title: Exploring the immune signalling pathway-related genes of the cattle tick Rhipicephalus microplus: From molecular characterization to transcriptional profile upon microbial challenge.
abstract: In dipteran insects, invading pathogens are selectively recognized by four major pathways, namely Toll, IMD, JNK, and JAK/STAT, and trigger the activation of several immune effectors. Although substantial advances have been made in understanding the immunity of model insects such as Drosophila melanogaster, knowledge on the activation of immune responses in other arthropods such as ticks remains limited. Herein, we have deepened our understanding of the intracellular signalling pathways likely to be involved in tick immunity by combining a large-scale in silico approach with high-throughput gene expression analysis. Data from in silico analysis revealed that although both the Toll and JAK/STAT signalling pathways are evolutionarily conserved across arthropods, ticks lack central components of the D. melanogaster IMD pathway. Moreover, we show that tick immune signalling-associated genes are constitutively transcribed in BME26 cells (a cell lineage derived from embryos of the cattle tick Rhipicephalus microplus) and exhibit different transcriptional patterns in response to microbial challenge. Interestingly, Anaplasma marginale, a pathogen that is naturally transmitted by R. microplus, causes downregulation of immune-related genes, suggesting that this pathogen may manipulate the tick immune system, favouring its survival and vector colonization.
authors.affiliation: Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil.
authors.forename: Rafael D
authors.initials: RD
authors.lastname: Rosa
authors.affiliation: Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil.
authors.forename: Janaína
authors.initials: J
authors.lastname: Capelli-Peixoto
authors.affiliation: Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, 21941-909 Rio de Janeiro, RJ, Brazil.
authors.forename: Rafael D
authors.initials: RD
authors.lastname: Mesquita
authors.affiliation: Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil.
authors.forename: Sandra P
authors.initials: SP
authors.lastname: Kalil
authors.affiliation: Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil.
authors.forename: Paula C
authors.initials: PC
authors.lastname: Pohl
authors.affiliation: Department of Biochemistry, Institute of Chemistry, Federal University of Rio de Janeiro, 21941-909 Rio de Janeiro, RJ, Brazil.
authors.forename: Glória R
authors.initials: GR
authors.lastname: Braz
authors.affiliation: Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil.
authors.forename: Andrea C
authors.initials: AC
authors.lastname: Fogaça
authors.affiliation: Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil. Electronic address: sidaffre@icb.usp.br.
authors.forename: Sirlei
authors.initials: S
authors.lastname: Daffre
mesh_terms: D042322:Anaplasma marginale / Q000276:immunology*; D000818:Animals; D002417:Cattle; D002460:Cell Line; D029721:Drosophila Proteins / Q000276:immunology; D004331:Drosophila melanogaster / Q000276:immunology; D020869:Gene Expression Profiling; D057166:High-Throughput Screening Assays; D048031:JNK Mitogen-Activated Protein Kinases / Q000276:immunology; D053612:Janus Kinases / Q000276:immunology; D048494:Rhipicephalus / Q000235:genetics / Q000276:immunology* / Q000382:microbiology*; D050791:STAT Transcription Factors / Q000276:immunology; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D051193:Toll-Like Receptors / Q000276:immunology
chemical_list: D029721:Drosophila Proteins; D050791:STAT Transcription Factors; D051193:Toll-Like Receptors; C439909:imd protein, Drosophila; D053612:Janus Kinases; D048031:JNK Mitogen-Activated Protein Kinases
keywords: Anaplasma marginale; Innate immunity; Rhipicephalus microplus; Signalling pathway; Tick