Nature and specificity of the immune response to collagen in type II collagen-induced arthritis in mice.

Abstract

A C T To determine the role of collagen-immunity in the development of collagen-induced ar- thritis, DBA/1 mice were immunized with type II collagen and observed for the development of polyarthritis.96% of the mice immunized with native type II collagen developed inflammatory arthritis between 4 and 5 wk after primary immunization.Im- munization with denatured type II collagen in exactly the same manner was not effective in inducing ar- thritis.Cell-mediated immunity in arthritic mice was assessed by measuring [3H]thymidine incorporation by mononuclear cells cultured in the presence of collagen.The maximal proliferative response to collagen oc- curred at 2 wk after immunization.Equally good in- corporation of label occurred when cells were cultured with native or denatured type II collagen or type I collagen.The cellular response of nonarthritic mice immunized with denatured collagen was indistinguishable from that seen in arthritic mice.Humoral im- munity was assessed by an ELISA assay for antibodies to collagen.The immunoglobulin M (IgM) response peaked at 2 wk and the IgG response at 5 wk after immunization.Antisera from arthritic mice immu- nized with native type II collagen were relatively spe- cific for conformational determinants on the native type II molecule although some reactivity with de- natured collagen was noted.Antisera from nonarthritic mice immunized with denatured collagen primarily recognized covalent structural determinants.It was concluded that native type II collagen was essential for the induction of arthritis and that an antibody re- sponse specific for native type II collagen may be im- portant for the development of arthritis.METHODS Mice.DBA/lJ, mice were obtained from The Jackson Laboratory, Bar Harbor, Maine.Only male mice between 8 and 12 wk of age were used.They were maintained on absorbent bedding (Bed O'Cobs, The Andersons, Cob Di- vision, Maumee, Ohio) in plastic cages and fed standard Purina rodent chow (Ralston Purina Co., St. Louis, Mo.).Preparation of collagen.Most experiments used native type II collagen prepared by limited pepsin digestion of pulverized chick sternal cartilage and purified as described (13).For studies of cross-reactivity type I collagen was iso- lated and purified from lathyritic chick skin, and bovine type II collagen was isolated and purified from fetal calf Egation, Inc.