Structures of the four  Ig-like domain LILRB2 and the four-domain LILRB1 and HLA-G1 complex.

Structures of the four Ig-like domain LILRB2 and the four-domain LILRB1 and HLA-G1 complex. Cell Mol Immunol. 2019 Jul 04;: Authors: Wang Q, Song H, Cheng H, Qi J, Nam G, Tan S, Wang J, Fang M, Shi Y, Tian Z, Cao X, An Z, Yan J, Gao GF Abstract Leukocyte immunoglobulin (Ig)-like receptors (LILRs), also known as CD85 and immunoglobulin-like transcripts (ILTs), play pivotal roles in regulating immune responses. These receptors define an immune checkpoint that immune therapy can target. Through cis or trans interactions with human leukocyte antigen (HLA)-G, the two most abundantly expressed inhibitory LILRs, LILRB1, and LILRB2 (LILRB1/2, also known as CD85j/d and ILT2/4), are involved in immunotolerance in pregnancy and transplantation, autoimmune diseases, and immune evasion by tumors. Although the discrete domains of LILRB1/2 are clear, the assembly mode of the four extracellular Ig-like domains (D1, D2, D3, and D4) remains unknown. Previous data indicate that D1D2 is responsible for binding to HLA class I (HLA-I), but the roles of D3D4 are still unclear. Here, we determined the crystal structure of the four Ig-like domain LILRB2 and four-domain LILRB1 in complex with HLA-G1. The angles between adjacent domains and the staggered assembly of the four domains suggest limited flexibility and limited plasticity of the receptors during ligand binding. The complex structure of four-domain LILRB1 and HLA-G1 supports the model that D1D2 is...
Source: Cellular and Molecular Immunology - Category: Molecular Biology Authors: Tags: Cell Mol Immunol Source Type: research