Human Leukocyte Immunoglobulin Like Receptor B1 (LILRB1) Protein

Background

Leukocyte Immunoglobulin-Like Receptor B1 (LILRB1), also known as CD85j, ILT2, or LIR-1, is a member of the leukocyte immunoglobulin-like receptor (LILR) family that plays an important role in modulating immune responses. LILRB1 is classified as an inhibitory receptor due to its immunoreceptor tyrosine-based inhibitory motifs (ITIMs), which enable it to dampen immune activation and promote immune tolerance. The LILR family consists of receptors involved in either activating or inhibiting immune responses, and they are predominantly expressed on myeloid and lymphoid cells, including monocytes, macrophages, dendritic cells, and natural killer (NK) cells.LILRB1 is encoded by a gene located on chromosome 19q13.4 within a cluster of LILR family genes. Its expression pattern includes myeloid cells and subsets of lymphocytes, such as T cells and NK cells, indicating its wide-ranging roles in both innate and adaptive immunity. The receptor functions by binding to a broad spectrum of ligands, including major histocompatibility complex (MHC) class I molecules and human cytomegalovirus (HCMV) proteins. Through its inhibitory action, LILRB1 regulates immune responses, helping prevent excessive immune activity that can lead to tissue damage or autoimmune diseases.