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Commentary

Tick Vaccines and Concealed versus Exposed Antigens

1
Global Health and Tropical Medicine, Institute of Hygiene and Tropical Medicine, NOVA University of Lisbon, Rua da Junqueira, 100, 1349-008 Lisboa, Portugal
2
Institute of Hygiene and Tropical Medicine, NOVA University of Lisbon, Rua da Junqueira, 100, 1349-008 Lisboa, Portugal
*
Author to whom correspondence should be addressed.
Pathogens 2023, 12(3), 374; https://doi.org/10.3390/pathogens12030374
Submission received: 21 December 2022 / Revised: 14 February 2023 / Accepted: 16 February 2023 / Published: 24 February 2023
(This article belongs to the Special Issue 10th Anniversary of Pathogens—Classic Papers in Tick Research)

Abstract

:
Anti-tick vaccines development mainly depends on the identification of suitable antigens, which ideally should have different features. These should be key molecules in tick biology, encoded by a single gene, expressed across life stages and tick tissues, capable of inducing B and T cells to promote an immunological response without allergenic, hemolytic, and toxic effects; and should not be homologous to the mammalian host. The discussion regarding this subject and the usefulness of “exposed” and “concealed” antigens was effectively explored in the publication by Nuttall et al. (2006). The present commentary intends to debate the relevance of such study in the field of tick immunological control.

1. Introduction

Ticks are ectoparasites capable of affecting their hosts in a dual manner as their hematophagous behavior directly affects the host, and their competency as vectors of a variety of pathogens makes these ectoparasites a major threat to animal and public health. The animal industry is familiar with ticks and tick transmitted diseases, such as anaplasmosis, ehrlichiosis, babesiosis and theileriosis, as significant economic losses are reported yearly, which are caused by animal mortality and morbidity, disease treatment and tick control. Currently, the main tick and tick-borne diseases (TTBD) control measure consists of chemical products which are directly applied to animals. These products contaminate soil, and animal derived products and are also conducive to tick resistance,. The idea of using host immunity and vaccination to combat ticks is not new. The use of naturally acquired immunity and salivary glands homogenates (known as “exposed” antigens) as sources of induced protection [1,2,3] was the first step in the endeavor to make vaccines an alternative method of tick control. Since the publication of the pioneering studies by William Trager in 1939 [3] and by Allen and Humphreys in 1979 [4], many projects have been carried out with the aim to create vaccines against ticks. In the pursuit of this goal, different paths have been followed, but the reality is that after Bm86-based vaccines were released in the 1990´s few candidates have reached the premarket stages [5]. The commercialization of these vaccines stimulated scientists to look for other antigens capable of reproducing or even surpassing the effects of the famous “Gut protein of unknown function” of the cattle tick, Rhipicephalus (Boophilus) microplus. This discovery focused the attention of the research community onto the idea that a “concealed” antigen could be used to elicit a robust immune response and from there the question of wheter both “exposed” and “concealed” antigens present the requisites needed to be included in a potential tick vaccine, emerged. In recent years, the usefulness of integrating one or another type of antigens in vaccines against ticks has been discussed in a diverse array of publications, in the consensus is that “concealed” antigens are defined as being usually hidden from the host immune machinery and, “exposed” antigens are defined as being secreted in tick saliva during attachment and feeding, eliciting immunological response. Hosts immunized with “exposed” antigens are boosted by permanent tick contact, while vaccination using “concealed” ones requires subsequent inoculations to ensure continuous protection [6]. After the experiments conducted by Allen and Humphreys [4], in which guinea pigs and cattle were immunized with antigens from partially fed Dermacentor andersoni gut and other internal organs, other reports showing that natural animal immunity against tick infestation could be enhanced using tick homogenates from whole ticks or specific organs have followed [7,8,9]. In 1988, Willadsen and Kemp, characterized a “concealed” antigen as having a key advantage in comparison to “exposed” antigens: the improbability of ticks developing immune evasion [10]. Soon after, this claim was further discussed and supported by experimental assays which included the Bm86 antigen [11,12]. Since then, several “concealed”, and “exposed” (secreted) antigens have been considered and assayed, showing both strong and weak properties toward tick infestation control. In addition to the already mentioned benefit of natural boosting, achieved using “exposed” antigens, vaccines formulated with these antigens present other relevant features: they stimulate naturally acquired resistance to tick feeding, and target different molecules and/or different stages compared with vaccines formulated with “concealed” antigens [13]. From the many experiments that have been conducted, to test potential vaccine candidates, a new idea arose which consisted of using antigens presenting characteristics offered by both the “exposed” and “concealed” types, which were named, dual-action vaccines. Using a putative tick cement protein (64P) from Rhipicephalus appendiculatus as an antigen, the induction of an inflammatory response at the feeding site and a simultaneous increase in antibody titers were demosntrated [14,15]. As research has advanced, other “exposed” and “concealed” antigens have shown potential as vaccine candidates and some, have been combined to improve a vaccine´s efficacy against different tick species and against tick-borne pathogens such as Anaplasma sp. and Babesia sp. [16]. Compiling relevant information regarding investigations that focused on the development of anti-tick vaccines based on both types of antigens, the 2006 publication by Nuttall et al., discussed optimal vaccine requisites and novel formulations and addressed the necessity of understanding host–parasite relationships to identify suitable candidates for vaccine development, making this manuscript a “classic paper” to researchers working in the field of TTBD immunological control.

2. Discovery

The path for a reduction in TTBD supported by integrated measures, to which recombinant vaccines are integral, continues to present a major constraint: the identification of protective antigens. The review by Nuttal et al. (2006), gathers experimental support for the use of both “concealed” and “exposed” antigens in the development of anti-tick vaccines, highlighting novel possibilities such as dual- action and transmission blocking vaccines (designed to block the development of parasites inside the tick, reducing tick infectivity and limiting transmission). The definition of “exposed” and “concealed” antigens and the characterization of their “mode of action”, regarding host immune response is presented. If “exposed” antigens naturally elicit a host immune response through the action of dendritic cells, which process and present these antigens to T lymphocytes, priming a cell- or antibody-mediated immune response, “concealed” ones, which are not naturally presented to host immune machinery, may provoke strong humoral immunity, producing antibodies capable of reaching and impairing their targets, which would be detrimental to tick survival [6,13]. The major problem with so-called “exposed” antigens is that during feeding, salivary glands secrete a panoply of bioactive molecules to overcome a host's haemostatic, inflammatory and immune mechanisms [17], making it improbable for a single tick antigen to induce an effective immune response. On the other hand, “concealed” antigens benefit from the element of surprise in the way that the parasite is not “prepared” for the blockage of these hidden proteins, however, the recurrent priming of the host’s immune mechanisms can be necessary.
The classic paper also puts forward a list of assays that used the two types of antigens which were published before 2006. The example of the previously mentioned Bm86 antigen is given, and to this example, other “concealed” antigens are added, such as Vitellin, which was tested against R. microplus in cattle. Other “concealed” antigens were studied in different settings, for example HLS1, HLS2 and P27/30, tested against Haemaphysalis longicornis, Voraxin against Amblyomma hebraeum, and 4D8 against Ixodes scapularis. In parallel, “exposed” antigens such as, calreticulin, immunoglobulin-binding protein, histamine-binding protein, P29, HL 34, RIM36 and 64TRPs have been tested against different tick species, Amblyomma americanum, D. variabilis and R. microplus, R. appendiculatus and H. longicornis, respectively [6]. Generally, the results have been discouraging and none have reached the commercial development stage, although some of them have been tested in cattle, which is the case for 64TRPs, which was assayed against R. appendiculatus. At the time, recombinant versions of 64P vaccine candidates showing, not only a humoral but also a delayed-type response was given special emphasis. In this case, after immunization, tick attachment, feeding and midgut integrity were affected, causing tick death. Another advantage of this antigen is the fact that it was built with more than one conserved epitope, increasing its chances of efficacy. Progressing from the concept and findings regarding “exposed” and “concealed” antigens and dual action and transmission-blocking vaccines, the method of targeting not only the vector control but also to inhibit or reduce pathogen transmission was considered. The R. appendiculatus 64TRP was also tested in this regard, using I. ricinus infected with tick-borne encephalitis virus (TBEV) in a mouse model, showing promising results. In this study, vaccination with the recombinant protein not only impaired tick feeding and disrupted tick gut but also protected mice against a lethal infection of TBEV. The authors suggested that infection control possibly results from interactions at the level of Langerhans cells, which play a role in tick-borne TBEV transmission and are modulated by component(s) in tick saliva [18]. Given the advancements in molecular biology techniques at the time (genomics, transcriptomics and proteomics associated to, for example, RNA interference-mediated gene silencing) it was anticipated that such technologies would be key to build knowledge on the complex interactions between ticks, parasites and hosts ultimately facilitating/assisting the proposal of novel anti-TTBD vaccines. A system biology approach has been put forward, highlighting the advantages of studying the networks supporting cellular functions [16].

3. Impact

Sixteen years after its publication, the review entitled “Exposed and concealed antigens as vaccine targets for controlling ticks and tick-borne diseases”, by Nuttall et al., remains a milestone. This is not because it presents a ground-breaking discovery, but rather because it is a robust collection of evidence supporting the different research paths being followed in the pursuit of effective tick and tick-borne pathogens vaccines. Since then, at least 68 different “exposed” and/or “concealed” antigens have been tested in vaccination trials against different tick species aiming to achieve a reduction in tick infestation (Table 1) [19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59]. The attractive idea of transmission blocking vaccines has also thrived, and some studies have included the hypothesis that impairing a tick targeted antigen could also affect the pathogen life cycle occurring within its vector (Table 1).
The involvement of the salivary glands in the fundamental process of blood feeding and in the transmission of pathogens has made it a target for research. Also, the access of host antibodies to midgut proteins has continued to stimulate interest in this tissue, but other antigens detected in ovary or eggs such as CDK10/Cyclin-dependent kinase from I. persulcatus [41] and vitellin-degrading enzyme [23] and yolk pro-cathepsin, from R. microplus [19] were also assayed in vaccination trials. However, if there was initially concern regarding the classification of antigens according to exposure to the host immune system, somewhere along the road researchers started to focus on the function and on role on tick biology rather in such classification. In recent years, what we can call the great revolution in omics approaches, has allowed the comparison of genomes, transcriptomes, proteomes and more recently metabolomes of different tick species, tissues, stages, infection and feeding statuses among others, which, allied with RNA interference technology have, from a more academic perspective, expanded knowledge on parasite biology, generating massive amounts of information on tick-host-pathogen interactions and, in a more applied view, pinpointed relevant molecules involved in fundamental tick biological processes that can be screened as protective antigens [60]. Catalogs of genes and proteins identified as differentially represented in response to a given condition are publicly available in repositories and can be screened as anti-tick vaccine candidates, with their selection being determined by the researchers’ criteria. Even though there is a growing awareness of the necessity to create models to analyze the existing data, unfortunately, these resources, which can be perceived as the first step on the road towards the discovery of suitable targets, tend to be underexplored. Reverse vaccinology, pioneered by Rino Rappuoli [61] has also been applied in anti-tick vaccine development, with the development of bioinformatic pipelines designed to identify suitable targets [54,62,63].
Gradually, it has also become clear that it is necessary to analyze and utilize the advantages of different antigens, epitopes, vaccine formulations and host immunological response to achieve effective protection. A synergistic effect on protection is expected when combining antigens with proved efficacy and activating different immunological mechanisms. A vaccine composed of three tick recombinant proteins, which alone conferred partial protection against R. microplus in confined cattle was tested in field conditions. Immunization with vitellin-degrading cysteine endopeptidase (VTDCE), Boophilus yolk pro-cathepsin (BYC) from R. microplus, and glutathione S-transferase from H. longicornis (GST-Hl) resulted in an increased protection level against R. microplus infestations in comparison to the single-antigen [64]. A promising antigen Subolesin (SUB) was combined with its ortholog Akirin, resulting in high vaccine efficacy in rabbits against I. ricinus and D. reticulatus [65] and recently, a study was published showing the potential to combine SUB with Bm86 [66]. This strategy also led to the combination of SUB with pathogen antigens to achieve a dual effect vaccine. Vaccination with SUB/ Anaplasma marginale Major Surface Protein 1a, resulted in a significant reduction in tick infestations in cattle and sheep, as well as a 30% reduction of Babesia bigemina [67]. Plus, the Q38 Subolesin/Akirin chimera containing conserved protective epitopes was also shown to be a candidate antigen to control multiple tick species infestations [68]. The peptide of the ribosomal protein P0 is another antigen presently under consideration for vaccine development. Despite being part of a conserved protein, the peptide sequence used is divergent from vertebrate hosts orthologs and is highly conserved among ticks. Peptides are small and therefore are weakly immunogenic, requiring carrier molecules to adjuvate, adding chemical stability and enhancing the immune response. The keyhole limpet haemocyanin from Megathura crenulata (KLH) was used together with P0 and the results showed high protection against tick infestation [37,69,70] in different tick genera. Therefore, the idea that individual Bm86 and P0 efficacies could be improved by the conjugation of both antigens [69,70,71] is being researched [37,69,70]. The great challenge of discovering an antigen suitable for anti-tick vaccine development and commercialization, remains today. However, remarkable progress in the identification and validation of candidates has been made and antigens showing promising results (particularly in cattle, due to the importance of TTBD in animal production) have supported the registration of patents. For example, alone or in alliance with Bm86, the protective antigen SUB is an antigen in which great hopes are deposited (patent US20050123554A1 and WO2014154847A1). Different studies have demonstrated positive effects against different arthropod ectoparasites and against pathogens, as reported for the mosquito borne Plasmodium sp. [72] and for the tick-borne A. marginale [38]. In 2009, results regarding the immunization of cattle with ferritin 2, against I. ricinus supported the request for a patent (US8168763B2). More recently, vaccination with a membrane associated protein, Aquaporin, was revealed to have high efficacy when explored in pen vaccine trials [39], allowing the registration of the US20180085443A1 patent in 2017. It is interesting to note that the latter antigens can be classified as “concealed”, supporting the concept that not only are saliva secreted (“exposed”) antigens part of an immunological equilibrium occurring between tick and host, but also that these “hidden” molecules stimulate a strong positive T cell and B cell mediated immune response. Whether an antigen is “concealed” or “exposed”, the identification of an effective antigen is only the first step in vaccine development. The work that follows its recognition as a suitable antigen for vaccine development, firstly includes the evaluation of immunogenicity, combination with adjuvants and vaccine formulations, the choice of the delivery system followed by the validation of the vaccine under controlled and in field conditions. If all the previous steps yield satisfactory results then large scale production and commercialization remain to be fulfilled.
Immunological protection is perceived as the most sustainable tick and tick-borne diseases control method, as it circumvents acaracides drawbacks namely, the emergence of tick resistance and animal and environmental contamination. Vaccination with tick “exposed” and “concealed” antigens take advantage on either naturally acquired or artificially induced humoral immune response but more studies are needed to understand specific immunological responses that depend on a wide array of factors such as host species and/or breed, host age, immunocompetence or prior exposure to ticks. To the multifaced host immune response, tick diversity and life cycle particularities make anti tick vaccine development a complex challenge [73,74], but even though the road ahead is long, the Nuttall et al.’s article, published in 2006, is an essential read when entering the tick research world.

Author Contributions

Conceptualization S.A. and A.D.; writing—original draft preparation, S.A. and A.D.; writing—review and editing, S.A. and A.D.; visualization, S.A. and A.D. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Acknowledgments

The authors would like to thank FCT for funding the R&D Centre, Global Health and Tropical Medicine (GHTM—UID/04413/2020).

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Randolph, S.E. Population Regulation in Ticks: The Role of Acquired Resistance in Natural and Unnatural Hosts. Parasitology 1979, 79, 141–156. [Google Scholar] [CrossRef]
  2. Brown, S.J. Immunology of Acquired Resistance to Ticks. Parasitol. Today 1985, 1, 166–171. [Google Scholar] [CrossRef] [PubMed]
  3. Trager, W. Acquired Immunity to Ticks. J. Parasitol. 1939, 25, 57. [Google Scholar] [CrossRef]
  4. Allen, J.R.; Humphreys, S.J. Immunisation of Guinea Pigs and Cattle against Ticks. Nature 1979, 280, 491–493. [Google Scholar] [CrossRef] [PubMed]
  5. de la Fuente, J.; Almazán, C.; Canales, M.; Pérez de la Lastra, J.M.; Kocan, K.M.; Willadsen, P. A Ten-Year Review of Commercial Vaccine Performance for Control of Tick Infestations on Cattle. Anim. Health Res. Rev. 2007, 8, 23–28. [Google Scholar] [CrossRef] [PubMed]
  6. Nuttall, P.A.; Trimnell, A.R.; Kazimirova, M.; Labuda, M. Exposed and Concealed Antigens as Vaccine Targets for Controlling Ticks and Tick-Borne Diseases. Parasite Immunol. 2006, 28, 155–163. [Google Scholar] [CrossRef] [PubMed]
  7. Johnston, L.A.Y.; Kemp, D.H.; Pearson, R.D. Immunization of Cattle against Boophilus microplus Using Extracts Derived from Adult Female Ticks: Effects of Induced Immunity on Tick Populations. Int. J. Parasitol. 1986, 16, 27–34. [Google Scholar] [CrossRef]
  8. Kemp, D.H.; Agbede, R.I.S.; Johnston, L.A.Y.; Gough, J.M. Immunization of Cattle against Boophilus microplus Using Extracts Derived from Adult Female Ticks: Feeding and Survival of the Parasite on Vaccinated Cattle. Int. J. Parasitol. 1986, 16, 115–120. [Google Scholar] [CrossRef]
  9. Opdebeeck, J.P.; Wong, J.Y.; Jackson, L.A.; Dobson, C. Vaccines to Protect Hereford Cattle against the Cattle Tick, Boophilus microplus. Immunology 1988, 63, 363–367. [Google Scholar]
  10. Willadsen, P.; Kemp, D.H. Vaccination with “concealed” Antigens for Tick Control. Parasitol. Today 1988, 4, 196–198. [Google Scholar] [CrossRef]
  11. Willadsen, P.; Kemp, D.H. Novel Vaccination for Control of the Babesia Vector, Boophilus microplus. Trans. R. Soc. Trop. Med. Hyg. 1989, 83, 107. [Google Scholar] [CrossRef] [PubMed]
  12. Willadsen, P.; Riding, G.A.; van McKenna, R.; Kemp, D.H.; Tellam, R.L.; Nielsen, J.N.; Lahnstein, J.; Cobon, G.S.; Gough, J.M. Immunologic Control of a Parasitic Arthropod. Identification of a Protective Antigen from Boophilus microplus. J. Immunol. 1989, 143, 1346–1351. [Google Scholar] [CrossRef]
  13. Opdebeeck, J.P. Vaccines against Blood-Sucking Arthropods. Vet. Parasitol. 1994, 54, 205–222. [Google Scholar] [CrossRef]
  14. Havlíková, S.; Roller, L.; Koči, J.; Trimnell, A.R.; Kazimírová, M.; Klempa, B.; Nuttall, P.A. Functional Role of 64P, the Candidate Transmission-Blocking Vaccine Antigen from the Tick, Rhipicephalus appendiculatus. Int. J. Parasitol. 2009, 39, 1485–1494. [Google Scholar] [CrossRef]
  15. Trimnell, A.R.; Hails, R.S.; Nuttall, P.A. Dual Action Ectoparasite Vaccine Targeting “exposed” and “Concealed” Antigens. Vaccine 2002, 20, 3560–3568. [Google Scholar] [CrossRef]
  16. de La Fuente, J.; Kocan, K.M. Strategies for Development of Vaccines for Control of Ixodid Tick Species. Parasite Immunol. 2006, 28, 275–283. [Google Scholar] [CrossRef] [PubMed]
  17. Šimo, L.; Kazimirova, M.; Richardson, J.; Bonnet, S.I. The Essential Role of Tick Salivary Glands and Saliva in Tick Feeding and Pathogen Transmission. Front. Cell. Infect. Microbiol. 2017, 7, 281. [Google Scholar] [CrossRef]
  18. Labuda, M.; Trimnell, A.R.; Ličková, M.; Kazimírová, M.; Davies, G.M.; Lissina, O.; Hails, R.S.; Nuttall, P.A. An Antivector Vaccine Protects against a Lethal Vector-Borne Pathogen. PLoS Pathog. 2006, 2, 251–259. [Google Scholar] [CrossRef] [Green Version]
  19. Leal, A.T.; Seixas, A.; Pohl, P.C.; Ferreira, C.A.S.; Logullo, C.; Oliveira, P.L.; Farias, S.E.; Termignoni, C.; da Silva Vaz, I.; Masuda, A. Vaccination of Bovines with Recombinant Boophilus Yolk Pro-Cathepsin. Vet. Immunol. Immunopathol. 2006, 114, 341–345. [Google Scholar] [CrossRef]
  20. Harnnoi, T.; Watchabunsook, S.; Sakaguchi, T.; Xuan, X.; Fujisaki, K. Characterization of Haemaphysalis longicornis Recombinant Cement-like Antigens and Preliminary Study of Their Vaccination Effects. J. Vet. Med. Sci. 2006, 68, 1289–1295. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  21. Andreotti, R. A Synthetic Bmti N-Terminal Fragment as Antigen in Bovine Immunoprotection against the Tick Boophilus microplus in a Pen Trial. Exp. Parasitol. 2007, 116, 66–70. [Google Scholar] [CrossRef] [PubMed]
  22. Gao, J.; Luo, J.; Fan, R.; Guan, G.; Ren, Q.; Ma, M.; Sugimoto, C.; Bai, Q.; Yin, H. Molecular Characterization of a Myosin Alkali Light Chain-like Protein, a “Concealed” Antigen from the Hard Tick Haemaphysalis qinghaiensis. Vet. Parasitol. 2007, 147, 140–149. [Google Scholar] [CrossRef] [PubMed]
  23. Seixas, A.; Leal, A.T.; Nascimento-Silva, M.C.L.; Masuda, A.; Termignoni, C.; da Silva Vaz, I. Vaccine Potential of a Tick Vitellin-Degrading Enzyme (VTDCE). Vet. Immunol. Immunopathol. 2008, 124, 332–340. [Google Scholar] [CrossRef] [PubMed]
  24. Kotsyfakis, M.; Anderson, J.M.; Andersen, J.F.; Calvo, E.; Francischetti, I.M.B.; Mather, T.N.; Valenzuela, J.G.; Ribeiro, J.M.C. Cutting Edge: Immunity against a “Silent” Salivary Antigen of the Lyme Vector Ixodes scapularis Impairs Its Ability to Feed. J. Immunol. 2008, 181, 5209–5212. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  25. Gao, J.; Luo, J.; Fan, R.; Fingerle, V.; Guan, G.; Liu, Z.; Li, Y.; Zhao, H.; Ma, M.; Liu, J.; et al. Cloning and Characterization of a CDNA Clone Encoding Calreticulin from Haemaphysalis qinghaiensis (Acari: Ixodidae). Parasitol. Res. 2008, 102, 737–746. [Google Scholar] [CrossRef]
  26. Imamura, S.; da Silva Vaz, I.; Konnai, S.; Yamada, S.; Nakajima, C.; Onuma, M.; Ohashi, K. Effect of Vaccination with a Recombinant Metalloprotease from Haemaphysalis longicornis. Exp. Appl. Acarol. 2009, 48, 345–358. [Google Scholar] [CrossRef]
  27. You, M.; Fujisaki, K. Vaccination Effects of Recombinant Chitinase Protein from the Hard Tick Haemaphysalis longicornis (Acari: Ixodidae). J. Vet. Med. Sci. 2009, 71, 709–712. [Google Scholar] [CrossRef] [Green Version]
  28. Gao, J.; Luo, J.; Fan, R.; Schulte-Spechtel, U.C.; Fingerle, V.; Guan, G.; Zhao, H.; Li, Y.; Ren, Q.; Ma, M.; et al. Characterization of a Concealed Antigen Hq05 from the Hard Tick Haemaphysalis qinghaiensis and Its Effect as a Vaccine against Tick Infestation in Sheep. Vaccine 2009, 27, 483–490. [Google Scholar] [CrossRef]
  29. Almazán, C.; Lagunes, R.; Villar, M.; Canales, M.; Rosario-Cruz, R.; Jongejan, F.; de La Fuente, J. Identification and Characterization of Rhipicephalus (Boophilus) microplus Candidate Protective Antigens for the Control of Cattle Tick Infestations. Parasitol. Res. 2010, 106, 471–479. [Google Scholar] [CrossRef] [Green Version]
  30. Parizi, L.F.; Utiumi, K.U.; Imamura, S.; Onuma, M.; Ohashi, K.; Masuda, A.; da Silva Vaz, I. Cross Immunity with Haemaphysalis longicornis Glutathione S-Transferase Reduces an Experimental Rhipicephalus (Boophilus) microplus Infestation. Exp. Parasitol. 2011, 127, 113–118. [Google Scholar] [CrossRef]
  31. Hajdusek, O.; Almazán, C.; Loosova, G.; Villar, M.; Canales, M.; Grubhoffer, L.; Kopacek, P.; de la Fuente, J. Characterization of Ferritin 2 for the Control of Tick Infestations. Vaccine 2010, 28, 2993–2998. [Google Scholar] [CrossRef] [PubMed]
  32. Hope, M.; Jiang, X.; Gough, J.; Cadogan, L.; Josh, P.; Jonsson, N.; Willadsen, P. Experimental Vaccination of Sheep and Cattle against Tick Infestation Using Recombinant 5’-Nucleotidase. Parasite Immunol. 2010, 32, 135–142. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  33. Zhang, P.; Tian, Z.; Liu, G.; Xie, J.; Luo, J.; Zhang, L.; Shen, H. Characterization of Acid Phosphatase from the Tick Haemaphysalis longicornis. Vet. Parasitol. 2011, 182, 287–296. [Google Scholar] [CrossRef] [PubMed]
  34. el Hakim, A.E.; Shahein, Y.E.; Abdel-Shafy, S.; Abouelella, A.M.K.; Hamed, R.R. Evaluation of Glycoproteins Purified from Adult and Larval Camel Ticks (Hyalomma dromedarii) as a Candidate Vaccine. J. Vet. Sci. 2011, 12, 243–249. [Google Scholar] [CrossRef] [Green Version]
  35. Bian, Y.; Chen, W.; Yang, G.; Gu, X.; Wang, S.; Sun, J.; Li, K.; Wei, H. Cloning, Expression and Evaluation of the Efficacy of a Recombinant Haemaphysalis concinna Hc-23 Antigen in Rabbits. Vaccine 2011, 29, 1041–1044. [Google Scholar] [CrossRef] [PubMed]
  36. Andreotti, R.; Cunha, R.C.; Soares, M.A.; Guerrero, F.D.; Leivas Leite, F.P.; Pérez de León, A.A. Protective Immunity against Tick Infestation in Cattle Vaccinated with Recombinant Trypsin Inhibitor of Rhipicephalus microplus. Vaccine 2012, 30, 6678–6685. [Google Scholar] [CrossRef] [Green Version]
  37. Rodríguez-Mallon, A.; Fernández, E.; Encinosa, P.E.; Bello, Y.; Méndez-Pérez, L.; Ruiz, L.C.; Pérez, D.; González, M.; Garay, H.; Reyes, O.; et al. A Novel Tick Antigen Shows High Vaccine Efficacy against the Dog Tick, Rhipicephalus sanguineus. Vaccine 2012, 30, 1782–1789. [Google Scholar] [CrossRef]
  38. Merino, O.; Antunes, S.; Mosqueda, J.; Moreno-Cid, J.A.; Pérez de la Lastra, J.M.; Rosario-Cruz, R.; Rodríguez, S.; Domingos, A.; de la Fuente, J. Vaccination with Proteins Involved in Tick-Pathogen Interactions Reduces Vector Infestations and Pathogen Infection. Vaccine 2013, 31, 5889–5896. [Google Scholar] [CrossRef]
  39. Guerrero, F.D.; Andreotti, R.; Bendele, K.G.; Cunha, R.C.; Miller, R.J.; Yeater, K.; de León, A.A.P. Rhipicephalus (Boophilus) microplus Aquaporin as an Effective Vaccine Antigen to Protect against Cattle Tick Infestations. Parasites Vectors 2014, 7, 475. [Google Scholar] [CrossRef] [Green Version]
  40. Ali, A.; Fernando Parizi, L.; Garcia Guizzo, M.; Tirloni, L.; Seixas, A.; da Silva Vaz, I.; Termignoni, C. Immunoprotective Potential of a Rhipicephalus (Boophilus) microplus Metalloprotease. Vet. Parasitol. 2015, 207, 107–114. [Google Scholar] [CrossRef] [Green Version]
  41. Gomes, H.; Moraes, J.; Githaka, N.; Martins, R.; Isezaki, M.; da Silva Vaz, I.; Logullo, C.; Konnai, S.; Ohashi, K. Vaccination with Cyclin-Dependent Kinase Tick Antigen Confers Protection against Ixodes Infestation. Vet. Parasitol. 2015, 211, 266–273. [Google Scholar] [CrossRef] [PubMed]
  42. Maruyama, S.R.; Garcia, G.R.; Teixeira, F.R.; Brandão, L.G.; Anderson, J.M.; Ribeiro, J.M.C.; Valenzuela, J.G.; Horackova, J.; Veríssimo, C.J.; Katiki, L.M.; et al. Mining a Differential Sialotranscriptome of Rhipicephalus microplus Guides Antigen Discovery to Formulate a Vaccine That Reduces Tick Infestations. Parasites Vectors 2017, 10, 1–16. [Google Scholar] [CrossRef]
  43. Rangel, C.K.; Parizi, L.F.; Sabadin, G.A.; Costa, E.P.; Romeiro, N.C.; Isezaki, M.; Githaka, N.W.; Seixas, A.; Logullo, C.; Konnai, S.; et al. Molecular and Structural Characterization of Novel Cystatins from the Taiga Tick Ixodes persulcatus. Ticks Tick Borne Dis. 2017, 8, 432–441. [Google Scholar] [CrossRef] [PubMed]
  44. Csordas, B.G.; Cunha, R.C.; Garcia, M.V.; da Silva, S.S.; Leite, F.L.; Andreotti, R. Molecular Characterization of the Recombinant Protein RmLTI-BmCG-LTB: Protective Immunity against Rhipicephalus (Boophilus) microplus. PLoS ONE 2018, 13, e0191596. [Google Scholar] [CrossRef] [Green Version]
  45. Kusakisako, K.; Miyata, T.; Tsujio, M.; Galay, R.L.; Talactac, M.R.; Hernandez, E.P.; Fujisaki, K.; Tanaka, T. Evaluation of Vaccine Potential of 2-Cys Peroxiredoxin from the Hard Tick Haemaphysalis longicornis. Exp. Appl. Acarol. 2018, 74, 73–84. [Google Scholar] [CrossRef] [PubMed]
  46. Contreras, M.; Villar, M.; de La Fuente, J. A Vaccinomics Approach for the Identification of Tick Protective Antigens for the Control of Ixodes ricinus and Dermacentor reticulatus Infestations in Companion Animals. Front. Physiol. 2019, 10, 977. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  47. Almazán, C.; Šimo, L.; Fourniol, L.; Rakotobe, S.; Borneres, J.; Cote, M.; Peltier, S.; Mayé, J.; Versillé, N.; Richardson, J.; et al. Multiple Antigenic Peptide-Based Vaccines Targeting Ixodes ricinus Neuropeptides Induce a Specific Antibody Response but Do Not Impact Tick Infestation. Pathogens 2020, 9, 900. [Google Scholar] [CrossRef]
  48. Almazán, C.; Fourniol, L.; Rakotobe, S.; Šimo, L.; Bornères, J.; Cote, M.; Peltier, S.; Maye, J.; Versillé, N.; Richardson, J.; et al. Failed Disruption of Tick Feeding, Viability, and Molting after Immunization of Mice and Sheep with Recombinant Ixodes ricinus Salivary Proteins IrSPI and IrLip1. Vaccines 2020, 8, 475. [Google Scholar] [CrossRef]
  49. Parizi, L.F.; Rangel, C.K.; Sabadin, G.A.; Saggin, B.F.; Kiio, I.; Xavier, M.A.; da Silva Matos, R.; Camargo-Mathias, M.I.; Seixas, A.; Konnai, S.; et al. Rhipicephalus microplus Cystatin as a Potential Cross-Protective Tick Vaccine against Rhipicephalus appendiculatus. Ticks Tick Borne Dis. 2020, 11, 101378. [Google Scholar] [CrossRef]
  50. Matias, J.; Kurokawa, C.; Sajid, A.; Narasimhan, S.; Arora, G.; Diktas, H.; Lynn, G.E.; DePonte, K.; Pardi, N.; Valenzuela, J.G.; et al. Tick Immunity Using mRNA, DNA and Protein-Based Salp14 Delivery Strategies. Vaccine 2021, 39, 7661–7668. [Google Scholar] [CrossRef]
  51. Trentelman, J.J.A.; Tomás-Cortázar, J.; Knorr, S.; Barriales, D.; Hajdusek, O.; Sima, R.; Ersoz, J.I.; Narasimhan, S.; Fikrig, E.; Nijhof, A.M.; et al. Probing an Ixodes ricinus Salivary Gland Yeast Surface Display with Tick-Exposed Human Sera to Identify Novel Candidates for an Anti-Tick Vaccine. Sci. Rep. 2021, 11, 15745. [Google Scholar] [CrossRef] [PubMed]
  52. Wu, P.X.; Cui, X.J.; Cao, M.X.; Lv, L.H.; Dong, H.M.; Xiao, S.W.; Liu, J.Z.; Hu, Y.H. Evaluation on Two Types of Paramyosin Vaccines for the Control of Haemaphysalis longicornis Infestations in Rabbits. Parasites Vectors 2021, 14, 1–9. [Google Scholar] [CrossRef] [PubMed]
  53. Wang, D.; Xu, X.; Lv, L.; Wu, P.; Dong, H.; Xiao, S.; Liu, J.; Hu, Y. Gene Cloning, Analysis and Effect of a New Lipocalin Homologue from Haemaphysalis longicornis as a Protective Antigen for an Anti-Tick Vaccine. Vet. Parasitol. 2021, 290, 109358. [Google Scholar] [CrossRef]
  54. Martínez Velázquez, M.; Barragán Álvarez, C.P.; Flores Fernández, J.M.; Lagunes Quintanilla, R.E.; Saines, E.C.; Ramírez Rodríguez, P.B.; Herrera Rodríguez, S.E.; Gutiérrez, R.H.; Ortega, A.G.; Álvarez, Á.H. Immunoprotection Evaluation of the Recombinant N-Terminal Domain of Cys-Loop Receptors against Rhipicephalus (Boophilus) microplus Tick Infestation. Parasite 2021, 28, 65. [Google Scholar] [CrossRef] [PubMed]
  55. Costa, G.C.A.; Ribeiro, I.C.T.; Melo-Junior, O.; Gontijo, N.F.; Sant’Anna, M.R.V.; Pereira, M.H.; Pessoa, G.C.D.; Koerich, L.B.; Oliveira, F.; Valenzuela, J.G.; et al. Amblyomma sculptum Salivary Protease Inhibitors as Potential Anti-Tick Vaccines. Front. Immunol. 2021, 11, 611104. [Google Scholar] [CrossRef] [PubMed]
  56. Lagunes-Quintanilla, R.; Valdez-Espinoza, U.M.; Hernández-Ortiz, R.; Castro-Saines, E.; Merino, O.; Mendoza-Martínez, N. Experimental Vaccination in Rabbits Using the Peptide RmS-17 Antigen Reduces the Performance of a Mexican Rhipicephalus microplus Tick Strain. Ticks Tick Borne Dis. 2022, 13, 102044. [Google Scholar] [CrossRef]
  57. Liang, N.; Dong, H.M.; Fan, X.Y.; Wu, Y.X.; Yang, F.; Liu, X.Y.; Hu, Y.H. Characterization and Evaluation of a New Triosephosphate Isomerase Homologue from Haemaphysalis longicornis as a Candidate Vaccine against Tick Infection. Ticks Tick Borne Dis. 2022, 13, 101968. [Google Scholar] [CrossRef]
  58. Rafiq, N.; Naseem, M.; Kakar, A.; Shirazi, J.H.; Masood, M.I. A Preliminary Evaluation of Tick Cement-Cone Protein Extract for a Vaccine against Hyalomma Infestation. Iran. J. Vet. Res. 2022, 23, 255–264. [Google Scholar] [CrossRef]
  59. Song, R.; Zhai, X.; Fan, X.; Li, Y.; Huercha; Ge, T.; Li, C.; Li, M.; He, W.; Zheng, H.; et al. Prediction and Validation of Cross-Protective Candidate Antigen of Hyalomma asiaticum Cathepsin L between H. asiaticum and H. anatolicum. Exp. Appl. Acarol. 2022, 86, 283–298. [Google Scholar] [CrossRef]
  60. Antunes, S.; Couto, J.; Ferrolho, J.; Sanches, G.S.; Charrez, J.O.M.; de La Cruz Hernández, N.; Mazuz, M.; Villar, M.; Shkap, V.; de La Fuente, J.; et al. Transcriptome and Proteome Response of Rhipicephalus annulatus Tick Vector to Babesia bigemina Infection. Front. Physiol. 2019, 10, 318. [Google Scholar] [CrossRef]
  61. Rappuoli, R. Reverse Vaccinology. Curr. Opin. Microbiol. 2000, 3, 445–450. [Google Scholar] [CrossRef] [PubMed]
  62. Hendawy, S.H.M.; Alzan, H.F.; Tanaka, T.; Mahmoud, M.S. Fundamental Tick Vaccinomic Approach to Evade Host Autoimmune Reaction. Methods Mol. Biol. 2022, 2411, 343–358. [Google Scholar] [CrossRef] [PubMed]
  63. Couto, J.; Seixas, G.; Stutzer, C.; Olivier, N.A.; Maritz-Olivier, C.; Antunes, S.; Domingos, A. Probing the Rhipicephalus bursa Sialomes in Potential Anti-Tick Vaccine Candidates: A Reverse Vaccinology Approach. Biomedicines 2021, 9, 363. [Google Scholar] [CrossRef] [PubMed]
  64. Parizi, L.F.; Reck, J.; Oldiges, D.P.; Guizzo, M.G.; Seixas, A.; Logullo, C.; de Oliveira, P.L.; Termignoni, C.; Martins, J.R.; da Silva Vaz, I. Multi-Antigenic Vaccine against the Cattle Tick Rhipicephalus (Boophilus) microplus: A Field Evaluation. Vaccine 2012, 30, 6912–6917. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  65. Contreras, M.; de la Fuente, J. Control of Ixodes ricinus and Dermacentor reticulatus Tick Infestations in Rabbits Vaccinated with the Q38 Subolesin/Akirin Chimera. Vaccine 2016, 34, 3010–3013. [Google Scholar] [CrossRef]
  66. Trentelman, J.J.A.; Teunissen, H.; Kleuskens, J.A.G.M.; van de Crommert, J.; de La Fuente, J.; Hovius, J.W.R.; Schetters, T.P.M. A Combination of Antibodies against Bm86 and Subolesin Inhibits Engorgement of Rhipicephalus australis (Formerly Rhipicephalus microplus) Larvae in Vitro. Parasites Vectors 2019, 12, 1–10. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  67. Torina, A.; Moreno-Cid, J.A.; Blanda, V.; Fernández De Mera, I.G.; de La Lastra, J.M.P.; Scimeca, S.; Blanda, M.; Scariano, M.E.; Briganò, S.; Disclafani, R.; et al. Control of Tick Infestations and Pathogen Prevalence in Cattle and Sheep Farms Vaccinated with the Recombinant Subolesin-Major Surface Protein 1a Chimeric Antigen. Parasites Vectors 2014, 7, 10. [Google Scholar] [CrossRef] [Green Version]
  68. Contreras, M.; San José, C.; Estrada-Peña, A.; Talavera, V.; Rayas, E.; Isabel León, C.; Luis Núñez, J.; García Fernández de Mera, I.; de la Fuente, J. Control of Tick Infestations in Wild Roe Deer (Capreolus capreolus) Vaccinated with the Q38 Subolesin/Akirin Chimera. Vaccine 2020, 38, 6450–6454. [Google Scholar] [CrossRef]
  69. Rodríguez-Mallon, A.; Encinosa Guzmán, P.E.; Bello Soto, Y.; Rosales Perdomo, K.; Montero Espinosa, C.; Vargas, M.; Estrada García, M.P. A Chemical Conjugate of the Tick P0 Peptide Is Efficacious against Amblyomma mixtum. Transbound. Emerg. Dis. 2020, 67, 175–177. [Google Scholar] [CrossRef]
  70. Rodríguez-Mallon, A.; Encinosa, P.E.; Méndez-Pérez, L.; Bello, Y.; Rodríguez Fernández, R.; Garay, H.; Cabrales, A.; Méndez, L.; Borroto, C.; Estrada, M.P. High Efficacy of a 20 Amino Acid Peptide of the Acidic Ribosomal Protein P0 against the Cattle Tick, Rhipicephalus microplus. Ticks Tick Borne Dis. 2015, 6, 530–537. [Google Scholar] [CrossRef]
  71. Mallón, A.R.; González, L.J.; Guzmán, P.E.E.; Bechara, G.H.; Sanches, G.S.; Pousa, S.; Cabrera, G.; Cabrales, A.; Garay, H.; Mejías, R.; et al. Functional and Mass Spectrometric Evaluation of an Anti-Tick Antigen Based on the P0 Peptide Conjugated to Bm86 Protein. Pathogens 2020, 9, 513. [Google Scholar] [CrossRef]
  72. da Costa, M.; Pinheiro-Silva, R.; Antunes, S.; Moreno-Cid, J.A.; Custódio, A.; Villar, M.; Silveira, H.; de La Fuente, J.; Domingos, A. Mosquito Akirin as a Potential Antigen for Malaria Control. Malar. J. 2014, 13, 1–8. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  73. Ndawula, C. From Bench to Field: A Guide to Formulating and Evaluating Anti-Tick Vaccines Delving beyond Efficacy to Effectiveness. Vaccines 2021, 9, 1185. [Google Scholar] [CrossRef] [PubMed]
  74. Tabor, A.E.; Ali, A.; Rehman, G.; Garcia, G.R.; Zangirolamo, A.F.; Malardo, T.; Jonsson, N.N. Cattle Tick Rhipicephalus microplus-Host Interface: A Review of Resistant and Susceptible Host Responses. Front. Cell. Infect. Microbiol. 2017, 7, 506. [Google Scholar] [CrossRef] [PubMed] [Green Version]
Table 1. Tick (Ixodidae) antigens screened in vaccination trials since 2006. The table was compiled by searching the PubMed database on November 2022, using the keywords: “tick”, “antigen” and “vaccination”. No orthologues were included and only the original vaccination study per antigen is presented.
Table 1. Tick (Ixodidae) antigens screened in vaccination trials since 2006. The table was compiled by searching the PubMed database on November 2022, using the keywords: “tick”, “antigen” and “vaccination”. No orthologues were included and only the original vaccination study per antigen is presented.
AntigenAccession NumberTick SpeciesAntigen Descripton/LocalizationPathogen EffectTrial HostYearRef.
Yolk pro-CathepsinGenBank: AY966003.1R. microplusEgg Cattle2006[19]
Hlim2 and Hlim3GenBank: AB259292.1; AB252633.1H. longicornisSalivary glands Mice2006[20]
Bmti n-terminal fragmentN/A (based on UniProt: P83609)R. microplusSalivary glands (serine proteinase inhibitor) Cattle2007[21]
Hq02 myosin alkali light chain (MLC) proteinsGenBank: AY626788.1H. qinghaiensisSalivary glands Sheep2007[22]
Vitellin-degrading enzymeUniProt: I3VGB9R. microplusEgg (cysteine endopeptidase; Cattle2008[23]
Sialostatin L2GenBank: MK524726.1I. scapularisSalivary glands (secreted immunomodulator) Guinea pigs2008[24]
CalreticulinGenBank: AY962875H qinghaiensisSalivary glands Sheep2008[25]
Metalloprotease HLMP1GenBank: AB218891H. longicornisSalivary glands Rabbits2009[26]
CHT1 chitinaseUniProt: Q8MY79H. longicornisExtracellular (secreted) Mice2009[27]
Hq05GenBank: AY626791.1H. qinghaiensisSalivary glands Sheep2009[28]
Subolesin and UbiquitinUniProt: Q1AER5; GenBank: XP_037276798.1R.; R. annulatusIntracellular Cattle2010[29]
Glutathione S-transferaseUniProt: Q6JVN0R. microplusSalivary glands Cattle2010[30]
Ferritin 2 (IrFER2 and RmFER2)GenBank: EU885951; CK190528 I.ricinus, R. microplus, R. annulatus Midgut Rabbits; Cattle2010[31]
5’ NucleotidaseN/A (close to UniProt: P52307)R. microplusEctoenzyme; Malpiguian tube Cattle2010[32]
Lysosomal acid phosphatase (HL-3)UniProt: G8C7A0H. longicornisMembrane glycoprotein (lysosome) Rabbits2011[33]
Glycoprotein 97, Glycoprotein 66 and Glycoprotein 40N/AH. dromedariiN/A Rabbits2011[34]
Concinna Hc-23GenBank: FJ425897H. concinnaIntracellular (troponin like) Rabbits2011[35]
Trypsin inhibitor 1-BmTI-6GenBank: CK186726R. microplusOvary (Kunitz-type serine protease inhibitor 6) Cattle2012[36]
60S acidic ribosomal protein P0GenBank: EU048401R.sanguineusCell cytoplasm Dogs2012[37]
SILK and TrospaGenBank: GO496219; JK489429R. microplusSalivary glands (receptor)A. marginale; B. bigeminaCattle2013[38]
AquaporinUniProt: A0A097ITI9R. microplusCell membrane channel Cattle2014[39]
Metalloproteases Bmi-MP4GenBank: DQ118970R. microplusSecreted in saliva Cattle2015[40]
CDK10/Cyclin-dependent kinaseN/A (close to UniProt: B7P2I5)I. persulcatusOvary Hamster2015[41]
Rm76/immunoglobulin binding-protein, Rm39/cement protein, Rm239/metalloprotease and Rm180/thrombin inhibitorENA/EMBL-EBI: LT795750; LT795749; LT795752; LT795751R. microplusSecreted in saliva Cattle2017[42]
BrBmcys2cGenBank: AF483724I. persulcatusSalivary glands and midgut Hamsters2017[43]
RmLTI and BmCGGenBank: ACA5782 and P83606R. microplusChimera: Bm86 + secreted serine protease inhibitors Cattle2018[44]
2-Cys peroxiredoxinN/A close to UniProt: B7Q8W6H. longicornisMidgut (peroxiredoxin) Mice2018[45]
Tick Protective Antigens cocktail (heme lipoprotein, two uncharacterized secreted protein, glypican-like protein, secreted protein involved in homophilic cell adhesion, sulfate/anion exchanger, signal peptidase complex subunit 3)GenBank: MK895447 to MK895468I. ricinus;D. reticulatusSalivary glands Rabbits; Dogs2019[46]
SIFamide /myoinhibitory peptideUniProt: B7QHG6; B7PFR9I. ricinusSynganglion (neuropeptides)Anaplasma sp.Mice; Sheep2020[47]
Serine protease inhibitor IrSPI and Lipocalin 1 IrLip1GenBank: KF531922.2; MT133882I. ricinusSalivary glandsA. phagocytophilumMice; Sheep2020[48]
Cystatin 2aUniProt: U3PXI8R. appendiculatusMidgut (cysteine peptidase) Rabbits2020[49]
Salp14UniProt: Q95WY7I. scapularisSalivary glands Guinea pigs2021[50]
Putative glycine rich protein; Putative salivary secreted protein;RNA-binding proteinUniProt: A0A0K8R6W3; V5H126;B7PDE7I. ricinusSalivary glands Cattle2021[51]
ParamyosinGenBank: JQ517315H. longicornisMyofibrillar protein Rabbits2017[52]
LipocalinGenBank: QGW48998H. longicornisSalivary glands Rabbits2021[53]
Glutamate receptor and of a glycine-like receptorGenBank: KF881800; KJ476181R. microplusNervous system (synganglion); (membrane channels) Cattle2021[54]
AsKunitz, AsBasicTail and As8.9kDaGenBank: JAC23688.1; JAC23973.1; JAC23736.1A. sculptumSalivary glands Mice2021[55]
Serpin RmS-17GenBank: KC990116.1R. microplusSalivary glands Rabbits2022[56]
Triosephosphate isomerase (TIM)GenBank: MK599255H. longicornisSalivary glands Rabbits2022[57]
Cement-cone protein fraction 23 kDaN/AHyalomma anatolicum; Hyalomma aegyptiumSalivary glands Cattle2022[58]
Cathepsin L-like cysteine proteaseGenBank: MT905075H. anatolicum; Hyalomma asiaticumIntracellular (not tissue specific) Rabbits2022[59]
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Antunes, S.; Domingos, A. Tick Vaccines and Concealed versus Exposed Antigens. Pathogens 2023, 12, 374. https://doi.org/10.3390/pathogens12030374

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Antunes, Sandra, and Ana Domingos. 2023. "Tick Vaccines and Concealed versus Exposed Antigens" Pathogens 12, no. 3: 374. https://doi.org/10.3390/pathogens12030374

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