Folate pathway modulation in Rhipicephalus ticks in response to infection

• Published in: Transboundary and emerging diseases Vol. 67; no. S2; pp. 94 - 99
• Main Authors: Dias, Filipa, Couto, Joana, Ferrolho, Joana, Seron, Gustavo S., Bell‐Sakyi, Lesley, Antunes, Sandra, Domingos, Ana
• Format: Journal Article
• Language: English
• Published: Germany John Wiley & Sons, Inc 01.07.2020
• Subjects: Animals; cell lines; Ehrlichia; Ehrlichia canis - genetics; Female; folate; Folic acid; Folic Acid - genetics; Functional analysis; Gene expression; Gene Expression Regulation - physiology; Gene sequencing; Genes; Genetic engineering; GTP cyclohydrolase; GTP Cyclohydrolase - genetics; GTP cyclohydrolase I; Infections - veterinary; Modulation; Pathogens; Phosphorus-Oxygen Lyases - genetics; Protozoan Proteins - genetics; Real-Time Polymerase Chain Reaction - veterinary; Rhipicephalus; Rhipicephalus - genetics; Ribonucleic acid; RNA; RNA Interference; RNA, Messenger - genetics; RNA-mediated interference; RNAi; sequence analysis; Statistical methods; Thymidylate synthase; Thymidylate Synthase - genetics; tick cell line; Ticks; tick‐borne diseases; vector‐pathogen interface; Vitamin B; RNAi; folate; vector-pathogen interface; tick-borne diseases; tick cell line
• DOI: 10.1111/tbed.13231
• ISSN: 1865-1674; 1865-1682

Folate pathways components were demonstrated to be present in RNA‐sequencing data obtained from uninfected and pathogen‐infected Rhipicephalus ticks. Here, PCR and qPCR allowed the identification of folate‐related genes in Rhipicephalus spp. ticks and in the tick cell line IDE8. Genes coding for GTP cyclohydrolase I (gch‐I), thymidylate synthase (ts) and 6‐pyrovoyltetrahydropterin (ptps) were identified. Differential gene expression was evaluated by qPCR between uninfected and infected samples of four biological systems, showing significant upregulation and largest fold‐change for the gch‐I gene in the majority of the biological systems, supporting the selection for functional analysis by RNAi silencing. Efficient knockdown of the gch‐I gene in uninfected and Ehrlichia canis‐infected IDE8 cells showed no detectable impact on the capacity of the bacteria to invade or replicate in the tick cells. Overall, this work demonstrated an increase in the expression of some folate‐related genes, though not always statistically significantly, in the presence of infection, suggesting gene expression modulation of these pathways, either as a tick response to an invader or manipulation of the tick cell machinery by the pathogens to their advantage. This discovery points to folate pathways as interesting targets for further studies.