OBJECTIVE: Type II collagen (CII) is a major component of hyaline cartilage, and antibodies against CII are found in a subgroup of patients with rheumatoid arthritis. We undertook this study to investigate whether and how antibodies directed against CII can form solid-phase immune complexes (ICs) with cytokine-inducing properties in a model theoretically resembling the situation in the inflamed joint, in which CII is exposed for interaction with anti-CII antibodies during periods of inflammation. METHODS: Sixty-five arthritis patients with varying levels of anti-native CII antibodies and 10 healthy controls were evaluated concerning anti-CII and cytokines induced in a solid-phase IC model. Monocytes were either depleted or enriched to define responder cells. Antibodies blocking Fc gamma receptors (Fc gammaR) were used to define the responsible T cell surface receptors. RESULTS: ICs containing anti-CII from arthritis patients induced the production of tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and IL-8. We found a close correlation between enzyme-linked immunosorbent assay optical density values and induction of TNFalpha (r = 0.862, P < 0.0001), IL-1beta (r = 0.839, P < 0.0001), and IL-8 (r = 0.547, P < 0.0001). The anti-CII-containing IC density threshold needed for cytokine induction differed among peripheral blood mononuclear cell donors. Anti-CII-containing IC-induced cytokine production was almost totally abolished (>99%) after monocyte depletion, and receptor blocking studies showed significant decreases in the production of TNFalpha, IL-1beta, and IL-8 after blocking Fc gammaRIIa, but not after blocking Fc gammaRIII. CONCLUSION: These findings represent a possible mechanism for perpetuation of joint inflammation in the subgroup of arthritis patients with high levels of anti-CII. Blockade of Fc gammaRIIa and suppression of synovial macrophages are conceivable treatment options in such patients.
OBJECTIVE: Type II collagen (CII) is a major component of hyaline cartilage, and antibodies against CII are found in a subgroup of patients with rheumatoid arthritis. We undertook this study to investigate whether and how antibodies directed against CII can form solid-phase immune complexes (ICs) with cytokine-inducing properties in a model theoretically resembling the situation in the inflamed joint, in which CII is exposed for interaction with anti-CII antibodies during periods of inflammation. METHODS: Sixty-five arthritispatients with varying levels of anti-native CII antibodies and 10 healthy controls were evaluated concerning anti-CII and cytokines induced in a solid-phase IC model. Monocytes were either depleted or enriched to define responder cells. Antibodies blocking Fc gamma receptors (Fc gammaR) were used to define the responsible T cell surface receptors. RESULTS: ICs containing anti-CII from arthritispatients induced the production of tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and IL-8. We found a close correlation between enzyme-linked immunosorbent assay optical density values and induction of TNFalpha (r = 0.862, P < 0.0001), IL-1beta (r = 0.839, P < 0.0001), and IL-8 (r = 0.547, P < 0.0001). The anti-CII-containing IC density threshold needed for cytokine induction differed among peripheral blood mononuclear cell donors. Anti-CII-containing IC-induced cytokine production was almost totally abolished (>99%) after monocyte depletion, and receptor blocking studies showed significant decreases in the production of TNFalpha, IL-1beta, and IL-8 after blocking Fc gammaRIIa, but not after blocking Fc gammaRIII. CONCLUSION: These findings represent a possible mechanism for perpetuation of joint inflammation in the subgroup of arthritispatients with high levels of anti-CII. Blockade of Fc gammaRIIa and suppression of synovial macrophages are conceivable treatment options in such patients.
Authors: Kutty Selva Nandakumar; Mattias Collin; Kaisa E Happonen; Allyson M Croxford; Susanna L Lundström; Roman A Zubarev; Merrill J Rowley; Anna M Blom; Rikard Holmdahl Journal: Proc Natl Acad Sci U S A Date: 2013-05-13 Impact factor: 11.205
Authors: Julie A Di Paolo; Tao Huang; Mercedesz Balazs; James Barbosa; Kai H Barck; Brandon J Bravo; Richard A D Carano; James Darrow; Douglas R Davies; Laura E DeForge; Lauri Diehl; Ronald Ferrando; Steven L Gallion; Anthony M Giannetti; Peter Gribling; Vincent Hurez; Sarah G Hymowitz; Randall Jones; Jeffrey E Kropf; Wyne P Lee; Patricia M Maciejewski; Scott A Mitchell; Hong Rong; Bart L Staker; J Andrew Whitney; Sherry Yeh; Wendy B Young; Christine Yu; Juan Zhang; Karin Reif; Kevin S Currie Journal: Nat Chem Biol Date: 2010-11-28 Impact factor: 15.040