4bkl
From Proteopedia
Crystal structure of the arthritogenic antibody M2139 (Fab fragment) in complex with the triple-helical J1 peptide
Structural highlights
DiseaseCO2A1_MOUSE Defects in Col2a1 are the cause of a phenotype resembling human spondyloepiphyseal dysplasia congenita (sedc). Homozygous sedc mice can be identified at birth by their small size and shortened trunk. Adults have shortened noses, dysplastic vertebrae, femora and tibias, and retinoschisis and hearing loss. FunctionCO2A1_MOUSE Type II collagen is specific for cartilaginous tissues. It is essential for the normal embryonic development of the skeleton, for linear growth and for the ability of cartilage to resist compressive forces. Publication Abstract from PubMedAutoantibody formation is essential for the development of certain autoimmune diseases like rheumatoid arthritis (RA). Anti-type II collagen (CII) antibodies are found in RA patients; they interact with cartilage in vivo and are often highly pathogenic in the mouse. Autoreactivity to CII is directed to multiple epitopes and conserved between mice and humans. We have previously mapped the antibody response to CII in a heterogeneous stock cohort of mice, with a strong association with the IgH locus. We positioned the genetic polymorphisms and determined the structural requirements controlling antibody recognition of one of the major CII epitopes. Polymorphisms at positions S31R and W33T of the associated variable heavy chain (VH) allele were identified and confirmed by gene sequencing. The Fab fragment binding the J1 epitope was crystallized, and site-directed mutagenesis confirmed the importance of those two variants for antigen recognition. Back mutation to germline sequence provided evidence for a preexisting recognition of the J1 epitope. These data demonstrate a genetic association of epitope-specific antibody responses with specific VH alleles, and it highlights the importance of germline-encoded antibodies in the pathogenesis of antibody-mediated autoimmune diseases. Epitope-specific antibody response is controlled by immunoglobulin VH polymorphisms.,Raposo B, Dobritzsch D, Ge C, Ekman D, Xu B, Lindh I, Forster M, Uysal H, Nandakumar KS, Schneider G, Holmdahl R J Exp Med. 2014 Mar 10;211(3):405-11. doi: 10.1084/jem.20130968. Epub 2014 Feb, 17. PMID:24534192[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Large Structures | Mus musculus | Dobritzsch D | Ekman D | Foerster M | Ge C | Holmdahl R | Lindh I | Raposo B | Schneider G | Uysal H
