Human natural killer cells express VLA-4 and VLA-5, which mediate their adhesion to fibronectin.
Very late Ag (VLA)-3, VLA-4, and VLA-5, belonging to the beta-1 subfamily of integrins, have been recently identified as receptors for different binding regions of fibronectin (FN). We have detected VLA-4 and VLA-5, but not VLA-3, on fresh CD3-, CD16+, CD56+ human NK cells by flow cytometry and immunochemical analyses using mAb directed against beta-1, alpha-3, alpha-4, and alpha-5 subunits. Binding assays, performed on FN-coated plates, showed that NK cells specifically adhere to FN and their binding capacity is increased by MgCl2 but not by CaCl2. Using as inhibitory probes a polyclonal antibody against the beta-1 chain of the human FN receptor, the synthetic peptide GRGDSP, which is able to inhibit cellular adhesion mediated by VLA-5, the CS1 fragment, which contains the principal adhesion site in the IIICS domain recognized by VLA-4, and functional mAb directed against alpha-4 or alpha-5 subunits, we show that both VLA-4 and VLA-5 mediate the adhesion of human NK cells to FN. The expression of these integrin receptors may be relevant for NK interaction with extracellular matrix components and other cell types.
Gismondi
A
A
Department of Experimental Medicine, University of Roma, Italy.
Morrone
S
S
Humphries
M J
MJ
Piccoli
M
M
Frati
L
L
Santoni
A
A
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D001665:Binding Sites; D019002:CD56 Antigen; D002448:Cell Adhesion; D005353:Fibronectins / Q000378:metabolism*; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000378:metabolism*; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D011961:Receptors, Fc / Q000032:analysis; D017469:Receptors, Fibronectin; D017452:Receptors, IgG; D011971:Receptors, Immunologic / Q000378:metabolism*; D016029:Receptors, Very Late Antigen / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D019002:CD56 Antigen; D005353:Fibronectins; D011961:Receptors, Fc; D017469:Receptors, Fibronectin; D017452:Receptors, IgG; D011971:Receptors, Immunologic; D016029:Receptors, Very Late Antigen