Immunotherapy Targeting the Streptococcus Pyogenes M Protein or Streptolysin O to Treat or Prevent Influenza A Superinfection
Posted by Adam Awdish on
Rabbit Red Blood Cells from Innovative Research was used in the following study:
Andrea L. Herrera, Christopher Van Hove, Mary Hanson, James B. Dale, Rodney K. Tweten, Victor C. Huber, Diego Diel, Michael S. Chaussee
PLoS ONE
June 23, 2020
Infection with influenza A virus (IAV) creates a permissive environment for secondary bacterial infections (often referred to as superinfections), which significantly increases the morbidity and mortality associated with both IAV epidemics and pandemics. Streptococcus pyogenes (the group A Streptococcus, GAS) typically causes pharyngitis but also can cause more serious invasive GAS infections (iGAS) such as bacteremia, toxic shock syndrome, necrotizing fasciitis, and IAV superinfections.
Many antibiotics, including penicillin, are effective against GAS. Nonetheless, iGAS diseases are associated with a surprisingly high fatality rate. Currently there are no vaccines available for GAS; however, vaccination with the surface-localized M protein elicits protective opsonic antibodies and experimental M protein-based vaccines have been used in animal studies and human clinical trials. In addition, studies previously showed that active vaccination targeting the M protein confers 100% protection against mortality by using a murine model of IAV-GAS superinfection.
Another potential GAS vaccine target is the secreted cholesterol-dependent cytolysin (CDC) streptolysin O (SLO). SLO contributes to virulence and orthologues are encoded in the genomes of a wide range of bacteria including Streptococcus pneumoniae (pneumolysin; PLY), which has historically been the most frequent cause of IAV superinfections. Passive immunotherapy with anti-PLY antibodies protects mice against S. pneumoniae bacteremia, indicating that the cytolytic CDC toxins may be good candidates for passive immunotherapy targeting bacterial pathogens associated with IAV superinfections.
While the development of an effective active vaccine against GAS is an ideal outcome, this study focused on assessing the efficacy of using passively administered antibodies to prevent or treat IAV-GAS superinfections. Researchers evaluated the prophylactic and therapeutic use of antisera targeting either the M protein or SLO in a murine model of IAV-GAS superinfection. Rabbit Red Blood Cells from Innovative Research were used in this study.
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