1.Isorhamnetin alleviates pathological damage in influenza A virus strain PR8-induced pneumonia by activating the Nrf2/HO-1 pathway and suppressing apoptosis
Yingli XU ; Shuran LI ; Ronghua ZHAO ; Lei BAO ; Zihan GENG ; Qiyue SUN ; Bo PANG ; Xiaolan CUI ; Shanshan GUO ; Jing SUN
Science of Traditional Chinese Medicine 2025;3(1):28-39
Background: Influenza A viruses (IAVs) are the major pathogens associated with respiratory infections which can result in extensive pathological damage in lungs and serious complications. Isorhamnetin, an abundant natural flavonoid in fruits and medicinal plants, has recently been shown to have strong antioxidative, anti-inflammatory, and antiviral effects. Objective: This study investigated the pharmacological effects of isorhamnetin on viral pneumonia and explored the underlying mechanisms by in vivo and in vitro experiments. Materials and methods: In the present study, the protective effect of isorhamnetin against IAV was evaluated by the cytopathogenic effect assay, cell counting kit-8 assay, real-time polymerase chain reaction, and immunofluorescence assay in vitro. Then the pathological damage associated with pneumonia was examined by calculating the pulmonary index and performing micro-CT and hematoxylin-eosin staining in vivo. Thereafter, the related protein or gene levels of factors in the mitogen-activated protein kinase (MAPK) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathways were determined by Western blot and immunofluorescence staining. Results: Isorhamnetin exerted significant anti-influenza effects and inhibited the expression of viral RNA in A549 cells, counteracting oxidative stress and apoptosis by suppressing the production of reactive oxygen species and caspase-3. The in vivo experiment results showed that isorhamnetin (20 and 40 mg/kg) caused a significant decrease in the pulmonary index, ameliorated pathological damage in the lung tissue, decreased viral load and NA activity, and reduced cytokines and nuclear factors. Furthermore, isorhamnetin could counteract the B cell lymphoma-2/B cell lymphoma-2–associated X protein (Bax) imbalance induced by PR8, suppress activation of the MAPK pathway, and upregulate the expression of Nrf2 and HO-1. Conclusions: Isorhamnetin can protect against viral pneumonia by activating the Nrf2/HO-1 pathway and suppressing the MAPK path-way. This study deciphers the pharmacological mechanism of isorhamnetin in alleviating pathological damage in viral pneumonia and provides rationale for the application of isorhamnetin in influenza treatment.
2.Isorhamnetin alleviates pathological damage in influenza A virus strain PR8-induced pneumonia by activating the Nrf2/HO-1 pathway and suppressing apoptosis
Yingli XU ; Shuran LI ; Ronghua ZHAO ; Lei BAO ; Zihan GENG ; Qiyue SUN ; Bo PANG ; Xiaolan CUI ; Shanshan GUO ; Jing SUN
Science of Traditional Chinese Medicine 2025;3(1):28-39
Background: Influenza A viruses (IAVs) are the major pathogens associated with respiratory infections which can result in extensive pathological damage in lungs and serious complications. Isorhamnetin, an abundant natural flavonoid in fruits and medicinal plants, has recently been shown to have strong antioxidative, anti-inflammatory, and antiviral effects. Objective: This study investigated the pharmacological effects of isorhamnetin on viral pneumonia and explored the underlying mechanisms by in vivo and in vitro experiments. Materials and methods: In the present study, the protective effect of isorhamnetin against IAV was evaluated by the cytopathogenic effect assay, cell counting kit-8 assay, real-time polymerase chain reaction, and immunofluorescence assay in vitro. Then the pathological damage associated with pneumonia was examined by calculating the pulmonary index and performing micro-CT and hematoxylin-eosin staining in vivo. Thereafter, the related protein or gene levels of factors in the mitogen-activated protein kinase (MAPK) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathways were determined by Western blot and immunofluorescence staining. Results: Isorhamnetin exerted significant anti-influenza effects and inhibited the expression of viral RNA in A549 cells, counteracting oxidative stress and apoptosis by suppressing the production of reactive oxygen species and caspase-3. The in vivo experiment results showed that isorhamnetin (20 and 40 mg/kg) caused a significant decrease in the pulmonary index, ameliorated pathological damage in the lung tissue, decreased viral load and NA activity, and reduced cytokines and nuclear factors. Furthermore, isorhamnetin could counteract the B cell lymphoma-2/B cell lymphoma-2–associated X protein (Bax) imbalance induced by PR8, suppress activation of the MAPK pathway, and upregulate the expression of Nrf2 and HO-1. Conclusions: Isorhamnetin can protect against viral pneumonia by activating the Nrf2/HO-1 pathway and suppressing the MAPK path-way. This study deciphers the pharmacological mechanism of isorhamnetin in alleviating pathological damage in viral pneumonia and provides rationale for the application of isorhamnetin in influenza treatment.
3.Isorhamnetin alleviates pathological damage in influenza A virus strain PR8-induced pneumonia by activating the Nrf2/HO-1 pathway and suppressing apoptosis
Yingli XU ; Shuran LI ; Ronghua ZHAO ; Lei BAO ; Zihan GENG ; Qiyue SUN ; Bo PANG ; Xiaolan CUI ; Shanshan GUO ; Jing SUN
Science of Traditional Chinese Medicine 2025;3(1):28-39
Background: Influenza A viruses (IAVs) are the major pathogens associated with respiratory infections which can result in extensive pathological damage in lungs and serious complications. Isorhamnetin, an abundant natural flavonoid in fruits and medicinal plants, has recently been shown to have strong antioxidative, anti-inflammatory, and antiviral effects. Objective: This study investigated the pharmacological effects of isorhamnetin on viral pneumonia and explored the underlying mechanisms by in vivo and in vitro experiments. Materials and methods: In the present study, the protective effect of isorhamnetin against IAV was evaluated by the cytopathogenic effect assay, cell counting kit-8 assay, real-time polymerase chain reaction, and immunofluorescence assay in vitro. Then the pathological damage associated with pneumonia was examined by calculating the pulmonary index and performing micro-CT and hematoxylin-eosin staining in vivo. Thereafter, the related protein or gene levels of factors in the mitogen-activated protein kinase (MAPK) and nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathways were determined by Western blot and immunofluorescence staining. Results: Isorhamnetin exerted significant anti-influenza effects and inhibited the expression of viral RNA in A549 cells, counteracting oxidative stress and apoptosis by suppressing the production of reactive oxygen species and caspase-3. The in vivo experiment results showed that isorhamnetin (20 and 40 mg/kg) caused a significant decrease in the pulmonary index, ameliorated pathological damage in the lung tissue, decreased viral load and NA activity, and reduced cytokines and nuclear factors. Furthermore, isorhamnetin could counteract the B cell lymphoma-2/B cell lymphoma-2–associated X protein (Bax) imbalance induced by PR8, suppress activation of the MAPK pathway, and upregulate the expression of Nrf2 and HO-1. Conclusions: Isorhamnetin can protect against viral pneumonia by activating the Nrf2/HO-1 pathway and suppressing the MAPK path-way. This study deciphers the pharmacological mechanism of isorhamnetin in alleviating pathological damage in viral pneumonia and provides rationale for the application of isorhamnetin in influenza treatment.
4.Pharmacological effects and mechanisms of Xuanfei Baidu Decoction in the treatment of viral pneumonia
Jingsheng ZHANG ; Bo PANG ; Qiyue SUN ; Jing SUN ; Shan CAO ; Yingli XU ; Yu ZHANG ; Xinqi DENG ; Shanshan GUO ; Lei BAO ; Zihan GENG ; Shuran LI ; Ronghua ZHAO ; Daohan WANG ; Xiaolan CUI ; Bin QU ; Yu WANG
Science of Traditional Chinese Medicine 2025;3(2):145-157
Objective: This study aims to investigate the therapeutic effects and underlying mechanisms of Xuanfei Baidu Decoction (XFBD) in a mouse model of dampness-heat toxin pneumonia. By exploring how XFBD exerts its effects, we seek to deepen our understanding of its role in treating pulmonary diseases and to address the current knowledge gap regarding its mechanisms of action, thereby supporting its clinical application. Methods: Ultra-high-performance liquid chromatography and high-resolution mass spectrometry (HRMS) were employed to analyze the chemical constituents of XFBD. The protective effects of XFBD were evaluated using a dampness-heat toxin-induced mouse model, established through dampness-heat exposure and HCoV-229E infection. XFBD was administered orally, followed by assessments including lung index measurement, micro-CT imaging, viral load quantification, cytokine analysis, and histological evaluation via hematoxylin-eosin staining. Proteomics and single-cell transcriptomic analyses were conducted to explore the potential mechanisms underlying XFBD’s pharmacological effects. A cellular model of HCoV-229E infection was developed to investigate changes in the cAMP/PKA signaling pathway. Molecular docking and surface plasmon resonance (SPR) experiments confirmed the strong binding affinity between key XFBD components and PKA. Finally, PKA activators and inhibitors were applied in vitro to validate these mechanistic findings. Results: In vivo studies demonstrated that XFBD significantly reduced the lung index, improved the structural integrity of lung and tongue tissues, and decreased levels of proinflammatory mediators, including IL-6, IL-8, and TNF-α. Proteomic and single-cell transcriptomic analyses showed that the differentially expressed proteins after XFBD treatment were primarily associated with inflammatory responses and immune regulation. The cAMP/PKA signaling pathway was identified as a key mechanism underlying these therapeutic effects. Notably, Western blot, ELISA, molecular docking, and SPR analyses confirmed that XFBD elevated cAMP levels and p-PKA expression, thereby activating the cAMP/PKA signaling pathway in vitro. Conclusion: This study demonstrated that XFBD significantly alleviates symptoms in mice with dampness-heat toxin pneumonia. Its therapeutic effects are mediated, at least in part, through activation of the cAMP/PKA signaling pathway. These findings provide compelling evidence that XFBD is an effective herbal remedy against HCoV-229E infection.
5.Discovery of a potential hematologic malignancies therapy: Selective and potent HDAC7 PROTAC degrader targeting non-enzymatic function.
Yuheng JIN ; Xuxin QI ; Xiaoli YU ; Xirui CHENG ; Boya CHEN ; Mingfei WU ; Jingyu ZHANG ; Hao YIN ; Yang LU ; Yihui ZHOU ; Ao PANG ; Yushen LIN ; Li JIANG ; Qiuqiu SHI ; Shuangshuang GENG ; Yubo ZHOU ; Xiaojun YAO ; Linjie LI ; Haiting DUAN ; Jinxin CHE ; Ji CAO ; Qiaojun HE ; Xiaowu DONG
Acta Pharmaceutica Sinica B 2025;15(3):1659-1679
HDAC7, a member of class IIa HDACs, plays a pivotal regulatory role in tumor, immune, fibrosis, and angiogenesis, rendering it a potential therapeutic target. Nevertheless, due to the high similarity in the enzyme active sites of class IIa HDACs, inhibitors encounter challenges in discerning differences among them. Furthermore, the substitution of key residue in the active pocket of class IIa HDACs renders them pseudo-enzymes, leading to a limited impact of enzymatic inhibitors on their function. In this study, proteolysis targeting chimera (PROTAC) technology was employed to develop HDAC7 drugs. We developed an exceedingly selective HDAC7 PROTAC degrader B14 which showcased superior inhibitory effects on cell proliferation compared to TMP269 in various diffuse large B cell lymphoma (DLBCL) and acute myeloid leukemia (AML) cells. Subsequent investigations unveiled that B14 disrupts BCL6 forming a transcriptional inhibition complex by degrading HDAC7, thereby exerting proliferative inhibition in DLBCL. Our study broadened the understanding of the non-enzymatic functions of HDAC7 and underscored the importance of HDAC7 in the treatment of hematologic malignancies, particularly in DLBCL and AML.
6.Effect of hydrogen on lipopolysaccharide and nigericin-induced pyroptosis in macrophages and the role of lncRNA NEAT1
Tao YANG ; Man LI ; Ling DING ; Shenyue PANG ; Lei WANG ; Licheng GENG ; Jiangang XU
Chinese Journal of Anesthesiology 2024;44(2):232-237
Objective:To evaluate the effect of hydrogen on lipopolysaccharide (LPS) and nigericin-induced pyroptosis in macrophages and the role of long non-coding RNA (lncRNA) nuclear-enriched abundant transcript 1 (NEAT1).Methods:Human monocyte-derived macrophages THP-1 cells were cultured in vitro and divided into 4 groups ( n=25 each) using a random number table method: control group (group C), LPS and nigericin group (group LN), hydrogen-rich medium+ LPS and nigericin group (group H+ LN), and lentiviral transfection+ hydrogen-rich medium+ LPS-nigericin group (group LV+ H+ LN). THP-1 cells were cultured in the common culture medium for 24 h in group C. LPS at a final concentration of 100 ng/ml and nigericin 10 μmol/L were added to the culture medium, and the cells were incubated for 24 h in group LN. In group H+ LN, the culture medium was replaced with 0.6 mmol/L hydrogen-rich medium, then LPS at a final concentration of 100 ng/ml and nigericin 10 μmol/L were immediately added, and the cells were incubated for 24 h. In group LV+ H+ LN, THP-1 cells over-expressing NEAT1 stably after being transfected with lentivirus were used, then LPS at a final concentration of 100 ng/ml and nigericin 10 μmol/L were immediately added, and the cells were incubated for 24 h. Cell viability was detected by CCK-8 assay. Lactic dehydrogenase (LDH) release was assessed by colorimetric method. The amount of LDH released was measured by colorimetry. The concentrations of interleukin-1beta (IL-1β) and IL-18 in culture medium were measured by enzyme-linked immunosorbent assay. The pyroptotic rate was detected by flow cytometry. The expression of nucleotide-binding oligomerization domain-like receptor-containing pyrin domain 3 (NLRP3), apoptosis-associated speck-like protein (ASC), caspase-1 and gasdermin D (GSDMD) was detected by Western blot. The expression of NEAT1 gene was determined by quantitative real-time polymerase chain reaction. Results:Compared with group C, the cell viability was significantly decreased, the amount of LDH released, concentrations of IL-1β and IL-18, and pyroptotic rate were increased, and the expression of NEAT1 gene, NLRP3, ASC, caspase-1 and GSDMD was up-regulated in group LN ( P<0.05). Compared with group LN, the cell viability was significantly increased, the amount of LDH released, concentrations of IL-1β and IL-18, and pyroptotic rate were decreased, and the expression of NEAT1 gene, NLRP3, ASC, caspase-1 and GSDMD was down-regulated in group H+ LN ( P<0.05). Compared with group H+ LN, the cell viability was significantly decreased, the amount of LDH released, concentrations of IL-1β and IL-18, and pyroptotic rate were increased, and the expression of NEAT1 gene, NLRP3, ASC, caspase-1 and GSDMD was up-regulated in group LV+ H+ LN ( P<0.05). Conclusions:Hydrogen can ameliorate LPS and nigericin-induced pyroptosis in macrophages, and the mechanism may be associated with down-regulating the expression of lncRNA NEAT1.
7.Effect of Influenza A Virus on BEAS-2B in Human Lung Epithelial Cells and Intervention Effect of Shufeng Jiedu Capsule-containing Serum
Shan CAO ; Zihan GENG ; Lei BAO ; Yingli XU ; Bo PANG ; Jingsheng ZHANG ; Yu ZHANG ; Mengping CHEN ; Yaxin WANG ; Ronghua ZHAO ; Shanshan GUO ; Xiaolan CUI
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(23):90-97
ObjectiveTo observe the effect of Shufeng Jiedu capsule (SFJD)-containing serum on human lung epithelial cells infected by influenza A virus, and investigate the protective effect of the drug on the cells and the potential antiviral effect. MethodThe SFJD-containing serum was prepared and used to treat human lung epithelial cells (BEAS-2B) cultured in vitro. The viability of cells treated with different concentrations of SFJD-containing serum was measured by the cell counting kit-8 (CCK-8), and the optimal concentration of SFJD-containing serum was screened for subsequent experiments. BEAS-2B cells were classified into normal control, virus infection, and SFJD-containing serum groups, and the CCK-8 method was used to detect the survival rate of BEAS-2B cells after virus infection and drug administration. The expression of influenza virus nucleic acid in the cells of each group was determined, and the apoptosis of cells in different groups was observed by fluorescence microscopy. Real-time PCR was employed to determine the mRNA levels of influenza virus nucleoprotein (NP), Toll-like receptor 4 (TLR4), and myeloid differentiation primary response gene 88 (MyD88) in each group of cells. The immunofluorescence assay was used to detect the fluorescence intensities of TLR4, MyD88, and phosphorylated nuclear factor-κB (p-NF-κB) in lung epithelial cells. ResultCompared with that in the control group (normal serum), the cell survival rates in the blank serum and the SFJD-containing serum (5%, 10%, and 20%) groups were 100.00%±0.00%, 89.05%±4.80%, 87.13%±5.90%, 93.83%±6.03%, and 99.33%±3.39%, respectively (P<0.01). The SFJD-containing serum of 20% was selected as the optimal treatment for subsequent experiments. Compared with the normal control group, the virus infection group showed reduced cell survival rate (P<0.01), and the reduction was increased by the SFJD-containing serum (P<0.01). Compared with the virus infection group, SFJD-containing serum reduced the virus load (P<0.01) to decrease apoptosis. Compared with the normal control group, the virus infection group showed up-regulated mRNA levels of NP, TLR4, and MyD88 (P<0.01), and the up-regulation was down-regulated by the SFJD-containing serum (P<0.05, P<0.01). The fluorescence intensities of TLR4, MyD88, and p-NF-κB proteins in the cells increased after virus infection compared with those in the normal control (P<0.05, P<0.01), and they were decreased after administration with the SFJD-containing serum (P<0.05). ConclusionThe SFJD-containing serum can inhibit influenza virus in vitro by increasing the survival rate, reducing the apoptosis, and down-regulating the protein levels of TLR4, MyD88, and p-NF-κB in BEAS-2B cells.
8.Efficacy and Mechanism of Lutongning Granules in Treatment of Trigeminal Neuralgia Induced by Injection of Talc into Infraorbital Foramen of Model Rats Based on P2X7R-mediated Neuroinflammation
Qiyue SUN ; Shuran LI ; Shuangrong GAO ; Shanshan GUO ; Zihan GENG ; Lei BAO ; Ronghua ZHAO ; Jingsheng ZHANG ; Bo PANG ; Yingli XU ; Yu ZHANG ; Shan CAO ; Yaxin WANG ; Xiaolan CUI ; Bing HAN ; Jing SUN
Chinese Journal of Experimental Traditional Medical Formulae 2024;30(15):56-63
ObjectiveTo evaluate the effectiveness of Lutongning granules in the treatment of trigeminal neuralgia in animal models and study its mechanism of action, so as to provide laboratory data support for the clinical application of Lutongning granules and precise treatment. MethodMale SD rats were randomly divided into normal group, model group, carbamazepine group (0.06 g·kg-1·d-1), high-dose Lutongning group (2.70 g·kg-1·d-1), and low-dose Lutongning group (1.35 g·kg-1·d-1) according to the stratified basic mechanical pain thresholds, with 10 rats in each group. A trigeminal neuralgia model of rats was prepared by injecting 30% talc suspension into the infraorbital foramen area of the rat. The drug groups were administered 10 mL·kg-1 of drugs by gavage after 2 h of modeling. The normal group and the model group were administered distilled water by gavage under the same conditions once a day for 10 consecutive days. Von Frey brushes were used to determine the mechanical pain threshold of rats. A fully automated blood and body fluid analyzer was employed to detect the blood routine of rats. Hematoxylin and eosin (HE) staining was utilized to detect the pathological changes in the trigeminal ganglion and medulla oblongata tissue. Transmission electron microscopy was used to scan the ultrastructure of the medulla oblongata tissue. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors interleukin (IL)-1, IL-6, IL-8, tumor necrosis factor (TNF)-α, neuropeptide substance P, and β-endorphins (β-EP) in the serum of rats, and Western blot was used to detect the protein expression levels of IL-1β, purinergic receptor P2X7 (P2X7R), and phosphorylated p38 mitogen-activated protein kinase (p-p38 MAPK). ResultCompared with that in the normal group, the pain threshold of rats in the model group was significantly lower (P<0.01). The absolute value of neutrophils (NEUT#) and the percentage of neutrophils (NEUT) were significantly improved, and the percentage of lymphocytes (LYMPH) was significantly reduced (P<0.01). The serum levels of IL-1, IL-6, IL-8, and TNF-α were significantly increased (P<0.01). SP content in brain tissue was significantly increased, and β-EP content was significantly decreased (P<0.01). The relative protein expression of IL-1β, P2X7R, and p-p38 MAPK was significantly increased (P<0.05). HE staining and transmission electron microscopy results of medulla oblongata tissue revealed neuronal degeneration, mild proliferation of microglial cells, reduction in the number of myelinated nerves, and obvious demyelination. The trigeminal nerve fibers of rats were disarranged, and some nerve fibers showed vacuolization. Axons were swollen, and Schwann cells proliferated. Demyelination was observed. Compared with the model group, each administration group significantly increased the pain threshold of rats (P<0.05, P<0.01), reduced NEUT# and NEUT, and elevated LYMPH (P<0.05, P<0.01). The administration group significantly decreased the levels of IL-1, IL-6, IL-8, and TNF-α in serum and SP in brain tissue (P<0.01) and increased the level of β-EP (P<0.01). They significantly down-regulated the protein expression of IL-1β, P2X7R, and p-p38 MAPK(P<0.05, P<0.01) and significantly ameliorated the pathological changes in medulla oblongata tissue and trigeminal nerves of rats. ConclusionLutongning Granules had significant therapeutic effects on trigeminal neuralgia induced by injection of talc into the infraorbital foramen of model rats, and the mechanism may be related to amelioration of P2X7R-mediated neuroinflammation and inhibition of demyelination of myelinated nerves.
9.High density fermentation and immune evaluation of porcine circovirus type 3 Cap protein
Kele LI ; Jinglong XU ; Xiaolin GENG ; Zhifei WANG ; Yanyu LIANG ; Xiaolin MO ; Yuxin HUANG ; Wenqiang PANG ; Kegong TIAN
Chinese Journal of Veterinary Science 2024;44(12):2507-2513
In order to achieve high-efficiency expression of the porcine circovirus type 3 Cap protein in recombinant Escherichia coli,dissolved oxygen(DO)control strategy,oxygen uptake rate(OUR)control strategy and combined control strategy of DO and OUR were selected to investi-gate their effect on the expression of target protein in a 10 L fermenter.The high-density fermenta-tion process of recombinant E.coli was determined by investigating the best control range of OUR.The recombinant protein was identified by SDS-PAGE and Western blot,and the immunoge-nicity of the protein was evaluated by the animal experiment.The results showed that when the DO control strategy and OUR control strategy were used,the expression of target protein was low.Acetic acid was the key factor affecting the expression of target protein.When acetic acid concen-tration reached 1.02 g/L,Cap protein yield was reduced by 55.8%.In order to reduce the produc-tion of acetic acid,DO was selected to control oxygen supply before feeding,and OUR was selected as the parameter to control oxygen supply after feeding.When OUR value was maintained at 140-160 mmol/(L·h),the Cap protein yield was up to 650 mg/L.Western blot analysis confirmed that PCV3 Cap possessed antigenicity and specificity.Animal experiment showed that the antibody pos-itive rate was 100%after the second immunization,indicating that the target protein had better immunogenicity.The high density fermentation controlled by the combined control strategy of DO and OUR could achieve efficiently soluble expression of PCV3 Cap in the fermenter,which laid the foundation for the vaccine development.
10.High density fermentation and immune evaluation of porcine circovirus type 3 Cap protein
Kele LI ; Jinglong XU ; Xiaolin GENG ; Zhifei WANG ; Yanyu LIANG ; Xiaolin MO ; Yuxin HUANG ; Wenqiang PANG ; Kegong TIAN
Chinese Journal of Veterinary Science 2024;44(12):2507-2513
In order to achieve high-efficiency expression of the porcine circovirus type 3 Cap protein in recombinant Escherichia coli,dissolved oxygen(DO)control strategy,oxygen uptake rate(OUR)control strategy and combined control strategy of DO and OUR were selected to investi-gate their effect on the expression of target protein in a 10 L fermenter.The high-density fermenta-tion process of recombinant E.coli was determined by investigating the best control range of OUR.The recombinant protein was identified by SDS-PAGE and Western blot,and the immunoge-nicity of the protein was evaluated by the animal experiment.The results showed that when the DO control strategy and OUR control strategy were used,the expression of target protein was low.Acetic acid was the key factor affecting the expression of target protein.When acetic acid concen-tration reached 1.02 g/L,Cap protein yield was reduced by 55.8%.In order to reduce the produc-tion of acetic acid,DO was selected to control oxygen supply before feeding,and OUR was selected as the parameter to control oxygen supply after feeding.When OUR value was maintained at 140-160 mmol/(L·h),the Cap protein yield was up to 650 mg/L.Western blot analysis confirmed that PCV3 Cap possessed antigenicity and specificity.Animal experiment showed that the antibody pos-itive rate was 100%after the second immunization,indicating that the target protein had better immunogenicity.The high density fermentation controlled by the combined control strategy of DO and OUR could achieve efficiently soluble expression of PCV3 Cap in the fermenter,which laid the foundation for the vaccine development.

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