MS. SONGNA WANG

Research on CD80 Fusion Protein in Tumor Immunotherapy

PD-1/PD-L1 immunotherapy has revolutionized cancer treatment over the past few years, but less than 30% of patients have a positive clinical response. So, we designed a CD80 fusion protein based on the nature of PD-1/PD-L1 immunotherapy and key issues that limit its efficacy. Then we constructed and expressed CD80 fusion protein by placing the extracellular domain of CD80 at the N-terminus and C-terminus of Fc using a Y-trap structure, respectively. The CD80 fusion protein can activate T cells by directly binding CD28 and blocking PD-L1 and CTLA-4 checkpoint simultaneously. Through in vivo experiments in tumor-bearing mice, we found that both proteins have good anti-tumor activities. In addition, we also constructed HER2-Fc-CD80 fusion protein, and in vivo experiments revealed that ligation of HER2 at the N-terminus did not affect the activity of CD80.