Anti-streptococcal antibodies and T-cells induce heart pathology in Lewis rats following adoptive transfer

Acute rheumatic fever (ARF) and rheumatic heart disease (RHD) are autoimmune mediated diseases caused by group A streptococcus (GAS). Structural similarity between GAS antigens and host tissue proteins is considered to initiate ARF/RHD. Antibody-mediated immune response to GAS pharyngitis initiates autoimmune reactions followed by immune cells infiltration of the heart tissues that leads to permanent heart damage in RHD. However, the individual role of anti-GAS antibodies and T-cells in the pathogenesis of autoimmune carditis is under-explored. In this study, Lewis rats (recipient) were adoptively transferred independently with serum or together with T-cells from GAS M5 protein injected rats (donor). The antibody and T-cell response, histological changes in the heart and ECG and Echo finding of the recipient rats were found indistinguishable from the donor rats. Moreover, the changes in the independent serum or T-cell recipient rats were observed similar to the integrated serum and T-cell transferred rats. The results indicate that both B-cell and T-cell has individual potential to develop autoimmune reactions in rheumatic heart disease