The function of multiple extracellular matrix receptors in mediating cell adhesion to extracellular matrix: preparation of monoclonal antibodies to the fibronectin receptor that specifically inhibit cell adhesion to fibronectin and react with platelet glycoproteins Ic-IIa.

Abstract

Abstract. We have identified monoclonal antibodies that inhibit human cell adhesion to collagen (P1H5), fibronectin (P1F8 or P1D6), and collagen and fibronectin (P1B5) that react with a family of structurally similar glycoproteins referred to as extracellular matrix receptors (ECMRs) II, VI, and I, respectively. Each member of this family contains a unique ¢t subunit, recognized by the antibodies, and a common [~ subunit, each of ~140 kD. We show here that ECMR VI is identical to the fibronectin receptor (FNR), very late antigen (VLA) 5, and platelet glycoproteins Ic-IIa and shall be referred to as FNR. Monoclonal antibodies to FNR inhibit lymphocyte, fibroblast, and platelet adhesion to fibronectin-coated surfaces. ECMRs I, H, and FNR were differentially expressed in platelets, resting or activated lymphocytes, and myeloid, epithelial, endothelial, and fibroblast cell populations, suggesting a functional role for the receptors in vascular emigration and selective tissue localization. Tissue staining of human fetal skin localized ECMRs I and II to the basal epidermis primarily, while monoclonal antibodies to the FNR stained both the dermis and epidermis. Experiments carried out to investigate the functional roles of these receptors in mediating cell adhesion to complex extracellular matrix (ECM) produced by cells in culture revealed that complete inhibition of cell adhesion to ECM required antibodies to both the FNR and ECMR II, the collagen adhesion receptor. These results show that multiple ECMRs function in combination to mediate cell adhesion to complex EMC templates and predicts that variation in ECM composition and ECMR expression may direct cell localization to specific tissue domains.ECENTLY, we identified a family of cell surface glycoproteins that mediate fibroblast adhesion to specific components of the extracellular matrix (ECM) ~ and are referred to as extracellular matrix receptors (ECMRs) I and II (Wayner and Carter, 1987). Monoclonal antibody to ECMR II (P1H5) specifically inhibited fibroblast (Wayner and Carter, 1987) and nonactivated platelet adhesion to collagen, while monoclonal antibody against ECMR I (P1B5) inhibited fibroblast adhesion to fibronectin (FN), collagen, and laminin (Wayner and Carter, T. J. Kunicki is an established investigator (83-186) of the American Heart Association.

The α2β1 integrin mediates the malignant phenotype on type I collagen in pancreatic cancer cell lines

“…Figure 5A and B demonstrate clearly that pancreatic cancer cell adhesion and migration on type I collagen is mediated exclusively by the a 2 b 1 integrin, and that neither the a 1 , a 3 , a 5 , or a 6 integrin subunits, nor the a v b 3 or a v b 5 integrins appear to be involved in the adhesive interactions between AsPC-1, BxPC-3, CFPAC, or FG pancreatic cancer cells and type I collagen. Immunoprecipitation studies shown in Figure 4 and previous studies by us and other laboratories (Cheresh and Spiro, 1987;Wayner and Carter, 1987;Sonnenberg et al, 1988;Wayner et al, 1988Wayner et al, , 1993Grzesiak et al, 1992Grzesiak et al, , 2005aFabbri et al, 1996) demonstrate that the monoclonal antibodies used for the type I collagen inhibition studies are functional.…”

“…The function-blocking monoclonal antibodies directed against particular integrin subunits and integrins used in these studies have been described (Cheresh and Spiro, 1987;Wayner and Carter, 1987;Sonnenberg et al, 1988;Wayner et al, 1988Wayner et al, , 1993Fabbri et al, 1996), and include FB12 (a 1 ), P1E6 (a 2 ), P1B5 (a 3 ), P1D6 (a 5 ), GoH3 (a 6 ), P5D2 (b 1 ), LM609 (a v b 3 ), P1F6 (a v b 5 ), and ASC-3 (b 4 ) (Chemicon International, Temecula, CA, USA). For immunoprecipitation (IP) experiments, we used the monoclonal antibodies described above along with rabbit polyclonal antisera against the a 5 integrin subunit, which has also been described previously (Ruoslahti and Pierschbacher, 1987).…”

Adhesion molecule expression in human synovial tissue

“…The as and a, subunits combine with PI to form receptors for fibronectin (36) and laminin (37), respectively. The as subunit is a 135-kd protein; the a, subunit is a 120-kd protein.…”

Fibronectin receptor overexpression and loss of transformed phenotype in a stable variant of the K562 cell line.

“…Soluble ligand or antibody to alpha5beta1 may displace this inhibitory substance, allowing normal signal transduction to occur. A central role of alpha5beta1 in growth control may explain why diverse transforming agents have been found to affect the structure, expression, or function of this particular integrin (Hirst eta/., 1986;Plantefaber and Hynes, 1989;Symington et al, 1989 (Hemler et a/, 1987;Wayner and Carter, 1987;Wayner et al, 1988). Monoclonal antibodies to the platelet glycoproteins (anti-llbill.…”