Integrin expression and function is largely modulated by cell activation. Here we provide evidence that long term activation of human NK cells results in a marked modulation of β1-integrin expression and adhesive functions. By flow cytometry and immunochemical analysis we have detected induction of α1β1 and α2β1, increased expression of α4β1 and α5β1, and decline of α6β1 on CD3-CD56+ NK cells generated from 10-day coculture of nonadherent PBMC with irradiated RPMI 8866 EBV+ lymphoblastoid B cell line. Adhesion assays performed on extracellular matrix-coated plates showed that, unlike fresh NK cells, long term-activated NK cells bind to native collagen I via α2β1 and to heat-denatured collagen I in an RGD-dependent manner, although they lose the ability to bind to laminin. In regard to the adhesion to FN, no major quantitative changes are observed after long term NK cell activation. However, whereas α4β1 and α5β1 completely mediate the adhesion of fresh NK cells to fibronectin, binding of activated NK cells is only partially β1-dependent and seems to involve also non-β1- integrin(s) recognizing an RGD sequence. The modulation of β1-integrin expression and the acquisition of new adhesive properties on long term- activated NK cells may be relevant for their traffic and tissue localization during inflammation and immune response.
|Number of pages||9|
|Journal||Journal of Immunology|
|Publication status||Published - Jan 15 1994|
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