Leukocyte immunoglobulin-like receptor subfamily A member 3 (LILR-A3) also known as CD85 antigen-like family member E (CD85e), immunoglobulin-like transcript 6 (ILT-6), and leukocyte immunoglobulin-like receptor 4 (LIR-4) is a protein that in humans is encoded by the LILRA3gene located within the leukocyte receptor complex on chromosome 19q13.4. Unlike many of its family, LILRA3 lacks a transmembrane domain. The function of LILRA3 is currently unknown; however, it is highly homologous to other LILR genes,[2] and can bind human leukocyte antigen (HLA) class I. Therefore, if secreted, the LILRA3 might impair interactions of membrane-bound LILRs (such as LILRB1, an inhibitory receptor expressed on effector and memory CD8 T cells) with their HLA ligands, thus modulating immune reactions and influencing susceptibility to disease.[3][4][5]
Like the closely related LILRA1, LILRA3 binds to both normal and 'unfolded' free heavy chains of HLA class I, with a preference for free heavy chains of HLA-C alleles [6]
Wiśniewski A, Łuszczek W, Mańczak M, Jasek M, Kubicka W, Cislo M, Kuśnierczyk P (April 2003). "Distribution of LILRA3 (ILT6/LIR4) deletion in psoriatic patients and healthy controls". Human Immunology. 64 (4): 458–61. doi:10.1016/S0198-8859(03)00025-9. PMID12651072.
Norman PJ, Carey BS, Stephens HA, Vaughan RW (June 2003). "DNA sequence variation and molecular genotyping of natural killer leukocyte immunoglobulin-like receptor, LILRA3". Immunogenetics. 55 (3): 165–71. doi:10.1007/s00251-003-0561-1. PMID12750859. S2CID52863887.
Overview of all the structural information available in the PDB for UniProt: Q8N6C8 (Leukocyte immunoglobulin-like receptor subfamily A member 3) at the PDBe-KB.
