New Publication from the Researchers at IBT
Efforts to develop effective vaccines against Staphylococcus aureus (S. aureus) have been largely unsuccessful, in part due to the variety of virulence factors produced by this organism. Recently, researchers lead by Dr. Rajan Adhikari at IBT have published a paper entitled 'Novel Structurally Designed Vaccine for S. aureus ?-Hemolysin: Protection against Bacteremia and Pneumonia' in PLoS ONE , an international, peer-reviewed, open-access, online publication. S. aureus alpha-hemolysin (Hla) is a pore-forming toxin expressed by most S. aureus strains and reported to play a key role in the pathogenesis of skin and soft tissue infections and pneumonia.
This article describes a novel recombinant subunit vaccine candidate for Hla, rationally designed based on the heptameric crystal structure. The vaccine candidate, called AT-62aa, has shown significant protection against pneumonia and is the first to be reported to reduce bacterial dissemination and to provide protection in a sepsis model of S. aureus infection. Antibodies to AT-62aa and sera from vaccinated mice effectively neutralized the toxin in vitro and inhibited the formation of Hla heptamers, suggesting antibody-mediated neutralization as the primary mechanism of action. This remarkable efficacy makes the Hla-based vaccine a prime candidate for inclusion in future multivalent S. aureus vaccines. Furthermore, identification of protective epitopes within AT-62aa could lead to novel immunotherapies for S. aureus infection.