Antitumoral effects of Amblyomma sculptum Berlese saliva in neuroblastoma cell lines involve cytoskeletal deconstruction and cell cycle arrest / Efeito antitumoral da saliva do carrapato Amblyomma sculptum Berlese em células de neuroblastoma envolve desconstrução do citoesqueleto e parada do ciclo celular

Abstract The antitumor properties of ticks salivary gland extracts or recombinant proteins have been reported recently, but little is known about the antitumor properties of the secreted components of saliva. The goal of this study was to investigate the in vitro effect of the saliva of the hard tick Amblyomma sculptum on neuroblastoma cell lines. SK-N-SK, SH-SY5Y, Be(2)-M17, IMR-32, and CHLA-20 cells were susceptible to saliva, with 80% reduction in their viability compared to untreated controls, as demonstrated by the methylene blue assay. Further investigation using CHLA-20 revealed apoptosis, with approximately 30% of annexin-V positive cells, and G0/G1-phase accumulation (>60%) after treatment with saliva. Mitochondrial membrane potential (Δψm) was slightly, but significantly (p < 0.05), reduced and the actin cytoskeleton was disarranged, as indicated by fluorescent microscopy. The viability of human fibroblast (HFF-1 cells) used as a non-tumoral control decreased by approximately 40%. However, no alterations in cell cycle progression, morphology, and Δψm were observed in these cells. The present work provides new perspectives for the characterization of the molecules present in saliva and their antitumor properties.

Resumo As propriedades antitumorais de extratos de glândulas salivares de carrapatos ou proteínas recombinantes foram relatadas recentemente, mas pouco se sabe sobre as propriedades antitumorais dos componentes secretados da saliva. O objetivo deste estudo foi investigar o efeito in vitro da saliva bruta do carrapato duro Amblyomma sculptum sobre as linhagens celulares de neuroblastoma. Células SK-N-SK, SH-SY5Y, Be(2)-M17, IMR-32 e CHLA-20 foram suscetíveis à saliva, com redução de 80% na sua viabilidade em comparação com controles não tratados, como demonstrado pelo ensaio de Azul de Metileno. Investigações posteriores utilizando CHLA-20 revelaram apoptose, com aproximadamente 30% de células positivas para anexina-V, e G0/G1 (> 60%) após tratamento com saliva. O potencial de membrana mitocondrial (Δψm) foi reduzido significativamente (p <0,05), e o citoesqueleto de actina foi desestruturado, como indicado pela microscopia de fluorescência. A viabilidade do fibroblasto humano (células HFF-1), usado como controle não tumoral, diminuiu em aproximadamente 40%. No entanto, não foram observadas alterações na progressão do ciclo celular, morfologia e Δψm nestas células. O presente trabalho fornece novas perspectivas para a caracterização das moléculas presentes na saliva e suas propriedades antitumorais.

Screening and Identification of Antigenic Proteins from the Hard Tick Dermacentor silvarum (Acari: Ixodidae)

In order to explore tick proteins as potential targets for further developing vaccine against ticks, the total proteins of unfed female Dermacentor silvarum were screened with anti-D. silvarum serum produced from rabbits. The results of western blot showed that 3 antigenic proteins of about 100, 68, and 52 kDa were detected by polyclonal antibodies, which means that they probably have immunogenicity. Then, unfed female tick proteins were separated by 12% SDS-PAGE, and target proteins (100, 68, and 52 kDa) were cut and analyzed by LC-MS/MS, respectively. The comparative results of peptide sequences showed that they might be vitellogenin (Vg), heat shock protein 60 (Hsp60), and fructose-1, 6-bisphosphate aldolase (FBA), respectively. These data will lay the foundation for the further validation of antigenic proteins to prevent infestation and diseases transmitted by D. silvarum.

Proteomic Screening of Antigenic Proteins from the Hard Tick, Haemaphysalis longicornis (Acari: Ixodidae)

Proteomic tools allow large-scale, high-throughput analyses for the detection, identification, and functional investigation of proteome. For detection of antigens from Haemaphysalis longicornis, 1-dimensional electrophoresis (1-DE) quantitative immunoblotting technique combined with 2-dimensional electrophoresis (2-DE) immunoblotting was used for whole body proteins from unfed and partially fed female ticks. Reactivity bands and 2-DE immunoblotting were performed following 2-DE electrophoresis to identify protein spots. The proteome of the partially fed female had a larger number of lower molecular weight proteins than that of the unfed female tick. The total number of detected spots was 818 for unfed and 670 for partially fed female ticks. The 2-DE immunoblotting identified 10 antigenic spots from unfed females and 8 antigenic spots from partially fed females. Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF) of relevant spots identified calreticulin, putative secreted WC salivary protein, and a conserved hypothetical protein from the National Center for Biotechnology Information and Swiss Prot protein sequence databases. These findings indicate that most of the whole body components of these ticks are non-immunogenic. The data reported here will provide guidance in the identification of antigenic proteins to prevent infestation and diseases transmitted by H. longicornis.

Proteomic Screening of Antigenic Proteins from the Hard Tick, Haemaphysalis longicornis (Acari: Ixodidae)

Proteomic tools allow large-scale, high-throughput analyses for the detection, identification, and functional investigation of proteome. For detection of antigens from Haemaphysalis longicornis, 1-dimensional electrophoresis (1-DE) quantitative immunoblotting technique combined with 2-dimensional electrophoresis (2-DE) immunoblotting was used for whole body proteins from unfed and partially fed female ticks. Reactivity bands and 2-DE immunoblotting were performed following 2-DE electrophoresis to identify protein spots. The proteome of the partially fed female had a larger number of lower molecular weight proteins than that of the unfed female tick. The total number of detected spots was 818 for unfed and 670 for partially fed female ticks. The 2-DE immunoblotting identified 10 antigenic spots from unfed females and 8 antigenic spots from partially fed females. Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF) of relevant spots identified calreticulin, putative secreted WC salivary protein, and a conserved hypothetical protein from the National Center for Biotechnology Information and Swiss Prot protein sequence databases. These findings indicate that most of the whole body components of these ticks are non-immunogenic. The data reported here will provide guidance in the identification of antigenic proteins to prevent infestation and diseases transmitted by H. longicornis.

Purification and characterization of two larval glycoproteins from the cattle tick, Boophilus annulatus

The present study was conducted to identify new target immunogenic molecules from the larval stage of the cattle tick, Boophilus annulatus (Acari: Ixodidae). Two specific larval glycoproteins (GLPs) were isolated by two-step affinity chromatography. The larval immunogens were first purified with CNBr-Sepharose coupled to rabbit anti-larval immunoglobulins, and the glycoproteins were then purified with Con-A Sepharose. These glycoproteins have molecular weights of approximately 32 and 15 kDa with isoelectric points between 6.8 and 7.2. Antibodies against the two GLPs, labeled I and II, were detected in the anti-whole tick, -whole larval, and -gut antigens through immunoblot analysis. These results suggest that these GLPs are good immunogens and can be useful in the vaccination of cattle against tick infestation.

Número de cerdas internas do órgão de Haller em larvas de Amblyoma cajennense (Fabricius, 1787) (Acari: Ixodidae) nos municípios de Silva Jardim e Itaguaí, RJ / Internal setae number of the larvae Haller’s organ of Amblyoma cajennense (Fabricius, 1787) (Acari: Ixodidae) from Silva Jardim and Itaguaí, RJ

Larvae of Amblyomma cajennense (Fabricius, 1787), were obtained under laboratory conditions. The larvae were killed in hot water, preserved in 70° ethanol and prepared in definitive whole mounts. Two hundred larvae were examined under brightjield microscopy with an immersion objective in order to analyze the variation of the number of internal setae of the right and left side of the Haller's organ chamber with the purpose of utilize them as chaetotaxy parameter for specific diagnosis.