Project description:There has been an emergence and expansion of tick-borne diseases in Europe, Asia and North America in recent years, including Lyme disease, tick-borne encephalitis, and human anaplasmosis. The primary tick vectors implicated are hard ticks of the Ixodes genera. Although much is known about the host response to these bacterial and viral pathogens, there is limited knowledge of the cellular responses to infection within the tick vector. The bacterium Anaplasma phagocytophilum (A. phagocytophilum), is able to bypass apoptotic processes in ticks, enabling infection to proceed. However, the tick cellular responses to infection with the flaviviruses tick-borne encephalitis virus (TBEV) and louping ill virus (LIV), which cause tick-borne encephalitis and louping ill respectively, are less clear. Infection of an Ixodes ricinus (I. ricinus) tick cell line with the viruses LIV and TBEV, and the bacterium A. phagocytophilum, identified activation of common and distinct cellular pathways. In particular, commonly-upregulated genes included those that modulate apoptotic pathways (HSP70), putative anti-pathogen genes (FKBP and XBL1), and genes that influence the tick innate immune response, including selective activation of toll genes. These data provide an insight into potentially key genes involved in the tick cellular response to viral or bacterial infection.
Project description:Ixodes species ticks are competent vectors of tick-borne viruses including tick-borne encephalitis and Powassan encephalitis. Tick saliva has been shown to facilitate and enhance viral infection. This likely occurs by saliva-mediated modulation of host responses into patterns favorable for viral infection and dissemination. Because of the rapid kinetics of tick-borne viral transmission, this modulation must occur as early as tick attachment and initiation of feeding. In this study, the gene expression profile of cutaneous bite-site lesions created by uninfected ticks were analyzed at 1, 3, 6, and 12 hours after Ixodes scapularis nymphal tick attachment to discover host pathways or responses potentially important in tick-borne viral establishment.
Project description:Ixodes species ticks are competent vectors of tick-borne viruses including tick-borne encephalitis and Powassan encephalitis. Tick saliva has been shown to facilitate and enhance viral infection. This likely occurs by saliva-mediated modulation of host responses into patterns favorable for viral infection and dissemination. Because of the rapid kinetics of tick-borne viral transmission, this modulation must occur as early as tick attachment and initiation of feeding. In this study, the gene expression profile of cutaneous bite-site lesions created by uninfected ticks were analyzed at 1, 3, 6, and 12 hours after Ixodes scapularis nymphal tick attachment to discover host pathways or responses potentially important in tick-borne viral establishment. Four milimeter ear biopsies from BALB/cJ mice infested with Ixodes scapularis nymphs were assayed using Affymetrix genechip 430A 2.0 arrays at 1, 3, 6, and 12 hours after infestation during a primary exposure. 3 mice were measured at each time point. Controls were 3 similarly housed but tick-free mice.
Project description:Tick-borne encephalitis (TBE) is the most common tick-borne viral infection in Eurasia, with outcomes ranging from asymptomatic to fatal encephalitis. While the reasons for this variability are unclear, host genetics likely plays a role. Our previous research showed that BALB/c mice have intermediate susceptibility to TBE virus (TBEV), STS mice are highly resistant, and the recombinant congenic strain CcS-11, which has 12.5% of the STS genome on the BALB/c background, is more susceptible than the BALB/c. In this study, we used these three mouse strains to investigate the host response to TBEV infection in both peripheral macrophages, one of the initial target cell populations, and in the brain, the terminal target organ for the virus.
Project description:There are very few studies exploring the genetic diversity of tick-borne encephalitis complex viruses. Most of the viruses have been sequenced using capillary electrophoresis, however, very few viruses have been analyzed using deep sequencing to look at the genotypes in each virus population. In this study, different viruses and strains belonging to the tick-borne encephalitis complex were sequenced and genetic diversity was analyzed. Shannon entropy and single nucleotide variants were used to compare the viruses. Then genetic diversity was compared to the phylogenetic relationship of the viruses.
Project description:Upon tick borne encephalitis virus exposure of brain-resident cells, astrocytes are important IFN-β producers that followed a biphasic response, which initially depends on MAVS- and later on MyD88/TRIF-signaling
