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Shi J, Li Q, Li J, Zhou J, Zhang X, Wang S, Guo L. Single-Cell RNA Sequencing Reveals the Spatial Heterogeneity and Functional Alteration of Endothelial Cells in Chronic Hepatitis B Infection. Int J Mol Sci 2024; 25:7016. [PMID: 39000126 PMCID: PMC11241719 DOI: 10.3390/ijms25137016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2024] [Revised: 06/24/2024] [Accepted: 06/24/2024] [Indexed: 07/16/2024] Open
Abstract
Chronic Hepatitis B virus (CHB) infection is a global health challenge, causing damage ranging from hepatitis to cirrhosis and hepatocellular carcinoma. In our study, single-cell RNA sequencing (scRNA-seq) analysis was performed in livers from mice models with chronic inflammation induced by CHB infection and we found that endothelial cells (ECs) exhibited the largest number of differentially expressed genes (DEGs) among all ten cell types. NF-κB signaling was activated in ECs to induce cell dysfunction and subsequent hepatic inflammation, which might be mediated by the interaction of macrophage-derived and cholangiocyte-derived VISFATIN/Nampt signaling. Moreover, we divided ECs into three subclusters, including periportal ECs (EC_Z1), midzonal ECs (EC_Z2), and pericentral ECs (EC_Z3) according to hepatic zonation. Functional analysis suggested that pericentral ECs and midzonal ECs, instead of periportal ECs, were more vulnerable to HBV infection, as the VISFATIN/Nampt- NF-κB axis was mainly altered in these two subpopulations. Interestingly, pericentral ECs showed increasing communication with macrophages and cholangiocytes via the Nampt-Insr and Nampt-Itga5/Itgb1 axis upon CHB infection, which contribute to angiogenesis and vascular capillarization. Additionally, ECs, especially pericentral ECs, showed a close connection with nature killer (NK) cells and T cells via the Cxcl6-Cxcr6 axis, which is involved in shaping the microenvironment in CHB mice livers. Thus, our study described the heterogeneity and functional alterations of three subclusters in ECs. We revealed the potential role of VISFATIN/Nampt signaling in modulating ECs characteristics and related hepatic inflammation, and EC-derived chemokine Cxcl16 in shaping NK and T cell recruitment, providing key insights into the multifunctionality of ECs in CHB-associated pathologies.
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Affiliation(s)
- Jingqi Shi
- Bioinformatics Center of AMMS, Beijing 100039, China
| | - Qingyu Li
- Bioinformatics Center of AMMS, Beijing 100039, China
| | - Jian Li
- Bioinformatics Center of AMMS, Beijing 100039, China
| | - Jianglin Zhou
- Bioinformatics Center of AMMS, Beijing 100039, China
| | | | - Shengqi Wang
- Bioinformatics Center of AMMS, Beijing 100039, China
| | - Liang Guo
- Bioinformatics Center of AMMS, Beijing 100039, China
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2
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Sabourirad S, Dimitriadis E, Mantamadiotis T. Viruses exploit growth factor mechanisms to achieve augmented pathogenicity and promote tumorigenesis. Arch Microbiol 2024; 206:193. [PMID: 38526562 PMCID: PMC10963461 DOI: 10.1007/s00203-024-03855-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/13/2024] [Accepted: 01/20/2024] [Indexed: 03/26/2024]
Abstract
Cellular homeostasis is regulated by growth factors (GFs) which orchestrate various cellular processes including proliferation, survival, differentiation, motility, inflammation and angiogenesis. Dysregulation of GFs in microbial infections and malignancies have been reported previously. Viral pathogens exemplify the exploitation of host cell GFs and their signalling pathways contributing to viral entry, virulence, and evasion of anti-viral immune responses. Viruses can also perturb cellular metabolism and the cell cycle by manipulation of GF signaling. In some cases, this disturbance may promote oncogenesis. Viral pathogens can encode viral GF homologues and induce the endogenous biosynthesis of GFs and their corresponding receptors or manipulate their activity to infect the host cells. Close investigation of how viral strategies exploit and regulate GFs, a will shed light on how to improve anti-viral therapy and cancer treatment. In this review, we discuss and provide insights on how various viral pathogens exploit different GFs to promote viral survival and oncogenic transformation, and how this knowledge can be leveraged toward the design of more efficient therapeutics or novel drug delivery systems in the treatment of both viral infections and malignancies.
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Affiliation(s)
- Sarvenaz Sabourirad
- Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville, VIC, Australia.
| | - Evdokia Dimitriadis
- Department of Obstetrics and Gynaecology, The University of Melbourne, Parkville, VIC, Australia
- Gynaecology Research Centre, Royal Women's Hospital, Parkville, VIC, Australia
- Centre for Reproductive Health, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Theo Mantamadiotis
- Department of Surgery RMH, The University of Melbourne, Parkville, Australia
- Department of Microbiology and Immunology, The University of Melbourne, Melbourne, Australia
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3
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Melano I, Lo YC, Su WC. Characterization of host substrates of SARS-CoV-2 main protease. Front Microbiol 2023; 14:1251705. [PMID: 37670988 PMCID: PMC10475589 DOI: 10.3389/fmicb.2023.1251705] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 07/31/2023] [Indexed: 09/07/2023] Open
Abstract
The main protease (Mpro) plays a crucial role in coronavirus, as it cleaves viral polyproteins and host cellular proteins to ensure successful replication. In this review, we discuss the preference in the recognition sequence of Mpro based on sequence-based studies and structural information and highlight the recent advances in computational and experimental approaches that have aided in discovering novel Mpro substrates. In addition, we provide an overview of the current understanding of Mpro host substrates and their implications for viral replication and pathogenesis. As Mpro has emerged as a promising target for the development of antiviral drugs, further insight into its substrate specificity may contribute to the design of specific inhibitors.
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Affiliation(s)
- Ivonne Melano
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
| | - Yan-Chung Lo
- Sinphar Pharmaceutical Co., Ltd., Sinphar Group, Yilan, Taiwan
| | - Wen-Chi Su
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan
- International Master’s Program of Biomedical Sciences, China Medical University, Taichung, Taiwan
- Department of Medical Research, China Medical University Hospital, Taichung, Taiwan
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4
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Blaszkiewicz J, Duncan SA. Advancements in Disease Modeling and Drug Discovery Using iPSC-Derived Hepatocyte-like Cells. Genes (Basel) 2022; 13:573. [PMID: 35456379 PMCID: PMC9030659 DOI: 10.3390/genes13040573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 02/05/2023] Open
Abstract
Serving as the metabolic hub of the human body, the liver is a vital organ that performs a variety of important physiological functions. Although known for its regenerative potential, it remains vulnerable to a variety of diseases. Despite decades of research, liver disease remains a leading cause of mortality in the United States with a multibillion-dollar-per-year economic burden. Prior research with model systems, such as primary hepatocytes and murine models, has provided many important discoveries. However, progress has been impaired by numerous obstacles associated with these models. In recent years, induced pluripotent stem cell (iPSC)-based systems have emerged as advantageous platforms for studying liver disease. Benefits, including preserved differentiation and physiological function, amenability to genetic manipulation via tools such as CRISPR/Cas9, and availability for high-throughput screening, make these systems increasingly attractive for both mechanistic studies of disease and the identification of novel therapeutics. Although limitations exist, recent studies have made progress in ameliorating these issues. In this review, we discuss recent advancements in iPSC-based models of liver disease, including improvements in model system construction as well as the use of high-throughput screens for genetic studies and drug discovery.
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Affiliation(s)
| | - Stephen A. Duncan
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425, USA;
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Multiomics Analysis of Endocytosis upon HBV Infection and Identification of SCAMP1 as a Novel Host Restriction Factor against HBV Replication. Int J Mol Sci 2022; 23:ijms23042211. [PMID: 35216324 PMCID: PMC8874515 DOI: 10.3390/ijms23042211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/08/2022] [Accepted: 02/11/2022] [Indexed: 02/04/2023] Open
Abstract
Hepatitis B virus (HBV) infection remains a major global health problem and the primary cause of cirrhosis and hepatocellular carcinoma (HCC). HBV intrusion into host cells is prompted by virus–receptor interactions in clathrin-mediated endocytosis. Here, we report a comprehensive view of the cellular endocytosis-associated transcriptome, proteome and ubiquitylome upon HBV infection. In this study, we quantified 273 genes in the transcriptome and 190 endocytosis-associated proteins in the proteome by performing multi-omics analysis. We further identified 221 Lys sites in 77 endocytosis-associated ubiquitinated proteins. A weak negative correlation was observed among endocytosis-associated transcriptome, proteome and ubiquitylome. We found 33 common differentially expressed genes (DEGs), differentially expressed proteins (DEPs), and Kub-sites. Notably, we reported the HBV-induced ubiquitination change of secretory carrier membrane protein (SCAMP1) for the first time, differentially expressed across all three omics data sets. Overexpression of SCAMP1 efficiently inhibited HBV RNAs/pgRNA and secreted viral proteins, whereas knockdown of SCAMP1 significantly increased viral production. Mechanistically, the EnhI/XP, SP1, and SP2 promoters were inhibited by SCAMP1, which accounts for HBV X and S mRNA inhibition. Overall, our study unveils the previously unknown role of SCAMP1 in viral replication and HBV pathogenesis and provides cumulative and novel information for a better understanding of endocytosis in response to HBV infection.
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Himeno M, Chen SW, Kido T. Co-culture Model for Hepatitis B Virus Infection Using iPSC-Derived Liver Progenitor Cells and Liver Sinusoidal Endothelial Cells. Methods Mol Biol 2022; 2544:107-117. [PMID: 36125713 DOI: 10.1007/978-1-0716-2557-6_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In order to understand the complicated life cycle of hepatitis B virus (HBV), it is necessary to develop a co-culture system for HBV infection using various liver cells. We have already developed culture systems to generate liver progenitor cells (LPCs), hepatocytes, and liver sinusoidal endothelial cells (LSECs) from human induced pluripotent cells (iPSCs). Using those cells, we established a co-culture system to study HBV infection and replication in vitro.
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Affiliation(s)
- Misao Himeno
- Laboratory of Cell Growth and Differentiation, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan.
| | - Shin-Wei Chen
- Laboratory of Cell Growth and Differentiation, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan.
| | - Taketomo Kido
- Laboratory of Cell Growth and Differentiation, Institute for Quantitative Biosciences, The University of Tokyo, Tokyo, Japan.
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Zhang T, Wang R, Li Z, Wang L, Gao Z, Tu Y, Cao X. Anti-EGFR Single-Chain Fv Antibody Fragment Displayed on the Surface of Ferritin H-Chain Protein Nanoparticle for Asthma Therapy. ACS APPLIED BIO MATERIALS 2021; 4:6690-6702. [DOI: 10.1021/acsabm.1c00308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tianbao Zhang
- School of Biotechnology, East China University of Science & Technology, Shanghai 200237, PR China
| | - Rongrong Wang
- School of Biotechnology, East China University of Science & Technology, Shanghai 200237, PR China
| | - Zihui Li
- School of Biotechnology, East China University of Science & Technology, Shanghai 200237, PR China
| | - Liang Wang
- School of Biotechnology, East China University of Science & Technology, Shanghai 200237, PR China
| | - Zonglin Gao
- School of Biotechnology, East China University of Science & Technology, Shanghai 200237, PR China
| | - Yaping Tu
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, Nebraska 68178, United States
| | - Xuni Cao
- School of Biotechnology, East China University of Science & Technology, Shanghai 200237, PR China
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8
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Zhao F, Xie X, Tan X, Yu H, Tian M, Lv H, Qin C, Qi J, Zhu Q. The Functions of Hepatitis B Virus Encoding Proteins: Viral Persistence and Liver Pathogenesis. Front Immunol 2021; 12:691766. [PMID: 34456908 PMCID: PMC8387624 DOI: 10.3389/fimmu.2021.691766] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 07/26/2021] [Indexed: 12/14/2022] Open
Abstract
About 250 million people worldwide are chronically infected with Hepatitis B virus (HBV), contributing to a large burden on public health. Despite the existence of vaccines and antiviral drugs to prevent infection and suppress viral replication respectively, chronic hepatitis B (CHB) cure remains a remote treatment goal. The viral persistence caused by HBV is account for the chronic infection which increases the risk for developing liver cirrhosis and hepatocellular carcinoma (HCC). HBV virion utilizes various strategies to escape surveillance of host immune system therefore enhancing its replication, while the precise mechanisms involved remain elusive. Accumulating evidence suggests that the proteins encoded by HBV (hepatitis B surface antigen, hepatitis B core antigen, hepatitis B envelope antigen, HBx and polymerase) play an important role in viral persistence and liver pathogenesis. This review summarizes the major findings in functions of HBV encoding proteins, illustrating how these proteins affect hepatocytes and the immune system, which may open new venues for CHB therapies.
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Affiliation(s)
- Fenglin Zhao
- Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China
| | - Xiaoyu Xie
- Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China.,Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Xu Tan
- Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Hongli Yu
- Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China
| | - Miaomiao Tian
- Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China.,Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Huanran Lv
- Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China.,Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Chengyong Qin
- Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China.,Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Jianni Qi
- Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China.,Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China
| | - Qiang Zhu
- Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, China.,Shandong Provincial Engineering and Technological Research Center for Liver Diseases Prevention and Control, Jinan, China.,Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China.,The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
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9
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Cao D, Ge JY, Wang Y, Oda T, Zheng YW. Hepatitis B virus infection modeling using multi-cellular organoids derived from human induced pluripotent stem cells. World J Gastroenterol 2021; 27:4784-4801. [PMID: 34447226 PMCID: PMC8371505 DOI: 10.3748/wjg.v27.i29.4784] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Revised: 04/30/2021] [Accepted: 07/15/2021] [Indexed: 02/06/2023] Open
Abstract
Chronic infection with hepatitis B virus (HBV) remains a global health concern despite the availability of vaccines. To date, the development of effective treatments has been severely hampered by the lack of reliable, reproducible, and scalable in vitro modeling systems that precisely recapitulate the virus life cycle and represent virus-host interactions. With the progressive understanding of liver organogenesis mechanisms, the development of human induced pluripotent stem cell (iPSC)-derived hepatic sources and stromal cellular compositions provides novel strategies for personalized modeling and treatment of liver disease. Further, advancements in three-dimensional culture of self-organized liver-like organoids considerably promote in vitro modeling of intact human liver tissue, in terms of both hepatic function and other physiological characteristics. Combined with our experiences in the investigation of HBV infections using liver organoids, we have summarized the advances in modeling reported thus far and discussed the limitations and ongoing challenges in the application of liver organoids, particularly those with multi-cellular components derived from human iPSCs. This review provides general guidelines for establishing clinical-grade iPSC-derived multi-cellular organoids in modeling personalized hepatitis virus infection and other liver diseases, as well as drug testing and transplantation therapy.
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Affiliation(s)
- Di Cao
- Institute of Regenerative Medicine and Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang 212001, Jiangsu Province, China
| | - Jian-Yun Ge
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Ibaraki, Japan
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, and School of Biotechnology and Heath Sciences, Wuyi University, Jiangmen 529020, Guangdong Province, China
| | - Yun Wang
- Institute of Regenerative Medicine and Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang 212001, Jiangsu Province, China
| | - Tatsuya Oda
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Ibaraki, Japan
| | - Yun-Wen Zheng
- Institute of Regenerative Medicine and Affiliated Hospital of Jiangsu University, Jiangsu University, Zhenjiang 212001, Jiangsu Province, China
- Department of Gastrointestinal and Hepato-Biliary-Pancreatic Surgery, Faculty of Medicine, University of Tsukuba, Tsukuba 305-8575, Ibaraki, Japan
- Guangdong Provincial Key Laboratory of Large Animal Models for Biomedicine, and School of Biotechnology and Heath Sciences, Wuyi University, Jiangmen 529020, Guangdong Province, China
- School of Medicine, Yokohama City University, Yokohama 234-0006, Kanagawa, Japan
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10
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Pasqua M, Di Gesù R, Chinnici CM, Conaldi PG, Francipane MG. Generation of Hepatobiliary Cell Lineages from Human Induced Pluripotent Stem Cells: Applications in Disease Modeling and Drug Screening. Int J Mol Sci 2021; 22:8227. [PMID: 34360991 PMCID: PMC8348238 DOI: 10.3390/ijms22158227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/28/2021] [Accepted: 07/28/2021] [Indexed: 12/13/2022] Open
Abstract
The possibility to reproduce key tissue functions in vitro from induced pluripotent stem cells (iPSCs) is offering an incredible opportunity to gain better insight into biological mechanisms underlying development and disease, and a tool for the rapid screening of drug candidates. This review attempts to summarize recent strategies for specification of iPSCs towards hepatobiliary lineages -hepatocytes and cholangiocytes-and their use as platforms for disease modeling and drug testing. The application of different tissue-engineering methods to promote accurate and reliable readouts is discussed. Space is given to open questions, including to what extent these novel systems can be informative. Potential pathways for improvement are finally suggested.
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Affiliation(s)
- Mattia Pasqua
- Fondazione Ri.MED, 90133 Palermo, Italy; (M.P.); (R.D.G.); (C.M.C.)
| | - Roberto Di Gesù
- Fondazione Ri.MED, 90133 Palermo, Italy; (M.P.); (R.D.G.); (C.M.C.)
| | - Cinzia Maria Chinnici
- Fondazione Ri.MED, 90133 Palermo, Italy; (M.P.); (R.D.G.); (C.M.C.)
- Dipartimento della Ricerca, IRCCS ISMETT, 90127 Palermo, Italy;
| | | | - Maria Giovanna Francipane
- Fondazione Ri.MED, 90133 Palermo, Italy; (M.P.); (R.D.G.); (C.M.C.)
- McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA 15219, USA
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Microfilaments and microtubules alternately coordinate the multi-step endosomal trafficking of Classical Swine Fever Virus. J Virol 2021; 95:JVI.02436-20. [PMID: 33627389 PMCID: PMC8139654 DOI: 10.1128/jvi.02436-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Cytoskeleton, as a ubiquitous structure in the cells, plays an important role in the process of virus entry, replication, and survival. However, the action mechanism of cytoskeleton in the invasion of Pestivirus into host cells remains unclear. In this study, we systematically dissected the key roles of the main cytoskeleton components, microfilaments and microtubules in the endocytosis of porcine Pestivirus, Classical swine fever virus (CSFV). We observed the dynamic changes of actin filaments in CSFV entry. Confocal microscopy showed that CSFV invasion induced the dissolution and aggregation of stress fibers, resulting in the formation of lamellipodia and filopodia. Chemical inhibitors and RNA interference were used to find that the dynamic changes of actin were caused by EGFR-PI3K/MAPK-RhoA/Rac1/Cdc42-cofilin signaling pathway, which regulates the microfilaments to help CSFV entry. Furthermore, co-localization of the microfilaments with clathrin and Rab5 (early endosome), as well as microtubules with Rab7 (late endosome) and Lamp1 (lysosome) revealed that microfilaments were activated and rearranged to help CSFV trafficking to early endosome after endocytosis. Subsequently, recruitment of microtubules by CSFV also assisted membrane fusion of the virions from late endosome to lysosome with the help of a molecular motor, dynein. Unexpectedly, vimentin, which is an intermediate filament, had no effect on CSFV entry. Taken together, our findings comprehensively revealed the molecular mechanisms of cytoskeletal components that regulated CSFV endocytosis and facilitated further understanding of Pestivirus entry, which would be conducive to explore antiviral molecules to control classical swine fever.IMPORTANCEEndocytosis, an essential biological process mediating cellular internalization events, is often exploited by pathogens for their entry into target cells. Previously, we have reported different mechanisms of CSFV endocytosis into the porcine epithelial cells (PK-15) and macrophages (3D4/21); however, the details of microfilaments/microtubules mediated virus migration within the host cells remained to be elucidated. In this study, we found that CSFV infection induced rearrangement of actin filaments regulated by cofilin through EGFR-PI3K/MAPK-RhoA/Rac1/Cdc42 pathway. Furthermore, we found that CSFV particles were trafficked along actin filaments in early and late endosomes, and through microtubules in lysosomes after entry. Here, we provide for the first time a comprehensive description of the cytoskeleton that facilitates entry and intracellular transport of highly pathogenic swine virus. Results from this study will greatly contribute to the understanding of virus-induced early and complex changes in host cells that are important in CSFV pathogenesis.
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