Oxidative modification of type II collagen differentially affects its arthritogenic and tolerogenic capacity in experimental arthritis.
BACKGROUND
Oxidative modification of proteins affects their biological properties. Previously we have shown that hypochlorite (HOCl), the product of activated neutrophils, enhances protein immunogenecity. Collagen type II, a primary component of cartilage, is commonly used in the induction of arthritis in animals (CIA). The aim of this study was to examine whether HOCl may affect immunogenic, tolerogenic, and arthritogenic properties of collagen.


METHODS
DBA/J mice were injected with either native (CNAT) or chlorinated collagen (CHOCl) to induce arthritis. The effect of chlorination on collagen properties was measured by evaluation of incidence and severity of CIA. Moreover, the concentration of serum anti-collagen IgG antibodies and myeloperoxidase (MPO) activity in inflamed joints was determined.


RESULTS
Mice immunized with CNAT in adjuvant developed arthritis (CIA) with an incidence of 69%. CNAT also exerted tolerogenic properties when injected intravenously either before or shortly after primary immunization, resulting in decreased incidence and severity of CIA, reduced MPO activity in inflamed joints, and lowered serum levels of anti-CNAT IgG anti-bodies. Chlorination of collagen significantly diminished its ability to induce CIA and to trigger generation of anti-CNAT IgG antibodies. Interestingly, chlorination did not affect tolerogenic properties of collagen administered prior to primary immunization with CNAT.


CONCLUSIONS
These results suggest that chlorination of collagen may selectively affect functional epitopes of collagen. It is likely that in inflamed joints, neutrophil derived HOCl, in some circumstances, will destroy arthritogenic and immunogenic B cell epitopes, while regulatory T cell epitopes will be preserved.
Department of Immunology, Jagiellonian University Medical College, Kraków, Poland. mmmarcin@cyf-kr.edu.pl
Janusz
J
Marcinkiewicz
Rafał
R
Biedroń
Katarzyna
K
Maresz
Beata
B
Kwaśny-Krochin
Małgorzata
M
Bobek
Ewa
E
Kontny
Wlodzimierz
W
Maśliński
Benjamin
B
Chain
D000818:Animals; D001169:Arthritis, Experimental / Q000139:chemically induced / Q000276:immunology* / Q000473:pathology / Q000517:prevention & control; D024043:Collagen Type II / Q000737:chemistry* / Q000276:immunology*; D000939:Epitopes; D006801:Humans; D006997:Hypochlorous Acid / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008297:Male; D051379:Mice; D008811:Mice, Inbred DBA; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000378:metabolism; D000685:Serum Amyloid A Protein / Q000378:metabolism
D024043:Collagen Type II; D000939:Epitopes; D007074:Immunoglobulin G; D000685:Serum Amyloid A Protein; D006997:Hypochlorous Acid; D009195:Peroxidase