In silico selection of functionally important proteins from the mialome of Ornithodoros erraticus ticks and assessment of their protective efficacy as vaccine targets

Pérez–Sánchez, Ricardo; Manzano-Román, Raúl; Obolo-Mvoulouga, Prosper; Oleaga, Ana

doi:10.1186/s13071-019-3768-1

Cited by 19 publications

(23 citation statements)

References 67 publications

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“…In the search for new tick protective antigens, scientists are currently targeting the molecules and biological processes specifically evolved by ticks to adapt to their hematophagous lifestyle, namely (i) processes related to host attachment and blood ingestion, including modulation of host defensive responses, which are essentially performed by secreted salivary proteins inoculated to the host in the tick saliva, and (ii) processes related to blood digestion, including nutrient transport and metabolism, haem group and iron management, detoxification and oxidative stress responses, which are carried out by proteins expressed in the midgut [ 11 – 16 ].…”

Section: Introductionmentioning

confidence: 99%

Sialotranscriptomics of the argasid tick Ornithodoros moubata along the trophogonic cycle

et al. 2021

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The argasid tick Ornithodoros moubata is the main vector of human relapsing fever (HRF) and African swine fever (ASF) in Africa. Salivary proteins are part of the host-tick interface and play vital roles in the tick feeding process and the host infection by tick-borne pathogens; they represent interesting targets for immune interventions aimed at tick control. The present work describes the transcriptome profile of salivary glands of O. moubata and assesses the gene expression dynamics along the trophogonic cycle using Illumina sequencing. De novo transcriptome assembling resulted in 71,194 transcript clusters and 41,011 annotated transcripts, which represent 57.6% of the annotation success. Most salivary gene expression takes place during the first 7 days after feeding (6,287 upregulated transcripts), while a minority of genes (203 upregulated transcripts) are differentially expressed between 7 and 14 days after feeding. The functional protein groups more abundantly overrepresented after blood feeding were lipocalins, proteases (especially metalloproteases), protease inhibitors including the Kunitz/BPTI-family, proteins with phospholipase A2 activity, acid tail proteins, basic tail proteins, vitellogenins, the 7DB family and proteins involved in tick immunity and defence. The complexity and functional redundancy observed in the sialotranscriptome of O. moubata are comparable to those of the sialomes of other argasid and ixodid ticks. This transcriptome provides a valuable reference database for ongoing proteomics studies of the salivary glands and saliva of O. moubata aimed at confirming and expanding previous data on the O. moubata sialoproteome.

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Section: Introductionmentioning

confidence: 99%

Sialotranscriptomics of the argasid tick Ornithodoros moubata along the trophogonic cycle

et al. 2021

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“…Searching for and identifying new protective tick antigens are being currently approached by the selection of candidate protective antigens that have important biological functions, particularly among the molecules and biological processes specifically evolved by ticks to adapt to a strict haematophagous lifestyle [ 23 – 26 ], namely, the processes that are involved in host attachment, blood ingestion and modulation of the host defensive responses and are carried out by salivary proteins secreted into the host by tick saliva [ 27 – 29 ]. Also involved are the processes related to blood digestion, including nutrient transport and metabolism, management of iron and heme groups, detoxification and oxidative stress responses, which are accomplished by proteins expressed in the midgut [ 30 – 35 ].…”

Section: Introductionmentioning

confidence: 99%

RNA-seq analysis and gene expression dynamics in the salivary glands of the argasid tick Ornithodoros erraticus along the trophogonic cycle

et al. 2021

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Background The argasid tick Ornithodoros erraticus is the main vector of tick-borne human relapsing fever (TBRF) and African swine fever (ASF) in the Mediterranean Basin. Tick salivary proteins secreted to the host at the feeding interface play critical roles for tick feeding and may contribute to host infection by tick-borne pathogens; accordingly, these proteins represent interesting antigen targets for the development of vaccines aimed at the control and prevention of tick infestations and tick-borne diseases. Methods To identify these proteins, the transcriptome of the salivary glands of O. erraticus was de novo assembled and the salivary gene expression dynamics assessed throughout the trophogonic cycle using Illumina sequencing. The genes differentially upregulated after feeding were selected and discussed as potential antigen candidates for tick vaccines. Results Transcriptome assembly resulted in 22,007 transcripts and 18,961 annotated transcripts, which represent 86.15% of annotation success. Most salivary gene expression took place during the first 7 days after feeding (2088 upregulated transcripts), while only a few genes (122 upregulated transcripts) were differentially expressed from day 7 post-feeding onwards. The protein families more abundantly overrepresented after feeding were lipocalins, acid and basic tail proteins, proteases (particularly metalloproteases), protease inhibitors, secreted phospholipases A2, 5′-nucleotidases/apyrases and heme-binding vitellogenin-like proteins. All of them are functionally related to blood ingestion and regulation of host defensive responses, so they can be interesting candidate protective antigens for vaccines. Conclusions The O. erraticus sialotranscriptome contains thousands of protein coding sequences—many of them belonging to large conserved multigene protein families—and shows a complexity and functional redundancy similar to those observed in the sialomes of other argasid and ixodid tick species. This high functional redundancy emphasises the need for developing multiantigenic tick vaccines to reach full protection. This research provides a set of promising candidate antigens for the development of vaccines for the control of O. erraticus infestations and prevention of tick-borne diseases of public and veterinary health relevance, such as TBRF and ASF. Additionally, this transcriptome constitutes a valuable reference database for proteomics studies of the saliva and salivary glands of O. erraticus.

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“…In this study, we tested the immunogenicity and protective efficacy of recombinant N-terminal ECD of two members of Cys-loop receptors, namely, GluCl and GlyR of R. microplus tick, following a reverse vaccinology approach. These candidates were evaluated on the basis that they fulfilled a series of selection criteria related to their expression level, biological function, accessibility and subcellular localization [ 8 , 26 , 34 ]. Moreover, both receptors were predicted to contain several potential linear B-cell epitopes and to be antigenic.…”

Section: Discussionmentioning

confidence: 99%

Immunoprotection evaluation of the recombinant N-terminal domain of Cys-loop receptors against Rhipicephalus (Boophilus) microplus tick infestation

et al. 2021

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Rhipicephalus (Boophilus) microplus ticks are obligatory hematophagous ectoparasites of cattle and act as vectors for disease-causing microorganisms. Conventional tick control is based on the application of chemical acaricides; however, their uncontrolled use has increased resistant tick populations, as well as food and environmental contamination. Alternative immunological tick control has shown to be partially effective. Therefore, there is a need to characterize novel antigens in order to improve immunological protection. The aim of this work was to evaluate Cys-loop receptors as vaccine candidates. N-terminal domains of a glutamate receptor and of a glycine-like receptor were recombinantly produced in Escherichia coli. Groups of BALB/c mice were independently immunized with four doses of each recombinant protein emulsified with Freund’s adjuvant. Both vaccine candidates were immunogenic in mice as demonstrated by western blot analysis. Next, recombinant proteins were independently formulated with the adjuvant Montanide ISA 50 V2 and evaluated in cattle infested with Rhipicephalus microplus tick larvae. Groups of three European crossbred calves were immunized with three doses of each adjuvanted protein. ELISA test was used to evaluate the IgG immune response elicited against the recombinant proteins. Results showed that vaccine candidates generated a moderate humoral response on vaccinated cattle. Vaccination significantly affected the number of engorged adult female ticks, having no significant effects on tick weight, egg weight and egg fertility values. Vaccine efficacies of 33% and 25% were calculated for the glutamate receptor and the glycine-like receptor, respectively.

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In silico selection of functionally important proteins from the mialome of Ornithodoros erraticus ticks and assessment of their protective efficacy as vaccine targets

Cited by 19 publications

References 67 publications

Sialotranscriptomics of the argasid tick Ornithodoros moubata along the trophogonic cycle

Sialotranscriptomics of the argasid tick Ornithodoros moubata along the trophogonic cycle

RNA-seq analysis and gene expression dynamics in the salivary glands of the argasid tick Ornithodoros erraticus along the trophogonic cycle

Immunoprotection evaluation of the recombinant N-terminal domain of Cys-loop receptors against Rhipicephalus (Boophilus) microplus tick infestation

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