TP02: Virus-specific CD8+ T cell responses in hepatitis B virus/ hepatitis D virus co-infection: mechanisms of failure and strategies for restoration

Based on the identification of HDV-specific CD8+ T cell epitopes achieved during the first funding period, we will now study the mechanisms of HDV- as well as HBV-specific CD8+ T cell failure in persistent HBV/HDV co-infection. These analyses will include low input/single cell RNAseq, metabolic studies as well as high-dimensional cytometry analyses. In addition, strategies to restore T cell function will be tested, including checkpoint inhibition, addition of pro-inflammatory cytokines and TCR re-direction. Finally, we will take advantage of novel antiviral therapies for HBV/HDV co-infection and analyze the effect of antigen removal on virus-specific CD8+ T cells in HBV/HDV co-infection.

Prof. Dr. Christoph Neumann-Haefelin

Schulien I, Kemming J, Oberhardt V, Wild K, Seidel LM, Killmer S, Sagar, Daul F, Salvat Lago M, Decker A, Luxenburger H, Binder B, Bettinger D, Sogukpinar O, Rieg S, Panning M, Huzly D, Schwemmle M, Kochs G, Waller CF, Nieters A, Duerschmied D, Emmerich F, Mei HE, Schulz AR, Llewellyn-Lacey S, Price DA, Boettler T, Bengsch B, Thimme R, Hofmann M, Neumann-Haefelin C. Characterization of pre-existing and induced SARS-CoV-2-specific CD8+ T cells. Nat Med. 2020 Nov 12. doi: 10.1038/s41591-020-01143-2. (TP01, TP02, TP11, TP20, TP21)

Kemming J, Thimme R, Neumann-Haefelin C. Adaptive Immune Response against Hepatitis C Virus. Int J Mol Sci. 2020 Aug 6;21(16):5644. doi: 10.3390/ijms21165644. (TP01, TP02)

Smits M, Zoldan K, Ishaque N, Gu Z, Jechow K, Wieland D, Conrad C, Eils R, Fauvelle C, Baumert TF, Emmerich F, Bengsch B, Neumann-Haefelin C, Hofmann M, Thimme R, Boettler T. 2020. Follicular T helper cells shape the HCV-specific CD4 T cell repertoire after viral elimination. J Clin Invest. 130(2):998-1009. (TP01, TP01A, TP02, TP04, Z02)

A. Karimzadeh H, Kiraithe MM, Oberhardt V, Salimi Alizei E, Bockmann J, Schulze Zur Wiesch J, Budeus B, Hoffmann D, Wedemeyer H, Cornberg M, Krawczyk A, Rashidi-Alavijeh J, Rodríguez-Frías F, Casil-las R, Buti M, Smedile A, Alavian SM, Heinold A, Emmerich F, Panning M, Gostick E, Price DA, Timm J, Hofmann M, Raziorrouh B, Thimme R, Protzer U, Roggendorf M, Neumann-Haefelin C. 2019. Muta-tions in hepatitis D virus allow it to escape detection by CD8+ T cells and evolve at the population lev-el. Gastroenterology. 156(6):1820-1833.

B. Schuch A, Salimi Alizei E, Heim K, Wieland D, Kiraithe MM, Kemming J, Llewellyn-Lacey S, Sogukpinar Ö, Ni Y, Urban S, Zimmermann P, Nassal M, Emmerich F, Price DA, Bengsch B, Luxenburger H, Neumann-Haefelin C, Hofmann M, Thimme R. 2019. Phenotypic and functional differences of HBV core-specific versus HBV polymerase-specific CD8+ T cells in chronically HBV-infected patients with low viral load. Gut. 68(5):905-915.

C. Schuch A, Zecher BF, Müller PA, Correia MP, Daul F, Rennert C, Tauber C, Schlitt K, Boettler T, Neumann-Haefelin C, Hengel H, Pircher H, Cerwenka A, Thimme R, Hofmann M. 2019. NK-cell re-sponses are biased towards CD16-mediated effector functions in chronic hepatitis B virus infection. J Hepatol. 70(3):351-360.

D. Jacobi FJ, Wild K, Smits M, Zoldan K, Csernalabics B, Flecken T, Lang J, Ehrenmann P, Emmerich F, Hofmann M, Thimme R, Neumann-Haefelin C, Boettler T. 2019. OX40 stimulation and PD-L1 blockade synergistically augment HBV-specific CD4 T cells in patients with HBeAg-negative infection. J Hepatol. 70(6):1103-1113.

E. Lang J, Neumann-Haefelin C, Thimme R. Immunological cure of HBV infection. 2019. Hepatol Int. 13(2):113-124.

F. Luxenburger H, Graß F, Baermann J, Boettler T, Marget M, Emmerich F, Panning M, Thimme R, Nitsch-ke K, Neumann-Haefelin C. 2018. Differential virus-specific CD8(+) T-cell epitope repertoire in hepatitis C virus genotype 1 versus 4. J Viral Hepat 25(7):779–790.

G. Grünvogel O, Colasanti O, Lee JY, Klöss V, Belouzard S, Reustle A, Esser-Nobis K, Hesebeck-Brinckmann J, Mutz P, Hoffmann K, Mehrabi A, Koschny R, Vondran FWR, Gotthardt D, Schnitzler P, Neumann-Haefelin C, Thimme R, Binder M, Bartenschlager R, Dubuisson J, Dalpke AH, Lohmann V. 2018. Secretion of hepatitis C virus replication intermediates reduces activation of toll like receptor 3 in hepatocytes. Gastroenterology. 154(8):2237-2251.

H. Karimzadeh H, Kiraithe MM, Kosinska AD, Glaser M, Fiedler M, Oberhardt V, Salimi Alizei E, Hofmann M, Mok JY, Nguyen M, van Esch WJE, Budeus B, Grabowski J, Homs M, Olivero A, Keyvani H, Ro-dríguez-Frías F, Tabernero D, Buti M, Heinold A, Alavian SM, Bauer T, Schulze Zur Wiesch J, Razior-rouh B, Hoffmann D, Smedile A, Rizzetto M, Wedemeyer H, Timm J, Antes I, Neumann-Haefelin C, Protzer U, Roggendorf M. 2018. Amino acid substitutions within HLA-B*27-restricted T cell epitopes prevent recognition by hepatitis delta virus-specific CD8+ T cells. J Virol. 92:e01891-17.

I. Neumann-Haefelin C, Thimme R. 2018. Entering the spotlight: hepatitis B surface antigen-specific B cells. J Clin Invest. 128(10):4257-4259.

J. Wieland D, Kemming J, Schuch A, Emmerich F, Knolle P, Neumann-Haefelin C, Held W, Zehn D, Hofmann M, Thimme R. 2017. TCF1(+) hepatitis C virus-specific CD8(+) T cells are maintained after cessation of chronic antigen stimulation. Nat Commun 8:15050.

Project in detail +

Chronic HBV/HDV co-infection is associated with the fastest progression to liver cirrhosis, liver failure, and hepatocellular carcinoma amongst all chronic viral hepatitis infections. To date, therapeutic options are lim-ited to pegylated interferon-alfa (pegIFN-α) and only 20-30% of patients have long-term benefits. New antivi-ral strategies such as the cell entry inhibitor myrcludex B may strongly enhance sustained virological re-sponse rates, but according to recent clinical trial data, in HBV/HDV co-infection combination with pegIFN-α or long-term treatment is required. Thus, immune-based approaches may be promising antiviral strategies against HBV/HDV co-infection. Virus-specific CD8+ T cells are of special interest in this setting, however, until very recently, no HDV-specific CD8+ T cell epitopes had been described and the role of HBV-specific CD8+ T cells in HBV/HDV co-infection remains elusive. In the first funding period, we have identified the first HDV-specific CD8+ T cell epitopes and have described a role of CD8+ T cell exhaustion as well as viral escape in the failure of HDV-specific CD8+ T cells in persistent infection (Karimzadeh, Kiraithe, Oberhardt et al., 2019; Karimzadeh et al., 2018). These findings offer the unique opportunity to study the mechanisms of HDV- as well as HBV-specific CD8+ T cell failure in persistent HBV/HDV co-infection and to test strategies for T cell restoration. In the next funding period, we will thus compare HDV- and HBV-specific CD8+ T cell exhaustion by analysing T cell transcriptional profiles, metabolism and phenotypes with the aim to identify differences in the exhaustion phenotype of virus-specific CD8+ T cells between HBV mono- and HBV/HDV co-infection and also to identify master regulators of T cell exhaustion as targets for new antiviral ap-proaches. We will perform low input/single cell RNAseq (in collaboration with Thimme, Hofmann and Z03N), metabolic studies including analyses of glucose metabolism and mitochondrial function (in collaboration with Bengsch) as well as high-dimensional cytometry analyses (in collaboration with Thimme, Hofmann, Bengsch and Z02). These studies will be correlated with observations regarding innate immunity in the same patients (in collaboration with Cerwenka and Urban). We will also test different strategies to restore HDV-specific CD8+ T cells in vitro. These strategies will include co-culture with checkpoint inhibitors and addition of cytokines as well as TCR re-direction of naïve CD8+ T cells (in collaboration with Protzer, Lohmann and Urban). Last, we will analyse the impact of novel therapies (such as the entry inhibitor myrcludex B, the far-nesyltransferase inhibitor lonarfarnib, and the nucleic acid polymer REP 2139) on HDV- and HBV-specific T cell restoration (in collaboration with Urban, Bartenschlager and Thimme). In sum, this project will define the mechanisms of virus-specific CD8+ T cell failure in chronic HBV/HDV co-infection and guide the way to-wards immune-based antiviral strategies. These strategies may become essential for patients that do not clear HDV by long-term treatment with novel antiviral compounds such as myrcludex B and do not tolerate the strongly synergistc pegIFN-α.

Milestones of the first funding period:
- Repertoire of HBV- and HDV-specific CD8+ T cell responses and associated viral escape mutations in HBV mono- and HBV/HDV co-infection
- Determinants and limitations of viral escape in HBV infection
- Relative contribution of HBV- and HDV-specific CD8+ T cell responses in HBV/HDV co-infection and strategies to enhance antiviral CD8+ T cell responses