TP18: Reconstitution of antiviral immunity and elimination of persisting hepatitis B virus infection

We developed the clinical candidate therapeutic hepatitis B vaccine TherVacB, a heterologous protein prime - recombinant MVA boost vaccine that induces strong and polyfunctional HBV-specific T-cell responses and cures HBV in low- to medium-titre HBV carrier mice. In high-titre HBV carrier mice, however, vaccine efficacy is blunted. This project aims at identifying which type of T cell response is required to cure HBV by single-cell analysis. We target HBV gene expression and immune checkpoints by siRNA to dissect how this affects immune control, and compare the immunotypes observed in our preclinical models to that obtained in clinical trials.

Dr. Anna Kosinska

Prof. Dr. Ulrike Protzer

Gehring AJ, Protzer U. (2019) Targeting Innate and Adaptive Immune Responses to Cure Chronic HBV Infection. Gastroenterology. 156(2):325-337. doi: 10.1053/j.gastro.2018.10.032.

Kosinska AD, Festag J, Mück-Häusl M, Festag MM, Asen T, Protzer U. (2021) Immunogenicity and Antiviral Response of Therapeutic Hepatitis B Vaccination in a Mouse Model of HBeAg-Negative, Persistent HBV Infection. Vaccines. 9(8):841. doi: 10.3390/vaccines9080841.

Su J, Brunner L, Ates Oz E, Sacherl J, Frank G, Kerth HA, Thiele F, Wiegand M, Mogler C, Cesar Aguilar J, Knolle PA, Collin N, Kosinska AD*, Protzer U*. (2023) Activation of CD4 T cells during prime immunization determines the success of a therapeutic hepatitis B vaccine in HBV-carrier mouse models. J Hepatol. 78: 717-730. doi: 10.1016/j.jhep.2022.12.013.

Sacherl J*, Kosinska AD*, Kemter K, Kächele M, Laumen SC, Kerth HA, Ates Oz E, Wolff LS, Su J, Essbauer S, Sutter G, Scholz M, Singethan K, Altrichter J, Protzer U. (2022) Efficient stabilization of therapeutic hepatitis B vaccine components by amino-acid formulation maintains its potential to break immune tolerance. JHEP Rep. 13;5(2):100603. doi: 10.1016/j.jhepr.2022.100603.

Michler T, Große S, Mockenhaupt S, Röder N, Stückler F, Knapp B, Ko C, Heikenwalder M, Protzer U*, Grimm D*. (2016) Blocking sense-strand activity improves potency, safety, and specificity of anti-hepatitis B virus short hairpin RNA. EMBO Mol Med. 8(9):1082-98. doi: 10.15252/emmm.201506172.

Michler T*, Kosinska AD*, Festag J, Bunse T, Su J, Ringelhan M, Imhof H, Grimm D, Steiger K, Mogler C, Heikenwalder M, Michel ML, Guzman CA, Milstein S, Sepp-Lorenzio L, Knolle PA, Protzer U. (2020) Knockdown of Virus Antigen Expression Increases Therapeutic Vaccine Efficacy in High-titer HBV Carrier Mice. Gastroenterology. 158(6):1762-1775.e9. doi: 10.1053/j.gastro.2020.01.032.

Ko C, Su J, Festag J, Bester R, Kosinska AD, Protzer U. (2021) Intramolecular recombination enables the formation of hepatitis B virus (HBV) cccDNA in mice after HBV genome transfer using recombinant AAV vectors. Antiviral Res. 194:105140. doi: 10.1016/j.antiviral.2021.105140.

Bunse T, Kosinska AD, Michler T, Protzer U. (2022) PD-L1 Silencing in Liver Using siRNAs Enhances Efficacy of Therapeutic Vaccination for Chronic Hepatitis B. Biomolecules. 12(3):470. doi 10.3390/biom12030470.

Wratil PR, Stern M, Priller A, Willmann A, Almanzar G, Vogel E, Feuerherd M, Cheng CC, Yazici S, Christa C, Jeske S, Lupoli G, Vogt T, Albanese M, Mejías-Pérez E, Bauernfried S, Graf N, Mijocevic H, Vu M, Tinnefeld K, Wettengel J, Hoffmann D, Muenchhoff M, Daechert C, Mairhofer H, Krebs S, Fingerle V, Graf A, Steininger P, Blum H, Hornung V, Liebl B, Überla K, Prelog M, Knolle P, Keppler OT, Protzer U. (2022) Three exposures to the spike protein of SARS-CoV-2 by either infection or vaccination elicit superior neutralizing immunity to all variants of concern. Nat Med. 28:496-503. doi: 10.1038/s41591-022-01715-4.

Backes S, Jäger C, Dembek CJ, Kosinska AD, Bauer T, Stephan AS, Dišlers A, Mutwiri G, Busch DH, Babiuk LA, Gasteiger G, Protzer U. (2016) Protein-prime/modified vaccinia virus Ankara vector-boost vaccination overcomes tolerance in high-antigenemic HBV-transgenic mice. Vaccine. 34(7):923-32. doi: 10.1016/j.vaccine.2015.12.060.

Project in detail +

In this funding period we aim to understand how HBV prevents vaccine-induced immunity and to define a targeted approach to improve the effectiveness of therapeutic vaccination in chronic hepatitis B patients. Using the AAV-HBV preclinical HBV carrier mouse model and our clinical candidate vaccine TherVacB, we will perform single-cell RNAseq of vaccine-elicited CD4 and CD8 T-cell subpopulations in low vs. high titer persistent HBV infection to identify molecular pathways and immune check-points determining the success or failure of TherVacB. By employing multicolour flow cytometry and ad-vanced liver histology (with Z02, Z03), we will determine which cell populations are homing to the liver un-der different conditions. In collaboration with Knolle (TP05), we will decipher the role of cAMP signaling, and with Wohlleber (TP13) and Binder/Beisel (TP11), we will analyse the contribution of type I interferons. To understand whether different conditions of persistent HBV infection impact the clonality of vaccine-elicited CD8 T cells, we will characterize the T cell receptor (TCR) repertoire early and late after TherVacB immunization of HBV carrier mice using a VDJ multiomic assay and further characterization of selected TCRs in vitro. To determine whether dysfunctional vaccine-elicited CD8 T cells can be reinvigorated by additional booster vaccinations, with or without checkpoint blockade, or a secondary HBV exposure, we aim to compare hepatic and systemic recall T cell responses after TherVacB vaccination in low- vs. high-titer persistent HBV infection and after pre-treatment with HBV- and checkpoint- targeting siRNAs. Results will be integrated into the multiomics cell atlas of the HBV-infected liver developed by Z02 and Z03. The TherVacB vaccination scheme entered a phase I clinical trial in Q1/2024. This project thus offers the unique opportunity to correlate therapeutic vaccine responses in our preclinical mouse model with patient data (in collaboration with Thimme (TP01), Knolle (TP05), Böttler (TP04) and Hofmann (TP20)).