Molecular cloning of the complementary DNA for an additional member of the family of aortic aneurysm antigenic proteins

• Published in: Journal of vascular surgery 1997-08, Vol.26 (2), p.313-318
• Main Authors: Hirose, Hitoshi, Ozsvath, Kathleen J., Xia, Shichao, Tilson, M.David
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Aortic Aneurysm, Abdominal - genetics; Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; Cloning, Molecular; Contractile Proteins - genetics; Diseases of the aorta; DNA, Complementary - chemistry; DNA, Complementary - genetics; Elastic Tissue - metabolism; Extracellular Matrix Proteins; Gene Expression Regulation; Humans; Immunoglobulin G - immunology; Medical sciences; Molecular Sequence Data; RNA, Messenger - genetics; Sequence Alignment; Sequence Homology, Nucleic Acid; Transcription, Genetic
• ISSN: 0741-5214; 1097-6809
• DOI: 10.1016/S0741-5214(97)70194-0

Purpose: We have purified and partially sequenced a protein from the adventitia of the human aorta (aortic aneurysm antigenic protein 40 kDa; AAAP-40) that has homologies to bovine aortic microfibril-associated glycoprotein (MAGP-36). It is immunoreactive with immunoglobulin G (IgGs) purified from the serum and aortic wall of patients with abdominal aortic aneurysms. AAAP-40 and MAGP-36 have fibrinogen-like and vitronectin-like motifs. Screening an expression library constructed from human aortic adventitial messenger RNA has resulted in the cloning of three complementary DNAs whose gene products are immunoreactive with immunoglobulin G from patients with abdominal aortic aneurysms. Two strongly resemble each other and have been described separately. The purpose of this article is to report the third clone. Methods: Messenger RNA from a specimen of human aortic aneurysmal adventitia was reverse-transcribed for insertion into the phagemid Uni Zap XR (Stratagene). A strain of Escherichia coli, engineered for expression (XL 1-Blue MFR`, Stratagene), was transfected, and rabbit antihuman vitronectin antibody was used to identify positive clones. Sequencing of the positive clones was performed by the Core Laboratories at Columbia University. Results: The hypothetical protein of rAAAP-CL4 (clone 4) shares sequence motifs with known microfibril-associated glycoproteins (MAGPs). The recombinant protein (rAAAP-CL4) is immunoreactive with serum from patients (three of four abdominal aortic aneurysm sera). In addition, similarities have been detected with immunoglobulins of the κ family and with a protein from cytomegalovirus that is a potential molecular mimic. Conclusions: There may several members of a novel family of human aortic autoantigenic proteins implicated in abdominal aortic aneurysm disease. (J Vasc Surg 1997 26:313-8.)