Tick-Borne Flaviviruses and the Type I Interferon Response

Abstract

Flaviviruses are globally distributed pathogens causing millions of human infections every year. Flaviviruses are arthropod-borne viruses and are mainly transmitted by either ticks or mosquitoes. Mosquito-borne flaviviruses and their interactions with the innate immune response have been well-studied and reviewed extensively, thus this review will discuss tick-borne flaviviruses and their interactions with the host innate immune response.

Population genomics of louping ill virus provide new insights into the evolution of tick-borne flaviviruses

“…Two studies have reported a recombination event between LIV and TBEV-Eu [ 20 , 24 ]; however, subsequent work has raised doubts about these findings [ 25 ]. Although the geographic ranges of the two viruses are largely distinct [ 26 ], creating limited opportunities for interaction, recent detection of TBEV in Britain [ 27 – 29 ], where LIV is endemic, has added new urgency to investigate the possibility of recombination between the two viruses.…”

Tick-Borne Encephalitis Virus: A Quest for Better Vaccines against a Virus on the Rise

“…Some important PRRs during infection of RNA viruses are Toll-like receptors (TLRs) 3, 7, 8 and 9 or retinoic-acid-inducible gene I (RIG-I)-like receptors. Their activation leads to the production of type I interferon (IFN) (reviewed in [ 68 ]), which was shown to have a protective role in TBEV infection (reviewed in [ 69 ]). Besides the crucial role of innate immune cells to combat TBEV, there is evidence that some of these cells are infected by TBEV, favor viral spread or contribute to pathogenesis in TBEV infection.…”

“…Besides the crucial role of innate immune cells to combat TBEV, there is evidence that some of these cells are infected by TBEV, favor viral spread or contribute to pathogenesis in TBEV infection. Some non-structural proteins of TBEV, such as NS1, NS2A, NS4A, NS4B or NS5, display antagonistic functions, thus, interfering with components of the innate immune response (reviewed in [ 3 , 69 , 70 , 71 , 72 ]; [ 73 ]). In addition, TBEV infection modulates expression patterns of many antiviral genes which are involved in the innate immune response such as genes for PRRs, cytokines or chemokines [ 74 ].…”

Population genomics of louping ill virus provide new insights into the evolution of tick-borne flaviviruses

“…Two studies have reported a recombination event between LIV and TBEV-Eu (19, 23); however, subsequent work has raised doubts about these findings (24). Although the geographic ranges of the two viruses are largely distinct (25), creating limited opportunities for interaction, recent detection of TBEV in Britain (26–28), where LIV is endemic, has added new urgency to investigate the possibility of recombination between the two viruses.…”