Recombinant Human NKp30 Fc Chimera Protein, CF

NKp30, along with NKp44 and NKp46, constitute a group of receptors termed “Natural Cytotoxicity Receptors” (1). These receptors play a major role in triggering NK-mediated killing of most tumor cells lines. NKp30 is a type I transmembrane protein having a single extracellular V-like immunoglobulin domain (2). A physical association with the ITAM‑bearing accessory protein, CD3 zeta, occurs via a charged residue in the NKp30 transmembrane domain. Ligation of NKp30 with a specific antibody results in phosphorylation of CD3 zeta (3). NKp30 is expressed on both resting and activated NK cells of the CD56^dim, CD16⁺ subset that account for more that 85% of NK cells found in peripheral blood and spleen (4). NKp30 is absent from the CD56^bright, CD16^- subset that constitutes the majority of NK cells in lymph node and tonsil, however, its expression is up-regulated in these cells upon IL-2 activation (4). Studies with neutralizing antibodies reveal that NKp30 is partially responsible for triggering lytic activity against several tumor cell types and that it is the main receptor responsible for NK-mediated lysis of immature dendritic cells (2, 5). The ligand(s) recognized by NKp30 has not been described.