Memory Natural Killer Cells: The Hidden Forces Combating Chronic Hepatitis B — ASN Events
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  2. Poster Session Two
  3. Memory Natural Killer Cells: The Hidden Forces Combating Chronic Hepatitis B

Memory Natural Killer Cells: The Hidden Forces Combating Chronic Hepatitis B (#217)

Dishen Corey CDS Chen 1 2 , Brian BG Gloss 3 , Harout HA Ajoyan 1 , Joshua JH Halpin 4 5 6 , Kavitha KG Gowrishankar 4 5 7 , David DB Bishop 6 8 9 10 11 , Thomas TT Tu 1 , Jacob JG George 1 12 , Scott SR Read 1 2 13 , Golo GA Ahlenstiel 1 2 13
  1. STORR Liver Center, Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW, Australia
  2. Blacktown Clinical School, Western Sydney University, Blacktown, Sydney, 2148, NSW, Australia
  3. Westmead Research Hub, Westmead Institute for Medical Research, The University of Sydney, Westmead, NSW, Australia
  4. The Children's Hospital Westmead, Hawksbury Road and Hainsworth Street, Westmead, Sydney, NSW, Australia
  5. Children’s Cancer Research Unit, The Children’s Hospital, Westmead, NSW, Australia
  6. Sydney Medical School, Faculty of Medicine and Health, The University of Sydney, Sydney Camperdown, NSW, Australia
  7. School of Medical Science, Faculty of Medicine and Health, The University of Sydney, Camperdown Sydney, NSW, Australia
  8. Blood Transplant and Cell Therapies Program, Westmead Hospital, Westmead, NSW, Australia
  9. Centre for Cancer Research, Westmead Institute for Medical Research, Westmead, NSW, Australia
  10. Department of Haematology, Institute for Clinical Pathology and Medical Research, NSW Health Pathology, Westmead, NSW, Australia
  11. Department of Haematology, Westmead Hospital, Westmead, NSW, Australia
  12. Westmead Hospital, WSLHD, Westmead, NSW, Australia
  13. Blacktown Hospital, WSLHD, Blacktown, NSW, Australia

Chronic Hepatitis B (CHB) affects over 300 million people globally, causing 800,000 annual deaths. Current therapies fail to reduce hepatitis B virus (HBV) surface antigen (HBsAg), driving viral persistence. Natural Killer (NK) cells, traditionally viewed as part of the innate immune system, have been recently demonstrated to possess antigen specificity against various viruses, offering new therapeutic potential. Building on our previous work characterising HBV-specific memory NK (mNK) cells, this project aims to 1) uncover the mechanism of NK cell memory and antigen specificity, and 2) develop a protocol to expand mNK cells ex vivo. This work is the first step towards developing a novel cell therapy to eliminate HBV-infected hepatocytes in vivo.

20 healthy HBV-vaccinated individuals and 70 patients with confirmed HBV diagnosis were recruited into this study. NK cells isolated from donors showed antigen-specific enhanced degranulation and killing against dendritic cells and hepatocytes presenting HBV antigens. HBV-peptide-loaded pentamers were employed, enabling the identification and in vitro expansion (up to 15-fold increase) of rare populations of HBV peptide-specific mNK cells. A 28-colour flow cytometry panel was developed to phenotype NK cells using the state-of-the-art CYTEK-Aurora spectral flow-cytometer. Pentamer-recognising mNK cells are currently undergoing single-cell RNA sequencing and surface protein profiling using BD AbSeq technology and the BD Rhapsody platform.

We have uncovered distinct populations of mNK cells that recognise and eliminate cells presenting HBV antigens. Notably, their proliferation can be driven not only by HBV-antigen-presenting cells but also by HBV-pentamers, suggesting that in vitro clonal expansion of mNK cells may occur. The long-term goal of this project is to refine and optimise an efficient expansion protocol to generate sufficient mNK cells for therapeutic applications. Understanding how mNK cells recognise their targets, proliferate and elicit memory responses will provide critical understanding necessary to optimise ex vivo expansion pipelines.