An analysis of the organ and species immunospecificity of elastin

The connective tissue protein elastin is largely responsible for maintaining the elasticity of major blood vessels and lung tissue. Comparatively few studies have been made of the immunologic properties of elastin because of its high degree of insolubility and because of its apparent limited capacity to elicit precipitating antibodies. Recent studies have focused on the possible role of elastolytic enzymes, particularly leukocyte elastase, in the pathogenesis of chronic obstructive lung disease, but there are no reports in the literature concerning the antigenic properties of peptides released by digestion of insoluble elastin with leukocyte elastase. In the present study, we have obtained antibodies in rabbits to peptides prepared by digestion of dog and human lung and aortic elastin with either oxalic acid or leukocyte elastase. By hemagglutination assays, we have shown generally that: (1) within a given species the peptides from aorta and lung cross-react strongly with one another, (2) there was rather poor cross-reactivity between peptides from different species (3) the peptides obtained by oxalic acid digestion cross-react poorly with those obtained by elastase digestion, (4) the antibodies to the peptides cross-reacted with the insoluble elastin from which the peptides were derived. These elastin-specific antibodies may be useful for ultrastructural localization of elastin and identification of fragments derived from elastin in the sera of humans and experimental animals.