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
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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.
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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.
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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.
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Tick innate immunity: We explore how ticks defend themselves against pathogens and other threats.
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Haemoglobin and iron biology: We unravel the intricate processes by which ticks manage ingested blood components like haem or iron from host blood macromolecules.
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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.
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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.
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PMID: 34450130
Unveiling Tick Symbiosis: A Functional Dive into Tick-Bacteria Partnerships
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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.
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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.
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How do symbionts influence tick development, reproduction, and feeding success?
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What role do symbionts play in tick immunity and defense against pathogens?
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Can understanding these partnerships pave the way for novel tick control strategies that target the tick-symbiont relationship?
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PMID: 35810301
PMID: 32457850
Research and development of vaccine prototypes against Lyme disease
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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.
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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.
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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
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Diatomaceous earth: While popular on smaller farms, it can be labor-intensive and less effective against large infestations.
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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.
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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.
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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.
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Joint project. We work closely with organic chemistry experts at Palacký University in Olomouc and industry partners.
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