PS-B04-12: DEVELOPMENT OF VACCINE AGAINST CONNECTIVE TISSUE GROWTH FACTOR TO PREVENT THE PROGRESSION OF RENAL FIBROSIS

Abstract

Objective: Hypertension is closely related with chronic kidney disease (CKD); Hypertension and CKD can cause and exacerbate each other, forming a vicious cycle. There is a critical need for efficient treatment of CKD. Renal fibrosis is a final common pathway to end-stage renal disease, and connective tissue growth factor (CTGF) is a well-recognized central profibrotic factor in fibrosis of various organ systems. Here, we developed a novel peptide vaccine against CTGF to prevent the progression of renal fibrosis. Design and method: Among sequences of CTGF, the sequence common to mice and humans in the interaction region with transforming growth factor-β; (TGF-β;) and bone morphogenic proteins was selected as the epitope for the vaccine. The efficacy of this vaccine was verified in two renal fibrosis models using male C57BL/6J mice: adenine-induced CKD and unilateral ureteral obstruction (UUO) models. Moreover, the functions of CTGF vaccine-elicited IgG antibodies were evaluated in an in vitro study. Results: Three immunizations with this CTGF vaccine at 2-week intervals elicited serum IgG antibodies specifically binding to human full-length CTGF, and the antigen-specific antibody titers were maintained at high level for > 30 weeks. In adenine-induced CKD model, histological analyses showed that immunization with the CTGF vaccine significantly attenuated renal interstitial fibrosis compared to the vehicle treatment (8.5 ± 0.8% vs 12.3 ± 0.8%; P < 0.01). The CTGF vaccination also suppressed the increased mRNA expressions of collagen 1α and α-smooth muscle actin (α-SMA) in kidney tissue samples. Moreover, vaccinated mice showed lower levels of serum urea nitrogen (UN) and creatinine and lower urine albumin-creatinine ratio compared with vehicle-treated mice (UN: 77.7 ± 5.0 vs 104.0 ± 6.8 mg/dL; P < 0.01. creatinine: 0.42 ± 0.02 vs 0.51 ± 0.04 mg/dL; P = 0.06. albumin-creatinine ratio: 74.7 ± 13.8 vs 132.0 ± 15.3 μg/mg; P < 0.05). In UUO model, the CTGF vaccination also ameliorated the expansion of the interstitial fibrotic areas (7.7 ± 0.4 vs 9.8 ± 0.7%; P < 0.05). In an in vitro study, CTGF vaccine-elicited IgG antibodies efficiently suppressed CTGF-induced- and TGF-β;-induced α-SMA expression in cultured kidney fibroblasts. Conclusions: The CTGF vaccine has the potential to prevent the progression of renal fibrosis and delay the deterioration of renal function with a low frequency of administration. Thus, this CTGF vaccine could be a promising preventive strategy for CKD patients.