Evidence that TNF-induced respiratory burst of adherent PMN is mediated by integrin L2 (original) (raw)

Evidence that TNF-induced respiratory burst of adherent PMN is mediated by integrin αLβ2

Journal of Leukocyte Biology, 2002

Polymorphonuclear leukocytes (PMN) respond to tumor necrosis factor (TNF) with a respiratory burst (RB) only after adherence to surfaces coated with extracellular matrix proteins such as fibronectin and fibrinogen (permissive substrates) but not with others such as laminin or collagen (nonpermissive substrates). As PMN adherence to both types of surfaces is dependent on ␤ 2 integrins, we investigated the molecular basis of the different metabolic response to TNF. In particular, we evaluated the relative role of each ␤ 2 integrin (␣ L ␤ 2 , ␣ M ␤ 2 , and ␣ X ␤ 2) in adherence and O 2 ؊ production of PMN residing on fibronectinand laminin-coated surfaces, which were considered as models of permissive and nonpermissive surfaces, respectively. By using ␣ chain-specific monoclonal antibodies (mAb), we show that ␣ M ␤ 2 and ␣ X ␤ 2 mediate adherence to fibronectin and laminin; ␣ L ␤ 2 is not involved in adherence to laminin and has only a minimal contribution in adherence to fibronectin. Furthermore, production of O 2 ؊ in response to TNF was induced by immobilized anti-␣ L ␤ 2 but not anti-␣ M ␤ 2 or anti-␣ X ␤ 2 mAb. A strong correlation was also found between expression of ␣ L ␤ 2 and TNF-induced RB on fibronectin. Lastly, PMN responded to TNF on laminin with a RB after the inclusion of ␣ L-specific mAb in the laminin coat. Thus, we conclude that TNFinduced RB by PMN residing on fibronectin is mediated by ␣ L ␤ 2 and that ␣ M ␤ 2 and ␣ X ␤ 2 are likely to play an ancillary role to the signaling activity of ␣ L ␤ 2 by facilitating its recruitment to sites of adherence. The nonpermissiveness of laminin appears to be a consequence of its inability to act as a ligand for ␣ L ␤ 2 .

Evidence that TNF-induced respiratory burst of adherent PMN is mediated by integrin alpha(L)beta(2)

Journal of leukocyte biology, 2002

Human neutrophil adherence to laminin in vitro. Evidence for a distinct neutrophil integrin receptor for laminin

Journal of Experimental Medicine, 1990

We used mAbs against polymorphonuclear leukocyte (PMN) surface proteins to investigate the mechanisms by which stimulated human neutrophils (PMNs) adhere in vitro to laminin, the major glycoprotein of mammalian basement membrane. mAb IB4, which is directed against the common beta 2 chain of the CD11/CD18, only partially inhibited the adherence of PMA-stimulated PMNs to both laminin and to subendothelial matrices. In contrast, IB4 completely inhibited PMA-stimulated PMN adherence to gelatin, fibronectin, collagen IV, and endothelial cell monolayers. PMA-stimulated PMNs from a patient with severe congenital CD11/CD18 deficiency also adhered to laminin, but not to gelatin or endothelial cell monolayers. Therefore, PMA-stimulated PMNs adhere to laminin by both CD11/CD18-dependent and CD11/CD18-independent mechanisms. Expression of CD11/CD18-independent adherence to laminin was agonist dependent, occurring after stimulation with the calcium ionophore A23187 and recombinant TNF-alpha, but...

TNF-α binds to the N-terminal domain of fibronectin and augments the β1-integrin-mediated adhesion of CD4+ T lymphocytes to the glycoprotein

The Journal of Immunology

Certain inflammatory cytokines and growth factors have been previously shown to interact with glycosaminoglycan moieties of the extracellular matrix (ECM). We have examined the association of the pleiotropic cytokine TNF-alpha with glycoprotein constituents of ECM. TNF-alpha interacted with fibronectin (FN) and laminin, and to a lesser degree with collagen. The major binding site for TNF-alpha on FN was localized to its 30-kDa N-terminal fragment (FN-N') with a Ki in the sub-nM range. The binding of 125I-labeled TNF-alpha to immobilized FN or FN-N' persisted for at least 24 h, and was specifically inhibited by antibodies to FN, mAb directed against the FN-N' domain, unlabeled TNF-alpha, and by the truncated forms of TNF-alpha receptors. Once bound to immobilized FN or FN-N', the cytokine could not be released by the soluble TNF-alpha-receptors, although it could be released by anti-TNF-alpha Ab. TNF-alpha was also found to interact with soluble FN, although with a lo...

Laminin promotes rabbit neutrophil motility and attachment

Journal of Clinical Investigation, 1986

Polymorphonuclear neutrophils (PMN) traverse basement membrane to reach sites of infection. We have studied the role of laminin, a specific basement membrane component, in this process using three assay systems. In the Boyden chamber, laminin was found to stimulate chemotaxis of neutrophils while fibronectin did not. Co-incubation of cells with antibody to laminin blocked this chemotaxis, while antibody to fibronectin was without effect. In the human amnion system, neutrophils were shown to penetrate through the tissue when the peptide chemoattractant f-Met-Leu-Phe was placed on the opposing side. Antibody to laminin, but not to fibronectin, blocked this penetration. In an attachment assay system, laminin, but not fibronectin, was found to increase dispase-treated neutrophil attachment to type IV (basement membrane) collagen-coated plastic and to a plastic substrate itself. Electrophoretic analysis of PMN extract indicated the presence of laminin, and indirect immunofluorescence suggested that laminin is localized on the surface of the neutrophils. These data suggest that PMN can bind laminin on their cell surfaces, use laminin to attach to basement (type IV) membrane collagen, and migrate toward a gradient of laminin. These properties may be important for the passage of neutrophils from the circulation to sites of infection.

Mechanisms of tumor necrosis factor-alpha alteration of PMN adhesion and migration

The American journal of pathology, 1990

We have investigated the effects of recombinant human tumor necrosis factor-alpha (rhTNF alpha) on polymorphonuclear leukocytes (PMNs), concentrating on the mechanisms involved in the alterations of PMN-directed migration and adherence by this cytokine. RhTNF alpha profoundly suppressed PMN chemotaxis toward FMLP by 80%. At similar concentrations, it enhanced adhesion to gelatin-coated plastic dishes by more than tenfold and increased the expression of the CD11b antigen to 182% of the control. The monoclonal antibody 60.1, which is directed against the alpha chain of the CD11b/CD18 complex, completely blocked rhTNF alpha, induced inhibition of the chemotactic response to FMLP, and rhTNF alpha induced hyperadherence, suggesting that these effects were related to rhTNF alpha's effects on CD11b antigen expression. The fluid state of the PMN membrane was also decreased by rhTNF alpha. N-butanol, a known membrane fluidizer, partially inhibited the effect of rhTNF alpha on membrane fl...

The laminin receptor modulates granulocyte-macrophage colony-stimulating factor receptor complex formation and modulates its signaling

Proceedings of the National Academy of Sciences, 2003

Basement membrane matrix proteins are known to up-regulate granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling in neutrophils and mononuclear phagocytes, but the mechanisms involved are poorly understood. We used the intracellular portion of the ␣ subunit of the GM-CSF receptor (␣GMR) to search for interacting proteins and identified the 67-kDa laminin receptor (LR), a nonintegrin matrix protein receptor expressed in several types of host defense cells and certain tumors, as a binding partner. LR was found to interact with the ␤ subunit of the GMR (␤GMR) as well. Whereas GM-CSF functions by engaging the ␣GMR and ␤GMR into receptor complexes, LR inhibited GM-CSF-induced receptor complex formation. Laminin and fibronectin binding to LR was found to prevent the binding of ␤GMR to LR and relieved the LR inhibition of GMR. These findings provide a mechanistic basis for enhancing host defense cell responsiveness to GM-CSF at transendothelial migration sites while suppressing it in circulation.

Integrin alpha 6 beta 4 mediates dynamic interactions with laminin

Journal of cell science, 1994

We present here a novel form of dynamic adhesion in which both the integrin receptor and the ligand supporting dynamic adhesion have been identified. Laminar flow assays showed that laminin supported attachment of alpha 6 beta 4-positive cells in the presence of fluid shear stress (tau < or = 2 dyn/cm2), indicating that these cells adhered to laminin within a fraction of a second. Further increases in flow rate (3.5 dyn/cm2 < or = tau < or = 100 dyn/cm2) initiated rolling of attached cells in the direction of flow, suggesting that rapidly formed adhesion is reversible and repeatable. Laminin fragment E8, which interacts with alpha 6 integrins, supported dynamic attachment and rolling but extracellular matrix glycoprotein fibronectin did not. In cell lines that express alpha 6 beta 4 but not alpha 6 beta 1 an anti-alpha 6 monoclonal antibody inhibited attachment to laminin in the presence of flow and following 5 minutes of static incubation. Infusion of this antibody onto ce...

Evidence that TNF-induced respiratory burst of adherent PMN is mediated by integrin L2 (original) (raw)

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