Human Chemokine C-C-Motif Receptor 1 / CD191 (CCR1) Protein

Background

C-C Chemokine Receptor Type 1 (CCR1) is a G-protein-coupled receptor (GPCR) primarily expressed on the surface of immune cells such as monocytes, macrophages, T lymphocytes, neutrophils, and eosinophils. CCR1 binds C-C chemokines, including CCL3 (MIP-1α), CCL5 (RANTES), and CCL14, driving immune cell chemotaxis, activation, and trafficking to sites of inflammation, infection, or tissue damage. This receptor plays a central role in the innate immune response and facilitates the migration of immune cells to areas where pathogens or damaged tissues trigger inflammatory signals. CCR1 signaling activates pathways such as MAPK, PI3K/AKT, and NF-κB, leading to cytokine secretion, increased cell adhesion, and immune cell recruitment. Dysregulated CCR1 activity is implicated in autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, and inflammatory bowel disease (IBD), where excessive recruitment of leukocytes amplifies inflammation and tissue damage. CCR1 also contributes to the pathogenesis of certain cancers, as its activation promotes tumor progression, angiogenesis, and metastasis by recruiting immune cells to the tumor microenvironment. Therapeutic strategies targeting CCR1, including small molecule antagonists and antibodies, are being developed to treat chronic inflammatory conditions and prevent tumor-associated immune infiltration. Research continues to uncover its role in infection, immunity, and cancer, highlighting its importance as a therapeutic target in immune-mediated diseases and oncology.