TP07: Dissecting NK cell-reactivity against hepatitis virus infection

The complexity of the innate immune response mediated by Natural Killer (NK) cells and other tissue-resident Innate Lymphoid Cell (ILC) subsets against different hepatitis viruses remains incompletely understood. Thus, in our project, we will study NK/ILC activation/dysfunction/exhaustion in response to HBV/HDV co-infection using in vitro co-culture systems and cells from hepatitis patients. Results of our study will not only facilitate the development of novel treatment options e.g. for HBV/HDV infection, but will also provide novel insight into general anti-viral mechanisms of NK cells and ILC subsets and their tissue specificity.

Prof. Dr. Adelheid Cerwenka

Groth C, Maric J, Garcés Lázaro I, Hofman T, Zhang Z, Ni Y, Keller F, Seufert I, Hofmann M, Neumann-Haefelin C, Sticht C, Rippe K, Urban S, Cerwenka A. (2023) Hepatitis D infection induces IFN-β-mediated NK cell activation and TRAIL-dependent cytotoxicity. Front Immunol. 14:1287367 doi: 10.3389/fimmu.2023.1287367.

Pollmann J, Götz JJ, Rupp D, Strauss O, Granzin M, Grünvogel O, Mutz P, Kramer C, Lasitschka F, Lohmann V, Björkström NK, Thimme R, Bartenschlager R, Cerwenka A. (2018) Hepatitis C virus-induced natural killer cell proliferation involves monocyte-derived cells and the OX40/OX40L axis. J Hepatol. 68, 421-430. doi: 10.1016/j.jhep.2017.10.021.

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 responses are biased towards CD16-mediated effector functions in chronic hepatitis B virus infection. J Hepatol. 70, 351-360. doi: 10.1016/j.jhep.2018.10.006.

Pahl JHW, Cerwenka A, Ni J. (2018) Memory-Like NK Cells: Remembering a Previous Activation by Cytokines and NK Cell Receptors. Front Immunol. 9:2796. doi: 10.3389/fimmu.2018.02796.

Siegler JJ, Correia MP, Hofman T, Prager I, Birgin E, Rahbari NN, Watzl C, Stojanovic A, Cerwenka A. (2022) Human ILC3 Exert TRAIL-Mediated Cytotoxicity Towards Cancer Cells. Front Immunol. 13, 742571. doi: 10.3389/fimmu.2022.742571.

Ni J, Wang X, Stojanovic A, Zhang Q, Wincher M, Bühler L, Arnold A, Correia MP, Winkler M, Koch P-S, Sexl V, Höfer T, Cerwenka A. (2020) Single-Cell RNA Sequencing of Tumor-Infiltrating NK Cells Reveals that Inhibition of Transcription Factor HIF-1α Unleashes NK Cell Activity. Immunity. 52, 1075-1087.e1078. doi: 10.1016/j.immuni.2020.05.001.

Papaioannou S, See JX, Jeong M, De La Torre C, Ast V, Reiners-Koch PS, Sati A, Mogler C, Platten M, *Cerwenka A, *Stojanovic A. (2023) Liver sinusoidal endothelial cells orchestrate NK cell recruitment and activation in acute inflammatory liver injury. Cell Rep. 42, 112836. doi: 10.1016/j.celrep.2023.112836. *shared last authors

Cerwenka A, Lanier LL. (2016) Natural killer cell memory in infection, inflammation and cancer. Nat Rev Immunol. 16, 112-123. doi: 10.1038/nri.2015.9.

Project in detail +

Viral hepatitis is a major health challenge that in many cases leads to fibrosis, liver cirrhosis and hepato-cellular carcinoma. The complexity of the innate immune response mediated e.g. by natural killer (NK) cells and other innate lymphocytes against different hepatitis viruses remains incompletely understood. In hepatitis C virus (HCV) infection, together with Bartenschlager, our previous study revealed a NK cell/myeloid cell cross-talk involving the OX40/OX40L axis that triggers NK cell proliferation. Together with Hofmann and Thimme we investigated NK cell heterogeneity in hepatitis B virus (HBV)-infected patients and observed an expansion of memory-like CD16-reactive NK cells. During the last funding period in close collaboration with Urban and Neumann-Haefelin, we focused on the potential of NK cells to target hepatitis D virus (HDV)-infected hepatocytes . We established an in vitro infection model with different HDV-infected hepatic cell lines co-cultured with primary human peripheral blood NK cells. Results were validated in hepatitis patient cohorts. Upon co-culture with HDV-infected hepatocytes, we observed robust NK cell activation. NK cells upregulated the activation marker CD69, interferon-stimulated genes (ISGs), including the death receptor ligand TNF-related apoptosis-inducing ligand (TRAIL), produced inter-feron (IFN)-γ and eliminated HDV-infected cells. The killing involved the interaction of TRAIL on NK cells with its receptor TRAIL-R2 on infected hepatocytes. Moreover, we identified IFN-β released by HDV-infected cells as an important enhancer of NK cell activity. Preliminary flow cytometric analysis of PBMCs from HBV/HDV coinfected patients revealed a reduction of circulating NK cells, which was associated with a shift towards the CD56bright NK cell compartment. Upon clearance of the infection, both the NK cell frequency and the shift in NK cell composition returned to steady state. For the next funding period, with Urban/Nkongolo we will focus on the innate immune cell response to HBV/HDV coinfection and decipher the molecular underpinnings how HBV/HDV coinfection modulates the reactivity of NK cells and other innate (-like) lymphocytes. To this end, we are currently refining the in vitro HBV/HDV coinfection model and co-cultures with NK cells and innate lymphoid cell subsets. Moreover, we will investigate co-cultures with γδ T cells that are considered innate (-like) cells that can reside in livers, express NK cell receptors and can perform NK-like reactivity. We hypothesize that HDV/HBV-infected hepatocytes use distinct and shared mechanisms to activate/escape from different types of innate (-like) cells. Since the infected liver harbors different innate (-like) lymphocytes in a unique microenvironment, we will study these effector cells with anti-viral potential in close collaboration with Knolle (myeloid cell states) and Böttcher (mucosal-associated invariant T (MAIT) cells). We will address effects of hypoxia present in infected livers, which can impair NK cell reactivity and decipher the role of IFNs, with a focus on IFN-λ in the innate immune crosstalk together with Bartenschlager and Binder/Beisel. Together with Z02 and Z03, we will visualize innate immune cells within infected livers, dissect their tissue niches and with Neumann-Haefelin/Luxenburger investigate innate (-like) immune cells during therapy of hepatitis patients. The results obtained by our study will provide insight into how to mobilize the potential of innate (-like) immune cells against persistent hepatitis virus infection without causing extensive tissue damage.