title: Generation of a monoclonal antibody to a cryptic site common to both integrin beta1 as well as gelatinase MMP9.
abstract: Integrins are one class of cell surface receptors that have been implicated in the regulation of a diverse set of cellular processes, including cell adhesion, migration, and invasion as well as gene expression, differentiation, and signal transduction. Cellular invasion not only requires the adhesive properties of integrins but also the proteolytic properties of matrix-degrading enzymes, such as the metalloproteinases (MMPs). Previous studies have shown that integrin alphavbeta3 is a receptor for MMP2, localizing its proteinase activity to the cell surface, ultimately leading to site-specific extracellular matrix (ECM) degradation. Here we develop reagents to investigate the possibility of an interplay between MMP9 and integrin alpha5beta1. With the use of EV22 viral studies, the tetrapeptide sequence, LRSG, was shown to be a dimerizing sequence mediating beta1 integrin binding to EV22. The same study also showed that cellular infection could be halted with the use of LRSG-containing peptides. In a later study, in an effort to isolate inhibitors of the MMP family, LRSG sequence was identified as one capable of binding MMP9. Interestingly, MMP9 contains an LRSG sequence, raising the possibility that MMP9 binds the cell surface via beta1 integrins through the dimerizing LRSG motif. We used the LRSG-containing sequence from beta1 integrins as an antigen to generate the monoclonal antibody (MAB) FM155 in the mouse model. MAB FM155 will help identify a cryptic epitope, LRSG, and its role in matrix remodeling as well as tumor growth, cancer cell migration, and angiogenesis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Norris Comprehensive Center, Keck School of Medicine at the University of Southern California, Los Angeles, California 90089, USA.
authors.forename: Loubna
authors.initials: L
authors.lastname: Hassanieh
authors.forename: Dorothy
authors.initials: D
authors.lastname: Rodriguez
authors.forename: Jinsong
authors.initials: J
authors.lastname: Xu
authors.forename: Peter C
authors.initials: PC
authors.lastname: Brooks
authors.forename: Daniel
authors.initials: D
authors.lastname: Broek
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism*; D000918:Antibody Specificity; D001665:Binding Sites; D006801:Humans; D006825:Hybridomas; D019012:Integrin beta1 / Q000737:chemistry / Q000276:immunology*; D020780:Matrix Metalloproteinase 9 / Q000737:chemistry / Q000276:immunology*; D051379:Mice; D008969:Molecular Sequence Data; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D019012:Integrin beta1; D020780:Matrix Metalloproteinase 9