A novel nanobody-heavy chain antibody against Angiopoietin-like protein 3 reduces plasma lipids and relieves nonalcoholic fatty liver disease

Xiaozhi Hu, Jiajun Fan, Qianqian Ma, Lei Han, Zhonglian Cao, Caili Xu, Jingyun Luan, Guangjun Jing, Yanyang Nan, Tao Wu, Yuting Zhang, Hanqi Wang, Yuanzhen Zhang, Dianwen Ju

Nonalcoholic fatty liver disease (NAFLD) is a metabolic disease mainly on account of hypercholesterolemia and may progress to cirrhosis and hepatocellular carcinoma. The discovery of effective therapy for NAFLD is an essential unmet need. Angiopoietin-like protein 3 (ANGPTL3), a critical lipid metabolism regulator, resulted in increased blood lipids and was elevated in NAFLD. Here, we developed a nanobody-heavy chain antibody (VHH-Fc) to inhibit ANGPTL3 for NAFLD treatment. In this study, we retrieved an anti-ANGPTL3 VHH and Fc fusion protein, C44-Fc, which exhibited high affinities to ANGPTL3 proteins and rescued ANGPLT3-mediated inhibition of lipoprotein lipase (LPL) activity. The C44-Fc bound a distinctive epitope within ANGPTL3 when compared with the approved evinacumab, and showed higher expression yield. Meanwhile, C44-Fc had significant reduction of the triglyceride (~ 44.2%), total cholesterol (~ 36.6%) and LDL-cholesterol (~ 54.4%) in hypercholesterolemic mice and ameliorated hepatic lipid accumulation and liver injury in NAFLD mice model. We discovered a VHH-Fc fusion protein with high affinity to ANGPTL3, strong stability and also alleviated the progression of NAFLD, which might offer a promising therapy for NAFLD.