Transgene-induced cell death following dengue-2 virus infection in Aedes aegypti

Author(s)

Carvalho, Danilo O. ; Costa-da-Silva, Andre L. ; Petersen, Vivian ; de Souza, Micael Santana ; Ioshino, Rafaella S. ; Marques, Isabel C. S. ; Franz, Alexander W. E. ; Olson, Ken E. ; James, Anthony A. ; Capurro, Margareth L.

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 13, n. 1, p. 11-pg., 2023-04-12.

Abstract

Dengue viruses (DENVs) are mosquito-borne flaviviruses causing millions of human infections each year and pose a challenge for public health systems worldwide. Aedes aegypti is the principal vector species transmitting DENVs to humans. Controlling Ae. aegypti is difficult due to the abundance of breeding sites and increasing insecticide resistance in the vector populations. Developing new vector control strategies is critical for decreasing the disease burden. One potential approach is genetically replacing Ae. aegypti populations with vector populations highly resistant to DENV transmission. Here, we focus on an alternative strategy for generating dengue 2 virus (DENV-2) resistance in genetically-modified Ae. aegypti in which the mosquitoes express an inactive form of Michelob_x (Mx), an antagonist of the Inhibitor of Apoptosis (IAP), to induce apoptosis in those cells in which actively replicating DENV-2 is present. The inactive form of Mx was flanked by the RRRRSAG cleavage motif, which was recognized by the NS2B/NS3 protease of the infecting DENV-2 thereby releasing and activating Mx which then induced apoptosis. Our transgenic strain exhibited a significantly higher mortality rate than the non-transgenic control when infected with DENV-2. We also transfected a DNA construct containing inactive Mx fused to eGFP into C6/36 mosquito cells and indirectly observed Mx activation on days 3 and 6 post-DENV-2 infections. There were clear signs that the viral NS2B/NS3 protease cleaved the transgene, thereby releasing Mx protein into the cytoplasm, as was confirmed by the detection of eGFP expression in infected cells. The present study represents proof of the concept that virus infection can be used to induce apoptosis in infected mosquito cells. (AU)

• FAPESP's process: 12/24105-3 - Immunobiology of Leishmania spp.: study of the role of CD200 and biogenesis of parasitophorous vacuole in fagocitic cells infected by Leishmania
• Grantee: Mauro Javier Cortez Véliz
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 20/13562-0 - Unveiling the role of the immune checkpoint ligand CD200 in the host infection by Leishmania spp.
• Grantee: Mauro Javier Cortez Véliz
• Support Opportunities: Regular Research Grants
• FAPESP's process: 08/10254-1 - Designing of a virus-regulated mosquito lethal gene
• Grantee: Margareth de Lara Capurro-Guimarães
• Support Opportunities: Regular Research Grants