Immunogenicity and Specificity of Collagen

Abstract

Summary Acid-soluble collagen (procollagen), collagen treated with hydroxylamine (“hydroxam-collagen”) and parent gelatine of calf origin, both from skin and joint capsule-periarticular connective tissue, were used to immunize rabbits. These preparations and similar ones prepared from rabbits were used to test the resultant antisera in passive hemagglutination, along with ovalbumin and bovine γ-globulin as specificity controls. The various preparations were examined for their content of hydroxyproline, tyrosine, hexoses, uronic acid and nitrogen. Procollagen induced mainly the formation of species-specific collagen antibodies, reacting also with hydroxam-collagen and parent gelatine of the same species. Hydroxam-collagen induced the formation of antibodies with a new specificity, that against a collagen preparation after hydroxylamine treatment. Hyperimmune sera reacted only with “hydroxam”-collagens. Early immune sera, however, showed cross-reactions with parent gelatine. Parent gelatine induced formation of antibodies against collagen preparations and their derivatives, having no species specificity and showing a broad spectrum of reactivity with gelatine and collagens. Used in serologic testing, however, parent gelatine also displayed properties of species specificity. No differences in specificity were found between preparations made from skin and from joint capsule-periarticular connective tissue. Hemagglutination-inhibition experiments were performed in addition. The results confirmed the observations made in direct hemagglutination: Hemagglutinating systems of anti-procollagen sera and calf-collagen preparations were inhibited only by species-specific (calf) parent gelatine and hydroxam-collagen. Hemagglutinating systems of early anti-hydroxam-collagen sera and hydroxamcollagen were inhibited significantly by hydroxam-collagen, less distinctly by parent gelatine. Identical systems prepared with hyperimmune sera, however, were inhibited only by hydroxam-collagen. Hemagglutinating systems of anti-parent gelatine sera and parent gelatine or hydroxam collagen of different origin were inhibited by all collagen preparations or collagen derivatives independently of their species or tissue origin. The results obtained are discussed in view of our present knowledge about the structure of collagen or its derivatives.