Heart Institute, School of Medicine, University of São Paulo, São Paulo, Brazil; Immunology Investigation Institute, National Institute for Science and Technology, University of São Paulo, São Paulo, Brazil
StreptIncor, a candidate vaccine against S. pyogenes is based on protective 55 amino acids residues of C-terminal portion of the M protein. Experimental assays have demonstrated that the StreptInCor peptide induces high titers of opsonic and neutralizing and protective antibodies in outbred immunized mice. Using HLA class II transgenic mice, it was possible to evaluate the immunogenicity and safety of the StreptInCor vaccine epitope for a period of one year. Specific and non - auto reactive antibodies were produced and no autoimmune or pathological reactions were observed in the heart or other organs of these animals. We also performed several studies in mini-pigs in order to evaluate the immune response as well as safety by submitting these animals to echocardiogram examination before immunization and after the four doses treatment. No alterations were observed. StreptInCor vaccine also induces regulatory T cells (Treg) that strongly indicate that the vaccine peptide may have therapeutic potential to control both inflammatory and autoimmune response in RF/RHD patients.