OP0012 INTERFERON-α MEDIATED THERAPEUTIC RESISTANCE IN EARLY RA IMPLICATES EPIGENETIC REPROGRAMMING

Background

An interferon gene signature (IGS) is present in approximately 50% of early, treatment naive rheumatoid arthritis (eRA) patients. We previously demonstrated it negatively impacts on initial disease outcomes.

Objectives

To 1) reproduce previous findings demonstrating the harmful effects of the IGS on early RA clinical outcomes, 2) identify which IFN class is responsible for the IGS and 3) seek evidence that IFN-α exposure contributes to harmful epigenetic footprint at disease onset.

Methods

In a large multicentre inception cohort (n=190) of eRA patients (RA-MAP TACERA) whole blood transcriptome, IGS (MxA, IFI44L, OAS1, ISG15, IFI6) and circulating interferons (IFN)-α, -β, -γ and -λ was examined at baseline and 6 months in conjunction with disease activity and clinical characteristics. A separate eRA cohort of paired methylome and transcriptome from CD4 T and CD19 B cells (n=41 for each) was used to explore any epigenetic influence of the IGS.

Results

The baseline IGS reproducibly and significantly negatively impacts on 6-month clinical outcomes. In the high IGS cohort there was increased DAS-28 (p=0.025) and reduced probability of achieving a good EULAR response (p=0.034) at 6-months. In addition, the IGS in eRA is shown for the first time to predominantly reflect raised circulating IFN-α protein, not other classes of IFN and examination of whole blood upstream nucleic acid sensors expression suggest a RNA trigger. Both the IGS and IFN-α significantly fell in parallel at 6 months (p<0.0001), whereas other classes of IFN remained statistically static. There was a significant association with IFN-α and RF titre but not ACPA. Comparison of CD4 T and CD19 B cells between IGS high and low eRA patients demonstrated differentially methylated CPG sites and altered transcript expression of disease relevant genes e.g. PARP9, STAT1, EPTSI1 which was similarly, and persistently, altered 6 months in the separate TACERA cohort. Differentially methylated CPGs implicated altered transcription factor binding in B cells (GATA3, ETSI, NFATC2, EZH2) and T cells (p300, HIF1α) which cumulatively suggested IFN-α induced epigenetic changes promoting increased, and sustained, lymphocyte activation, proliferation and loss of anergy in the IGS high cohort.

Conclusion

We validate that the IGS is a robust prognostic biomarker in eRA predicting poor therapeutic response. Its persistent harmful effects may be driven via epigenetic modifications. These data have relevance for other IFN-α states, such as COVID-19, but also provide a rationale for the initial therapeutic targeting of IFN-α signalling, such as with JAKi, at disease onset in stratified eRA subsets.

References

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Acknowledgements

JDI is a National Institute for Health Research (NIHR) Senior Investigator. The authors acknowledge the support of TACERA Principal Investigators from all contributing NHS sites and the members of the TACERA Study Steering and Data Monitoring Committee. Additional acknowledgements include patient volunteers and administrative support from Ben Hargreaves. Newcastle researchers received infrastructural support via the Versus Arthritis Research into Inflammatory Arthritis Centre (Ref 22072), funding from The Medical Research Council; Academy of Medical Sciences; British Society of Rheumatology; The Wellcome Trust; JGW Patterson Foundation; Immune-Mediated Inflammatory Disease Biobank in the UK (IMID-Bio-UK), ANR and RTCure. This work was supported by the NIHR Newcastle Biomedical Research Centre at Newcastle Hospitals Foundation Trust and Newcastle University; views expressed are the authors’ and not necessarily those of the National Health Service, the National Institute of Health Research or the Department of Health.

Disclosure of Interests

Faye Cooles Speakers bureau: Astrazeneca: December 2021, Jessica Tarn: None declared, Dennis Lendrem: None declared, Najib Naamane: None declared, Alice Lin: None declared, Ben Millar: None declared, Nicola Maney: None declared, Nishanthi Thalayasingam: None declared, Vincent Bondet: None declared, Darragh Duffy: None declared, Michael Barnes: None declared, Graham Smith: None declared, Sandra Ng: None declared, David Watson: None declared, Rafael Henkin: None declared, Andrew Cope: None declared, Louise Reynard: None declared, Arthur Pratt: None declared, RA-MAP Consortium: None declared, John Isaacs Speakers bureau: speaker/consulting fees from AbbVie, Gilead, Roche and UCB., Grant/research support from: JDI discloses research grants from Pfizer, Janssen and GSK.

HIV DNA reservoir and elevated PD-1 expression of CD4 T-cell subsets particularly persist in the terminal ileum of HIV-positive patients despite cART

OBJECTIVES

Despite its importance as an HIV anatomic sanctuary, little is known about the characteristics of the HIV reservoir in the terminal ileum (TI). In blood, the immune checkpoint inhibitor programmed-death-1 (PD-1) has been linked to the HIV reservoir and T-cell immune dysfunction. We thus evaluated PD-1 expression and cell-associated HIV DNA in memory CD4 T-cell subsets from TI, peripheral blood (PB) and rectum (RE) of untreated and treated HIV-positive patients to identify associations between PD-1 and HIV reservoir in other sites.

METHODS

Using mononuclear cells from PB, TI and RE of untreated HIV-positive (N = 6), treated (n = 18) HIV-positive and uninfected individuals (n = 16), we identified and sorted distinct memory CD4 T-cell subsets by flow cytometry, quantified their cell-associated HIV DNA using quantitative PCR and assessed PD-1 expression levels using geometric mean fluorescence intensity. Combined HIV-1 RNA in situ hybridization and immunohistochemistry was performed on ileal biopsy sections.

RESULTS

Combined antiretroviral therapy (cART)-treated patients with undetectable HIV RNA and significantly lower levels of HIV DNA in PB showed particularly high PD-1 expression in PB and TI, and high HIV DNA levels in TI, irrespective of clinical characteristics. By contrast, in treatment-naïve patients HIV DNA levels in memory CD4 T-cell subsets were high in PB and TI.

CONCLUSION

Elevated PD-1 expression on memory CD4 T-cells in PB and TI despite treatment points to continuous immune dysfunction and underlines the importance of evaluating immunotherapy in reversing HIV latency and T-cell reconstitution. As HIV DNA particularly persists in TI despite cART, investigating samples from TI is crucial in understanding HIV immunopathogenesis.