QIMR Berghofer

Group G streptococcus induces an autoimmune IL-17A/IFN-? mediated carditis in the Lewis rat model of Rheumatic Heart Disease.

Abstract

Acute rheumatic fever and rheumatic heart disease (ARF/RHD) have long been described as autoimmune sequelae of Streptococcus pyogenes or group A streptococcal (GAS) infection. Both antibody and T-cell responses against immunodominant GAS virulence factors including M-protein, cross-react with host tissue proteins triggering an inflammatory response leading to permanent heart damage. However, in some ARF/RHD endemic regions, throat carriage of GAS is low. As Streptococcus dysgalactiae subspecies equisimilis (SDSE), also known as ß-hemolytic groups C and G streptococci (GCS/GGS) also express M-protein, we postulated that streptococci other than GAS may have the potential to initiate or exacerbate ARF/RHD. Using a model initially developed to investigate the uniquely human disease of ARF/RHD, we have now discovered that GGS does indeed causes IL-17A/IFN-? induced myocarditis and valvulitis, hallmarks of ARF/RHD. Remarkably the histological, immunological and functional changes in the hearts of rats exposed to GGS are identical to those exposed to GAS. Furthermore, antibody cross-reactivity to cardiac myosin was comparable in both GGS and GAS exposed animals providing additional evidence that GGS can induce and/or exacerbate ARF/RHD.

Authors Sikder, Suchandan; Williams, Natasha L; Sorenson, Alanna E; Alim, Md A; Vidgen, Miranda E; Moreland, Nicole J; Rush, Catherine M; Simpson, Robert S; Govan, Brenda L; Norton, Robert E; Cunningham, Madeleine W; McMillan, David J; Sriprakash, Kadaba S; Ketheesan, Natkunam
Journal The Journal of infectious diseases
Pages
Volume
Date 1/12/2017
Grant ID
Funding Body
URL http://www.ncbi.nlm.nih.gov/pubmed/?term=10.1093/infdis/jix637