Investigating the impact of oxygen concentration on the assembly of human papillomavirus virus like particles.

In HPV vaccine production, the thermal stability, particulate morphology, homogeneity, and immunogenicity of virus-like particles (VLPs) are critical for vaccine efficacy. Disulfide bonds play a key role in the assembly of HPV L1 pentamers into VLPs, contributing to the structural stability and immunogenicity of VLPs. This study investigated the effect of oxygen concentration on VLPs assembly using L1 pentamers of HPV types 6, 33, and 45 at the Beijing R&D Center. Experimental and control groups (with and without oxygen supplementation) were compared in terms of particle size, antigen relative potency, HPLC purity, disulfide bond content, and disulfide bond ratio at various time points. Results demonstrated that increased oxygen concentration significantly accelerated the assembly of L1 pentamers into complete VLPs and enhanced their in vitro relative potency. These findings were further validated at the Kunming Commercial Production Base, leading to optimized HPV vaccine manufacturing processes and improved vaccine potency. This study provides a scientific basis for ensuring the quality of VLPs-based vaccine antigens.