Recently, the Animal Parasites and Vector Control Team of SHVRI Successfully Towards Modelling the Tick-virus Interactions by using the Weakly Pathogenic Sindbis Virus. The related results were published in Frontiers in Cellular and Infection Microbiology.

Background

Most tick-borne viruses (TBVs) are highly pathogenic and require high biosecurity, which severely limits their study. We found that  Sindbis  virus (SINV), predominantly transmitted by mosquitoes, can replicate in ticks and be subsequently transmitted, with the potential to serve as a model for studying tick-virus interactions.

Research progress

In this study, researchers found that both larval and nymphal stages of  Rhipicephalus haemaphysaloides  can be infected with SINV-wild-type (WT) when feeding on infected mice. SINV replicated in two species of ticks ( R. haemaphysaloides  and  Hyalomma asiaticum ) after infecting them by microinjection. Injection of ticks with SINV expressing enhanced Green Fluorescent Protein (eGFP) revealed that SINV-eGFP specifically aggregated in the tick midguts for replication. During blood-feeding, SINV-eGFP migrated from the midguts to the salivary glands and was transmitted to a new host. SINV infection caused changes in expression levels of tick genes related to immune responses, substance transport and metabolism, cell growth and death. SINV mainly induced autophagy during the early stage of infection; with increasing time of infection, the level of autophagy decreased, while the level of apoptosis increased. During the early stages of infection, the transcript levels of immune-related genes were significantly upregulated, and then decreased. In addition, SINV induced changes in the transcription levels of some functional genes that play important roles in the interactions between ticks and tick-borne pathogens. These results confirm that the SINV-based transmission model between ticks, viruses, and mammals can be widely used to unravel the interactions between ticks and viruses.

SINV transmission through mouse-tick experiment

Scheme showing the replication and transmission of SINV in female R. haemaphysaloides

Project funding

This work was sponsored by grants from the National Natural Science Foundation of China (NSFC) and Shanghai Sailing Program. Associate prof. Yanan Wang and PhD Zhengmao Xu from SHVRI are co-first authors on this study, with Prof. Jinlin Zhou serving as corresponding author.

Link to original article

https://www.frontiersin.org/articles/10.3389/fcimb.2024.1334351/full