Towards a vaccine against rheumatic fever

Area of Science:

• Immunology
• Infectious Diseases
• Cardiovascular Medicine

Background:

• Rheumatic fever (RF) is a significant autoimmune disease affecting millions globally, primarily children in developing nations.
• It stems from Streptococcus pyogenes throat infections and can lead to chronic rheumatic heart disease (RHD) with permanent valvular damage.
• Understanding the autoimmune mechanisms driving RF/RHD is crucial for developing preventative strategies.

Purpose of the Study:

• To investigate the cellular and molecular pathogenesis of rheumatic heart disease.
• To identify protective T and B cell epitopes from the M protein of Streptococcus pyogenes.
• To lay the groundwork for a potential vaccine against this post-infection autoimmune disease.

Main Methods:

• Analyzed 620 human blood samples against overlapping peptides from the M protein's C-terminal portion.
• Focused on identifying specific T and B cell epitopes involved in the autoimmune response.
• Utilized in vitro assays to assess the functional impact of identified epitopes.

Main Results:

• Identified distinct T and B cell epitopes (22 and 25 amino acids, respectively) within the M protein.
• Discovered a conserved 16-amino acid core shared by both T and B cell epitopes.
• Antibodies targeting the B cell epitope demonstrated inhibition of bacterial invasion and adhesion in vitro.

Conclusions:

• The identified T and B cell epitopes show promise as targets for a vaccine against Streptococcus pyogenes.
• These findings contribute to a deeper understanding of RHD pathogenesis.
• Further development could lead to effective prevention of RF/RHD, particularly in high-risk populations.