Chaperonin 10 of Mycobacterium tuberculosis induces a protective immune response to foot-and-mouth disease virus

Summary

Chaperonin 10 of M. tuberculosis conferred partial or total protection against generalized foot-and-mouth disease (FMD) in guinea-pigs challenged with O₁ Lausanne FMD virus. Chaperonin 10-immunized animals mounted an antibody response to the protein, one epitope of which was found in the C-terminal half. A similar recognition pattern was observed in FMD-convalescent guinea-pigs, swine and cattle. Anti-chaperonin 10 sera showed antiviral activity against FMDV-infected BHK-21 cells. There was strong evidence that early after infection these cells actively secrete their histones and that antisera to the chaperonin recognize them. The same antisera reacted with purified histones in immunoblotting. Most important, exogenously added histones abrogated the anti-viral activity of the antiserum and an anti-histone monoclonal antibody had strong antiviral activity against FMDV-infected BHK-21 cells. These results are consistent with previous reports on displacement of histones from the nuclear compartment and immune recognition of self-histones after viral infections. On the whole, they * indicate that M. tuberculosis chaperonin 10 enables the immune system to react against early abnormalities of virus-infected cells; this is accomplished by antibody cross-reacting with histones released during virus infection.