Breadth Redesign And Detection Of Respiratory Syncytial Virus Neutralizing Antibody

Respiratory Syncytial Virus(RSV)is one of the major pathogen which caused lower respiratory tract infection in infants and young children around the world,the infants before 2 years almost infected with RSV,50%of them will reinfect.In the latest global disease mortality analysis,about 6.7%of children death while one to twelve months were caused by RSV infection.Furthermore,infection in the elderly population will cause serious illness and death cases.There is no safe and effective vaccine yet,the only licensed RSV-specific drug is neutralization monoclonal antibody palivizumab(Synagis'),but because of its lack of affordable dose,high IMD and its high prices,palivizumab is currently only used to reduce high risk of infection in immunodeficiency and congenital heart disease children.In the previous study,we obtained a high neutralizing antibody 5C4 against protein F,which is 50-100 times more active than palivizumab in vitro.In the prophylactic experiment in mouse model,5C4 reduced RSV infection more effective compare to 1129(palivizumab mouse antibody),it is potential to develop as a drug in the future,but the 5C4's high neutralization is unique to RSV type A strain,the ability to neutralize B strain is poor.Because of its potential in the drug industry,we decided to optimize 5C4 neutralization antibody properties.In this study,the rapid design of the optimization of antibody properties was achieved by calculating the energy-based analysis and stability calculation of biology,then screened by cell experiments.Firstly,to establish a rapid mutant antibody screening system,we initially built 293F eukaryotic cell expression system,to achieve the efficient expression of mutant antibodies.Next,three neutralization 5C4 variants were selected from 34 candidate mutant antibodies by cell system,then tested in animal models.The results showed that the mutant antibodies were still maintained the same prophylactic efficacy compare to the original 5C4.Furthermore,we used predictive model that modeled the dominant mutant antibodies,and analyzed the reason why the dominant antibody neutralized with RSV B virus.These results have important implications for antibody design because they reveal the potential of computational modeling to design antibodies with improved function.The computational experiments provided enrichment for variants with improved binding,leading to an efficient laboratory process.Computational biology also provides a new direction for antibody and protein function optimization.