Development of therapeutic strategies against Crimean-Congo hemorrhagic Fever (CCHF)

Abstract

Crimean-Congo Hemorrhagic Fever (CCHF) is a highly fatal and zoonotic arboviral infection in humans. It is caused by the CCHF virus, which precipitates severe hemorrhagic outbreaks with a mortality rate reaching up to 40%. CCHF is classified as an arboviral disease due to its transmission through tick vectors of the Hyalomma species, which are arthropods. Human infection occurs either via bites from infected ticks or through exposure to the bodily fluids of infected animals or patients. Since the initial reported case in Turkey in 2002, a total of 9,700 cases have been documented. The disease is endemic in Turkey, positioning it as one of the most affected countries by CCHF within the European region. Currently, there is no effective protective measure, such as a vaccine or specific antiviral treatment, for CCHF. This lack of effective countermeasures constitutes a significant public health threat and a serious sociological issue. The aim of this study is to develop virus-specific and host-safe strategies against CCHF to directly inhibit virus infection and/or subsequent treatment of the disease. For this purpose, the CRISPR/Cas13b genome editing tool will be utilized. RNA editing systems, such as CRISPR-Cas13b, offer the advantage of controlling gene expression without altering the underlying DNA sequence and can exert transient modifications at the RNA level, making them promising tools in combating RNA viruses. The two virus genome segments, the S segment, which encodes the nucleocapsid protein to protect and organize the viral genome, and the L segment, which encodes RNA polymerase for replication and transcription processes necessary for viral propagation, will be rendered ineffective using the CRISPR/Cas tool. Finally, to demonstrate the inhibition of CCHFV replication in HEK293 cells via the CRISPR/Cas13b system, recombinant adeno-associated virus (rAAV) will be used as the gene delivery agent. If the proposed hypothesis is confirmed, the project will significantly impact the country with the know-how generated.