Validation of heat-inducible Ixodes scapularis HSP70 and tick-specific 3xP3 promoters in ISE6 cells

• Published in: iScience 2024-08, Vol.27 (8), p.110468, Article 110468
• Main Authors: Pham, Michael, Hoffmann, Hans-Heinrich, Kurtti, Timothy J., Chana, Randeep, Garcia-Cruz, Omar, Aliabadi, Simindokht, Gulia-Nuss, Monika
• Format: Article
• Language: English
• Subjects: Cell biology; Entomology; Molecular biology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2024.110468

Ixodes scapularis is an important vector of many pathogens, including the causative agent of Lyme disease. The gene function studies in I. scapularis and other ticks are hampered by the lack of genetic tools, including an inducible promoter for temporal control over transgene-encoding protein or double-stranded RNA. We characterized an intergenic sequence upstream of a heat shock protein 70 (HSP70) gene that can drive Renilla luciferase and mCherry expression in the I. scapularis cell line ISE6 (IsHSP70). In another construct, we replaced the Drosophila melanogaster minimal HSP70 promoter of the 3xP3 promoter with a minimal portion of IsHSP70 promoter and generated an I. scapularis-specific 3xP3 (Is3xP3) promoter. Both IsHSP70 and Is3xP3 have a heat-inducible expression of mCherry fluorescence in ISE6 cells with an approximately 10-fold increase in the percentage of fluorescent cells upon 2 h heat shock. These promoters described will be valuable tools for gene function studies. [Display omitted] •Two heat-inducible promoters functional in Ixodes scapularis cells•A tick-specific 3xP3 synthetic promoter was developed•Inducible HSP70 and tick-specific 3xP3 promoters developed•Temporal gene expression now possible Entomology; Molecular biology; Cell biology