<i>Chlamydia</i> Infections and Heart Disease Linked Through Antigenic Mimicry

TLDR

Chlamydia infections are epidemiologically linked to human heart disease. In mice, Chlamydia peptides homologous to a heart‑muscle α‑myosin heavy chain peptide induced autoimmune inflammatory heart disease, perivascular inflammation, fibrosis, vessel occlusion, and T/B‑cell reactivity, with Chlamydia DNA acting as an adjuvant and infection producing autoantibodies, demonstrating that Chlamydia‑mediated heart disease is driven by antigenic mimicry.

Abstract

Chlamydia infections are epidemiologically linked to human heart disease. A peptide from the murine heart muscle–specific α myosin heavy chain that has sequence homology to the 60-kilodalton cysteine-rich outer membrane proteins of Chlamydia pneumoniae , C. psittaci , and C. trachomatis was shown to induce autoimmune inflammatory heart disease in mice. Injection of the homologous Chlamydia peptides into mice also induced perivascular inflammation, fibrotic changes, and blood vessel occlusion in the heart, as well as triggering T and B cell reactivity to the homologous endogenous heart muscle–specific peptide. Chlamydia DNA functioned as an adjuvant in the triggering of peptide-induced inflammatory heart disease. Infection with C. trachomatis led to the production of autoantibodies to heart muscle–specific epitopes. Thus, Chlamydia -mediated heart disease is induced by antigenic mimicry of a heart muscle–specific protein.