LFA-1 mediates binding of cytotoxic T lymphocytes (CTLs) to target cells. However, the role of LFA-1 in CTLs beyond its cell adhesion function has been unclear. We have investigated the role of LFA-1 in reorganization of the actin cytoskeleton, an essential step in cell-mediated cytotoxicity. Binding of LFA-1 to ICAM-1, but not anti-LFA-1 cross-linking, induces the accumulation of talin, WASP a...

CD2, also known as LFA-2, T11, and the E rosette receptor, is a T lymphocyte surface protein functionally important in adhesion to target cells and T cell triggering. LFA-3 is a widely distributed cell surface protein that functions in adhesion on target cells. We find that LFA-3 is expressed on human E, and that CD2 is a receptor for LFA-3 that mediates T cell adhesion to human E. Pretreatment...

To identify the intracellular signals which increase the adhesiveness of leukocyte function-associated antigen 1 (LFA-1), we established an assay system for activation-dependent adhesion through LFA-1/intercellular adhesion molecule 1 ICAM-1 using mouse lymphoid cells reconstituted with human LFA-1 and then introduced constitutively active forms of signaling molecules. We found that the phorbol...

The activity of the lymphocyte-function associated antigen 1 (LFA-1; CD11a/CD18) must be tightly controlled during the onset of cellular immunity. It is well known that the sialoglycoprotein CD43 can influence LFA-1-mediated cell adhesion in an either anti- or pro-adhesive manner through mechanisms not well understood. By using a yeast-2-hybrid screen and co-immunoprecipitation we identified ph...

Lymphocyte function-associated antigen 3 (LFA-3) is a widely distributed cell surface glycoprotein that binds to the T lymphocyte CD2 surface glycoprotein. This interaction mediates CTL-target cell conjugate formation and adhesion of thymocytes to thymic epithelial cells. CD2 is also the E rosette receptor of T lymphocytes and mediates rosetting with autologous E by binding to LFA-3. We describ...

The interactions of intercellular adhesion molecules-1 and -3 (ICAM-1 and ICAM-3) with lymphocyte function-associated antigen-1 (LFA-1) have been characterized and compared on the molecular and cellular level. Enzyme-linked immunosorbent-based molecular assays have been utilized to calculate the binding affinities of soluble ICAM-1 (sICAM-1) and soluble ICAM-3 (sICAM-3) for LFA-1. Consistent wi...

A subset of integrin a subunits contain an I domain, which is important for ligand binding. We have deleted the I domain from the b2 integrin lymphocyte function-asssociated antigen-1 (LFA-1) and expressed the resulting non–I domain-containing integrin (DI-LFA-1) in an LFA-1-deficient T cell line. DI-LFA-1 showed no recognition of LFA-1 ligands, confirming the essential role of the I domain in ...

The dynamic regulation of ligand binding is considered crucial for integrin function. However, the importance of activity regulation for integrin function in vivo is largely unknown. Here, we have applied gene targeting to delete the GFFKR sequence of the lymphocyte function-associated antigen-1 (LFA-1) alpha(L) subunit cytoplasmic domain in mouse germline. Lymphocytes from Lfa-1(d/d) mutant mi...

The topic of farms that deal with environmental constraints is an ongoing agricultural policy issue, including within the Common Agricultural Policy. We propose empirical evidence based on a sample Farm Accountancy Data Network (FADN) farm households, evaluate influence chosen factors financially sustainable development and verify less-favoured area (LFA) farms’ growth compared non-LFA househol...

LFA-1 regulates T cell activation and signal transduction through the immunological synapse. T cell receptor (TCR) stimulation rapidly activates LFA-1, which provides unique LFA-1-dependent signals to promote T cell activation. However, the detailed molecular pathways that regulate these processes and the precise mechanism by which LFA-1 contributes to TCR activation remain unclear. We found LF...