{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T17:27:58Z","timestamp":1785432478598,"version":"3.56.0"},"reference-count":38,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2026,6,27]],"date-time":"2026-06-27T00:00:00Z","timestamp":1782518400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"crossref","award":["PJT165854"],"award-info":[{"award-number":["PJT165854"]}],"id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"crossref","award":["PS173314"],"award-info":[{"award-number":["PS173314"]}],"id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"crossref","award":["HET85517"],"award-info":[{"award-number":["HET85517"]}],"id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"crossref"}]},{"award":["PJT165854"],"award-info":[{"award-number":["PJT165854"]}],"id":[{"id":"https:\/\/ror.org\/01gavpb45","id-type":"ROR","asserted-by":"publisher"}]},{"award":["PS173314"],"award-info":[{"award-number":["PS173314"]}],"id":[{"id":"https:\/\/ror.org\/01gavpb45","id-type":"ROR","asserted-by":"publisher"}]},{"award":["HET85517"],"award-info":[{"award-number":["HET85517"]}],"id":[{"id":"https:\/\/ror.org\/01gavpb45","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cells"],"abstract":"<jats:p>Background: Hepatitis B and C viral infections remain a significant global health challenge, despite the implementation of an effective direct-acting antiviral (DAAs) and nucleos(t)ide analogues (NAs). Current HBV therapy is not curative as stopping therapy usually leads to active disease in most patients requiring long-term treatment. Although current HCV-DAAs are highly effective they fall short due to arising drug-resistance and have limited ability to avert re-infections. Furthermore, current HCV DAA treatments lead to the reactivation of occult HBV infection, compromising the effectiveness of current antiviral therapies, and increasing the risk of severe liver complications like cirrhosis and hepatocellular carcinoma. In addition, current treatments do not restore the immune dysfunction, a characteristic of chronic HBV infection. Given the global burden of disease, there is an urgent need for more effective therapy that can shorten the duration of treatment and achieve high rates of HBsAg reduction. Combining an antiviral to reduce viral antigen burden and an immunomodulator to boost the immune response could provide an effective treatment for HBV\/HCV infections. Methods: In this study, we explored the potential of a novel bacterial therapeutic agent, heat-killed Caulobacter crescentus (HKCC), as an alternative and\/or adjunct host-based therapy for HCV and HBV infections. Here, we have investigated the antiviral effects of the HKCC-stimulated human PBMCs using in vitro HCV and HBV infection models to assess viral replication, viral relapse responses, protein expression, and cytotoxicity. Results: Our findings reveal that HKCC induced a multi-functional cytokine response (IFN, TNF, IL-2, IL-10, IL-6, IL-17A, and IL-22) in PBMCs obtained from multiple healthy donors. Supernatants collected from these HKCC-stimulated human PBMCs, alone and in combination with antivirals, strikingly inhibited HCV replication and viral relapse responses without inducing any cytotoxic effects on HCV-1a replicon cells. In addition, these PBMC supernatants, with or without antivirals, led to the suppression of HBV DNA replication and inhibited HBsAg and HBeAg production in HepG 2.2.15 cells. Conclusions: In conclusion, HKCC is a promising candidate for eliminating HBV and HCV infections, and warrants further investigation to potentially contribute to the development of a novel host-based immunotherapy.<\/jats:p>","DOI":"10.3390\/cells15131172","type":"journal-article","created":{"date-parts":[[2026,6,29]],"date-time":"2026-06-29T00:54:42Z","timestamp":1782694482000},"page":"1172","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Novel Host-Based Immunotherapy for the Suppression of HBV and HCV Replication: Heat-Killed Caulobacter crescentus (HKCC)"],"prefix":"10.3390","volume":"15","author":[{"given":"Raj S.","family":"Patel","sequence":"first","affiliation":[{"name":"Department of Surgery, Faculty of Medicine and Dentistry, College of Health Sciences, University of Alberta, Edmonton, AB T6G 2S3, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nancy","family":"Gupta","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, College of Health Sciences, University of Alberta, Edmonton, AB T6G 2S3, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Satish","family":"Vedi","sequence":"additional","affiliation":[{"name":"Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, College of Health Sciences, University of Alberta, Edmonton, AB T6G 2S3, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rakesh","family":"Kumar","sequence":"additional","affiliation":[{"name":"ImMed Biotechnologies, Edmonton, AB T6R 2E8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1957-6371","authenticated-orcid":false,"given":"Babita","family":"Agrawal","sequence":"additional","affiliation":[{"name":"Department of Surgery, Faculty of Medicine and Dentistry, College of Health Sciences, University of Alberta, Edmonton, AB T6G 2S3, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,6,27]]},"reference":[{"key":"ref_1","unstructured":"(2024). Global Hepatitis Report 2024: Action for Access in Low- and Middle-Income Countries, World Health Organization."},{"key":"ref_2","unstructured":"Beno, J., Silen, A.P., and Yanti, M. (2022). Global Health Sector Strategies on, Respectively, HIV, Viral Hepatitis and Sexually Transmitted Infections for the Period 2022\u20132030, World Health Organization."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1177\/2040622310384308","article-title":"Pegylated interferon and ribavirin treatment for hepatitis C virus infection","volume":"2","author":"Palumbo","year":"2011","journal-title":"Ther. Adv. Chronic Dis."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Minosse, C., Gruber, C.E.M., Rueca, M., Taibi, C., Zaccarelli, M., Grilli, E., Montalbano, M., Capobianchi, M.R., Antinori, A., and D\u2019offizi, G. (2021). Late relapse and reinfection in hcv patients treated with direct-acting antiviral (Daa) drugs. Viruses, 13.","DOI":"10.3390\/v13061151"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"20986","DOI":"10.1073\/pnas.1006370107","article-title":"Drug resistance against HCV NS3\/4A inhibitors is defined by the balance of substrate recognition versus inhibitor binding","volume":"107","author":"Romano","year":"2010","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Singer, J.B., Thomson, E.C., McLauchlan, J., Hughes, J., and Gifford, R.J. (2018). GLUE: A flexible software system for virus sequence data. BMC Bioinform., 19.","DOI":"10.1186\/s12859-018-2459-9"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1016\/j.drup.2018.01.004","article-title":"Hepatitis C virus drug resistance associated substitutions and their clinical relevance: Update 2018","volume":"37","author":"Sorbo","year":"2018","journal-title":"Drug Resist. Updates"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"637","DOI":"10.7326\/M16-2575","article-title":"Oral direct-acting agent therapy for hepatitis c virus infection: A systematic review","volume":"166","author":"Nelson","year":"2017","journal-title":"Ann. Intern. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1111\/jvh.13270","article-title":"Prevalence of HCV resistance-associated substitutions among treatment-failure patients receiving direct-acting antiviral agents","volume":"27","author":"Liu","year":"2020","journal-title":"J. Viral Hepat."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"7457","DOI":"10.1038\/s41467-023-42550-6","article-title":"Direct-acting antiviral resistance of Hepatitis C virus is promoted by epistasis","volume":"14","author":"Zhang","year":"2023","journal-title":"Nat. Commun."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1007\/s11901-010-0060-4","article-title":"Current concepts of HBV\/HCV coinfection: Coexistence, but not necessarily in harmony","volume":"9","author":"Jamma","year":"2010","journal-title":"Curr. Hepat. Rep."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"296","DOI":"10.14218\/JCTH.2018.00016","article-title":"Hbv-hcv coinfection: Viral interactions, management, and viral reactivation","volume":"6","author":"Mavilia","year":"2018","journal-title":"J. Clin. Transl. Hepatol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Dimitriadis, K., Katelani, S., Pappa, M., Fragkoulis, G.E., and Androutsakos, T. (2023). The Role of Interleukins in HBV Infection: A Narrative Review. J. Pers. Med., 13.","DOI":"10.3390\/jpm13121675"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Moini, M., and Fung, S. (2022). HBsAg Loss as a Treatment Endpoint for Chronic HBV Infection: HBV Cure. Viruses, 14.","DOI":"10.3390\/v14040657"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"113","DOI":"10.1007\/s12072-018-9912-8","article-title":"Immunological cure of HBV infection","volume":"13","author":"Lang","year":"2019","journal-title":"Hepatol. Int."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"260","DOI":"10.1016\/j.antiviral.2008.01.006","article-title":"APOBEC and iNOS are not the main intracellular effectors of IFN-\u03b3-mediated inactivation of Hepatitis B virus replication","volume":"78","author":"Proto","year":"2008","journal-title":"Antivir. Res."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"287","DOI":"10.4049\/jimmunol.0902761","article-title":"CD8+ T Cell Control of Hepatitis B Virus Replication: Direct Comparison between Cytolytic and Noncytolytic Functions","volume":"184","author":"Phillips","year":"2010","journal-title":"J. Immunol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1111","DOI":"10.1080\/21505594.2022.2093444","article-title":"Novel therapeutic strategies for chronic hepatitis B","volume":"13","author":"Phillips","year":"2022","journal-title":"Virulence"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e49568","DOI":"10.15252\/embr.201949568","article-title":"Interferon-induced degradation of the persistent hepatitis B virus cccDNA form depends on ISG20","volume":"22","author":"Stadler","year":"2021","journal-title":"EMBO Rep."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Gupta, N., Vedi, S., Garg, S., Loo, E., Li, J., Kunimoto, D.Y., Kumar, R., and Agrawal, B. (2023). Harnessing Innate Immunity to Treat Mycobacterium tuberculosis Infections: Heat-Killed Caulobacter crescentus as a Novel Biotherapeutic. Cells, 12.","DOI":"10.3390\/cells12040560"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Werellagama, S., Patel, R.S., Gupta, N., Vedi, S., Duque, D., Bavananthasivam, J., Kumar, R., Tran, A., and Agrawal, B. (2026). Host-directed broad-spectrum immunotherapeutic strategy for respiratory infections: Heat-killed Caulobacter crescentus (HKCC) as an innate-immune based biotherapeutic\/postbiotic. PLoS Pathog., 22.","DOI":"10.1371\/journal.ppat.1013994"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"4784","DOI":"10.1128\/AAC.48.12.4784-4792.2004","article-title":"Combination of a hepatitis C virus NS3-NS4A protease inhibitor and alpha interferon synergistically inhibits viral RNA replication and facilitates viral RNA clearance in replicon cells","volume":"48","author":"Lin","year":"2004","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1092","DOI":"10.1128\/JVI.77.2.1092-1104.2003","article-title":"Antiviral Effect and Virus-Host Interactions in Response to Alpha Interferon, Gamma Interferon, Poly(I)-Poly(C), Tumor Necrosis Factor Alpha, and Ribavirin in Hepatitis C Virus Subgenomic Replicons","volume":"77","author":"Lanford","year":"2003","journal-title":"J. Virol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"6790","DOI":"10.1016\/j.bmcl.2010.08.120","article-title":"Antiviral activity of 2,3\u2032-anhydro and related pyrimidine nucleosides against hepatitis B virus","volume":"20","author":"Srivastav","year":"2010","journal-title":"Bioorg. Med. Chem. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Zhong, S., Zhang, T., Tang, L., and Li, Y. (2021). Cytokines and Chemokines in HBV Infection. Front. Mol. Biosci., 8.","DOI":"10.3389\/fmolb.2021.805625"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"4184","DOI":"10.4049\/jimmunol.1203449","article-title":"IL-12\u2013Based Vaccination Therapy Reverses Liver-Induced Systemic Tolerance in a Mouse Model of Hepatitis B Virus Carrier","volume":"191","author":"Zeng","year":"2013","journal-title":"J. Immunol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.ajpath.2012.08.043","article-title":"Protective and pathological properties of IL-22 in liver disease: Implications for viral hepatitis","volume":"182","author":"Cobleigh","year":"2013","journal-title":"Am. J. Pathol."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Jo, J., Tan, A.T., E Ussher, J., Sandalova, E., Tang, X.-Z., Tan-Garcia, A., To, N., Hong, M., Chia, A., and Gill, U.S. (2014). Toll-Like Receptor 8 Agonist and Bacteria Trigger Potent Activation of Innate Immune Cells in Human Liver. PLoS Pathog., 10.","DOI":"10.1371\/journal.ppat.1004210"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"320","DOI":"10.1016\/j.jhep.2015.02.037","article-title":"The oral toll-like receptor-7 agonist GS-9620 in patients with chronic hepatitis B virus infection","volume":"63","author":"Gane","year":"2015","journal-title":"J. Hepatol."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1237","DOI":"10.1016\/j.jhep.2014.12.026","article-title":"Sustained efficacy and seroconversion with the toll-like receptor 7 agonist GS-9620 in the woodchuck model of chronic hepatitis B","volume":"62","author":"Menne","year":"2015","journal-title":"J. Hepatol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1508","DOI":"10.1053\/j.gastro.2013.02.003","article-title":"GS-9620, an oral agonist of toll-like receptor-7, induces prolonged suppression of hepatitis B virus in chronically infected chimpanzees","volume":"144","author":"Lanford","year":"2013","journal-title":"Gastroenterology"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1273","DOI":"10.1128\/AAC.04321-14","article-title":"Sting agonists induce an innate antiviral immune response against hepatitis B virus","volume":"59","author":"Guo","year":"2015","journal-title":"Antimicrob. Agents Chemother."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1038\/nrgastro.2018.6","article-title":"Viral hepatitis: Biomarker for HBV therapy discontinuation","volume":"15","author":"Dickson","year":"2018","journal-title":"Nat. Rev. Gastroenterol. Hepatol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"926","DOI":"10.1016\/j.jhep.2022.12.018","article-title":"A multicenter randomized-controlled trial of nucleos(t)ide analogue cessation in HBeAg-negative chronic hepatitis B","volume":"78","author":"Stein","year":"2023","journal-title":"J. Hepatol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"300","DOI":"10.1016\/0042-6822(90)90298-6","article-title":"Replication of hepatitis B virus in transfected nonhepatic cells","volume":"179","author":"Seifer","year":"1990","journal-title":"Virology"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"535","DOI":"10.1038\/nri3463","article-title":"25 years of interferon-based treatment of chronic hepatitis C: An epoch coming to an end","volume":"13","author":"Heim","year":"2013","journal-title":"Nat. Rev. Immunol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"161","DOI":"10.1186\/1743-422X-8-161","article-title":"An overview of HCV molecular biology, replication and immune responses","volume":"8","author":"Ashfaq","year":"2011","journal-title":"Virol. J."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1016\/j.fob.2012.07.005","article-title":"Repressed induction of interferon-related microRNAs miR-146a and miR-155 in peripheral blood mononuclear cells infected with HCV genotype 4","volume":"2","author":"Hamdi","year":"2012","journal-title":"FEBS Open Bio"}],"container-title":["Cells"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4409\/15\/13\/1172\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,3]],"date-time":"2026-07-03T04:13:49Z","timestamp":1783052029000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4409\/15\/13\/1172"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,6,27]]},"references-count":38,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["cells15131172"],"URL":"https:\/\/doi.org\/10.3390\/cells15131172","relation":{},"ISSN":["2073-4409"],"issn-type":[{"value":"2073-4409","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,6,27]]}}}