Leukocyte immunoglobulin-like receptor subfamily B (LILRB)

The Leukocyte immunoglobulin-like receptor subfamily B (LILRB) is a group of inhibitory receptors primarily expressed on myeloid cells, including macrophages, monocytes, and dendritic cells (UniProt: Q8N423, P59901). These receptors, which include members LILRB1 through LILRB5, play a critical role in maintaining immune homeostasis by delivering inhibitory signals through their cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs) (PMID: 30104605). In the context of oncology, LILRBs are often upregulated in the tumor microenvironment, where they contribute to immune evasion by suppressing the activity of T cells and promoting the polarization of macrophages toward a pro-tumorigenic M2 phenotype (PMID: 33046818). Therapeutic strategies currently focus on using monoclonal antibodies to block these receptors, particularly LILRB2 and LILRB4, to reprogram the myeloid compartment and enhance the efficacy of existing immunotherapies like PD-1/PD-L1 inhibitors (ClinicalTrials.gov: NCT03564717). Beyond cancer, LILRBs are implicated in viral infections and autoimmune disorders due to their broad regulatory effects on the innate and adaptive immune systems (PMID: 29158403).

Other names

LIRILTCD85MIRImmunoglobulin-like transcriptMonocyte/macrophage immunoglobulin-like receptor

Antagonistic monoclonal antibodies that block the interaction between LILRB receptors and their ligands (such as HLA-G, MHC class I, or ANGPTLs), thereby relieving the inhibitory signals on myeloid cells and enhancing anti-tumor immune responses (PMID: 33046818).