Immune-related redox metabolism of embryonic cells of the tick Rhipicephalus microplus (BME26) in response to infection with Anaplasma marginale

Author(s)

Kalil, Sandra Patricia ^[1] ; da Rosa, Rafael Diego ^{[1, 2]} ; Capelli-Peixoto, Janaina ^[1] ; Pohl, Paula Cristiane ^[1] ; de Oliveira, Pedro Lagerblad ^[3] ; Fogaca, Andrea Cristina ^[1] ; Daffre, Sirlei ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Biomed Sci, Dept Parasitol, BR-05508900 Sao Paulo, SP - Brazil

^[2] Univ Fed Santa Catarina, Dept Cell Biol Embryol & Genet, Lab Immunol Appl Aquaculture, BR-88040900 Florianopolis, SC - Brazil

^[3] Univ Fed Rio de Janeiro, Inst Med Biochem Leopoldo de Meis, Lab Biochem Hematophagous Arthropods, BR-21941909 Rio De Janeiro, RJ - Brazil

• Document type: Journal article
• Source: PARASITES & VECTORS; v. 10, DEC 19 2017.
• Web of Science Citations: 4

Abstract

Background: It is well known that reactive oxygen species (ROS) and reactive nitrogen species (RNS) are involved in the control of pathogens and microbiota in insects. However, the knowledge of the role of ROS and RNS in tickpathogen and tick-microbiota interactions is limited. Here, we evaluated the immune-related redox metabolism of the embryonic cell line BME26 from the cattle tick Rhipicephalus microplus in response to Anaplasma marginale infection. Methods: A high-throughput qPCR approach was used to determine the expression profile of 16 genes encoding proteins involved in either production or detoxification of ROS and RNS in response to different microbial challenges. In addition, the effect of RNAi-mediated gene silencing of catalase, glutathione peroxidase, thioredoxin and protein oxidation resistance 1 in the control of infection with A. marginale was evaluated. Results: Infection with A. marginale resulted in downregulation of the genes encoding ROS-generating enzymes dual oxidase and endoplasmic reticulum oxidase. In contrast, the genes encoding the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, glutathione S-transferase, thioredoxin, thioredoxin reductase and peroxiredoxin were upregulated. The gene expression pattern in response to infection with Rickettsia rickettsii and exposure to heat-killed microorganisms, Micrococcus luteus, Enterobacter cloacae or S. cerevisiae was the opposite of that triggered by A. marginale challenge. The simultaneous silencing of three genes, catalase, glutathione peroxidase, and thioredoxin as well as the oxidation resistance 1 gene by RNAi apparently favoured the colonization of BME26 cells by A. marginale, suggesting that the antioxidant response might play a role in the control of infection. Conclusions: Taken together, our results suggest that a general response of tick cells upon microbial stimuli is to increase ROS/RNS production. In contrast, A. marginale infection triggers an opposite profile, suggesting that this pathogen might manipulate the tick redox metabolism to evade the deleterious effect of the oxidant-based innate immune response. (AU)

• FAPESP's process: 13/26450-2 - Molecular characterization of the interactions among ticks, rickettsiae and vertebrate hosts
• Grantee: Sirlei Daffre
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 11/23549-2 - Signaling pathways involved in the immune response of the cattle tick Rhipicephalus microplus
• Grantee: Janaína Capelli Peixoto
• Support Opportunities: Scholarships in Brazil - Doctorate