Overview
Molecular mimicry occurs when microbial antigens share structural similarity with host proteins, triggering cross-reactive immune responses that attack host tissue. It is a primary mechanism linking infections and dysbiosis to autoimmune disease — the immune system correctly targets a pathogen but collaterally damages self-tissue bearing similar epitopes.
Key Examples
- Campylobacter → Guillain-Barré: campylobacter lipooligosaccharide (LOS) mimics ganglioside GM1 on peripheral nerve myelin. Anti-LOS antibodies cross-react with nerve tissue → acute demyelinating polyneuropathy.
- Gut microbiota → Type 1 diabetes: Virus-induced dysbiosis alters gut microbial antigens that cross-react with pancreatic beta-cell proteins [1].
- Gut microbiota → Graves' disease: Microbial antigens mimicking TSH receptor may trigger stimulatory autoantibodies [2] [3].
- Gut microbiota → Hashimoto's: Microbial homologues of thyroid peroxidase (TPO) and thyroglobulin [4].
- Gut microbiota → MS: Cross-reactive T cells recognizing both microbial and myelin antigens [5].
Metal Connection
Metal-driven dysbiosis may increase molecular mimicry risk by selecting for pathobionts with cross-reactive antigens, enhancing epitope exposure through metal-induced cell lysis, and promoting inflammatory environments that break immune tolerance [6].
Cross-References
- campylobacter — Guillain-Barré via ganglioside mimicry
- hashimotos thyroiditis — TPO/thyroglobulin mimicry
- graves disease — TSHR mimicry
- type 1 diabetes — beta-cell antigen mimicry
- multiple sclerosis — myelin antigen cross-reactivity
- immune balance — tolerance breakdown enabling cross-reactive attack