Immune Response to Peptides Produced by Enzymatic Digestion of Microfibrils And Elastin of Human Lung Parenchyma

Abstract

Antibodies were raised in rabbits against human lung elastic fiber and peptides derived from human lung elastin and microfibrils. Elastic fiber produced antibodies with very low liter. Elastin peptides had low immunogenicity and multiple injections of at least 100 mg per rabbit per injection were required to produce antibodies. Microfibril peptides had a much higher immunogenicity and produced antibodies with multiple injections of only 10 mg per rabbit per injection. Anti-elastic fiber serum did not react with peptides derived from microfibrils or elastin at concentrations of 5 mg or 10 mg per ml solution. At 25 mg/ml solution microfibril peptides gave a faint precipitin line in Ouchterlony double diffusion tests, but elastin peptides did not react. There was no cross reactivity between microfibril peptides and anti-elastin serum or elastin peptides and anti-microfibril serum at low concentration. At higher concentration, i.e. 25 mg/ml, some cross reactivity was observed with both antigens and both antisera, but absorption of anti-elastin serum with microfibril peptides or antimicrofibril serum with elastin peptides eliminated the cross reactivity and showed that each antigen has specific antigenic determinants which are lacking in the other. Both anti-microfibril serum and anti-elastin serum were found to be species and organ specific except for slight cross reactivity of anti-human lung elastin serum with elastin peptides of human aorta.