Recombinant Human ICAM4 protein

ICAM-4 (Intercellular Adhesion Molecule-4), also known as CD242. is a cell surface glycoprotein belonging to the immunoglobulin (Ig) superfamily. Primarily expressed on red blood cells (RBCs) and erythroid precursors, it plays a critical role in cell-cell interactions, particularly in erythroid adhesion and immune modulation. Structurally, ICAM-4 consists of two extracellular Ig-like domains, a transmembrane region, and a cytoplasmic tail. It binds to integrins such as αVβ3. α4β1. and αLβ2 on endothelial cells, leukocytes, and platelets, facilitating RBC adhesion to vascular endothelium and immune cells—a process implicated in both physiological and pathological contexts, including erythropoiesis, transfusion compatibility, and hematologic disorders like sickle cell disease.

Recombinant ICAM-4 protein is engineered using expression systems (e.g., mammalian, bacterial) to produce purified, functional forms of the molecule for research and therapeutic applications. Its production typically involves cloning the ICAM-4 gene into a plasmid, transfection into host cells, and purification via affinity chromatography. Recombinant ICAM-4 retains ligand-binding capabilities, enabling studies on RBC adhesion mechanisms, integrin interactions, and immune responses. It is also used to develop inhibitors targeting pathological adhesion in diseases like sickle cell anemia or malaria, where aberrant RBC adhesion causes vascular occlusion.

In transfusion medicine, recombinant ICAM-4 aids in understanding blood group antigen compatibility, as ICAM-4 carries the Landsteiner-Wiener (LW) blood group system antigens. Additionally, it serves as a tool for antibody detection and vaccine development. Quality assessments, including SDS-PAGE, Western blot, and functional binding assays, ensure bioactivity and purity. By providing a controlled, scalable source of ICAM-4. recombinant technology advances both basic research and clinical innovations in hematology and immunology.