Identification of laminin-10/11 as a strong cell adhesive complex for a normal and a malignant human epithelial cell line

1999 ◽  
Vol 112 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. Ferletta ◽  
P. Ekblom

Laminins are heterotrimeric proteins of basement membranes. More than 50 different trimers may exist. Laminin-10 (alpha5beta1gamma1 rather than laminin-1 (alpha1beta1gamma1) could be the most abundant isoform in the adult stage, and laminin-10 is made by several developing epithelial sheets. We show here that a much used commercial human preparation contains laminin-10 (alpha5beta1gamma1), some laminin-11 (alpha5beta2gamma1), but no laminin-1. Moreover, the laminin-10/11 mixture was found to be a strong adhesive for two human cell lines derived from epithelia. Antibodies against integrin beta1, alpha6 or alpha3 (at 50 microgram/ml) or dystroglycan did not inhibit cell attachment to laminin-10/11, although lower concentrations of anti-dystroglycan and integrin alpha6 antibodies inhibited cell binding to laminin-1.

Development ◽  
1990 ◽  
Vol 110 (3) ◽  
pp. 823-837 ◽  
Author(s):  
G. Klein ◽  
M. Ekblom ◽  
L. Fecker ◽  
R. Timpl ◽  
P. Ekblom

Laminin is a large glycoprotein of basement membranes. The best described laminin from a mouse tumor contains three polypeptide chains (A, B1 and B2), but there is recent evidence that some cell types produce laminin isoforms lacking the A chain. We have here studied the occurrence of the isoforms during mouse organogenesis. In all tissues studied, the A chain mRNA and polypeptide were more weakly expressed than those of the B chains. Laminin A chain polypeptides showed a much more restricted tissue distribution than the B chains. Laminin A chain polypeptide was mainly detected in basement membranes of epithelial cells, suggesting that this chain is important for morphogenesis of epithelial sheets. Most endothelial basement membranes and all embryonic mesenchyme matrices studied seemed to lack the A chain even though they contained B chains. Several of the cells producing laminin devoid of A chain seem to produce other polypeptides that become complexed to the B chains. With an anti-laminin antiserum, which in immunoblots reacts only with A and B polypeptide chains, additional polypeptides of 160 and 190 × 10(3) Mr were co-precipitated from all tissues studied. In developing heart, a polypeptide of 300 × 10(3) Mr was co-precipitated in addition. Our data suggest that these laminin-associated polypeptides are not formed by a differential splicing of the known A chain mRNA. Northern blotting of poly (A)+ RNA showed only 10kb A chain transcripts but no truncated forms. We conclude that several cell types in the mouse embryo produce laminin variants that lack the 400 × 10(3) Mr A chain. Since a major cell binding site of laminin contains parts of the A chain, the variants should differ in biological function from laminin containing this A chain.


1991 ◽  
Vol 266 (5) ◽  
pp. 3045-3051
Author(s):  
F Kimizuka ◽  
Y Ohdate ◽  
Y Kawase ◽  
T Shimojo ◽  
Y Taguchi ◽  
...  

1994 ◽  
Vol 124 (3) ◽  
pp. 373-380 ◽  
Author(s):  
E Koivunen ◽  
B Wang ◽  
E Ruoslahti

Our previous studies showed that the alpha 5 beta 1 integrin selects cysteine pair-containing RGD peptides from a phage display library based on a random hexapeptide. We have therefore searched for more selective peptides for this integrin using a larger phage display library, where heptapeptides are flanked by cysteine residues, thus making the inserts potentially cyclic. Most of the phage sequences that bound to alpha 5 beta 1 (69 of 125) contained the RGD motif. Some of the heptapeptides contained an NGR motif. As the NGR sequence occurs in the cell-binding region of the fibronectin molecule, this sequence could contribute to the specific recognition of fibronectin by alpha 5 beta 1. Selection for high affinity peptides for alpha 5 beta 1 surprisingly yielded a sequence RRETAWA that does not bear obvious resemblance to known integrin ligand sequences. The synthetic cyclic peptide GACRRETAWACGA (*CRRETAWAC*) was a potent inhibitor of alpha 5 beta 1-mediated cell attachment to fibronectin. This peptide is nearly specific for the alpha 5 beta 1 integrin, because much higher concentrations were needed to inhibit the alpha v beta 1 integrin, and there was no effect on alpha v beta 3- and alpha v beta 5-mediated cell attachment to vitronectin. The peptide also did not bind to the alpha IIb beta 3 integrin. *CRRETAWAC* appears to interact with the same or an overlapping binding site in alpha 5 beta 1 as RGD, because cell attachment to *CRRETAWAC* coated on plastic was divalent cation dependent and could be blocked by an RGD-containing peptide. These results reveal a novel binding specificity in the alpha 5 beta 1 integrin.


1996 ◽  
Vol 109 (7) ◽  
pp. 1965-1973 ◽  
Author(s):  
G. Plopper ◽  
J. Falk-Marzillier ◽  
S. Glaser ◽  
M. Fitchmun ◽  
G. Giannelli ◽  
...  

Laminin-5r is a basement membrane component that promotes rapid adhesion and hemidesmosome formation in epithelial cells. We raised monoclonal antibodies and identified their corresponding epitopes on the constituent chains of laminin-5r by western blotting. Using a combination of immunoprecipitation and ELISA assays, we determined that these epitopes are differentially exposed on two forms of the laminin-5r heterotrimer: soluble (passively adsorbed onto plastic) and cell-associated. Antibody 5C5 epitope is exposed on the cell-associated form, but not the soluble/passively adsorbed form of laminin-5r. Epitopes reactive with antibodies CM6, FM3, and TR1 are also preferentially exposed on cell-associated laminin-5r, such that reactivity of these antibodies with the cell-associated form is fourfold higher than with the soluble/passively adsorbed form in ELISA assays. Incubation of passively adsorbed laminin-5r with the human epithelial cell line SCC12 induced exposure of 5C5 and CM6, FM3, or TR1 epitopes. These data suggest that cells actively modify laminin-5r, perhaps during matrix assembly, and that the 5C5 epitope may serve as a marker for assembled laminin-5r matrix.


2001 ◽  
Vol 114 (2) ◽  
pp. 423-433 ◽  
Author(s):  
T. Geberhiwot ◽  
D. Assefa ◽  
J. Kortesmaa ◽  
S. Ingerpuu ◽  
C. Pedraza ◽  
...  

Laminins are a growing family of large heterotrimeric proteins with cell adhesive and signalling functions. They are major components of basement membranes and are found in many organs, including the vasculature and other compartments of bone marrow, thymus, lymph nodes and spleen. However, expression, recognition and use of laminin isoforms by lymphoid cells are poorly understood. In the present study, lymphoid T cells (Jurkat) were found to synthesize laminin alpha4, beta1 and gamma1 mRNAs and polypeptides and to assemble the chains into laminin-8. Lymphoblastoid B (NAD-20) cells, lymphoid NK (NKL) cells and blood lymphocytes also contained laminin-8 and, after cell permeabilization, practically all blood lymphocytes reacted with mAbs to laminin beta1 and gamma1 chains. Following stimulation, blood lymphocytes secreted laminin-8, and this laminin isoform, but not laminin-10/11(alpha5beta1gamma1/alpha5beta2gamma1), promoted chemokine-induced migration of the cells. In an activation-dependent manner, purified blood CD4 T cells adhered to immobilized laminin-8 and laminin-10/11 by using alpha6beta1 integrin, but minimally to laminin-1 (alpha1beta1gamma1). Accordingly, laminin-8 and laminin-10/11, but not laminin-1, strongly costimulated proliferation of the T cells via the same integrin. Thus, lymphoid cells are able to synthesize and secrete complete laminin molecules. In addition, synthesis of laminin-8 and recognition of laminin-8 and -10/11 by lymphocytes indicate relevance of these laminin isoforms in lymphocyte physiology.


2016 ◽  
Vol 26 (3) ◽  
pp. 187-192
Author(s):  
A.N. Atre ◽  
A. Mehta ◽  
P.R. Chandorkar ◽  
M.S. Patole ◽  
S.S. Diwanay ◽  
...  

Development ◽  
1991 ◽  
Vol 113 (4) ◽  
pp. 1069-1084 ◽  
Author(s):  
T. Lallier ◽  
M. Bronner-Fraser

The mechanisms of neural crest cell interaction with laminin were explored using a quantitative cell attachment assay. With increasing substratum concentrations, an increasing percentage of neural crest cells adhere to laminin. Cell adhesion at all substratum concentrations was inhibited by the CSAT antibody, which recognizes the chick beta 1 subunit of integrin, suggesting that beta 1-integrins mediate neural crest cell interactions with laminin. The HNK-1 antibody, which recognizes a carbohydrate epitope, inhibited neural crest cell attachment to laminin at low coating concentrations (greater than 1 microgram ml-1; Low-LM), but not at high coating concentration of laminin (10 micrograms ml-1; High-LM). Attachment to Low-LM occurred in the absence of divalent cations, whereas attachment to High-LM required greater than 0.1 mM Ca2+ or Mn2+. Neural crest cell adherence to the E8 fragment of laminin, derived from its long arm, was similar to that on intact laminin at high and low coating concentrations, suggesting that this fragment contains the neural crest cell binding site(s). The HNK-1 antibody recognizes a protein of 165,000 Mr which is also found in immunoprecipitates using antibodies against the beta 1 subunit of integrin and is likely to be an integrin alpha subunit or an integrin-associated protein. Our results suggest that the HNK-1 epitope on neural crest cells is present on or associated with a novel or differentially glycosylated form of beta 1-integrin, which recognizes laminin in the apparent absence of divalent cations. We conclude that neural crest cells have at least two functionally independent means of attachment to laminin which are revealed at different substratum concentrations and/or conformations of laminin.


1991 ◽  
Vol 113 (6) ◽  
pp. 1475-1483 ◽  
Author(s):  
P Vandenberg ◽  
A Kern ◽  
A Ries ◽  
L Luckenbill-Edds ◽  
K Mann ◽  
...  

The aim of this investigation was to identify the domains of type IV collagen participating in cell binding and the cell surface receptor involved. A major cell binding site was found in the trimeric cyanogen bromide-derived fragment CB3, located 100 nm away from the NH2 terminus of the molecule, in which the triple-helical conformation is stabilized by interchain disulfide bridges. Cell attachment assays with type IV collagen and CB3 revealed comparable cell binding activities. Antibodies against CB3 inhibited attachment on fragment CB3 completely and on type IV collagen to 80%. The ability to bind cells was strictly conformation dependent. Four trypsin derived fragments of CB3 allowed a closer investigation of the binding site. The smallest, fully active triple-helical fragment was (150)3-amino acid residues long. It contained segments of 27 and 37 residues, respectively, at the NH2 and COOH terminus, which proved to be essential for cell binding. By affinity chromatography on Sepharose-immobilized CB3, two receptor molecules of the integrin family, alpha 1 beta 1 and alpha 2 beta 1, were isolated. Their subunits were identified by sequencing the NH2 termini or by immunoblotting. The availability of fragment CB3 will allow for a more in-depth study of the molecular interaction of a short, well defined triple-helical ligand with collagen receptors alpha 1 beta 1 and alpha 2 beta 1.


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