Interactions between human monocytes and fibronectin are suppressed by interferons beta and gamma, but not alpha: correlation with Rho-paxillin signaling.
Modulation of the adhesive responses of monocytic cells may reflect their motility at sites of diseased tissues (inflammation, tumors). Integrins alpha5beta1 mediate fibronectin (Fn)-dependent adhesion of human monocytes and their precursors. The effect of type I IFNs (alpha, beta) and type II IFN (gamma) was assessed on the adhesive capacities of promonocytic U937 cells and monocytes. IFN-beta and IFN-gamma abrogated monocytic cell adhesion to Fn, but such impaired cell attachment was not due to altered levels of alpha5beta1 integrins. In contrast, IFN-alpha did not affect cell adhesion to Fn. Participation of cytoskeleton assembly in IFN-mediated cell detachment was evaluated. Activation of RhoA activity with lysophosphatidic acid (LPA) increased 2-fold the adhesion of monocytic cells to Fn in a alpha5beta1-mediated fashion, and IFN-gamma treatment reversed the enhancing effect of LPA. Moreover, U937 cells and monocytes dominantly expressed the 44-46 kDa paxillin forms and IFN-beta and IFN-gamma led to the accumulation of 66-70 kDa paxillin forms. These results indicate that IFN-mediated loss of monocyte adhesion to Fn is associated with changes in the cytoskeleton associated proteins paxillin and Rho.
Surin
Brigitte
B
Unite 365 INSERM, Institut Curie, 75231 Paris cedex 05, France.
Rouillard
Dany
D
Bauvois
Brigitte
B
D002448:Cell Adhesion / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D039482:Integrin alpha5 / Q000378:metabolism; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000378:metabolism; D016899:Interferon-beta / Q000378:metabolism; D007371:Interferon-gamma / Q000378:metabolism; D007372:Interferons / Q000378:metabolism*; D008246:Lysophospholipids / Q000378:metabolism; D009000:Monocytes / Q000378:metabolism*; D051419:Paxillin; D010750:Phosphoproteins / Q000378:metabolism*; D011994:Recombinant Proteins; D015398:Signal Transduction / Q000502:physiology; D013755:Tetradecanoylphorbol Acetate / Q000031:analogs & derivatives* / Q000378:metabolism; D016596:Vinculin / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
D003598:Cytoskeletal Proteins; D005353:Fibronectins; D039482:Integrin alpha5; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D008246:Lysophospholipids; C496061:PXN protein, human; D051419:Paxillin; D010750:Phosphoproteins; D011994:Recombinant Proteins; D016596:Vinculin; C016658:phorbolol myristate acetate; D016899:Interferon-beta; D007371:Interferon-gamma; D007372:Interferons; D020742:rhoA GTP-Binding Protein; D013755:Tetradecanoylphorbol Acetate