Takeshi Saito, MD, PhD

Associate Professor of Medicine, Molecular Microbiology and Immunology, and Pathology, of the Keck School of Medicine of USC.

Image of Takeshi Saito, MD, PhD
Is this your profile? Click to edit


Dr. Saito specializes in the care and research of liver diseases. His research focuses on understanding the mechanisms of innate immunity that regulate hepatic inflammation that underlies a variety of liver diseases.

His current research focuses are the following: (1) the interplay between virulence of hepatotropic viral pathogens and antiviral immunity of the liver, (2) the viral evolution of resistance to antiviral therapy, (3) the identification of proviral and antiviral host factors that determine the organotropism of viral infection, (4) the role of micronutrients in the regulation of innate immunity, and (5) the macrophage immunobiology in liver disease. In these research programs, Dr. Saito’s laboratory employs a full range of in vitro and in vivo research tools, including cell lines, animal models such as humanized-liver chimeric mice, and clinical specimens.

As a physician-scientist, Dr. Saito’s research program has the unique opportunity to bridge basic science and clinical hepatology. Currently, his laboratory is supported by multiple federal grants as well as industry funding. For further detail, visit Dr. Saito’s research laboratory website: https://sites.usc.edu/saito-lab/.

Dr. Saito earned his medical degree and Ph.D. degree from Showa University School of Medicine. He then completed his internal medicine residency and gastroenterology-hepatology fellowship at Show University Hospital, Tokyo, Japan, followed by post-doctoral training at the University of Texas Southwestern Medical Center (virology) and University of Washing (Immunology). Dr. Saito Joined the Keck School of Medicine as an Assistant Professor in 2010.


  • ASCI: Elected Member of the American Society for Clinical Investigation (ASCI), 2024
  • NIH (NIAID): R01AI179019, 2023-2028
  • PhoenixBio: PhoenixBio R&D Grant, 2018-2028
  • NIH (NIAID): R21AI139954, 2018-2021
  • CRDFG: CRDF Global Research Award, 2017-2018
  • L.K. Whittier Foundation: L.K. Whittier Foundation Award, 2016-2017
  • American Federation For Medical Research: Western Region American Federation For Medical Research (WAFMR) Outstanding Investigator Award, 2016
  • NIH (NIDDK): R01DK101773, 2015-2021
  • NIH (NIAAA): R21AA022751, 2014-2017
  • ISHSR: Young Investigator Award International Symposium on Cells of the Hepatic Sinusoid, 2013
  • International Meeting on Hepatitis C Virus & Related Viruses: Travel Scholarship for 18th International Meeting on Hepatitis C Virus & Related Viruses, 2011
  • Baxter Foundation : Donald E. and Delia B. Baxter Foundation Faculty Fellow Award, 2011
  • AASLD and American Liver Foundation: Liver Scholar Award, 2010-2012
  • AGA: American Gastroenterological Association Foundation’s Research Scholar Award (Declined for LSA), 2010-2012
  • Japan Society of Hepatology: 2010 Hepatology Research High Citation Award, 2010
  • Viral Hepatitis Research Foundation of Japan : Viral Hepatitis Research Foundation of Japan Research Fellowship, 2009
  • ISICR: International Society for Interferon & Cytokine Research Milstein Young Investigator Award, 2008


  • Function of hepatocyte spheroids in bioactive microcapsules is enhanced by endogenous and exogenous hepatocyte growth factor Bioact Mater. 2023 Oct; 28:183-195. . View in PubMed
  • Hepatocellular organellar abnormalities following elimination of hepatitis C virus Liver Int. 2023 08; 43(8):1677-1690. . View in PubMed
  • Impact of Bacteria Types on the Clinical Outcomes of Spontaneous Bacterial Peritonitis Dig Dis Sci. 2023 05; 68(5):2140-2148. . View in PubMed
  • Long-term cell fate and functional maintenance of human hepatocyte through stepwise culture configuration FASEB J. 2023 02; 37(2):e22750. . View in PubMed
  • Clinical Significance of Ascitic Fluid Polymorphonuclear Leukocyte Percentage in Patients With Cirrhosis Without Spontaneous Bacterial Peritonitis Clin Transl Gastroenterol. 2023 09 01; 14(9):e00614. . View in PubMed
  • Guiding Hepatic Differentiation of Pluripotent Stem Cells Using 3D Microfluidic Co-Cultures with Human Hepatocytes Cells. 2023 08 01; 12(15). . View in PubMed
  • Persistent hepatic IFN system activation in HBV-HDV infection determines viral replication dynamics and therapeutic response JCI Insight. 2023 05 08; 8(9). . View in PubMed
  • Downregulation of SOCS1 increases interferon-induced ISGylation during differentiation of induced-pluripotent stem cells to hepatocytes JHEP Rep. 2022 Dec; 4(12):100592. . View in PubMed
  • Development and characterization of secondary standards for nucleic acid amplification technology (NAAT) assays for detection of hepatitis E virus J Clin Virol. 2022 12; 157:105325. . View in PubMed
  • Loss of mitochondrial ATPase ATAD3A contributes to nonalcoholic fatty liver disease through accumulation of lipids and damaged mitochondria J Biol Chem. 2022 06; 298(6):102008. . View in PubMed
  • Lipoprotein Z, a hepatotoxic lipoprotein, predicts outcome in alcohol-associated hepatitis Hepatology. 2022 04; 75(4):968-982. . View in PubMed
  • Differential IgG4-Producing Plasma Cell Infiltration in Non- and Post-Transplant Plasma Cell Hepatitis Transpl Int. 2022; 35:10182. . View in PubMed
  • Macrophages activated by hepatitis B virus have distinct metabolic profiles and suppress the virus via IL-1ß to downregulate PPARa and FOXO3 Cell Rep. 2022 01 25; 38(4):110284. . View in PubMed
  • Reply to: Comments on: Differential IgG4-Producing Plasma Cell Infiltration in Non- and Post-Transplant Plasma Cell Hepatitis Transpl Int. 2022; 35:10679. . View in PubMed
  • Autophagic membranes participate in hepatitis B virus nucleocapsid assembly, precore and core protein trafficking, and viral release Proc Natl Acad Sci U S A. 2022 07 26; 119(30):e2201927119. . View in PubMed
  • Cholesterol-binding translocator protein TSPO regulates steatosis and bile acid synthesis in nonalcoholic fatty liver disease iScience. 2021 May 21; 24(5):102457. . View in PubMed
  • Suppression of hepatitis B virus through therapeutic activation of RIG-I and IRF3 signaling in hepatocytes iScience. 2021 Jan 22; 24(1):101969. . View in PubMed
  • Infection courses, virological features and IFN-a responses of HBV genotypes in cell culture and animal models J Hepatol. 2021 12; 75(6):1335-1345. . View in PubMed
  • A Case of Benign Hepatic Cyst with Supra-elevated Cyst Fluid Tumor Markers Dig Dis Sci. 2021 11; 66(11):4063-4067. . View in PubMed
  • High Prevalence of Chronic Viral Hepatitis and Liver Fibrosis Among Mongols in Southern California Dig Dis Sci. 2021 08; 66(8):2833-2839. . View in PubMed
  • Art of Making Artificial Liver: Depicting Human Liver Biology and Diseases in Mice Semin Liver Dis. 2020 05; 40(2):189-212. . View in PubMed
  • Development of Capsular Fibrosis Beneath the Liver Surface in Humans and Mice Hepatology. 2020 01; 71(1):291-305. . View in PubMed
  • Hepatic IFN-Induced Protein with Tetratricopeptide Repeats Regulation of HCV Infection J Interferon Cytokine Res. 2019 03; 39(3):133-146. . View in PubMed
  • Regulation of Hepatitis C Virus Infection by Cellular Retinoic Acid Binding Proteins through the Modulation of Lipid Droplet Abundance J Virol. 2019 04 15; 93(8). . View in PubMed
  • Special Issue “IFN-Independent ISG Expression and its Role in Antiviral Cell-Intrinsic Innate Immunity” Viruses. 2019 10 24; 11(11). . View in PubMed
  • Hepatic angiosarcoma with clinical and histological features of Kasabach-Merritt syndrome World J Gastroenterol. 2017 Apr 07; 23(13):2443-2447. . View in PubMed
  • Reply Gastroenterology. 2017 07; 153(1):328-329. . View in PubMed
  • Detection of Occult Hepatitis C Virus Infection in Patients Who Achieved a Sustained Virologic Response to Direct-Acting Antiviral Agents for Recurrent Infection After Liver TransplantationGastroenterology. 2017 02; 152(3):550-553. e8. . View in PubMed
  • Dual modulation of human hepatic zonation via canonical and non-canonical Wnt pathways Exp Mol Med. 2017 12 15; 49(12):e413. . View in PubMed
  • Organ system view of the hepatic innate immunity in HCV infection J Med Virol. 2016 12; 88(12):2025-2037. . View in PubMed
  • Comparison of Demographic and Clinical Characteristics of Hispanic and Asian Chronic Hepatitis B Patients in Southern California J Clin Gastroenterol. 2016 08; 50(7):602-7. . View in PubMed
  • Retinoid regulation of antiviral innate immunity in hepatocytes Hepatology. 2016 06; 63(6):1783-95. . View in PubMed
  • An Internally Translated MAVS Variant Exposes Its Amino-terminal TRAF-Binding Motifs to Deregulate Interferon Induction PLoS Pathog. 2015 Jul; 11(7):e1005060. . View in PubMed
  • Novel antiviral host factor, TNK1, regulates IFN signaling through serine phosphorylation of STAT1 Proc Natl Acad Sci U S A. 2014 Feb 04; 111(5):1909-14. . View in PubMed
  • Isolated arterioportal fistula presenting with variceal hemorrhage World J Gastroenterol. 2013 May 07; 19(17):2714-7. . View in PubMed
  • Innate immune tolerance and the role of kupffer cells in differential responses to interferon therapy among patients with HCV genotype 1 infectionGastroenterology. 2013 Feb; 144(2):402-413. e12. . View in PubMed
  • RNase L releases a small RNA from HCV RNA that refolds into a potent PAMP RNA. 2010 Nov; 16(11):2108-19. . View in PubMed
  • Innate immunity induced by composition-dependent RIG-I recognition of hepatitis C virus RNA Nature. 2008 Jul 24; 454(7203):523-7. . View in PubMed
  • Differential recognition of double-stranded RNA by RIG-I-like receptors in antiviral immunity J Exp Med. 2008 Jul 07; 205(7):1523-7. . View in PubMed
  • Regulation of innate immunity against hepatitis C virus infection Hepatol Res. 2008; 38(2):115-22. . View in PubMed
  • Principles of intracellular viral recognition Curr Opin Immunol. 2007 Feb; 19(1):17-23. . View in PubMed
  • Regulation of innate antiviral defenses through a shared repressor domain in RIG-I and LGP2 Proc Natl Acad Sci U S A. 2007 Jan 09; 104(2):582-7. . View in PubMed
  • Viral and therapeutic control of IFN-beta promoter stimulator 1 during hepatitis C virus infection Proc Natl Acad Sci U S A. 2006 Apr 11; 103(15):6001-6. . View in PubMed
  • Translational enhancement of HCV RNA genotype 1b by 3′-untranslated and envelope 2 protein-coding sequences Virology. 2006 Feb 20; 345(2):404-15. . View in PubMed
  • Sequence analysis of PePHD within HCV E2 region and correlation with resistance of interferon therapy in Japanese patients infected with HCV genotypes 2a and 2b Am J Gastroenterol. 2003 Jun; 98(6):1377-83. . View in PubMed
  • A case of autoimmune pancreatitis responding to steroid therapyEvidence of histologic recovery. Pancreatology. 2002; 2(6):550-6. . View in PubMed