Description

The TARM1 Knockout THP-1 Cell Line is a CRISPR/Cas9-edited knockout cell line derived from the THP-1 human acute monocytic leukemia line, offering a loss-of-function model for studying TARM1 in myeloid biology. This ready-to-use resource, generated through CRISPR/Cas9-mediated gene disruption, eliminates the need for in-house editing, ensuring consistent and reproducible experiments in innate immunity research.

THP-1 cells were originally isolated from a pediatric acute monocytic leukemia patient and serve as a well-established model for monocyte/macrophage differentiation and function. Treatment with phorbol myristate acetate (PMA) induces macrophage-like properties, including adhesion, phagocytosis, and cytokine production. Their monocytic origin and retention of key signaling pathways make them ideal for investigating myeloid-specific receptors and innate immune responses.

TARM1 is an activating receptor expressed on myeloid cells that mediates innate immune activation upon interaction with as-yet-unidentified ligands on activated T cells. The receptor signals through the ITAM-bearing adaptor DAP12 (TYROBP), which upon engagement recruits and activates Src family kinases, leading to phosphorylation of SYK. Activated SYK initiates a cascade involving PI3K and AKT, as well as the IKK complex, resulting in NF-??B nuclear translocation. Parallel MAPK pathways, including ERK, JNK, and p38, activate AP-1. Together, these events promote transcription of proinflammatory cytokines, including TNF-??, IL-6, and IL-1??.

In THP-1 cells, which endogenously express DAP12 and the relevant signaling components, TARM1 knockout provides a precise tool to delineate receptor-specific contributions to myeloid activation and cytokine production, without interference from other ITAM-coupled receptors. This model is particularly suited to investigate how TARM1 modulates innate immune responses at distinct differentiation stages, as THP-1 cells can be differentiated into macrophage-like cells with PMA. It holds significant relevance for studying inflammatory diseases, autoimmune disorders, and sepsis, where dysregulated myeloid-T cell crosstalk contributes to pathogenesis.

The knockout cell line enables a range of experimental approaches: co-culture with activated T cells to probe ligand-receptor interactions and functional consequences; ELISA for quantification of TNF-??, IL-6 secretion; luciferase-based assays to assess NF-??B or AP-1 activity; and western blotting to monitor phosphorylation of SYK, AKT, and ERK1/2. Flow cytometry verifies TARM1 expression ablation, and macrophage differentiation assays extend analysis to matured cells. It is amenable to drug target validation and screening for modifiers of myeloid activation. For further information, please contact Ascent Research.