Nanoscale Mechanical and Morphological Characterization of Ebolavirus-like Particles: Implications for Therapeutic Development

Zaire Ebolavirus (EBOV) is one type of filovirus that causes the deadly EBOV disease, with an average fatality rate of around 50%. EBOV outbreaks are devastating and unpredictable and may emerge as the next global pandemic. As a BSL-4 pathogen, EBOV is inaccessible to regular biological laboratories. Therefore, EBOV virus-like particles (EBOV-VLPs) and EBOV pseudoviruses (EBOV-PVs) are utilized in the initial development of many potential therapies, for safety reasons and ease of procurement, as opposed to using infectious viruses. To investigate the host cell entry of EBOV and develop viral entry blockers, the EBOV model virions must accurately represent the morphological and mechanical properties of infectious EBOV virions. Due to the nanometer scale and irregular shape of EBOVs, these properties are challenging to characterize. In this research, state-of-the-art nanoscale characterization techniques are employed to examine the mechanical and structural elements of a selection of commonly used EBOV-approximating model virions. This study comprehensively determines the accuracy of EBOV approximation with a variety of model virions and the uniformity of mechanical and structural traits across different model virion types and preparation methods. This provides important implications for developing therapeutic treatments against EBOV using these model virions.