Related Experiment Video

Updated: Aug 14, 2026

Assay of Adhesion Under Shear Stress for the Study of T Lymphocyte-Adhesion Molecule Interactions
07:40

Assay of Adhesion Under Shear Stress for the Study of T Lymphocyte-Adhesion Molecule Interactions

Published on: June 29, 2016

A peptide from ICAM-2 binds to the leukocyte integrin CD11a/CD18 and inhibits endothelial cell adhesion

R Li1, P Nortamo, L Valmu

  • 1Department of Biochemistry, University of Helsinki, Finland.

The Journal of Biological Chemistry
|August 15, 1993
PubMed

Insights

Researchers identified a specific peptide region on ICAM-2 that binds to the leukocyte integrin CD11a/CD18 (LFA-1). This peptide inhibits cell adhesion, offering insights into leukocyte interactions.

Area of Science:

  • Immunology
  • Cell Biology
  • Molecular Biology

Background:

  • Leukocyte adhesion is crucial for immune cell function.
  • Integrins like CD11a/CD18 (LFA-1) and CD11b/CD18 (Mac-1) mediate adhesion by binding to ICAM-1 and ICAM-2.
  • The molecular details of these binding interactions are not fully understood.

Purpose of the Study:

  • To identify the specific molecular region of ICAM-2 responsible for binding to CD11a/CD18 (LFA-1).
  • To investigate the functional consequences of this interaction on leukocyte adhesion.

Main Methods:

  • Synthesis of a peptide from residues 21-42 of the ICAM-2 immunoglobulin domain.
  • Testing the binding of the synthetic peptide to purified CD11a/CD18 (LFA-1).
  • Assessing the peptide's ability to inhibit endothelial cell adhesion and B lymphoblastoid cell binding to CD11a/CD18 (LFA-1).
  • Evaluating leukocyte adhesion to plastic surfaces coated with the peptide.

Main Results:

  • A synthetic peptide (residues 21-42) from ICAM-2 specifically bound to purified CD11a/CD18 (LFA-1).
  • This peptide inhibited endothelial cell adhesion to CD11a/CD18 (LFA-1).
  • The peptide also inhibited B lymphoblastoid cell binding to endothelial cells.
  • Leukocytes demonstrated binding to the peptide-coated surface, with shorter peptides showing reduced activity.

Conclusions:

  • A defined peptide region within ICAM-2 is critical for CD11a/CD18 (LFA-1) binding.
  • This ICAM-2 peptide region plays a significant role in mediating leukocyte adhesion.
  • The findings provide molecular insights into leukocyte-integrin interactions and adhesion processes.

More Related Videos

Dynamic Adhesion Assay for the Functional Analysis of Anti-adhesion Therapies in Inflammatory Bowel Disease08:27

Dynamic Adhesion Assay for the Functional Analysis of Anti-adhesion Therapies in Inflammatory Bowel Disease

Published on: September 20, 2018

A Flow Cytometry-Based High-Throughput Technique for Screening Integrin-Inhibitory Drugs04:15

A Flow Cytometry-Based High-Throughput Technique for Screening Integrin-Inhibitory Drugs

Published on: February 2, 2024

Related Concept Videos

Integrins01:10

Integrins

Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM.
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
Activation of Integrins01:15

Activation of Integrins

Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding events provide an effective stimulus.
Intracellular Signaling Affects Focal Adhesions01:17

Intracellular Signaling Affects Focal Adhesions

Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Cell Adhesion Molecules - Types and Functions01:20

Cell Adhesion Molecules - Types and Functions

Cell adhesion molecules (CAMs) are pivotal to multicellularity and the coordinated functioning of tissues and organ systems. They enable physical interactions between cells and provide mechanical strength to tissues. They also function as receptors for signal transmission across the plasma membrane. The CAMs are broadly classified into four families - integrins, cadherins, selectins, and immunoglobulin-like CAMs (IgCAMs).
CAM Families
The Integrin family of proteins is primarily  involved in a...
Selectins01:25

Selectins

Cell adhesion is  an essential aspect of multicellularity. While stable cell interactions usually occur between cells of the same type, transient cell interactions occur between cells of different tissue types, such as between neutrophils and endothelial cells. Selectins are one class of cell adhesion molecules (CAMs) that bind carbohydrate ligands to form transient cell adhesion. They are rod-like proteins with a long extracellular part of variable length ending with the lectin domain, which...
Immunoglobulin-like Cell Adhesion Molecules01:31

Immunoglobulin-like Cell Adhesion Molecules

Immunoglobulin-like cell adhesion molecules or Ig-CAMs are a versatile group of cell surface glycoproteins belonging to the immunoglobulin protein superfamily. Ig-CAMs possess the characteristic immunoglobulin protein domains and other domains such as the fibronectin type III domain. The Ig domains are glycosylated to varying degrees in different Ig-CAMs.
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...