Ladislav Simo

Ladislav Simo
French National Institute for Agriculture, Food, and Environment (INRAE) | INRAE · Department of Animal Health

PhD. RNDr. HDR.
Tick neurophysiology

About

61
Publications
13,700
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1,218
Citations
Introduction
The research interests include the fields of tick molecular physiology and neurobiology. The major goal of my research is to improve the molecular understanding of the host – vector interactions and elucidate how tick neuropeptides, protein hormones, neurotransmitters and their receptors may be manipulated to control of these important vectors of pathogens. www.neuropatick.com
Additional affiliations
February 2016 - present
INRA - French National Institute for Agricultural Research
Position
  • Principal Investigator
Description
  • Tenure obtained in February 2017
June 2014 - January 2016
ANSES - French Agency for Food, Environmental and Occupational Health Safety, position was funded by Pasteur Institute, Laboratory of Excellence, Integrative Biology of Emerging Infectious Diseases, Paris, France.
Position
  • Research Associate
October 2011 - June 2014
Kansas State University
Position
  • Research Assistant Professor

Publications

Publications (61)
Article
The hindgut, as a part of the tick excretory system, plays an important physiological role in maintaining homeostasis and waste elimination. Immunoreactive projections from the synganglion to the hindgut were found using antibodies against four different neuropeptides: FGLamide related allatostatin (FGLa/AST), myoinhibitory peptide (MIP), SIFamide,...
Chapter
Full-text available
In this chapter, we review the neural systems of ticks, including the anatomy of the central nervous system (synganglion) and the peripheral nervous system. We also discuss the signaling molecules that regulate most body functions, such as neuropeptides, neurotransmitters, and their receptors. This review also includes the external sensilla used fo...
Article
The peptidergic signaling system is an ancient cell-cell communication mechanism that is involved in numerous behavioral and physiological events in multicellular organisms. We identified two novel neuropeptides in the neuronal projections innervating the salivary glands of the black-legged tick, Ixodes scapularis (Say, 1821). Myoinhibitory peptide...
Article
The control of tick salivary secretion, which plays a crucial role in compromising the host immune system, involves complex neural mechanisms. Dopamine is known to be the most potent activator of salivary secretion, as a paracrine/autocrine factor. We describe the invertebrate specific D1-like dopamine receptor (InvD1L), which is highly expressed i...
Article
Full-text available
Ticks that feed on vertebrate hosts use their salivary secretion, which contains various bioactive components, to manipulate the host's responses. The mechanisms controlling the tick salivary gland in this dynamic process are not well understood. We identified the tick D1 receptor activated by dopamine, a potent inducer of the salivary secretion of...
Chapter
Full-text available
Both nervous and sensory systems play a key role in the interaction between animals and their environment. The abiotic factors associated with climate change can directly affect the functioning of these systems, which subsequently influences animal actions (Musolin and Saulich, 2012). The tick nervous and sensory systems direct responses to environ...
Article
Full-text available
The lack of tools for the precise manipulation of the tick microbiome is currently a major limitation to achieve mechanistic insights into the tick microbiome. Anti-tick microbiota vaccines targeting keystone bacteria of the tick microbiota alter tick feeding, but their impact on the taxonomic and functional profiles of the tick microbiome has not...
Preprint
Full-text available
Anti-tick microbiota vaccines have been shown to impact tick feeding but its specificity has not been demonstrated. In this study we aimed to investigate the impact of immune targeting of keystone microbiota bacteria on tick performance, and tick microbiota structure and function. Vaccination against Escherichia coli, the selected keystone taxon, i...
Article
Full-text available
Ixodid ticks are hematophagous arthropods considered to be prominent ectoparasite vectors that have a negative impact on cattle, either through direct injury or via the transmission of several pathogens. In this study, we investigated the molecular infection rates of numerous tick-borne pathogens in ticks sampled on cattle from the Kabylia region,...
Article
Full-text available
Neuropeptides are small signaling molecules expressed in the tick central nervous system, i.e., the synganglion. The neuronal-like Ixodes scapularis embryonic cell line, ISE6, is an effective tool frequently used for examining tick–pathogen interactions. We detected 37 neuropeptide transcripts in the I. scapularis ISE6 cell line using in silico met...
Chapter
Full-text available
This chapter describes the biology of the tick Ixodes scapularis in relation to its role as the vector of the Lyme disease agent, Borrelia burgdorferi. Following a review of the internal anatomy of the tick, we review basic molecular processes that contribute to an understanding of the dynamics of the tick’s specialized parasitic processes, includi...
Article
Full-text available
The tick microbiota is a highly complex ensemble of interacting microorganisms. Keystone taxa, with a central role in the microbial networks, support the stability and fitness of the microbial communities. The keystoneness of taxa in the tick microbiota can be inferred from microbial co-occurrence networks. Microbes with high centrality indexes are...
Article
Full-text available
Synthetic peptide vaccines were designed to target the neuropeptides innervating Ixodes ricinus salivary glands and hindgut and they were tested for their capacity to afford protective immunity against nymphs or larvae and Anaplasma phagocytophilum-infected nymph infestation, in mice and sheep, respectively. In both models, the assembly of SIFamide...
Article
Full-text available
Regulatory factors controlling tick salivary glands (SGs) are direct upstream neural signaling pathways arising from the tick’s central nervous system. Here we investigated the cholinergic signaling pathway in the SG of two hard tick species. We reconstructed the organization of the cholinergic gene locus, and then used in situ hybridization to loc...
Article
Full-text available
To identify potential vaccine candidates against Ixodes ricinus and tick-borne pathogen transmission, we have previously sequenced the salivary gland transcriptomes of female ticks infected or not with Bartonella henselae. The hypothesized potential of both IrSPI (I. ricinus serine protease inhibitor) and IrLip1 (I. ricinus lipocalin 1) as protecti...
Article
Ticks are obligatory blood feeding parasites at all stages of development (except eggs) and are recognized as vectors of various pathogens. The use of mouse models in tick research is critical for understanding their biology and tick-host-pathogen interactions. Here we demonstrate a non-laborious technique for the feeding of immature stages of hard...
Article
Full-text available
The different components of the mouthparts of hard ticks (Ixodidae) enable these parasites to penetrate host skin, secrete saliva, embed, and suck blood. Moreover, the tick’s mouthparts represent a key route for saliva-assisted pathogen transmission as well as pathogen acquisition from blood meal during the tick feeding process. Much has been learn...
Article
Full-text available
Ticks are important ectoparasites and vectors of numerous human and animal pathogens. Ticks secrete saliva that contains various bioactive materials to evade the host defense system, and often facilitates the pathogen transmission. In addition, the Lone star tick saliva is thought to be the sensitizer in red meat allergy that is characterized by an...
Article
Arthropod EFLamide genes in chelicerates, myriapods, decapods and non pterygote hexapods encode various EFLamide paracopies on a single precursor. However, in more advanced insect species such multiple EFLamide paracopies encoding genes are absent. In some Hemiptera putative exons of an EFLamide gene coding for a single EFLamide have been identifie...
Article
Full-text available
Ticks are the most important vectors of pathogens affecting both domestic and wild animals worldwide. Hard tick feeding is a slow process—taking up to several days—and necessitates extended control over the host response. The success of the feeding process depends upon injection of tick saliva, which not only controls host hemostasis and wound heal...
Article
Full-text available
The salivary gland of hard ticks is a highly innervated tissue where multiple intertwined axonal projections enter each individual acini. In the present study, we investigated the ultrastructural architecture of axonal projections within granular salivary gland type II and III acini of Ixodes ricinus female. Using immunogold labeling, we specifical...
Article
Full-text available
Background The tick midgut and salivary glands represent the primary organs for pathogen acquisition and transmission, respectively. Specifically, the midgut is the first organ to have contact with pathogens during the blood meal uptake, while salivary glands along with their secretions play a crucial role in pathogen transmission to the host. Curr...
Article
Full-text available
The use of live animals in tick research is crucial for a variety of experimental purposes including the maintenance of hard tick colonies in the laboratory. In ticks, all developmental stages (except egg) are hematophagous, and acquiring a blood-meal when attached to their vertebrate hosts is essential for the successful completion of their life c...
Article
Full-text available
The carbohydrate Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) is produced in all mammals except for humans, apes and old world monkeys that lost the ability to synthetize this carbohydrate. Therefore, humans can produce high antibody titers against α-Gal. Anti-α-Gal IgE antibodies have been associated with tick-induced allergy (i.e. α-Gal syndrome) and anti-α...
Data
Supplementary Material of our paper: Cabezas-Cruz A, Espinosa PJ, Alberdi P, Šimo L, Valdés JJ, Mateos-Hernández L, Contreras M, Rayo MV, de la Fuente J. Tick galactosyltransferases are involved in α-Gal synthesis and play a role during Anaplasma phagocytophilum infection and Ixodes scapularis tick vector development. Sci Rep. 2018; 8(1):14224.
Article
Ticks can survive in harsh and fluctuating vegetated environments for long durations between blood feedings with highly developed osmoregulatory mechanisms. Like the unique life history of hematophagous ticks, osmoregulatory organs and their regulatory mechanisms are significantly different from those in the closely related insect taxa. Over the la...
Article
Understanding salivation in hematophagous arthropod vectors is crucial to developing novel methods to prevent vector-borne disease transmission. The interactions between the tick, host, and pathogens during salivation are highly complex, and are dynamically regulated by the tick central nervous system (synganglion). Recently, tick salivary modulati...
Chapter
Full-text available
Ticks are major vectors of pathogens affecting both humans and animals worldwide and surpass all other arthropods in the variety of microorganisms-including viruses, bacteria, and parasites (protozoa and helminths)-they are able to transmit. They are strict hematophagous arthropods and pool feeders, ingesting all the fluids that are exuded into the...
Article
Full-text available
As long-term pool feeders, ticks have developed myriad strategies to remain discreetly but solidly attached to their hosts for the duration of their blood meal. The critical biological material that dampens host defenses and facilitates the flow of blood—thus assuring adequate feeding—is tick saliva. Saliva exhibits cytolytic, vasodilator, anticoag...
Article
Full-text available
Ticks transmit more pathogens to humans and animals than any other arthropod. We describe the 2.1 Gbp nuclear genome of the tick, Ixodes scapularis (Say), which vectors pathogens that cause Lyme disease, human granulocytic anaplasmosis, babesiosis and other diseases. The large genome reflects accumulation of repetitive DNA, new lineages of retro-tr...
Data
Supplementary Figures 1-25, Supplementary Tables 1-38, Supplementary Note 1, Supplementary Methods and Supplementary References
Article
Orcokinins are conserved neuropeptides within the Arthropoda but their cellular distribution and functions in ticks are unknown. We use an antibody against the highly conserved N-terminal (NFDEIDR) of mature orcokinin peptides to examine their distribution in six ixodid species: Amblyomma variegatum, Dermacentor reticulatus, Hyalomma anatolicum, Ix...
Article
Over the last decade, peptides have emerged as a new family of potential carriers in gene therapy. Peptides are easy to synthesize and quitestable. Additionally, sequences shared by the host proteome are not expected to be immunogenic or trigger inflammatory responses, which are commonly observed with viral approaches. We recently reported on a new...
Article
Full-text available
Salivary secretion is crucial for successful tick feeding, and it is the mediator of pathogen transmission. Salivation functions to inhibit various components of the host immune system and remove excess water and ions during the ingestion of large blood meals. Control of salivary glands involves autocrine/paracrine dopamine, which is the most poten...
Conference Paper
Ticks are obligatory ectoparasites of many vertebrates and transmit various pathogens that cause numerous diseases, including Lyme disease, the most commonly reported vector-borne disease in the United States. Tick salivary secretions are crucial for successful tick feeding, and include several bioactive components, which are responsible for compro...
Article
Full-text available
An arthropod-specific peptidergic system, the neuropeptide designated here as natalisin and its receptor, was identified and investigated in three holometabolous insect species: Drosophila melanogaster, Tribolium castaneum, and Bombyx mori. In all three species, natalisin expression was observed in 3-4 pairs of the brain neurons: the anterior dorso...
Article
Full-text available
Obtaining reliable gene expression data using real-time quantitative polymerase chain reaction (qPCR) is highly dependent on the choice of normalization method. We tested the expression stability of multiple candidate genes in the salivary glands (SG) and synganglia (SYN) of female Ixodes scapularis (Say) ticks in multiple blood-feeding phases. We...
Conference Paper
Ticks are obligatory ectoparasites that transmit pathogens causing human diseases, such as Lyme disease. Salivary secretion in ticks is crucial, not only for the injection of bioactive salivary components into the host, but also for osmoregulation after the ingestion of large amounts of blood. Paracrine or autocrine dopamine in the salivary glands...
Chapter
A problem in tsetse mass rearing facilities is the increased incidence of abortions of underdeveloped larvae or pupariation of larvae within the mother’s uterus. We analysed the problem by investigating neural, hormonal and environmental factors controlling parturition. Input from the mother’s brain is essential for normal parturition, since a fema...
Article
Studies of tick salivary glands (SGs) and their components have produced a number of interesting discoveries over the last four decades. However, the precise neural and physiological mechanisms controlling SG secretion remain enigmatic. Major studies of SG control have identified and characterized many pharmacological and biological compounds that...
Data
Full-text available
Agonistic activities of different compounds on the D1 receptor in the reporter assay measuring the induced elevation of cAMP. Data are percent luminescent values normalized by the response to 10 µM forskolin. (PDF)
Data
Full-text available
Pre-immune negative controls for D1 receptor. (A) acinus II and (B) acinus III of unfed female. Scale bar 10 µm. Doted lines indicate the boundary of an acinus. (PDF)
Article
Ecdysis triggering hormones (ETHs) from endocrine Inka cells initiate the ecdysis sequence through action on central neurons expressing ETH receptors (ETHR) in model moth and dipteran species. We used various biochemical, molecular and BLAST search techniques to detect these signaling molecules in representatives of diverse arthropods. Using peptid...
Article
Full-text available
Neuropeptides are crucial regulators of development and various physiological functions but little is known about their identity, expression and function in vectors of pathogens causing serious diseases, such as ticks. Therefore, we have used antibodies against multiple insect and crustacean neuropeptides to reveal the presence of these bioactive m...
Conference Paper
Peptidergic signal system is an ancient cell-cell communication mechanism and involved in numerous behavioral and physiology events of multicellular organisms. We have been interested in exploring neuropeptidergic system in the blacklegged tick (Ixodes scapularis Say) that transmits Lyme disease. We focused to the neuropeptides that are involved in...
Article
Full-text available
Ticks have developed their own immunomodulatory mechanisms to inhibit the host inflammatory response. One of them involves the ability to subvert the cytokine network at the site of tick feeding by secreting cytokine binding molecules. Most studies have focused on the immunomodulatory prowess of adult female ticks. Here we describe anti-cytokine ac...
Article
Full-text available
Ticks secrete a cocktail of immunomodulatory molecules in their saliva during blood-feeding, including chemokine-binding factors that help control the activity of host immunocompetent cells. Here we demonstrate differential dynamics of anti IL-8 (CXCL8), MCP-1 (CCL2), MIP-1 (CCL3), RANTES (CCL5) and eotaxin (CCL11) activities in salivary gland extr...
Article
Full-text available
The effects of host, size of tick males and tick density per host on feeding of Dermacentor reticulatus females were investigated in the laboratory. Comparison of feeding performances on laboratory animals suggests that mice and rabbits are more suitable hosts than guinea pigs. The size of male ticks did not influence the feeding rate of females. D...

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