The subjective relief of overall symptoms in the digestive tract and airway problem was 90% (80%, 100%) and 100%, respectively. The PPI discontinuation rate was 86%, and the overall satisfaction rate of the treatment was 92%, and the satisfaction rate of patients with respiratory symptoms was 89%. 7% of patients experienced varying degrees of symptomatic recurrence, 4% of patients re-underwent endoscopic treatment and/or laparoscopic fundoplication due to symptom recurrence. The incidence of long-term postoperative dysphagia, bloating, belching, increased exhaust, abdominal pain, diarrhea, and constipation were 11.3%, 16.9%, 0, 1.3%, 0, 2.5%, and 5.6%, respectively. Conclusions:Laparoscopic fundoplication has good long-term efficacy in the treatment of GERD. A small number of patients may experience postoperative recurrence, as well as complications such as dysphagia and gas-bloat syndrome. Most recurrent patients can achieve good therapeutic effect by redoing endoscopic treatment or redoing surgery.
4.The association of cholesterol crystals and non-culprit plaque characteristics in AMI patients: an OCT study
Jiawei ZHAO ; Rui ZHAO ; Chao FANG ; Yuzhu CHEN ; Xueming XU ; Lina CUI ; Xianqin MA ; Jingbo HOU ; Jiannan DAI ; Bo YU
Chinese Journal of Cardiology 2024;52(6):659-666
Objective:To analyze plaque characteristics of non-culprit coronary lesions with cholesterol crystals in patients with acute myocardial infarction(AMI) by using optical coherence tomography(OCT). We also investigated the potential association between cholesterol crystals with plaque rupture and healed plaque at non-culprit segment.Methods:This study was a retrospective cohort study. Between January 2017 and December 2017, patients with AMI who underwent 3-vessel OCT imaging were included in this study. Patients were divided into two groups according to the presence or absence of cholesterol crystals at the non-culprit lesions. All patients underwent coronary angiography and OCT examination, and non-culprit plaque characteristics were compared between the two groups. The generalized estimating equation log-binomial multirariate regression model was used to assess the relationship between non-culprit lesions with cholesterol crystals and plaque rupture and plaque healing. The follow-up data collection ended in October 2023. Kaplan-Meier survival curves were plotted, and log-rank tests were used to compare the cumulative incidence of major adverse cardiovascular events between the two groups.Results:A total of 173 AMI patients were included (aged (56.8±11.6) years; 124 men (71.7%)). Among 710 non-culprit lesions identified by OCT, there were 102 (14.4%) in cholesterol crystals group and 608 (85.6%) in non-cholesterol crystals group. Compared with non-culprit lesions without cholesterol crystals, those with cholesterol crystals had smaller minimum lumen diameter, severer diameter stenosis, and longer lesion length (all P<0.01). The prevalence of plaque rupture (17.6% (18/102) vs. 4.9% (30/608), P=0.001) and thin-cap fibroatheroma (31.4% (32/102) vs. 11.5% (70/608), P<0.01) was higher in the cholesterol crystals groups than in the non-cholesterol crystals group. In addition, vulnerable plaque characteristics such as (44.1% (45/102) vs. 25.8% (157/608), P<0.01), macrophages were more frequently observed in non-culprit lesions with cholesterol crystals. The generalized estimating equation log-binomial multivariate regression analyses showed that non-culprit cholesterol crystals were positively correlated with healed plaque ( OR=1.583, 95% CI: 1.004-2.495, P=0.048). Conversely, cholesterol crystals were not associated with plaque rupture ( OR=1.632, 95% CI: 0.745-3.576, P=0.221). The follow-up time was 2 142 (1 880, 2 198) days. Non-culprit cholesterol crystals were not related to the major adverse cardiovascular events in patients with AMI (log-rank P=0.558). Conclusions:Among AMI patients, non-culprit lesions with cholesterol crystals presented with severer luminal stenosis and increased plaque vulnerability. The presence of non-culprit cholesterol crystals was associated with rather than plaque rupture.
5.Artemisinins inhibit oral candidiasis caused by Candida albicans through the repression on its hyphal development.
Xiaoyue LIANG ; Ding CHEN ; Jiannan WANG ; Binyou LIAO ; Jiawei SHEN ; Xingchen YE ; Zheng WANG ; Chengguang ZHU ; Lichen GOU ; Xinxuan ZHOU ; Lei CHENG ; Biao REN ; Xuedong ZHOU
International Journal of Oral Science 2023;15(1):40-40
Candida albicans is the most abundant fungal species in oral cavity. As a smart opportunistic pathogen, it increases the virulence by switching its forms from yeasts to hyphae and becomes the major pathogenic agent for oral candidiasis. However, the overuse of current clinical antifungals and lack of new types of drugs highlight the challenges in the antifungal treatments because of the drug resistance and side effects. Anti-virulence strategy is proved as a practical way to develop new types of anti-infective drugs. Here, seven artemisinins, including artemisinin, dihydroartemisinin, artemisinic acid, dihydroartemisinic acid, artesunate, artemether and arteether, were employed to target at the hyphal development, the most important virulence factor of C. albicans. Artemisinins failed to affect the growth, but significantly inhibited the hyphal development of C. albicans, including the clinical azole resistant isolates, and reduced their damage to oral epithelial cells, while arteether showed the strongest activities. The transcriptome suggested that arteether could affect the energy metabolism of C. albicans. Seven artemisinins were then proved to significantly inhibit the productions of ATP and cAMP, while reduced the hyphal inhibition on RAS1 overexpression strain indicating that artemisinins regulated the Ras1-cAMP-Efg1 pathway to inhibit the hyphal development. Importantly, arteether significantly inhibited the fungal burden and infections with no systemic toxicity in the murine oropharyngeal candidiasis models in vivo caused by both fluconazole sensitive and resistant strains. Our results for the first time indicated that artemisinins can be potential antifungal compounds against C. albicans infections by targeting at its hyphal development.
Animals
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Mice
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Candida albicans
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Candidiasis, Oral/drug therapy*
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Antifungal Agents/pharmacology*
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Hyphae
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Artemisinins/pharmacology*
6.Establishment of an in vivo neutralization model based on H5N1 pseudovirus
Nan CHEN ; Xiangjun HAO ; Jing WANG ; Guojiang CHEN ; Chunxia QIAO ; Xinying LI ; Beifen SHEN ; Jiannan FENG ; Lihui CHAI ; He XIAO
Chinese Journal of Microbiology and Immunology 2023;43(6):458-463
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.
7.Clinical and epidemiological analysis of 18 cases of Japanese spotted fever in Zigui County
Ping GONG ; Xin CHEN ; Junlin LU ; Haixia SHI ; Youxiang KOU ; Changzhen WANG ; Faming GONG ; Xuefen QIN ; Jiannan ZHOU ; Xuebing LIN
Chinese Journal of Laboratory Medicine 2023;46(2):150-154
Objective:The epidemiological and clinical characteristics of 18 cases of Japanese spotted fever (JSF) in Zigui County were analyzed in order to improve the prevention and treatment of JSF.Methods:This is a case series analysis. The epidemiological and clinical data, laboratory tests and imaging characteristics of 18 JSF cases with median age of 60 years (54, 68) identified by The People′s Hospital of Zigui from April 2021 to August 2022 were collected and analyzed retrospectively.Results:Most (17/18) of the patients were farmers and all had a field exposure history. The patient′s onset was from April to October. Spring and autumn were the seasons with the highest incidence of JSF. The first symptoms of patients were high fever, headache, and fatigue. Of the 18 cases, 15 had a rash and 12 presented an eschar and 3 had neither rash nor eschar. In addition, 10 of 18 cases experienced edema of both lower extremities, and 3 got disturbance of consciousness. Laboratory tests found that 15 patients had abnormal white blood cells and 11 patients had decreased platelets. C-reactive protein, procalcitonin, D-dimer, lactate dehydrogenase, and alpha-hydroxybutyrate dehydrogenase were elevated in all patients; 13 patients with elevated alanine aminotransferase, 14 patients with elevated aspartate transamination. Kidney damage caused by Rickettsia japonica infection showed by abnormal proteinuria in 11 of the patients. Conclusions:The most common clinical manifestations of JSF are non-specific indications such as high fever, chills, fatigue, headache. The eschar and rash, which are the main features of Rickettsia infection, are not present in all patients, resulting delay of diagnosis or misdiagnosis. Medical workers should be more alert to rickettsial infections in patients with fever of unknown origin, especially in seasons of high incidence of spotted fever. Early diagnosis and correct antibiotic treatment shall be given according to the patient′s clinical manifestations, laboratory results and imaging test to control disease progression.
8.Clinical, pathological and genetic characteristics of 8 patients with Emery-Dreifuss muscular dystrophy
Zhe ZHAO ; Xuan GUO ; Hongrui SHEN ; Qi BING ; Jiannan CHEN ; Shanshan WEI ; Shi XIE ; Jing HU
Chinese Journal of Neurology 2023;56(12):1333-1340
Objective:To summarize the clinical manifestations, electrophysiological, muscle magnetic resonance imaging (MRI), pathological, and genetic characteristics of 8 patients with Emery-Dreifuss muscular dystrophy (EDMD) to improve the recognition and diagnosis of EDMD.Methods:Eight patients with EDMD confirmed by gene analysis admitted to Hebei Medical University Third Hospital from 2011 to 2022 were enrolled. The detailed clinical symptoms, neurophysiological examination, electrophysiological changes (electromyography and electrocardiography), skeletal muscle MRI characters, skeletal muscle pathological features and gene mutations were analyzed retrospectively.Results:The age of onset ranged from 2.0 to 6.0 (3.6±1.2) years. All patients had insidious onset and progressive development. Muscle weakness was the first symptom for 7 cases that manifested as difficulty in squatting and walking up stairs. Later, spinal ankylosis and joint contracture occurred. One patient had scoliosis as the first symptoms. Abnormal electrocardiogram was found in 4 cases. The electromyography of all patients showed myogenic damage. Muscle biopsy demonstrated dystrophic features in 1 patient, and other myopathic features, including a variation in muscle fiber size, a marked increase in internal nuclei, and, smaller diameter of typeⅠfibers. Next-generation sequencing result showed that 6/8 cases carried 4 LMNA heterozygous mutations (c.1583C>G, c.1357C>T, c.148C>T, c.1336A>G); 1/8 case carried EMD hemizygous mutation (c.501C>G); 1/8 carried SYNE1 heterozygous mutation (c.4364G>A). Conclusions:EDMD has highly clinical and genetical heterogeneity. The onset age is usually in childhood. The first symptom is characterized by weakness of lower limbs and abnormal walking posture. Electromyography shows myogenic lesion. Skeletal muscle MRI shows selective fat infiltrations. Muscle biopsy pathology lacks characteristic pathological findings. It is difficult to make diagnosis and differential diagnosis by clinical manifestations and auxiliary examination in the early stage of the disease. The second generation sequencing technology can improve the early diagnosis rate of EDMD.
9.Preparation and identification of a broad-spectrum antibody targeting hemagglutinin protein of influenza A virus
Nan CHEN ; Lihui CHAI ; Guojiang CHEN ; Jing WANG ; Chunxia QIAO ; Xinying LI ; Chenghua LIU ; Beifen SHEN ; Jiannan FENG ; He XIAO
Chinese Journal of Microbiology and Immunology 2022;42(8):636-641
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.
10.Preparation and identification of antibodies targeting influenza A virus N1 subtype neuraminidase
Nan CHEN ; Lihui CHAI ; Guojiang CHEN ; Jing WANG ; Chunxia QIAO ; Xinying LI ; Chenghua LIU ; Beifen SHEN ; Jiannan FENG ; He XIAO
Chinese Journal of Microbiology and Immunology 2022;42(11):851-856
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.

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