1
|
Costa GCA, Ribeiro ICT, Melo-Junior O, Gontijo NF, Sant'Anna MRV, Pereira MH, Pessoa GCD, Koerich LB, Oliveira F, Valenzuela JG, Giunchetti RC, Fujiwara RT, Bartholomeu DC, Araujo RN. Amblyomma sculptum Salivary Protease Inhibitors as Potential Anti-Tick Vaccines. Front Immunol 2021; 11:611104. [PMID: 33633731 PMCID: PMC7901972 DOI: 10.3389/fimmu.2020.611104] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 12/17/2020] [Indexed: 11/20/2022] Open
Abstract
Amblyomma sculptum is the main tick associated with human bites in Brazil and the main vector of Rickettsia rickettsii, the causative agent of the most severe form of Brazilian spotted fever. Molecules produced in the salivary glands are directly related to feeding success and vector competence. In the present study, we identified sequences of A. sculptum salivary proteins that may be involved in hematophagy and selected three proteins that underwent functional characterization and evaluation as vaccine antigens. Among the three proteins selected, one contained a Kunitz_bovine pancreatic trypsin inhibitor domain (named AsKunitz) and the other two belonged to the 8.9 kDa and basic tail families of tick salivary proteins (named As8.9kDa and AsBasicTail). Expression of the messenger RNA (mRNA) encoding all three proteins was detected in the larvae, nymphs, and females at basal levels in unfed ticks and the expression levels increased after the start of feeding. Recombinant proteins rAs8.9kDa and rAsBasicTail inhibited the enzymatic activity of factor Xa, thrombin, and trypsin, whereas rAsKunitz inhibited only thrombin activity. All three recombinant proteins inhibited the hemolysis of both the classical and alternative pathways; this is the first description of tick members of the Kunitz and 8.9kDa families being inhibitors of the classical complement pathway. Mice immunization with recombinant proteins caused efficacies against A. sculptum females from 59.4% with rAsBasicTail immunization to more than 85% by immunization with rAsKunitz and rAs8.9kDa. The mortality of nymphs fed on immunized mice reached 70–100%. Therefore, all three proteins are potential antigens with the possibility of becoming a new tool in the control of A. sculptum.
Collapse
Affiliation(s)
- Gabriel Cerqueira Alves Costa
- Laboratory of Physiology of Hematophagous Insects, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Izabela Cosso Tavares Ribeiro
- Laboratory of Physiology of Hematophagous Insects, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Otoni Melo-Junior
- Laboratory of Cell-Cell Interactions, Department of Morphology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Nelder F Gontijo
- Laboratory of Physiology of Hematophagous Insects, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Mauricio R V Sant'Anna
- Laboratory of Physiology of Hematophagous Insects, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Marcos H Pereira
- Laboratory of Physiology of Hematophagous Insects, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Grasielle C D Pessoa
- Laboratory of Physiology of Hematophagous Insects, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Leonardo B Koerich
- Laboratory of Physiology of Hematophagous Insects, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Fabiano Oliveira
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Jesus G Valenzuela
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Rodolfo Cordeiro Giunchetti
- Laboratory of Cell-Cell Interactions, Department of Morphology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ricardo Toshio Fujiwara
- Laboratory of Immunology and Genomics of Parasites, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Daniella Castanheira Bartholomeu
- Laboratory of Immunology and Genomics of Parasites, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Ricardo N Araujo
- Laboratory of Physiology of Hematophagous Insects, Department of Parasitology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| |
Collapse
|
3
|
Nunes PH, Bechara GH, Camargo Mathias MI. Secretory process of salivary glands of female Amblyomma cajennense (Acari: Ixodidae) ticks fed on resistant rabbits. EXPERIMENTAL & APPLIED ACAROLOGY 2011; 53:179-187. [PMID: 20711802 DOI: 10.1007/s10493-010-9388-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 07/13/2010] [Indexed: 05/29/2023]
Abstract
Ticks have great economic and health importance since infested animals have reduced milk and meat production, and, besides that, they are expensive ectoparasites to control. While feeding, ticks can transmit to their hosts a large amount of pathogens, including Rickettsia rickettsii responsible for the "spotted fever" or "fever of the mountains." It is known that animals infested with ticks or artificially immunized with their salivary gland extracts develop resistance, which is related to a decrease in engorged female weight, in egg-laying by adults, in egg viability and, in some cases, in the capacity of pathogens transmission. The present study aimed to examine morpho-histochemically the female salivary glands of semi and engorged Amblyomma cajennense fed on resistant rabbits. The results revealed that acinus I had no changes when compared to that of females fed on naive rabbits. The c cells of acinus II showed signs of early degeneration, which may result in feeding efficiency decrease. In acinus III d cells, activity time was longer. Such occurrence was associated with the time of female fixation, which increased in females fed on resistant hosts.
Collapse
Affiliation(s)
- P H Nunes
- Instituto de Biociências, UNESP campus de Rio Claro, Av. 24 A no. 1515 Bela Vista, Rio Claro, SP, CEP. 13506-900, Brazil
| | | | | |
Collapse
|
4
|
Freitas C, Leite R, Oliveira P, Fernández F. Biological parameters of larvae, nymphs, and engorged females of Amblyomma cajennense (Fabricius, 1787) (Acari: Ixodidae) obtained from artificial and successive infestations on Oryctolagus cuniculus (Linnaeus, 1758) (Lagomorpha: Ochotonidae). ARQ BRAS MED VET ZOO 2009. [DOI: 10.1590/s0102-09352009000500011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The development of acquired resistance to Amblyomma cajennense ticks was evaluated. A total of 18 rabbits were uniformly distributed into three groups named GL, GN, and GA that were submitted to three consecutive infestations with, respectively, larvae, nymphs, and adults of A. cajennense. After the infestations, the parasitic and reproductive parameters of recovered instars were evaluated. A significant reduction of recovery rates of inoculated ticks was observed only after the third infestation of animals in groups GL and GN (P<0.01). The modal day for drop-off of engorged larvae and nymphs increased along the infestations. The recovered engorged nymphs presented a significant reduction of the mean body weight between the first and the third infestations (P<0.01). A significant reduction in the mean recovery rate of engorged females was only observed during the third infestation. However, significant reductions (P<0.05) in body weight, egg mass weight, and larva eclosions were observed for recovered engorged females after the second infestation onwards. The results suggest the occurrence of resistance of rabbits to A. cajennense infestations, being more evident against the adult stage.
Collapse
|