Effects of immunization with Streptococcus mutans surface antigens in auto-reactivity of BALB/c mice
BALB/c mice were hiperimmunized with surface antigens of Streptococcus mutans, GS5 strain. The immunization increased significantly anti-heart and anti-myosin IgG, free and present in immunecomplexes. In Western-blotting, the autoantibodies displayed a notable reactivity with cardiac myosin and cardiac tissue proteins, mainly with a 35 kDa peptide. The histological analysis of hearts demonstrated absence of significant damage in valves and myocardium, and immunohistochemistry showed absence of antibodies linked in cardiac tissue. The treatment with cyclophosphamide was able to reduce autoantibody levels but did not alter de histological aspect of heart. These findings demonstrated that surface antigens S. mutans, GS5 strain, were able to induce autoantibody synthesis without potential to initiate cardiac damage.