TSLP Responsive Luciferase Reporter Ba/F3 Cell Line

The TSLP Responsive Luciferase Reporter Ba/F3 Cell Line is a murine Ba/F3 cell line engineered to express both TSLP-R (thymic stromal lymphopoietin receptor, also known as CRLF2, cytokine receptor like factor 2) (NM_022148.4) and IL-7Ra (Interleukin 7 receptor alpha) (NM_002185.5) separated by a self-cleaving P2A peptide. The construct was delivered bytransduction of STAT5 Luciferase Reporter Ba/F3 cells (#79772), which express a firefly luciferase reporter driven by STAT5 response elements located upstream of the minimal TATA promoter. After activation by TSLP, the endogenous transcription factor STAT5 binds to the response elements, inducing transcription of the luciferase reporter gene. This cell line has been validated to respond to TSLP. Additional functional validation demonstrates that TSLP-induced luciferase activity can be inhibited by either anti-TSLP or anti-TSLPR neutralizing antibodies. TSLP binds to TSLPR, recruits the IL-7Ra co-receptor and activates downstream JAK1/2 (janus kinase 1/2) tyrosine kinases, which phosphorylate the transcription factor STAT5. STAT5 phosphorylation triggers the formation of a homodimer and translocation to the nucleus, where it can activate the transcription of the Firefly luciferase reporter driven by STAT5 response elements present in the promoter.