Laboratory of Molecular Biology of Ticks (Jan Perner)

Research in our laboratory is focused on molecular descriptions of proteins that are key for the successful blood-feeding of ticks (mainly Ixodes ricinus) and the red poultry mite (Dermanyssus gallinae), or play a role in the acquisition & transmission of tick-borne pathogens. We cover a wide range of topics including metal biology, description of proteolytic apparatuses, systemic and epithelial immunity to experimental infection, integration of functional microbiota, and mapping of protein-ligand interactions.

Our keystone experimental approaches comprise:

i) ex vivo artificial membrane feeding for all developmental stages of I. ricinus ticks and adults of D. gallinae mites

ii) RNA interference in Ixodes spp. ticks or D. gallinae mites

iii) An acquisition & transmission mouse model for Ixodes ricinus - Borrelia afzelii

iv) Vaccination studies against ticks, D. gallinae mites, and Borrelia transmission

v) A culture model for Babesia divergens and an animal model for Babesia microti

vi) A culture model for Anaplasma phagocytophilum

vii) Recombinant protein expression & purification (enzyme kinetics, binding assays, vaccination studies)

viii) Immunodetection of proteins in tick tissues using confocal microscopy, TEM, and array tomography

Apart from basic research, we also carry out contractual research offering throughput ex vivo membrane feeding for acaricidal screening through oral ingestion of blood meal, or in vivo vaccine assessment studies against ticks or D. gallinae mites in small mammals or hens respectively.

Research projects

Functional Genomics of ticks

PI: Dr. Ondřej Hajdušek, Dr. Petr Kopáček, Dr. Daniel Sojka, Dr. Jan Perner
GAČR: 22-18424M, 20-05736S, 21-08826S,
Prime focus of our research group lays in the functional biology of ticks, ranging from  single molecule approach to systems level understanding. By taking a systems biology approach, we can explore the impact of specific molecules on tick physiology and their role in tick-borne disease transmission (vectorial capacity).
Our toolbox includes:
  • RNA interference (RNAi): This well-established technique allows us to silence specific transcripts in ticks, revealing the critical roles their protein products in their biology.
  • Ex vivo membrane feeding with protein inhibitors: This method enables us to deliver enzyme inhibitors and receptor blockers to ticks while they feed, providing insights into the functions of specific proteins and pathways within the context of blood feeding.
  • Laboratory models for tick-borne diseases: We have set up in our laboratory, complete transmission models for Borrelia, Babesia, and Anaplasma infections. We use them mainly to test the involvement of tick candidate genes in tick-pathogen interactions using the RNAi method.
Using these cutting-edge approaches, we investigate several key aspects of tick biology:
  • Tick innate immunity: We explore how ticks defend themselves against pathogens and other threats.
  • Haemoglobin and iron biology: We unravel the intricate processes by which ticks manage ingested blood components like haem or iron from host blood macromolecules.
  • Proteolytic systems and protease inhibitors of ticks: We examine the enzymes involved in breaking down blood proteins in the tick's digestive system and enzymes or inhibitors secreted by the salivary glands to facilitate feeding.
  • Chitin biology: We study chitin, a key component of the tick's exoskeleton, and its role in tick development and molting and transmission of pathogens.
Multiple-level understanding of processes inherent to tick blood-feeding biology help us construct knowledge base to guide research and development of strategies reducing impacts of tick parasitism and pathogen transmission.
Research Articles:
PMID: 37586557
PMID: 38185274
PMID: 36958097
PMID: 37832788
PMID: 35346896
PMID: 33706210
PMID: 33737931
PMID: 34465215
PMID: 33312963
PMID: 26949258
PMID: 38396918
PMID: 34450130

Unveiling Tick Symbiosis: A Functional Dive into Tick-Bacteria Partnerships

PI: Dr. Jan Perner, Dr. Petr Kopáček
GAČR: 22-18424M, 19-04301S, 22-12648J
Beyond their role as pathogen transmitters, ticks harbor bacteria, with which they formed a functional alliance, called symbionts. Unlike disease-causing pathogens that pass through ticks “horizontally”, symbionts are inherited from a tick generation to another “vertically”, forming a tight partnership with their tick hosts.
Our research group investigates this critical tick-symbiont relationship through innovative approaches:
  • Developing "apo-symbiotic" ticks: We utilise ex vivo blood-feeding systems with antibiotic-treated blood meals to create ticks devoid of their bacterial symbionts. This allows us to compare "symbiont-free" and "symbiont-harboring" cohorts of ticks and understand the impact of these partnerships.
  • Focus on key model systems: We primarily study the partnership between the bacterium Midichloria mitochondrii and the European tick Ixodes ricinus, but also explore symbiosis in Francisella and Ornithodoros ticks. This comparative approach provides valuable insights into function of diverse tick-symbiont interactions.
By unraveling the secrets of tick-symbiont partnerships, we aim to uncover novel biological features of ticks:
  • How do symbionts influence tick development, reproduction, and feeding success?
  • What role do symbionts play in tick immunity and defense against pathogens?
  • Can understanding these partnerships pave the way for novel tick control strategies that target the tick-symbiont relationship?
Our research delves into the intricate world of tick symbiosis, holding the potential to revolutionise our understanding of tick biology.
Research Articles:
PMID: 36699720
PMID: 35810301
PMID: 32457850



Research and development of vaccine prototypes against Lyme disease

PI: Dr. Ondřej Hajdušek, Dr. Radek Šíma
Vaccination against Lyme borreliosis represents the most promising, cost-effective, and safe approach for decreasing the risk of infection in animals, as well as in humans. In collaboration with Sanofi USA, we successfully tested novel transmission-blocking vaccines for Lyme borreliosis, where OspA (the hLFA-1 cross-reacting antigen from Borrelia burgdorferi was replaced by the sequence from B. afzelii) was fused with ferritin from Helicobacter pylori, allowing self-assembly of the 24 ferritin units into a hollow spherical nanoparticle (nanovaccine), presenting the OspA antigen on its surface. The vaccine was tested for antibody production in mice and monkeys. It induced antibody titers several times higher than the control subunit OspA canine vaccine RECOMBITEK® and fully protected mice from infection with B. burgdorferii and B. afzelii in the tick-murine challenge model. The recombinant nanovaccine technology has been recently adopted by our laboratory.
We are able to :
  • produce in an E. coli expression system and purify native his-tagged nanovaccines, immunise mice, and efficiently (100% effective) block transmission of B. afzelii (local strain) from laboratory-infected I. ricinus nymphs to naïve mice.
  • describe mechanistic understanding of the mode-of-action of the anti-OspA antibodies inhibit the B. afzelii spirochetes in the tick Ixodes ricinus and whether tick physiology and tick (immune) proteins contribute to the elimination of antibody-bound Borrelia.
Research Articles:
doi: 10.1016/S1473-3099(23)00312-2
doi: 10.1038/s41541-020-0183-8
doi: 10.3389/fimmu.2020.612412

Nutritional sensing of ticks

PI: Dr. Petr Kopáček, Dr. Jan Perner
GAČR: 18-01832S, 24-10659S

In this project, we address two highly intriguing but contrasting features of the parasitic lifestyle of ticks - the ability to ingest and digest enormous amounts of blood, and the ability to survive long periods of starvation between blood meals. The striking contrast between food surplus and scarcity must be tightly controlled by mechanisms of nutrition signaling and sensing. Using the European Lyme disease vector, the tick Ixodes ricinus, we will investigate the role of upstream components of the tick's insulin signaling pathway, specifically the tick's four insulin-like peptides and their putative antagonist Impl2. We will also functionally characterize the amino acid (leucine) sensing pathway leading to the activation of TORC1 in the tick and the role of the lysosomal v-ATPase in controlling the intracellular digestive machinery. The phenotypes obtained by RNA interference or chemical inhibition, as manifested by impairment of tick feeding or reproduction, will serve for future rational development of vaccines or preparations for effective tick control.

Research Articles:
PMID: 33706210

Combating the Poultry Red Mite (Dermanyssus gallinae): A Fight for Safer Eggs and Healthier Hens

TAČR TREND10: FW10010308
PI: Dr. Jan Perner
The poultry red mite (Dermanyssus gallinae) poses a major problem for egg producers. Infesting large poultry farms, these mites cause significant economic losses and threaten consumer health. In Europe, a staggering close-to-100% of large farms face this challenge. Our research group tackles this challenge head-on by developing the next generation of safer acaricides.
Current control methods pose a dilemma:
  • Diatomaceous earth: While popular on smaller farms, it can be labor-intensive and less effective against large infestations.
  • Neurotoxic acaricides: These broad-spectrum pesticides offer strong control but carry a significant risk. Residues can contaminate eggs, leading to product withdrawals and even farm closures, as seen in recent fipronil cases.
Here's how we contribute to safeguarding human health:
  • High-throughput testing platform: We've developed a sophisticated system for testing potential acaricides using ex vivo (outside the living host) blood feeding of mites. This allows us to efficiently evaluate a large number of compounds rapidly.
  • Focus on safer options: Our goal is to develop acaricides that are effective against mites but pose minimal risk of contaminating eggs or harming humans.
  • Joint project. We work closely with organic chemistry experts at Palacký University in Olomouc and industry partners.
Our research paves the way for a future mitigation of harmful mite infestations and the associated risks.
Researc Articles:
DOI: 10.1016/j.heliyon.2024.e30539
PMID: 37179447
PMID: 37249591

Functional Analysis of Babesia Calcium-Dependent Protein Kinases

Project:GAČR: 21-11299S

EN: This research is aimed at tick-borne apicomplexan parasites of the genus Babesia, which infects a range of animals and humans. We focus on the parasite's ability to invade host erythrocytes, a trait it shares with its relative Plasmodium, the cause of malaria. Our team is employing cutting-edge transgenic techniques to conduct a thorough examination of previously unknown calcium-dependent protein kinases (CDPKs) in Babesia divergens. By exploring the role of these enzymes in key biological processes, we aim to understand their function and potential as drug targets. This includes using Bumped Kinase Inhibitors (BKIs) to selectively inhibit these enzymes and assessing their effectiveness in combating the parasite.

Researc Articles:

PMID: 36014069

PMID: 38156314

PMID: 38104025

PMID: 38287902

Master proteases driving the apical complex of Babesia parasites

GAČR: GA23-07850S

This project focuses on specific proteolytic enzymes appearing on the top of a proteolytic cascade directly driving the function of apical complex during host cell egress and invasion by apicomplexan parasites. An in silico comparative analysis of Babesia omics datasets utilizing Toxoplasma and Plasmodium queries determined candidate proteolytic enzymes in Babesia divergens that will be further functionally and biochemically characterized to confirm their essential role for the parasite and their potential druggability with low molecular weight inhibitors.  Main focus is dedicated to two B. divergens aspartyl protease homologues of Plasmodium falciparum plasmepsins IX/X  and Toxoplasma gondii TgASP3  tagged BdASP3a/b as potential master drivers of the apical complex and molecular events associated with egress and invasion of host red blood cells.  

Research Articles: PMID: 37271664

Define Biology of Babesia – Hemoglobin as a Source of Nutrients for Intracellular Parasite Development and Disease Progression

Project: MSCA4Ukraine-Viktoriya Levytska

A deeper understanding of uptake and utilization of hemoglobin may result in the identificatin of numerous potential vulnerable targets ultimately leading to the rational design of alternative anti-Babesia strategies and hereby become a valuable basis for translational research by human and/or veterinary pharma companies.


Biology Centre CAS
Institute of Parasitology
Branišovská 1160/31
370 05 České Budějovice

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