NOVEL THERAPY THAT SELECTIVELY TARGETS NEUTROPHIL EXTRACELLULAR TRAPS ATTENUATES INFLAMMATION AND KIDNEY INJURY IN EXPERIMENTAL ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY VASCULITIS
Dr Kim Maree O’Sullivan1, Dr Diana Tan1, Dr Stephanie (U-Shane) Huang1, Ms Anne Cao Le1, Ms Valentina Dubljevic2, Dr Deanne Greenwood2, Dr James Campbell2
1Centre for Inflammatory Diseases, Monash University, Melbourne, Australia, 2Patrys, Ltd, Melbourne, Australia
Aim: This study aimed to investigate the therapeutic benefit of a novel nuclear penetrating antibody DX-1 that specifically targets neutrophil extracellular traps (NETs) in an experimental model of anti-neutrophil cytoplasmic antibody vasculitis (AAV).
Background: AAV is characterised by small blood vessel inflammation of the kidneys and development of glomerulonephritis (GN). Neutrophils either degranulate or form NETs depositing the autoantigen myeloperoxidase (MPO) perpetuating inflammation. We hypothesised that targeting NETs with DX-1 would be therapeutic in experimental AAV.
Methods: We utilised purified human neutrophils (n=20) to perform in vitro NET, phagocytosis and cell viability assays with DX-1. We used a well-established 20-day model of anti-MPO GN. Mice received either control antibody (n=8) or intravenous DX-1 (n=8) after establishment of autoimmunity to MPO on day 16. Kidney injury was assessed via albuminuria and histology. Glomerular neutrophils, NETs, macrophage and T cell infiltration was assessed by immunohistochemistry.
Results: DX-1 inhibited NET formation in stimulated human neutrophils (P<0.05) whilst leaving healthy neutrophils untouched, with no impact on phagocytosis, nor did it trigger apoptosis or necrosis. In the experimental model, DX- 1 treated mice had significantly reduced MPO specific IFNγ and IL17A splenocytes when compared to the control group (both, P<0.05). Kidney injury was significantly reduced in the DX-1 treated group as evidenced by a reduction in segmental necrosis (P<0.001) and a reduction in protein and leukocytes in the urine (P<0.05). Glomerular neutrophils, NETs, macrophages and T cells were all significantly reduced.
Conclusions: DX-1 has no off-target effects on healthy human neutrophils. Therapeutic targeting of NETs with DX-1 in the experimental model reduced inflammation and kidney injury suggesting it may be of potential benefit as an alternative targeted treatment for AAV.
Presentation Slides PDF – Click here
Biography:
Kim O’Sullivan is the head of the Translational Kidney Therapy Group at the Centre for Inflammatory Diseases at Monash University in Melbourne. Kim has been awarded > $3 million in grant funding (2x NHMRC Ideas Grants, 1 X MRFF and Industry funding) to develop new therapeutics for anti-neutrophil cytoplasmic antibody vasculitis (AAV). Her particular area of focus is preventing the formation of Neutrophil extracellular traps (NETs) which mediate kidney damage in AAV. Her therapeutic approach is to selectively target NETs whilst keeping healthy neutrophil function intact as an alternative therapy to current standard of care which has multiple side effects.