A new study clarifies how Group A Streptococcus (strep) bacteria resist the human immune system.
The research could eventually lead to the development of a safe vaccine against strep throat, necrotising fasciitis (flesh-eating disease), and rheumatic heart disease.
Previous efforts to develop a strep throat vaccine had resulted in immune system reactions that caused other diseases such as rheumatic fever and heart damage, says co-lead author Jason Cole of the University of Queensland School of Chemistry and Molecular Biosciences.
“We have discovered genes that make up the cell wall of the strep bacteria, which is composed mainly of the group A carbohydrate or GAC,” he says.
The group A carbohydrate was previously thought to play a largely structural role in the bacteria cell walls.
“We have now confirmed that it actually plays a critical role in how the bacteria resist the immune response.
“This may trigger diseases such as rheumatic heart disease, which has hindered the development of a safe vaccine.
“Based on this information, we are now able to produce a modified group A carbohydrate for further vaccine studies, avoiding previous safety concerns associated with a strep vaccine.”
Strep throat is responsible for more than 700 million infections and 500,000 deaths each year.
The study appears online in Cell Host & Microbe.
University of Queensland Professor Mark Walker, in collaboration with Emory University and University of California, San Diego, are working on additional pre-clinical testing of the modified vaccine.
Walker says the pre-clinical trials were designed to demonstrate that the vaccine was safe and effective before proceeding to human clinical trials.
The University of California, San Diego Program in Excellence in Glycosciences, the Australian National Health and Medical Research Council, the Wellcome Trust, and the Netherlands Organization for Scientific Research supported the work.
《The Classical Lancefield Antigen of Group A Streptococcus Is a Virulence Determinant with Implications for Vaccine Design》, Published on Journal 《Cell Host & Microbe》in May, 2014.