A UNIQUE AND NOVEL Fc-FUSION I-BODY AD-214 ATTENUATES KIDNEY FIBROSIS THROUGH BLOCKING LEUKOCYTE INFILTRATION
Qinghua Cao1, Michael Foley 2, Anthony Gill3, Angela Chou3, Xin-Ming Chen1, Carol Pollock1 1Kolling Institute of Medical Research, Royal North Shore Hospital, Sydney Medical School, The University Of Sydney, St Leonards, NSW, Australia2AdAlta Pty. Ltd., Bundoora, Victoria, Australia3Department of Anatomical Pathology, NSW Health Pathology, Royal North Shore Hospital, St Leonard, NSW, Australia
Abstract
Aim: To define the role of i-body AD-214 in renal fibrosis.
Background: Tissue fibrosis is the common pathological pathway in progressive chronic kidney disease (CKD). Current clinical practices are ineffective in limiting renal fibrosis. CXCR4 has been demonstrated to be central to the development of fibrosis. An i-body is a human protein engineered with two loops that mimic the shape of shark antibodies. The second generation i-body AD-214 binds with high affinity to CXCR4. AD-214 has been shown to be effective in limiting lung fibrosis. However, the role of AD-214 in renal fibrosis has not been investigated.
Methods: Renal proximal tubular cells (PTC) were incubated with TGFβ1 with/without AD-214 for 48 hours. Supernatant was collected and collagen-3 (Col-3) and collagen-4 (Col-4) were measured by Western blot. Mice with unilateral ureteral obstruction (UUO) were administrated AD-214 every two days for 14 days. Changes in renal morphology were examined by H&E and PSR staining. Renal histology, mRNA, analysed by qRT-PCR, extracellular matrix (ECM) and leukocyte markers detected by immunohistochemistry (IHC) and kidney function, assessed by the blood urea nitrogen (BUN) and kidney injury molecule-1 (KIM-1) were examined.
Results: AD-214 suppressed TGFβ1-induced overexpression of Col-3 and Col-4 by RPTEC cells compared to negative control. In UUO model, administration of AD-214 significantly attenuated the COL-4 and FN deposition by 74.4% and 34.6% respectively (P<0.01) relative to negative i-body treatment group. Consistently, BUN (38% reduction) and KIM-1(33% reduction) were markedly reduced in mice treated with AD-214. Mechanism studies revealed AD-214 inhibited the infiltration of leukocytes into UUO kidneys.
Conclusions: Blocking CXCR4 using the i-body AD-214 is a promising therapeutic strategy to prevent the development of CKD.
Biography
Dr Cao’s research aims to develop innovative strategies to both prevent and treat CKD. Specifically, Dr Cao investigates the renoprotective effects of gene editing and potential translational value of novel proteins including a small molecule, a protein scaffold which mimic the shape of shark antibodies and a scorpion toxin analogue in clinically relevant models of CKD. In addition, by collaborating closely with clinicians, Dr Cao have been working towards identifying novel biomarkers reflecting kidney maldevelopment in preterm born infants.