Histamine H1 Receptor (F5Q1L) Rabbit mAb #55550

Histamine is a biogenic amine that is involved in a range of physiological responses and signaling events through binding to histamine receptors (1,2). Histamine was initially discovered as a key molecule involved in allergic response and anaphylaxis, and the use of antihistamines for allergic disorders can be traced back to the 1950s (1,4).

Histamine mediates its effects through a family of G-protein coupled receptors, each characterized by a specific pattern of cellular expression and functions. Most allergic and inflammatory actions of histamine are mediated by the type 1 histamine receptor (H1R) (1-4). The H1R protein contains seven transmembrane domains and an extracellular amino-terminal glycosylated domain (2). Binding of histamine to H1R results in signaling cascades for notable pathways such as phospholipase C, calcium ion transport, protein kinase C (PKC) activation, and NF-κB signaling (3,4). H1R activation leads to increased chemotaxis of inflammatory eosinophils and neutrophils, increased activity of antigen-presenting cells (APCs), activation of T cells, decreased humoral immunity, and increased IgE production (1,3,4). H1R is expressed in a diverse group of cell types such as neurons, endothelial cells, muscle, hepatocytes, and chondrocytes, in addition to key immune cell types such as monocytes, neutrophils, eosinophils, dendritic cells (DCs), T cells, and B cells (3,4).

H1R knockout mice show reduced T cell response and decreased inflammatory response (4). By analyzing publicly available RNA-seq databases (5), the co-expression and interaction of CXCR4 and HRH1 are implicated in lower survival in breast cancer, and dysregulated H1R expression was observed as an early event in the onset of malignant transformation of some cancer cell types (5-8). Recently, it has been observed that H1R promotes cell proliferation in several cancer types, including brain, pancreatic, and breast cancers, underscoring that H1R is a potential target in cancer therapy (5-8).