Autoimmunity to type II collagen an experimental model of arthritis.

TLDR

The disease is a chronic proliferative synovitis resembling adjuvant arthritis in rats and rheumatoid arthritis in humans. The study establishes a new animal model of arthritis induced by homologous type II collagen emulsified in oil, demonstrating experimentally‑inducible autoimmunity to a tissue component. Intradermal injection of native type II collagen from human, chick, or rat cartilage induces inflammatory arthritis in about 40 % of rats across several strains, regardless of Freund’s adjuvant, whereas type I/III collagen or type II collagen without adjuvant does not, and pepsin‑digested type II collagen still triggers disease, implicating helical region determinants.

Abstract

We have found that intradermal injection of native type II collagen extracted from human, chick or rat cartilage induces an inflammatory arthritis in approximately 40% of rats of several strains whether complete Freund's adjuvant or incomplete Freund's adjuvant is used. Type I or III collagen extracted from skin, cartilage proteoglycans and alpha1(II) chains were incapable of eliciting arthritis, as was type II collagen injected without adjuvant. The disease is a chronic proliferative synovitis, resembling adjuvant arthritis in rats and rheumatoid arthritis in humans. Native type II co-lagen modified by limited pepsin digestion still produces arthritis, suggesting that type-specific determinants residing in the helical region of the molecule are responsible for the induction of disease. Since homologous type II collagen emulsified in oil without bacterial preparations regularly causes the disease, this new animal model of arthritis represents a unique example of experimentally-inducible autoimmunity to a tissue component.