The Toll pathway regulates tick immune response

Wednesday, November 13, 2024

11:30 AM – 11:42 AM MST

Location: Phoenix Convention Center, 221 C, PCC

Presenting Author(s)

OH

Ondrej Hajdusek

Czech Academy of Sciences
Ceske Budejovice, Jihocesky kraj, Czech Republic

Co-Author(s)

MJ

Marie Jalovecka

Institute of Parasitology
České Budějovice, Czech Republic

Co-Author(s)

VU

Veronika Urbanova

Czech Academy of Sciences
Ceske Budejovice, Jihocesky kraj, Czech Republic
RS

Radek Sima

Czech Academy of Sciences
Ceske Budejovice, Jihocesky kraj, Czech Republic
PK

Petr Kopacek

Czech Academy of Sciences
Ceske Budejovice, Jihocesky kraj, Czech Republic
JP

Jan Perner

Czech Academy of Sciences
Ceske Budejovice, Jihocesky kraj, Czech Republic

Ticks transmit various pathogens to animals and humans through their bites, which are recognized by the tick innate immune system via the Toll and IMD signaling pathways. In this study, the Toll pathway in the tick Ixodes ricinus and its role in the transmission of pathogens was investigated. We employed RNA interference (RNAi) to knock out components of the Toll pathway to modulate the tick immune response and used laboratory transmission models for Borrelia afzelii and Babesia microti to investigate the involvement of the Toll pathway in pathogen recognition, acquisition, and transmission. We identified homologs of the Toll and insect IMD signaling pathways in I. ricinus and validated the first readout gene of the tick Toll pathway, which is significantly upregulated after injection of Gram-negative Escherichia coli. Our results show that the Toll pathway regulates infection rates of the apicomplexan protozoan B. microti, suggesting that it is fully functional in the tick and capable of recognizing extracellular bacteria and responding with the expression of antimicrobial genes. This study underscores the critical role of tick immunity in determining Babesia infection rates and paves the way for further identification of molecules and mechanisms that influence the ability of arthropods to transmit apicomplexan parasites.