The integrin LFA-1 signals through ZAP-70 to regulate expression of high-affinity LFA-1 on T lymphocytes

Blood ◽  
2011 ◽  
Vol 117 (12) ◽  
pp. 3331-3342 ◽  
Author(s):  
Rachel Evans ◽  
Annemarie C. Lellouch ◽  
Lena Svensson ◽  
Alison McDowall ◽  
Nancy Hogg

Abstract The integrin lymphocyte function-associated antigen 1 (LFA-1) controls many functions of T lymphocytes and is particularly essential during lymphocyte migration from blood into tissues. LFA-1 is considered to initiate “outside-in” signaling when bound to ligand intercellular adhesion molecule 1 (ICAM-1), but little is known about the proteins involved or where in the cell such LFA-1–mediated signaling might be operating. Here we show that LFA-1 is constitutively associated with the protein tyrosine kinases Lck and zeta chain–associated protein of 70 kDa (ZAP-70). When LFA-1 binds ICAM-1, both kinases become phosphorylated and the consequence of kinase activation is the conversion of intermediate- to high-affinity LFA-1 and an increase in close contact with ICAM-1. In the polarized T lymphocyte, phospho-ZAP-70 is concentrated within a region of high-affinity LFA-1 that includes talin and encompasses the lamella/lamellipodial interface as well as further back in the cell. Deficiency of ZAP-70 through inhibition or knockdown in T lymphocytes decreases the speed of migration on ICAM-1, as well as reducing firm adhesion under shear-flow conditions. Through its control of high-affinity LFA-1, the LFA-1/Lck/ZAP-70 complex is in position to initiate the rapid adhesion strengthening and migration necessary for T-lymphocyte responses when stimulated vasculature is encountered at sites of infection or injury.

2008 ◽  
Vol 205 (1) ◽  
pp. 195-205 ◽  
Author(s):  
Nicole A. Morin ◽  
Patrick W. Oakes ◽  
Young-Min Hyun ◽  
Dooyoung Lee ◽  
Y. Eugene Chin ◽  
...  

Precise spatial and temporal regulation of cell adhesion and de-adhesion is critical for dynamic lymphocyte migration. Although a great deal of information has been learned about integrin lymphocyte function–associated antigen (LFA)-1 adhesion, the mechanism that regulates efficient LFA-1 de-adhesion from intercellular adhesion molecule (ICAM)-1 during T lymphocyte migration is unknown. Here, we show that nonmuscle myosin heavy chain IIA (MyH9) is recruited to LFA-1 at the uropod of migrating T lymphocytes, and inhibition of the association of MyH9 with LFA-1 results in extreme uropod elongation, defective tail detachment, and decreased lymphocyte migration on ICAM-1, without affecting LFA-1 activation by chemokine CXCL-12. This defect was reversed by a small molecule antagonist that inhibits both LFA-1 affinity and avidity regulation, but not by an antagonist that inhibits only affinity regulation. Total internal reflection fluorescence microscopy of the contact zone between migrating T lymphocytes and ICAM-1 substrate revealed that inactive LFA-1 is selectively localized to the posterior of polarized T lymphocytes, whereas active LFA-1 is localized to their anterior. Thus, during T lymphocyte migration, uropodal adhesion depends on LFA-1 avidity, where MyH9 serves as a key mechanical link between LFA-1 and the cytoskeleton that is critical for LFA-1 de-adhesion.


2005 ◽  
Vol 170 (1) ◽  
pp. 141-151 ◽  
Author(s):  
Andrew Smith ◽  
Yolanda R. Carrasco ◽  
Paula Stanley ◽  
Nelly Kieffer ◽  
Facundo D. Batista ◽  
...  

Cells such as fibroblasts and endothelial cells migrate through the coordinated responses of discrete integrin-containing focal adhesions and complexes. In contrast, little is known about the organization of integrins on the highly motile T lymphocyte. We have investigated the distribution, activity, and cytoskeletal linkage of the integrin lymphocyte function associated antigen-1 (LFA-1) on human T lymphocytes migrating on endothelial cells and on ligand intercellular adhesion molecule-1 (ICAM-1). The pattern of total LFA-1 varies from low expression in the lamellipodia to high expression in the uropod. However, high affinity, clustered LFA-1 is restricted to a mid-cell zone that remains stable over time and over a range of ICAM-1 densities. Talin is essential for the stability and formation of the LFA-1 zone. Disruption of the talin–integrin link leads to loss of zone integrity and a substantial decrease in speed of migration on ICAM-1. This adhesive structure, which differs from the previously described integrin-containing attachments displayed by many other cell types, we have termed the “focal zone.”


1999 ◽  
Vol 10 (6) ◽  
pp. 1891-1907 ◽  
Author(s):  
José Luis Rodrı́guez-Fernández ◽  
Manuel Gómez ◽  
Alfonso Luque ◽  
Nancy Hogg ◽  
Francisco Sánchez-Madrid ◽  
...  

Integrin receptors play a central role in the biology of lymphocytes, mediating crucial functional aspects of these cells, including adhesion, activation, polarization, migration, and signaling. Here we report that induction of activation of the β2-integrin lymphocyte function-associated antigen 1 (LFA-1) in T lymphocytes with divalent cations, phorbol esters, or stimulatory antibodies is followed by a dramatic polarization, resulting in a characteristic elongated morphology of the cells and the arrest of migrating lymphoblasts. This cellular polarization was prevented by treatment of cells with the specific tyrosine kinase inhibitor genistein. Furthermore, the interaction of the activated integrin LFA-1 with its ligand intercellular adhesion molecule 1 induced the activation of the cytoplasmic tyrosine kinases focal adhesion kinase (FAK) and proline-rich tyrosine kinase 2 (PYK-2). FAK activation reached a maximum after 45 min of stimulation; in contrast, PYK-2 activation peaked at 30 min, declining after 60 min. Upon polarization of lymphoblasts, FAK and PYK-2 redistributed from a diffuse localization in the cytoplasm to a region close to the microtubule-organizing center in these cells. FAK and PYK-2 activation was blocked when lymphoblasts were pretreated with actin and tubulin cytoskeleton-interfering agents, indicating its cytoskeletal dependence. Our results demonstrate that interaction of the β2-integrin LFA-1 with its ligand intercellular adhesion molecule 1 induces remodeling of T lymphocyte morphology and activation and redistribution of the cytoplasmic tyrosine kinases FAK and PYK-2.


1993 ◽  
Vol 178 (5) ◽  
pp. 1753-1763 ◽  
Author(s):  
V A Boussiotis ◽  
G J Freeman ◽  
G Gray ◽  
J Gribben ◽  
L M Nadler

Presentation of antigen by the major histocompatibility complex to T lymphocytes without the requisite costimulatory signals does not induce an immune response but rather results in a state of antigen-specific unresponsiveness, termed anergy. To determine which costimulatory signals are critical for the T cell commitment to activation or anergy, we developed an in vitro model system that isolated the contributions of alloantigen and each candidate costimulatory molecule. Here, we show that transfectants expressing HLA-DR7 and either B7 or intercellular adhesion molecule 1 (ICAM-1) deliver independent costimulatory signals resulting in alloantigen-induced proliferation of CD4-positive T lymphocytes. Although equivalent in their ability to costimulate maximal proliferation of alloreactive T cells, B7 but not ICAM-1 induced detectable interleukin 2 secretion and prevented the induction of alloantigen-specific anergy. These results are consistent with the hypothesis that blockade of the ICAM-1:lymphocyte function-associated 1 pathway results in immunosuppression, whereas blockade of the B7:CD28/CTLA4 pathway results in alloantigen-specific anergy. This approach, using this model system, should facilitate the identification of critical costimulatory pathways which must be inhibited in order to induce alloantigen-specific tolerance before human organ transplantation.


2017 ◽  
Vol 114 (10) ◽  
pp. 2693-2698 ◽  
Author(s):  
Marianne Strazza ◽  
Inbar Azoulay-Alfaguter ◽  
Michael Peled ◽  
Alan V. Smrcka ◽  
Edward Y. Skolnik ◽  
...  

Regulation of integrins is critical for lymphocyte adhesion to endothelium and migration throughout the body. Inside-out signaling to integrins is mediated by the small GTPase Ras-proximate-1 (Rap1). Using an RNA-mediated interference screen, we identified phospholipase Cε 1 (PLCε1) as a crucial regulator of stromal cell-derived factor 1 alpha (SDF-1α)-induced Rap1 activation. We have shown that SDF-1α-induced activation of Rap1 is transient in comparison with the sustained level following cross-linking of the antigen receptor. We identified that PLCε1 was necessary for SDF-1α-induced adhesion using shear stress, cell morphology alterations, and crawling on intercellular adhesion molecule 1 (ICAM-1)–expressing cells. Structure–function experiments to separate the dual-enzymatic function of PLCε1 uncover necessary contributions of the CDC25, Pleckstrin homology, and Ras-associating domains, but not phospholipase activity, to this pathway. In the mouse model of delayed type hypersensitivity, we have shown an essential role for PLCε1 in T-cell migration to inflamed skin, but not for cytokine secretion and proliferation in regional lymph nodes. Our results reveal a signaling pathway where SDF-1α induces T-cell adhesion through activation of PLCε1, suggesting that PLCε1 is a specific potential target in treating conditions involving migration of T cells to inflamed organs.


1994 ◽  
Vol 179 (1) ◽  
pp. 359-363 ◽  
Author(s):  
B Ybarrondo ◽  
A M O'Rourke ◽  
A A Brian ◽  
M F Mescher

A rapid induction of adhesion to immobilized intercellular adhesion molecule (ICAM)-1 occurs when cytotoxic T lymphocytes (CTL) are stimulated with either soluble anti-T cell receptor (TCR) monoclonal antibodies (mAb) or with immobilized alloantigen, and this binding is blocked by the addition of anti-lymphocyte function-associated (LFA)-1 mAbs. Requirements for activating LFA-1 adhesion to ICAM-1 are similar to those found for induction of binding to immobilized fibronectin (FN), but distinct from those for activating CD8-mediated adhesion to class I major histocompatibility complex. A distinct role for LFA-1 in co-signaling for TCR-dependent degranulation could not be demonstrated. In contrast, both CD8 and the FN-binding integrin provide costimulatory signals for this response. Thus, if co-signaling via LFA-1 occurs, it clearly differs from that provided by CD8 or the FN-binding integrin. On the basis of antibody blocking effects, alloantigen-dependent activation of adhesion to ICAM-1 involves both the TCR and CD8. These results support a view of CTL activation as a cascade of adhesion and signaling events, with different coreceptors making distinct contributions.


Sign in / Sign up

Export Citation Format

Share Document