The leucocyte β2 (CD18) integrins: the structure, functional regulation and signalling properties

Abstract

<jats:p>Leucocytes are highly motile cells. Their ability to migrate into tissues and organs is dependent on cell adhesion molecules. The integrins are a family of heterodimeric transmembrane cell adhesion molecules that are also signalling receptors. They are involved in many biological processes, including the development of metazoans, immunity, haemostasis, wound healing and cell survival, proliferation and differentiation. The leucocyte-restricted β2 integrins comprise four members, namely αLβ2, αMβ2, αXβ2 and αDβ2, which are required for a functional immune system. In this paper, the structure, functional regulation and signalling properties of these integrins are reviewed.</jats:p>

Integrins in Wound Healing

“…Integrin functions in other wound cells (e.g., platelets or infiltrating macrophages) have been comprehensively reviewed elsewhere (Table 2). 56,65,68 Much of the data presented are drawn from reports on human and animal skin wound healing and from experiments with cultured cells. Information about integrin functions during oral mucosal healing is also presented when available.…”

“…48,67 In general, integrin heterodimers containing either b 2 or b 7 subunit participate in immunodefence, for example, by recognizing components of the complement system or by mediating leukocyte extravasation. 65,68 The most important task of most other integrins is to anchor cells to tissues. However, these receptors also often participate in other processes, including innate immunity and cell regulation by growth …”

“…3; Table 2). [46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65] Integrins can be divided into four subfamilies based on their ligand specificity and/or phylogenetic comparison of the a subunits (Fig. 3).…”

Integrin CD11c/CD18 α-Chain Phosphorylation Is Functionally Important

“…CD11c/CD18 is expressed on macrophages, monocytes, granulocytes, subsets of T and B cells, and dendritic cells (6). It interacts with extracellular matrix molecules such as collagen I (7), soluble ligands such as iC3b (8,9), heparin (10), and fibrinogen (11), and the cell surface immunoglobulin superfamily proteins intercellular adhesion molecules ICAM-1 (12), ICAM-2 (13), and ICAM-4 (14) and vascular adhesion molecule VCAM-1 (13).…”

“…Other members include CD11a/CD18 (␣ L ␤ 2 , LFA-1), CD11b/CD18 (␣ M ␤ 2 , Mac-1), and CD11d/CD18 (␣ D ␤ 2 ). The leukocyte CD11/CD18 integrins are involved in various immunological functions, including cell adhesion, migration, and phagocytosis (2)(3)(4)(5)(6).…”