How does HBV interact with the immune system? International Workshop on HBV Cure Toronto 2017 Mala Maini Division of Infection and Immunity UCL
Disclosures Mala Maini: collaborative research funding from Gilead Sciences, Roche and Immunocore advisory boards and /or consultant for Gilead Sciences, Roche, Arbutus Biopharma
CD8 T cell depletion and dysfunction in persistent HBV? Acute resolving HBV Chronic HBV CD8 T cells Granzyme Perforin INF-g TNF-a IL-2 Infected hepatocytes Effective T cells control virus Infected hepatocytes Exhausted T cells loose control of virus
Restoration of endogenous T cells for functional cure Acute resolving HBV Chronic HBV CD8 T cells Granzyme Perforin INF-g TNF-a IL-2 Infected hepatocytes Effective T cells control virus Infected hepatocytes Exhausted T cells loose control of virus Feasible? Safe? How? In whom? Reviewed in Maini and Pallett, Lancet Gastro Hep in press
High antigen load and the liver environment drive T cell exhaustion in HBV Persistent high antigen load Infected hepatocytes + Defective particles 10 3-10 6 fold excess over virions Tolerogenic liver environment Hepatocyte Blood from portal vein MAIT B cell CD4 NK CD8 T reg Space of Disse LSEC MDSC Kupffer cell Stellate cell
Multiple immune defects in HBV infection B cells skewed: IL-10-mediated T cell suppression Das JI 2012 B cell MAIT CD4 NK CD8 T reg Space of Disse MDSC Hepatocyte LSEC Kupffer cell Classical memory B cells replaced with atypicals Stellate cell Burton unpublished
Multiple immune defects in HBV infection Hepatocyte MAIT NK T reg Space of Disse LSEC MDSC Kupffer cell CD4 CD8 Stellate cell NK cells have defective IFN-g production Oliviero Gastro 2009 Bonorino J Hep 2009 Peppa PLoS Path 2010 Tjwa J Hep 2011
HBV hijacks the tolerogenic liver landscape Hepatocyte NK T reg Space of Disse LSEC Rapid, contact-dependent NK cell killing of HBV-specific T cells Kupffer cell CD4 CD8 Peppa JEM 2013 Boni Hepatol 2015 Huang JI 2017 Stellate cell Liver-resident NK cells have inducible TRAIL Stegmann et al, Sci Rep 2016 HBV-specific T cells upregulate TRAIL-R2 rendering them susceptible to NK cell-mediated deletion
HBV hijacks the tolerogenic liver landscape HBV-specific T cells are exhausted and pro-apoptotic Hepatocyte MAIT NK T reg Space of Disse LSEC MDSC Kupffer cell B cell CD4 CD8 Stellate cell Intrahepatic priming predisposes to Bim-mediated apoptosis Lopes et al JCI 2008 Ongoing exposure to co-inhibitory receptors and immunoregulatory cytokines drives exhaustion Dunn et al Gastroenterology 2009, Schurich et al Hepatology 2011, Das et al JI 2012 Nebbia et al PLoS One 2012, Schurich et al PLoS Path 2013
IL-12 synergises PD-1 rescue and overcomes mitochondrial defects
Going deeper than Checkpoint inhibitors: Targeting mitochondrial dysfunction Reversal of defects with mitochondrial antioxidants Mito-Q and MitoTempo
Metabolic checkpoints in HBV infection HBV-specific T cells are exhausted and pro-apoptotic Hepatocyte MAIT NK T reg Space of Disse LSEC MDSC Kupffer cell CD4 CD8 NK cells have defective IFN-g production NK cells delete HBV-specific T cells Stellate cell MDSC inhibit T cells through nutrient deprivation Das JEM 2008 Pallett Nat Med 2015
Expanded arginase+ myeloid-derived suppressor cells deprive T cells of arginine Hepatocyte Laura Pallett CD4 NK CD8 T reg Space of Disse LSEC MDSC Kupffer cell MDSC inhibit T cells through nutrient deprivation Stellate cell gmdsc
gmdsc (% of myeloid) Arginase I MFI ( 10 3 ) CD63 MFI Degranulating arginase+ gmdsc accumulate in the liver Hepatocyte Circulation NK T reg Space of Disse MDSC LSEC Kupffer cell CD4 CD8 Stellate cell Liver gmdsc: 60 Frequency Arginase Degranulation *** 30 ** 4,000 ** 40 20 3,000 2,000 20 10 1,000 0 PBMC IHL 0 PBMC IHL 0 PBMC IHL
Metabolic regulation of T cells in viral hepatitis gmdsc arginase1 depletes extracellular arginine Pallett et al, Nat Med 2015 T cell arginase2 depletes intracellular arginine Geiger et al, Cell 2016 Arginine starvation of T cells: Impairs T cell proliferation, survival & antiviral function?drives mitochondrial defects
Boosting immunity in HBV: will it be safe? The trade-off between immunity and immunopathology HBV is a non-cytopathic virus Resultant liver disease is immune-mediated Immune responses e.g. CD8 T cells can mediate protection and liver injury Hepatic flares an inevitable result of effective immune boosting? Minimise antigen load need studies on extent of infected hepatocytes Select patients with good liver reserve Focus T cell boosting on HBV-specific component Develop adjunctive approaches to limit collateral damage
Which patients should be targeted for HBV functional cure? No consensus May vary depending on therapeutic strategy Suppressed on antivirals +/- prior HBeAg seronconversion Low level carriers Consider early in course of disease/younger patients -early HBV integration -major pool of infection -subtle liver damage -immune system less exhausted : Experimental immunotherapies can be tested first in HBV-related HCC e.g. Nivolumab
Tissue-resident T cells: front-line sentinels Laura Pallett Circulation Liver
CD103 % CD69 + CD103 + CD8+ T cells (as % of CD8+) CD8 T cells expressing tissue-retention signals sequestered in healthy human liver Blood Liver 0.53 30.1 7.2 25 20 15 Healthy liver CRC margin Perfusate **** **** **** CD69 + CD103 + tissue-resident population 10 5 69 CD69 0 Blood Liver 16 colour flow cytometry of 54 fresh liver samples Transcriptionally distinct: T-bet lo Eomes lo Blimp-1 hi Hobit lo Pallett et al J Exp Med 2017
(% CD45RA - ) (% CD45RA - ) (% CD45RA - ) Expansion of liver-resident CD8 T cell compartment in HBV immune controllers 60 **** 80 **** % CD69 + CD103 + T RM 40 20 0 Blood Liver HBV % CD69 + CD103 + T RM 60 40 20 0 Control HBV % CD69 + CD103 + T RM 40 30 20 10 **** ** * 0 2x10 3 2x10 3-2x10 5 Viral load (IU/ml) 2x10 5 healthy
Multispecific HBV-specific T cells compartmentalised in the liver following HBV resolution Resolved HBV: sag-, anti-hbc+ Only reactivate upon immune suppression Gold-standard immune response to HBV Liver immunity never previously studied in this setting Overnight peptide stimulation of liver perfusate from HBV resolved donor:
Tissue-resident T cells in the human liver: Poised for frontline defence Hepatocyte NK T reg Space of Disse LSEC Kupffer cell CD4 CD8 Stellate cell Define signature of tissue-resident CD8 T cells in human liver --cannot be sampled in periphery -expand in HBV especially in those with good viral control -features that instruct their retention, survival, rapid non-cytolytic antiviral function -signals capable of recapitulating their induction Aim for induction of tissue-resident memory cells for functional cure Need for liver sampling in functional cure studies
Ross Lopes Abhishek Das Claire Dunn Pooja Khanna Lorenzo Micco Gaia Nebbia Wei-Chen Huang Simran Singh Itziar Otano Kasha Singh Dimitra Peppa Emily Colbeck UCL collaborators Niclas Thomas Nathan Davies Victoria Male Guiseppe Fusai Eleni Nastouli Richard Gilson Amir Gander Brian Davidson Francis Robertson William Rosenberg Tu Vinh Luong Acknowledgements Division of Infection and Immunity, UCL Barts & the London Hospital Upkar Gill Jyoti Hansi Patrick Kennedy All healthy donors, patients and clinic staff Laura Pallett Kerstin Stegmann Anna Schurich Jessica Davies Nicholas Easom Alice Burton Nathalie Schmidt Leo Swadling Mariana Diniz Kornelija Suveizdyte Oliver Amin University of Dundee Linda Sinclair Doreen Cantrell A*Star, Singapore Antonio Bertoletti