Human Respiratory Syncytial Virus was first isolated in 1956 from a laboratory chimpanzee with a respiratory illness and was later discovered to be of human origin. RSV consists of two antigenic subtypes, A and B. Subtype B is characterized as the asymptomatic strains that of which the majority of individuals experiences. The more severe illnesses and which usually predominate during outbreaks are associated with subtype A strains. RSV was determined to be the leading cause of lower respiratory tract infections particularly in young infants. The severity of the disease is very diverse ranging from mild cold symptoms to severe and life-threatening. It's the leading cause of pneumonia and bronchiolitis in infants.
An overview of RSV
RSV (Respiratory syncytial virus) is a virus that causes respiratory tract infections. RSV is a negative-sense, single-stranded RNA virus of the family Paramyxoviridae, which includes common respiratory viruses such as those causing measles and mumps. RSV is a member of the paramyxovirus subfamily Pneumovirinae, as well as a major cause of lower respiratory tract infections and hospital visits during infancy and childhood. Syncytial viruses have only one serotype, and recent molecular biological methods have shown two subtypes.
The structure of RSV
The genome consists of about 15,000 nucleotides, encoding 11 proteins, 3 transmembrane proteins (F, G, SH), 2 matrix proteins (M1, M2), 3 nucleocapsid proteins (N, P, L) and two non-structural proteins (NS1, NS2). Two glycoproteins are expressed on the surface of the virus membrane, and fusion proteins F and adhesive proteins G.
The species of RSV
According to the difference of main antigen of RSV, it can be divided into A and B subtypes. The two subtypes of RSV are independently prevalent, but type A is often dominant. None of the 10 proteins in the two subtypes are completely the same, the most significant difference is in G protein, which has only 53% amino acid homology. The same subtype can be further divided into subtype strains, among which G protein has 80~98% amino acid homology.
The inhibitor of RSV
Currently, the most effective antibody drugs include RSV immunoglobulins (RSV-IGIV) and monoclonal antibody Palivizumab. But both drugs are expensive and difficult to spread. There are also other inhibitors:
I is an effective respiratory syncytial virus (RSV) fusion inhibitor, EC 50 is 9.9.
IV RD3-0028 is an effective and selective RSV replication inhibitor with an EC 50 value of 4.5m.
V RSV604 is an RSV virus replication inhibitor, with an EC 50 value of 0.86uM and an RSV nucleoprotein inhibitor
1. Miller, M., Cho, J. Y., Baek, K. J., Castaneda, D., Nayar, J., Rodriguez, M., ... & Broide, D. H. (2002). Plasmid DNA encoding the respiratory syncytial virus G protein protects against RSV-induced airway hyperresponsiveness. Vaccine, 20 (23-24), 3023-3033.
2. Whitehead, S. S., Bukreyev, A., Teng, M. N., Firestone, C. Y., Claire, M. S., Elkins, W. R., ... & Murphy, B. R. (1999). Recombinant respiratory syncytial virus bearing a deletion of either the NS2 or SH gene is attenuated in chimpanzees. Journal of Virology, 73 (4), 3438-3442.
3. Girard, M. P., Cherian, T., Pervikov, Y., & Kieny, M. P. (2005). A review of vaccine research and development: human acute respiratory infections. Vaccine, 23 (50), 5708-5724.
Products for RSV