Interferon-lambda: Novel Biologics for Controlling Neutrophil-mediated Pathology in Rheumatic Diseases?

Interferon-lambda: Novel Biologics for Controlling Neutrophil-mediated Pathology in Rheumatic Diseases?

Neutrophils emerge as key immune cells in the initiation and perpetuation of immune responses in autoimmune diseases. They display marked abnormalities in phenotype and function in various autoimmune diseases, including systemic vasculitis, systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).

These neutrophils are characterised by an extended life span, increased capacity to produce reactive oxygen species, active gene expression and release of extracellular traps. Consequently, there is a need for better understanding of neutrophil phenotype and functions in these conditions, as well as for identifying molecules capable of specifically manipulating neutrophil function. The investigators have recently discovered that interferon lambdas (IFN-λs), also known as interleukin 28 (IL28) and interleukin 29 (IL29), class II cytokines with previously studied anti-viral biological functions, specifically suppress neutrophil infiltration and interleukin-1β production and thereby, halt and reverse the development of collagen induced arthritis (CIA). The investigators propose to further investigate the cellular and molecular mechanisms behind this suppression and examine the translational potential of the investigators' finding by examining the IFN-λ receptor expression and function in neutrophils isolated from the blood of healthy donors and rheumatic patients (early rheumatoid arthritis and vasculitis).

Expression of Interferon lambda receptor 1 (IFNLR1)/interleukin 28 Receptor Alpha (IL28RA) in human neutrophils.

Neutrophils will be isolated from freshly drawn human blood with subsequent removal of red blood cells with dextran and/or magnetic-activated cell sorting (MACS). The investigators' preliminary results show that neutrophils isolated from the blood of a healthy donor express higher level of IL28RA messenger Ribonucleic Acid (mRNA) compared to Cluster of Differentiation-14 (CD14) negative or CD14 positive lymphocytes. To better understand the relative spread of IL28RA mRNA levels due to human heterogeneity, the investigators will compare the levels of IL28RA expression in neutrophils isolated from blood of 20 healthy donors. The investigators will examine whether treatment of human neutrophils ex vivo with recombinant human IL29 (Bristol- Meyers Squibb, BMS) induces Signal Transducer and Activators of Transcription 1 (STAT1) signalling. The investigators will also test newly generated antibodies to human IL28RA which have shown some specificity in IL28RA detection in cell lines, on neutrophil isolated from blood.

Expression of IFNLR1/IL28RA in neutrophils isolated from blood of rheumatic patients.

The investigators will then compare the levels of IL28RA expression on neutrophils isolated from blood of (1) 15 patients in the early phases of rheumatoid arthritis (RA) and while naïve to biologic therapeutic intervention; (2) 15 vasculitis patients with giant cell arteritis (GCA) (within one week of commencing high dose glucocorticoid) and (3) 15 vasculitis patients with granulomatosis with polyangitis (GPA; Wegener's) at presentation or during a relapse, prior to initiation of immunosuppressive therapy with either cyclophosphamide or rituximab. All patients will undergo standardised assessment of disease activity and damage, i.e. the Birmingham Vasculitis Activity Score version 3.0 (BVAS 3.0) and the Vasculitis Damage Index version 1.0 (VDI) for vasculitis or the disease activity score for 28 joints (DAS-28) for RA. This will allow the investigators to predict whether rheumatic patients are likely to respond to IL29 treatment.

Functional characterisation of human neutrophils treated with IL29.

The investigators will conduct a selective evaluation of the expression of adhesion molecules, the migratory responses and functional properties of human neutrophils treated with IL29 ex vivo. These selected activities will be examined in the IL29 treated neutrophils from blood of healthy donors, with or without stimulation with lipopolysaccharide (LPS), phorbol myristate acetate (PMA) or serum from RA and vasculitis patients. The investigators will assess the impact of IL29 treatment on neutrophils isolated from the blood of patients with RA and vasculitis.

Inclusion Criteria:

• Healthy volunteer or
• Recent diagnosis of rheumatoid arthritis within 1 month or
• New diagnosis of giant cell arteritis within 1 month or
• New diagnosis of anti-neutrophil cytoplasm antibody associated vasculitis within 1 month or
• Flare of anti-neutrophil cytoplasm antibody associated vasculitis within one month

Exclusion Criteria:

• Unable to provide written informed consent