T cell immunoglobulin and mucin domain 1 (TIM-1)

T cell immunoglobulin and mucin domain 1 (TIM-1) is a type I transmembrane glycoprotein, primarily expressed on activated T cells, B cells, and renal epithelial cells, and encoded by the human HAVCR1 gene[6][2][3][4]. Its extracellular region comprises an immunoglobulin variable (IgV) domain and a mucin-like domain, which facilitate interactions with ligands such as phosphatidylserine (a marker of apoptotic cells), TIM-4, selectins, and various viruses including hepatitis A virus and Ebola virus[2][3][5][6]. Functionally, TIM-1 acts as an immune checkpoint receptor regulating T cell response, cytokine secretion, and immune tolerance, while also serving as a receptor for viral entry and as a biomarker of kidney injury[2][3][4][5][6]. TIM-1 is implicated in cancer—where it can be overexpressed—as well as immune diseases (autoimmunity, allergy), infection, and transplant biology. Antibodies and other therapies targeting TIM-1 are under preclinical and early clinical investigation, with potential safety concerns related to immune modulation and infection susceptibility[2][3][5].

Other names

Hepatitis A virus cellular receptor 1 (HAVCR1)Kidney injury molecule-1 (KIM-1)HAVcr-1

Antibody blockade of TIM-1 can inhibit ligand binding and reduce immune activation or viral entry Ligand blockade can disrupt apoptotic cell clearance or T cell stimulation Small molecule inhibitors or antibodies may modulate immune checkpoint activity to enhance anti-tumor immunity