Internal medicine

Heart failure

Pathogenesis

Myosin light-chain kinase

Biology

Antigen

Immunology

Cardiomyopathy

Inflammation

Molecular mimicry

Peptide

Myocarditis

Heart disease

Myosin

Cell biology

Biochemistry

Medicine

Immune system

Science

Peptide mimicry breaks the heart Myocarditis, a prolonged chronic inflammation of heart muscle, can eventually progress to inflammatory cardiomyopathy, a serious condition associated with heart failure. Activated T helper (T H ) cells that recognize myosin heavy chain 6–derived peptides are thought to play a central role in this pathogenesis. Using a mouse model of myocarditis, Gil-Cruz et al. found that cardiac myosin–reactive T H cells are initially primed by myosin-peptide mimics derived from commensal Bacteroides species in the gut (see the Perspective by Epelman). Unlike heathy controls, human myocarditis patients also showed detectable immune reactivity to both Bacteroides and cardiac myosin antigens. Treatment with antibiotics dampened inflammatory responses and prevented lethal heart disease. Science , this issue p. 881 ; see also p. 806

Microbiota-derived peptide mimics drive lethal inflammatory cardiomyopathy