Please use this identifier to cite or link to this item: https://www.arca.fiocruz.br/handle/icict/25440
Title: Inhibition of the complement system by saliva of Anopheles (Nyssorhynchus) aquasalis.
Authors: Sousa, Antonio Ferreira Mendes
Vale, Vladimir Fazito
Queiroz, Daniel Costa
Pereira Filho, Adalberto Alves
Silva, Naylene Carvalho Sales da
Koerich, Leonardo Barbosa
Moreira, Luciano Andrade
Pereira, Marcos Horácio
Sant’Anna, Maurício Roberto
Araújo, Ricardo Nascimento
Andersen, John
Valenzuela, Jesus Gilberto
Gontijo, Nelder Figueiredo
Affilliation: Universidade Federaldo de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil
Universidade Federaldo de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil
Universidade Federaldo de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil
Universidade Federaldo de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil
Universidade Federal do Maranhão. Programa de Pós-graduação em Ciências da Saúde. São Luís, MA, Brazil
Universidade Federaldo de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil
Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brazil
Universidade Federaldo de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil
Universidade Federaldo de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil
Universidade Federaldo de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil
National Institutes of Health. National Institute of Allergy and Infectious Diseases. Laboratory of Malaria and Vector Research. Vector Molecular Biology Section. Rockville, MD, USA
National Institutes of Health. National Institute of Allergy and Infectious Diseases. Laboratory of Malaria and Vector Research. Vector Molecular Biology Section. Rockville, MD, USA
Universidade Federaldo de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Parasitologia. Belo Horizonte, MG, Brazil
Abstract: Anopheline mosquitoes are vectors of malaria parasites. Their saliva contains anti-hemostatic and immune-modulator molecules that favor blood feeding and parasite transmission. In this study, we describe the inhibition of the alternative pathway of the complement system (AP) by Anopheles aquasalis salivary gland extracts (SGE). According to our results, the inhibitor present in SGE acts on the initial step of the AP blocking deposition of C3b on the activation surfaces. Properdin, which is a positive regulatory molecule of the AP, binds to SGE. When SGE was treated with an excess of properdin, it was unable to inhibit the AP. Through SDS-PAGE analysis, A. aquasalis presented a salivary protein with the same molecular weight as recombinant complement inhibitors belonging to the SG7 family described in the saliva of other anopheline species. At least some SG7 proteins bind to properdin and are AP inhibitors. Searching for SG7 proteins in the A. aquasalis genome, we retrieved a salivary protein that shared an 85% identity with albicin, which is the salivary alternative pathway inhibitor from A. albimanus. This A. aquasalis sequence was also very similar (81% ID) to the SG7 protein from A. darlingi, which is also an AP inhibitor. Our results suggest that the salivary complement inhibitor from A. aquasalis is an SG7 protein that can inhibit the AP by binding to properdin and abrogating its stabilizing activity. Albicin, which is the SG7 from A. albimanus, can directly inhibit AP convertase. Given the high similarity of SG7 proteins, the SG7 from A. aquasalis may also directly inhibit AP convertase in the absence of properdin.
Keywords: Anopheles aquasalis
Saliva
Complement system
Alternative pathway
Complement system inhibition
Hematophagy
keywords: Anopheles aquasalis
sistema complementar
Issue Date: 2018
Publisher: Pergamon Press
Citation: SOUSA, Antonio Ferreira Mendes et al. Inhibition of the complement system by saliva of Anopheles (Nyssorhynchus) aquasalis. Insect Biochem Mol Biol., v. 92, p. 12-20, 2018.
DOI: 10.1016/j.ibmb.2017.11.004
ISSN: 0965-1748
Copyright: restricted access
Appears in Collections:MG - IRR - Artigos de Periódicos




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