Determination of the differential proteome and lipidome of Amblyomma aureolatum ticks in response to Rickettsia rickettsii infection

• Grant number: 14/11513-1
• Support type: Regular Research Grants
• Duration: May 01, 2015 - July 31, 2017
• Field of knowledge: Biological Sciences - Parasitology
• Principal Investigator: Andréa Cristina Fogaça
• Grantee: Andréa Cristina Fogaça
• Home Institution: Instituto de Ciências Biomédicas (ICB). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Assoc. researchers: Giuseppe Palmisano ; Marcelo Bahia Labruna ; Sirlei Daffre

Abstract

Rock Mountain Spotted Fever, known in Brazil as Brazilian Spotted Fever (BSF), is the most severe rickettsiosis that affects humans. The etiologic agent of BSF, the obligate intracellular bacterium Rickettsia rickettsii, is transmitted by bite of different tick species. In Brazil, the ticks Amblyomma cajennense and A. aureolatum are the two major vectors. Besides the low prevalence of infected ticks from BSF endemic areas, experimentally infected ticks present lower reproductive and survival rates. These data suggest that the bacterium is also detrimental to its vector ticks. With the aim of elucidating the molecular mechanisms of R. rickettsii pathogenicity against its vectors, we determined the effects of an infection on the gene expression profile of A. aureolatum and A. cajennense. We observed the induction of one antimicrobial peptide (hebraein), proteins with serine protease inhibidor domain (Kunitz-type), secreted proteins, and mitochondrial proteins in the salivary glands of both tick species. The central aim of the present study is to determine if the gene expression modulation observed reflects in alterations of protein concentrations in salivary glands of infected ticks. To that end, we will use a proteomic approach. In addition, we intend to identify proteins and lipids that are differentially secreted in infected tick saliva. Therefore, the specifc objectives of the present study are to determine, using mass spectrometry (MS): (i) the proteome (set of proteins) of salivary glands and (ii) the proteome and lipidome (set of lipids) of saliva of A. aureolatum infected or not with R. rickettsii. Some of the proteins and lipds identified by MS will be then selected for the determination of their specific role in acquisition and transmission of the bacterium. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

ESTEVES, ELIANE; MARUYAMA, SANDRA R.; KAWAHARA, REBECA; FUJITA, ANDRE; MARTINS, LARISSA A.; RIGHI, ADNE A.; COSTA, FRANCISCO B.; PALMISANO, GIUSEPPE; LABRUNA, MARCELO B.; SA-NUNES, ANDERSON; RIBEIRO, JOSE M. C.; FOGACA, ANDREA C. Analysis of the Salivary Gland Transcriptome of Unfed and Partially Fed Amblyomma sculptum Ticks and Descriptive Proteome of the Saliva. FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY, v. 7, NOV 21 2017. Web of Science Citations: 8.

MARTINS, LARISSA A.; DE MELO GALLETTI, MARIA F. B.; RIBEIRO, JOSE M.; FUJITA, ANDRE; COSTA, FRANCISCO B.; LABRUNA, MARCELO B.; DAFFRE, SIRLEI; FOGACA, ANDREA C. The Distinct Transcriptional Response of the Midgut of Amblyomma sculptum and Amblyomma aureolatum Ticks to Rickettsia rickettsii Correlates to Their Differences in Susceptibility to Infection. FRONTIERS IN CELLULAR AND INFECTION MICROBIOLOGY, v. 7, APR 28 2017. Web of Science Citations: 4.