Recombinant Human ICAM3 protein

ICAM-3 (Intercellular Adhesion Molecule 3), also known as CD50. is a transmembrane glycoprotein belonging to the immunoglobulin (Ig) superfamily. It is constitutively expressed on leukocytes, particularly T cells, neutrophils, and antigen-presenting cells, playing a critical role in immune regulation and cell-cell interactions. Structurally, ICAM-3 consists of five extracellular Ig-like domains, a transmembrane region, and a short cytoplasmic tail. It serves as a ligand for lymphocyte function-associated antigen 1 (LFA-1. CD11a/CD18) and dendritic cell-specific ICAM-3-grabbing non-integrin (DC-SIGN), facilitating leukocyte adhesion, immune synapse formation, and T-cell activation.

Recombinant ICAM-3 proteins are engineered versions of the native protein, typically produced using mammalian expression systems (e.g., HEK293 or CHO cells) to ensure proper post-translational modifications, such as glycosylation. These proteins often include the extracellular domain (amino acids 1-460) to retain binding functionality while excluding the transmembrane and cytoplasmic regions for solubility. Purification methods commonly involve affinity tags like Fc-fusion or His-tags.

The development of recombinant ICAM-3 has enabled detailed studies of its immunological roles, including its involvement in HIV-1 infection (via DC-SIGN-mediated viral capture) and autoimmune diseases. It is also used to screen therapeutic agents targeting inflammatory pathways or to develop diagnostic tools for immune disorders. Additionally, ICAM-3 recombinant proteins serve as critical reagents in flow cytometry, ELISA, and cell adhesion assays to dissect leukocyte interactions. Their stability and standardized activity make them valuable for both basic research and translational applications in immunology and immunotherapy.