Publications

Publications

wasp ovary
Ca2+ signaling in cells begins with the opening of Ca2+ channels in either the plasma membrane (PM) or endoplasmic reticulum (ER), leading to a sharp increase in the physiologically low (<100 nM) cytosolic Ca2+ level. The temporal and spatial regulation of Ca²+ is crucial for ...
As a continuation of the project aimed at searching for new chemotherapeuticagents against Chagas disease or American trypanosomiasis, new selenocyanate derivatives are designed, synthesized, and biologically evaluated against the clinically more relevant dividing amastigote form of Trypanosoma cruzi, the etiologic agent of this illness. Furthermore, ...
Next-generation DNA sequencing (NGS) is used to study the genome sequences of Cryptosporidium spp., but NGS is challenging when pure Cryptosporidium oocysts are limited in number or not available. Varying levels of parasites present in fecal samples, combined with the abundance of host cells, bacterial ...
The ability of organisms to replace and regenerate anatomical structures following their loss or damage has piqued the curiosity of biologists for centuries. In addition to Development's 'Model systems for regeneration' collection, which introduced some of the most well-studied model organisms in the field, we ...
Malaria, caused by Plasmodium falciparum, remains a major global health challenge, with an estimated 263 million new infections and 597,000 deaths annually. Increasing resistance to current antimalarial drugs underscores the urgent need for new therapeutics that target novel pathways in the parasite. We previously reported a ...
Cryptosporidium is a globally endemic parasite genus with over 40 recognized species. While C. hominis and C. parvum are responsible for most human infections, human cases involving other species have also been reported. Furthermore, there is increasing evidence of simultaneous infections with multiple species. Therefore, we devised a new means ...
Many types of viruses have been identified in parasitoid wasps and other Hymenoptera. Parasitoid wasps also transmit several viruses to hosts through the piercing ovipositors that females use to lay eggs. Most viruses that are known to be transmitted by parasitoids have large double-stranded DNA ...
Competence to regenerate lost tissues varies widely across species. The rat tapeworm, Hymenolepis diminuta, undergoes continual cycles of shedding and regenerating thousands of reproductive segments to propagate the species. Despite its prowess, H. diminuta can only regenerate posteriorly from a singular tissue: the neck or ...
Background: The mosquito family Culicidae diverged into the subfamilies Anophelinae and Culicinae approximately 179 million years ago. Most female mosquitoes are anautogenous and must blood-feed on a vertebrate to produce eggs. Regulation of egg-producing gonotrophic cycles is best understood in the culicine Aedes aegypti. Anopheline mosquitoes ...
Many, but not all, parasitic filarial nematodes (Onchocercidae) carry intracellular, maternally-transmitted, alphaproteobacterial Wolbachia symbionts. The association between filarial nematodes and Wolbachia is often portrayed as mutualist, where the nematode is reliant on Wolbachia for an essential but unknown service. Wolbachia are targets for anti-filarial chemotherapeutic ...
Buprenorphine is an opioid used for pain management in veterinary medicine but which requires frequent dosing to maintain therapeutic levels. Sustained-release buprenorphine (BSR) formulations can overcome this limitation, but genera- or species-specific studies that determine the time profiles of buprenorphine after dosing are sparse for ...
Hemocytes mediate defense responses that are collectively referred to as cellular immunity. Here I highlight recent progress in the study of hemocyte ontogeny and function. Studies conducted primarily in D. melanogaster, mosquitoes and Lepidoptera identify a number of transcription factors and signaling pathways that regulate ...
Toxoplasma gondii is a highly successful intracellular mammalian and avian pathogen that must adapt to a wide range of intracellular and extracellular environments. A mechanism that may support this is the modification of hydroxyamino acid rich sequences of nucleocytoplasmic proteins with O-fucose. O-fucosylation of possibly ...
Influenza virus is a leading cause of global morbidity and mortality due to acute lower respiratory infection, even with the widespread use of multiple licensed influenza vaccines. However, antigenic drift during influenza replication can cause vaccine-induced antibodies to poorly neutralize influenza virus, thereby reducing vaccine ...
We investigated the antiparasitic activity of several antimicrobial drug leads against Toxoplasma gondii tachyzoites and, in one case, bradyzoites. Carbazole and phenylthiazole aminoguanidine anti-infectives, originally developed as antibacterial and antifungal agents, showed potent activity, with IC50 values as low as 2 μM. This potency was comparable to that ...
Tetrahydro-β-carboline 1 (MMV008138) controls growth of asexual blood-stage Plasmodium falciparum by inhibiting IspD, an enzyme in the MEP pathway for synthesis of a critical metabolite, isopentenyl pyrophosphate (IPP). We have previously investigated the structure activity relationship (SAR) of three of its four rings (B, C, ...
OSMAC (one strain many compounds) provides a convenient strategy to produce chemically diverse and novel natural products. In the study, the application of an OSMAC approach on a fungus Penicillium citrinum YSC-1 isolated from a medicinal plant Chloranthus japonicus, using different culture media, led to ...
Parasites of the genus Cryptosporidium have evolved to have a highly compact genome of ∼9.1 Mb. The mechanisms that regulate gene expression in Cryptosporidium spp. remain incompletely understood at all levels, including chromatin accessibility, transcription factor activation and repression and RNA processing. This review discusses possible mechanisms of gene ...
Cryptosporidium parvum is a significant pathogen causing gastrointestinal infections in humans and animals. It is spread through ingesting contaminated food and water. Despite its global health significance, generating a C. parvum genome sequence has been challenging for many reasons including cloning and challenging subtelomeric regions ...
CD8+ T cells are key effectors in immune control of Trypanosoma cruzi infection. Within C57BL/6 mice, the T. cruzi-specific CD8+ T cell response is largely comprised of T cells recognizing trans-sialidase (TS)- and mucin-encoded epitopes. Despite their immunodominance, these epitope-specific CD8+ T cells are entirely ...
A target specimen profile (TSP) corresponds to the required characteristics of the specimen panels needed to demonstrate that a diagnostic kit meets the target product profile (TPP). TSPs can guide biobanks in the prospective collection of sample panels to support the development and validation of ...
Human infections by Trypanosoma cruzi propagate via its blood-feeding triatomine vector. Investigating parasite-vector interactions depends upon robust techniques to rear insects and analyze infections. Here, we present a protocol for laboratory rearing and infection tracking of Rhodnius prolixus. We describe steps for housing, feeding, and ...
Trypanosoma cruzi typically establishes a life-long infection in its mammalian hosts, causing the destruction of muscle tissues and ultimately resulting in potentially fatal Chagas disease. In this review, we consider the array of avoidance mechanisms that allow for T. cruzi persistence, many of which are ...
The Trypanosoma brucei group of parasites causes Nagana in cattle and human African trypanosomiasis, or sleeping sickness, in humans. Current drugs against these parasites have severe toxicity, vaccines are not available, and development of drug resistance makes finding new chemotherapeutic targets imperative. Ion channels, which are involved ...
Targeted protein degradation (TPD) is a novel strategy for developing therapeutics against pathogens. Prior to causing malaria, Plasmodium parasites replicate within hepatocytes as liver stages, surrounded by a parasitophorous vacuole membrane (PVM). We hypothesized that TPD can be employed to trigger host-driven degradation of essential ...
Peptide hormones in insects are primarily expressed in specialized brain, ventral nerve chord, and midgut cells. When released, peptide hormones play crucial roles in regulating physiology, reproduction, and behavior. Here, we present a protocol for detecting peptide hormones in mosquito tissues such as the brain, ...
Animals often exhibit increased aggression in response to starvation, while parasites often manipulate host behavior. In contrast, underlying molecular mechanisms for these behavioral changes are mostly unknown. The diamondback moth, Plutella xylostella, is an agricultural pest that feeds on cruciferous plants as larvae, while Cotesia ...
Regulatory T cells (Tregs) can persist as memory cells (mTregs) in both infectious and non-infectious settings. However, their functional behavior, phenotypic stability, and suppressive properties upon antigen re-exposure remain poorly understood. Emerging evidence suggests that mTregs exhibit enhanced proliferation and suppressive capacity upon re-encountering the ...
Trypanosoma cruzi, the causative agent of Chagas disease, is a parasitic protist that affects millions of people worldwide. Currently there are no fully effective drugs or vaccines available. Contact of T. cruzi infective forms with their host cells or with the extracellular matrix increases their ...
Infection with the protozoan parasite Trypanosoma cruzi is generally well-controlled by host immune responses, but appears to be rarely eliminated. The resulting persistent, low-level infection results in cumulative tissue damage with the greatest impact generally in the heart in the form of chagasic cardiomyopathy. The ...
Artemisinin combination therapies (ACTs) are critical components of malaria control worldwide. Alarmingly, ACTs have begun to fail, owing to the rise in artemisinin resistance. Thus, there is an urgent need for an expanded set of novel antimalarials to generate new combination therapies. Herein, we have ...
Plasmodium parasites undergo development and replication within hepatocytes before infecting erythrocytes and initiating clinical malaria. Although type I interferons (IFNs) are known to hinder Plasmodium infection within the liver, the underlying mechanisms remain unclear. Here, we describe two IFN-I-driven hepatocyte antimicrobial programs controlling liver-stage malaria ...
Background/Objectives: Individuals with HIV on combined antiretroviral therapy (ART) with virologic suppression exhibit chronic immune activation and immune dysfunction. Numerous studies have shown that human milk oligosaccharide (HMO) controls the postnatal transmission of HIV-1, but its effect on adult HIV-1 infection is not known. The ...
Trypanosoma cruzi is a single-celled eukaryotic parasite responsible for Chagas disease, a major cause of morbidity and mortality in Central and South America. While the host-pathogen interactions of T. cruzi have been extensively studied in vertebrate models, investigations into its interactions within its insect host ...
The cytosolic Ca2+ concentration of all cells is highly regulated demanding the coordinated operation of Ca2+ pumps, channels, exchangers and binding proteins. In the protozoan parasite Toxoplasma gondii calcium homeostasis, essential for signaling, governs critical virulence traits. However, the identity of most molecular players involved ...
Multiple displacement amplification (MDA) outperforms conventional PCR in long fragment and whole-genome amplification, making it attractive to couple MDA with long-read sequencing of samples with limited quantities of DNA to obtain improved genome assemblies. Here, we explore the efficacy and limits of MDA for efficient ...
While advances in genome editing technologies have simplified gene disruption in many organisms, the study of essential genes requires development of conditional disruption or knockdown systems that are not available in most organisms. Such is the case for Trypanosoma cruzi, a parasite that causes Chagas ...
Hymenolepis diminuta is a parasitic tapeworm that utilizes rats as hosts and offers advantages over human parasitic tapeworms and free-living flatworms as a model system to study the biology and pathology of helminth infections. H. diminuta is minimally infectious to humans, easy to maintain in the lab, demonstrates ...
Plasmodium species replicate via schizogony, which involves asynchronous nuclear divisions followed by semi-synchronous segmentation and cytokinesis. Successful segmentation requires a double-membranous structure known as the inner membrane complex (IMC). Here we demonstrate that PfFBXO1 (PF3D7_0619700) is critical for both asexual segmentation and gametocyte maturation. In ...
Diego Huet works in molecular parasitology, focusing on the organellar biology of Toxoplasma gondii. In this mSphere of Influence article, he reflects on how the article "Efficient proximity labeling in living cells and organisms with turboID" (Branon et al., 2018) impacted his research and the ...
Cellular adaptations to change often involve post-translational modifications of nuclear and cytoplasmic proteins. An example found in protists and plants is the modification of serine and threonine residues of dozens to hundreds of nucleocytoplasmic proteins with a single fucose (O-fucose). A nucleocytoplasmic O-fucosyltransferase occurs in ...
Toxoplasma bradyzoites reside in tissue cysts that undergo cycles of expansion, rupture, and release to foster chronic infection. The glycosylated cyst wall acts as a protective barrier, although the processes responsible for formation, remodeling, and turnover are not understood. Herein, we identify a noncanonical chitinase-like ...
Half the world's population is at risk of developing a malaria infection, which is caused by parasites of the genus Plasmodium. Currently, resistance has been identified to all clinically available antimalarials, highlighting an urgent need to develop novel compounds and better understand common mechanisms of ...
Unique for a eukaryote, protein-coding genes in trypanosomes are arranged in polycistronic transcription units (PTUs). This genome arrangement has led to a model where Pol II transcription of PTUs is unregulated and changes in gene expression are entirely post-transcriptional. Trypanosoma brucei brucei is unable to infect humans ...
Cryptosporidium spp. are medically and scientifically relevant protozoan parasites that cause severe diarrheal illness in infants, immunosuppressed populations and many animals. Although most human Cryptosporidium infections are caused by C. parvum and C. hominis, there are several other human-infecting species including C. meleagridis, which are ...
Plumerianoids A-D (1-4) with a new intact spirocyclic iridoid alkaloid skeleton, along with a new degraded alkaloid 8-epi-plumerianine (5), and a known one (6), were isolated and characterized from Plumeria rubra. The structure of 6 was revised as (8R,13S)-plumerianine. These alkaloids consist of three epimeric pairs ...
The production of energy in the form of ATP by the mitochondrial ATP synthase must be tightly controlled. One well-conserved form of regulation is mediated via ATPase inhibitory factor 1 (IF1), which governs ATP synthase activity and gene expression patterns through a cytoprotective process known ...
The present document outlines the next steps recommended by the Skin NTDs subgroup of the DTAG to operationalise individual disease TPPs and to advance the NTD road map approach of scaling up integrated approaches to skin NTDs. Michael Marks, Sundeep Chaitanya Vedithi, Wendy W J ...
Background: Malaria, a disease caused by parasites of the genus Plasmodium, continues to impact many regions globally. The rise in resistance to artemisinin-based anti-malarial drugs highlights the need for new treatments. Ideally, new anti-malarials will kill the asymptomatic liver stages as well as the symptomatic blood ...
The development of parasite resistance to both artemisinin derivatives and their partner drugs jeopardizes the effectiveness of the artemisinin combination therapy. Thus, the discovery of new antimalarial drugs, with new mechanisms of action, is urgently needed. We recently disclosed that β-carboline 1a was orally efficacious ...
Many types of viruses infect insects and other arthropods. In contrast, little is known about how arthropods sense viruses, although several innate immune pathways including Toll have antiviral functions. Large DNA viruses in the family Baculoviridae are used to control a number of pest insects. Here, we ...
Calophyllum tomentosum belonging to Clusiaceae family is an Indian medicinal plant used as folklore medicine to cure various kinds of diseases reported in Ayurveda, and the leaves of the plant are also used as an active ingredient for the preparation of a botanical medicine known ...
The current treatments for toxoplasmosis are only active against fast-growing tachyzoites, present in acute infections, with little effect on slow-growing bradyzoites within tissue cysts, present in latent chronic infections. The mitochondrion of Toxoplasma gondii is essential for its survival, and one of the major anti-parasitic drugs, atovaquone, ...
Maximum dose bioassays were conducted to assess the efficacy of multiple registered active ingredients for diamondback moth (DBM), Plutella xylostella (L.), control in Georgia and Florida from 2021 to 2023 as a follow-up to an earlier study. Low efficacy (<40% mortality) was recorded for the ...
Acidocalcisomes of Trypanosoma brucei are membrane-bounded organelles characterized by their acidity and high content of polyphosphate and cations, like calcium and magnesium. They have important roles in cation and phosphorus storage, osmoregulation, autophagy initiation, calcium signaling, and virulence. Acidocalcisomes of T. brucei possess several membrane ...
Malaria is a global and deadly human disease caused by the apicomplexan parasites of the genus Plasmodium. Parasite proliferation within human red blood cells (RBCs) is associated with the clinical manifestations of the disease. This asexual expansion within human RBCs begins with the invasion of ...
We report the discovery of MED6-189, an analog of the kalihinol family of isocyanoterpene natural products that is effective against drug-sensitive and drug-resistant Plasmodium falciparum strains, blocking both asexual replication and sexual differentiation. In vivo studies using a humanized mouse model of malaria confirm strong efficacy of ...
Filarial nematodes of the genus Brugia include parasites that are significant to both human and veterinary medicine. Accurate diagnosis is essential for managing infections by these parasites and supporting elimination programs. Traditional diagnostic methods, such as microscopy and serology, remain vital, especially in resource-limited settings. However, advancements ...
Glycosylphosphatidylinositols (GPIs) are highly conserved anchors for eukaryotic cell surface proteins. The apicomplexan parasite, Toxoplasma gondii, is a widespread intracellular parasite of warm-blooded animals whose plasma membrane is covered with GPI-anchored proteins, and free GPIs called GIPLs. While the glycan portion is conserved, species differ ...
A dynamic proteome is required for cellular adaption to changing environments including levels of O2, and the SKP1/CULLIN-1/F-box protein/RBX1 (SCF) family of E3 ubiquitin ligases contributes importantly to proteasome-mediated degradation. We examine, in the apicomplexan parasite Toxoplasma gondii, the influence on the interactome of SKP1 ...
In both mice and humans, Type II interferon gamma (IFNγ) is crucial for the regulation of Toxoplasma gondii (T. gondii) infection, during acute or chronic phases. To thwart this defense, T. gondii secretes protein effectors hindering the host’s immune response. For example, T. gondii relies ...
Trypanosoma cruzi is the etiologic agent of Chagas disease, an infection that can lead to the development of cardiac fibrosis, which is characterized by the deposition of extracellular matrix (ECM) components in the interstitial region of the myocardium. The parasite itself can induce myofibroblast differentiation of ...
Intracellular infection by a pathogen induces significant rewiring of host cell signaling and biological processes. Understanding how an intracellular pathogen such as Toxoplasma gondii modulates host cell metabolism with single-cell resolution has been challenged by the variability of infection within cultures and difficulties in separating ...
Background: Chagas disease or American trypanosomiasis, caused by Trypanosoma cruzi and vectored by triatomines, affects millions of people worldwide. In endemic countries including Mexico, infections in domestic animals, such as dogs, may affect the risk of human disease when they serve as a source of infection to vectors ...
Female mosquitoes produce eggs in gonadotrophic cycles that are divided between a previtellogenic and vitellogenic phase. Previtellogenic females consume water and sugar sources like nectar while also being attracted to hosts for blood feeding. Consumption of a blood meal activates the vitellogenic phase, which produces ...
Lymphatic filariasis is a mosquito-borne parasitic infection affecting an estimated 51.4 million people. Brugia malayi and Brugia pahangi are used in research because common nonprimate research species such as Mongolian gerbils (Meriones unguiculatus), cats (Felis catus), and dogs (Canis familiaris) can maintain the life cycle of these species of ...
The increase in research funding for the development of antimalarials since 2000 has led to a surge of new chemotypes with potent antimalarial activity. High-throughput screens have delivered several thousand new active compounds in several hundred series, including the 4,7-diphenyl-1,4,5,6,7,8-hexahydroquinolines, hereafter termed dihydropyridines (DHPs). We ...
Background: Dirofilaria immitis, commonly known as heartworm (HW), is a parasitic nematode transmitted by various mosquito species, leading to heartworm disease (HWD) in dogs. Diagnosis of HW typically involves antigen or microfilariae detection, or visualization of adult worms through imaging or post mortem examination. Polymerase chain ...
As Toxoplasma gondii disseminates through its host, the parasite must sense and adapt to its environment and scavenge nutrients. Oxygen (O2) is one such environmental factor and cytoplasmic prolyl 4-hydroxylases (PHDs) are evolutionarily conserved O2 cellular sensing proteins that regulate responses to changes in O2 ...
The first biennial Cryptosporidium meeting was held on 10–12 March 2024 in Philadelphia, PA, USA. The organizers, Dr Boris Striepen and Dr Christopher Hunter, welcomed more than 130 attendees to the University of Pennsylvania School of Veterinary Medicine. The meeting opened with a panel discussion ...
Purpose of review: Here we highlight the significant contribution that genomics-based approaches have had on the field of Cryptosporidium research and the insights these approaches have generated into Cryptosporidium biology and transmission. Recent findings: There are advances in genomics, genetic manipulation, gene expression, and single-cell ...
Toxoplasma gondii is a foodborne pathogen that can cause severe and life-threatening infections in fetuses and immunocompromised patients. Felids are its only definitive hosts, and a wide range of animals, including humans, serve as intermediate hosts. When the transmissible bradyzoite stage is orally ingested by ...
Radical cure of Plasmodium vivax malaria must include elimination of quiescent ‘hypnozoite’ forms in the liver; however, the only FDA-approved treatments are contraindicated in many vulnerable populations. To identify new drugs and drug targets for hypnozoites, we screened the Repurposing, Focused Rescue, and Accelerated Medchem (ReFRAME) library ...
Asexual replication in the apicomplexan Sarcocystis neurona involves two main developmental stages: the motile extracellular merozoite and the sessile intracellular schizont. Merozoites invade host cells and transform into schizonts that undergo replication via endopolygeny to form multiple (64) daughter merozoites that are invasive to new ...
The genomes of Leishmania and trypanosomes are organized into polycistronic transcription units flanked by a modified DNA base J involved in promoting RNA polymerase II (Pol II) termination. We recently characterized a Leishmania complex containing a J-binding protein, PP1 protein phosphatase 1, and PP1 regulatory ...
Background: Like other oviparous organisms, the gonotrophic cycle of mosquitoes is not complete until they have selected a suitable habitat to oviposit. In addition to the evolutionary constraints associated with selective oviposition behavior, the physiological demands relative to an organism's oviposition status also influence their nutrient ...
The Plasmodium parasites that cause malaria undergo asymptomatic development in the parenchymal cells of the liver, the hepatocytes, prior to infecting erythrocytes and causing clinical disease. Traditionally, hepatocytes have been perceived as passive bystanders that allow hepatotropic pathogens such as Plasmodium to develop relatively unchallenged ...
Thousands of endoparasitoid wasp species in the families Braconidae and Ichneumonidae harbor "domesticated endogenous viruses" (DEVs) in their genomes. This study focuses on ichneumonid DEVs, named ichnoviruses (IVs). Large quantities of DNA-containing IV virions are produced in ovary calyx cells during the pupal and adult ...
Testing Plasmodium vivax antimicrobial sensitivity is limited to ex vivo schizont maturation assays, which preclude determining the IC50s of delayed action antimalarials such as doxycycline. Using Plasmodium cynomolgi as a model for P. vivax, we determined the physiologically significant delayed death effect induced by doxycycline [IC50(96 h), 1,401 ± 607 nM]. As ...
Trypanosoma cruzi, the protozoan parasite and cause of Chagas disease, is widely distributed in many vertebrate and triatomine species throughout North, Central, and South America. Variations in housing quality largely determines human infection risk in the Americas. However, the southern U.S. contains widespread, infected triatomine ...
FungiDB (https://fungidb.org) serves as a valuable online resource that seamlessly integrates genomic and related large-scale data for a wide range of fungal and oomycete species. As an integral part of the VEuPathDB Bioinformatics Resource Center (https://veupathdb.org), FungiDB continually integrates both published and unpublished data addressing ...
Trypanosoma cruzi infection in dogs can cause heart failure and sudden death with few treatment options available. A litter of 4 dogs living in a T cruzi endemic area were randomized to prophylaxis and nonprophylaxis groups as part of a study evaluating a modified benznidazole ...
Recent advances in the in vitro cultivation of Cryptosporidium parvum using hollow fiber bioreactor technology (HFB) have permitted continuous growth of parasites that complete all life cycle stages. The method provides access to all stages of the parasite and provides a method for non-animal production ...
Ca2+ signaling impacts almost every aspect of cellular life. Ca2+ signals are generated through the opening of ion channels that permit the flow of Ca2+ down an electrochemical gradient. Cytosolic Ca2+ fluctuations can be generated through Ca2+ entry from the extracellular milieu or release from ...
Trichothecenes (TCNs) are a large group of tricyclic sesquiterpenoid mycotoxins that have intriguing structural features and remarkable biological activities. Herein, we focused on three TCNs (anguidine, verrucarin A, and verrucarol) and their ability to target both the blood and liver stages of Plasmodium species, the parasite responsible ...
Parasites and their hosts are engaged in reciprocal coevolution that balances competing mechanisms of virulence, resistance, and evasion. This often leads to host specificity, but genomic reassortment between different strains can enable parasites to jump host barriers and conquer new niches. In the apicomplexan parasite Cryptosporidium, ...
Dolichols are isoprenoid end-products of the mevalonate and 2C-methyl-D-erythritol-4-phosphate pathways. The synthesis of dolichols is initiated with the addition of several molecules of isopentenyl diphosphate to farnesyl diphosphate. This reaction is catalyzed by a cis-prenyltransferase and leads to the formation of polyprenyl diphosphate. Subsequent steps ...
Inflammasome-mediated caspase-1 activation facilitates innate immune control of Plasmodium in the liver, thereby limiting the incidence and severity of clinical malaria. However, caspase-1 processing occurs incompletely in both mouse and human hepatocytes and precludes the generation of mature IL-1β or IL-18, unlike in other cells ...
The mosquito family Culicidae is divided into two subfamilies named the Culicinae and Anophelinae. Nix, the dominant male-determining factor, has only been found in the culicines Aedes aegypti and Ae. albopictus, two important arboviral vectors that belong to the subgenus Stegomyia. Here we performed sex-specific ...
Apicomplexan parasites exhibit tremendous diversity in much of their fundamental cell biology, but study of these organisms using light microscopy is often hindered by their small size. Ultrastructural expansion microscopy (U-ExM) is a microscopy preparation method that physically expands the sample by ~4.5×. Here, we ...
Acidocalcisomes are organelles conserved during evolution and closely related to the so-called volutin granules of bacteria and archaea, to the acidocalcisome-like vacuoles of yeasts, and to the lysosome-related organelles of animal species. All these organelles have in common their acidity and high content of polyphosphate ...
Background: Onchocerca volvulus is a filarial parasite that is a major cause of dermatitis and blindness in endemic regions primarily in sub-Saharan Africa. Widespread efforts to control the disease caused by O. volvulus infection (onchocerciasis) began in 1974 and in recent years, following successful elimination ...
Trypanosoma cruzi, a heme auxotrophic parasite, can control intracellular heme content by modulating heme responsive gene (TcHRG) expression when a free heme source is added to an axenic culture. Herein, we explored the role of TcHRG protein in regulating the uptake of heme derived from ...
The host-specific microbiotas of animals can both reduce and increase disease risks from pathogens. In contrast, how environmental microbial communities affect pathogens is largely unexplored. Aquatic habitats are of interest because water enables environmental microbes to readily interact with animal pathogens. Here, we focused on ...
Ingestion of an additional blood meal(s) by a hematophagic insect can accelerate development of several vector-borne parasites and pathogens. Most studies, however, offer blood from the same vertebrate host species as the original challenge (for e.g., human for primary and additional blood meals). Here, we ...
Mosquitoes shift from detritus-feeding larvae to blood-feeding adults that can vector pathogens to humans and other vertebrates. The sugar and blood meals adults consume are rich in carbohydrates and protein but are deficient in other nutrients including B vitamins. Facultatively hematophagous insects like mosquitoes have ...
The Eukaryotic Pathogen, Vector and Host Informatics Resource (VEuPathDB, https://veupathdb.org) is a Bioinformatics Resource Center funded by the National Institutes of Health with additional funding from the Wellcome Trust. VEuPathDB supports >600 organisms that comprise invertebrate vectors, eukaryotic pathogens (protists and fungi) and relevant free-living ...
PP1 phosphatases associate with specific regulatory subunits to achieve, among other functions, substrate selectivity. Among the eight PP1 isotypes in Leishmania, PP1-8e associates with the regulatory protein PNUTS along with the structural factors JBP3 and Wdr82 in the PJW/PP1 complex that modulates RNA polymerase II ...
Toxoplasma gondii is a zoonotic protist pathogen that infects up to one third of the human population. This apicomplexan parasite contains three genome sequences: nuclear (65 Mb); plastid organellar, ptDNA (35 kb); and mitochondrial organellar, mtDNA (5.9 kb of non-repetitive sequence). We find that the nuclear ...
Mosquitoes including Aedes aegypti are human disease vectors because females must blood feed to produce and lay eggs. Blood feeding triggers insulin-insulin growth factor signaling (IIS) which regulates several physiological processes required for egg development. A. aegypti encodes 8 insulin-like peptides (ILPs) and one insulin-like ...
Bracoviruses (BVs) are endogenized nudiviruses in parasitoid wasps of the microgastroid complex (order Hymenoptera: Family Braconidae). BVs produce replication-defective virions that adult female wasps use to transfer DNAs encoding virulence genes to parasitized hosts. Some BV genes are shared with nudiviruses and baculoviruses with studies ...
Pathogenic free-living amoebae (pFLA) can cause life-threatening central nervous system (CNS) infections and warrant the investigation of new chemical agents to combat the rise of infection from these pathogens. Naegleria fowleri glucokinase (NfGlck), a key metabolic enzyme involved in generating glucose-6-phosphate, was previously identified as a potential ...
Coiled-coil-helix-coiled-coil-helix (CHCH) domains consist of two pairs of cysteine residues that are oxidized to form disulfide bonds upon mitochondrial import. Proteins containing these domains play important roles in mitochondrial ultrastructure and in the biogenesis, function, and stability of electron transport chain complexes. Interestingly, recent investigations ...
The malaria-causing parasite, Plasmodium falciparum completely remodels its host red blood cell (RBC) through the export of several hundred parasite proteins, including transmembrane proteins, across multiple membranes to the RBC. However, the process by which these exported membrane proteins are extracted from the parasite plasma ...
Introduction: As global temperatures rise to unprecedented historic levels, so too do the latitudes of habitable niches for the pathogenic free-living amoeba, Naegleria fowleri. This opportunistic parasite causes a rare, but >97% fatal, neurological infection called primary amoebic meningoencephalitis. Despite its lethality, this parasite remains one of ...
As part of ongoing efforts to isolate biologically active fungal metabolites, a cyclic pentapeptide, sheptide A (1), was discovered from strain MSX53339 (Herpotrichiellaceae). The structure and sequence of 1 were determined primarily by analysis of 2D NMR and HRMS/MS data, while the absolute configuration was ...
Like most eukaryotes, the pre-metazoan social amoeba Dictyostelium depends on the SCF (Skp1/cullin-1/F-box protein) family of E3 ubiquitin ligases to regulate its proteome. In Dictyostelium, starvation induces a transition from unicellular feeding to a multicellular slug that responds to external signals to culminate into a fruiting body containing ...
The vector-borne protozoan parasite Trypanosoma cruzi causes Chagas disease in humans, dogs, and many other mammalian hosts. Canine Chagas disease is increasingly diagnosed in dogs of the southern United States where triatomine insect vectors occur, and there are limited veterinary testing options; only the indirect ...
Host cell invasion by Trypanosoma cruzi is a markedly silent process, with limited host transcriptional changes indicative of innate immune recognition, except for a modest type I IFN (IFN-I) response. In this study, we show that T. cruzi-induced IFN-β production was nearly abolished in primary ...
Apicomplexan parasites are a group of protists that cause disease in humans and include pathogens like Plasmodium spp., the causative agent of malaria, and Toxoplasma gondii, the etiological agent of toxoplasmosis and one of the most ubiquitous human parasites in the world. Membrane contact sites ...
Background: The American Heartworm Society canine guidelines recommend treatment with doxycycline prior to adulticide administration to reduce levels of Wolbachia and its associated metabolites, which are known to be a leading cause of pulmonary pathology. Studies have determined that doxycycline administered at 10 mg/kg BID for ...
Trypanosoma cruzi, the causative agent of Chagas disease, is a zoonotic, vector-borne, protozoan hemoflagellate with a wide host range. An 11-yr-old, captive-bred male De Brazza's monkey (Cercopithecus neglecus) presented with weight loss despite normal appetite. Examination revealed hypoglycemia, nonregenerative anemia, and many trypanosomes on a ...
Human bone marrow (BM) plasma cells are heterogeneous, ranging from newly arrived antibody-secreting cells (ASCs) to long-lived plasma cells (LLPCs). We provide single-cell transcriptional resolution of 17,347 BM ASCs from five healthy adults. Fifteen clusters are identified ranging from newly minted ASCs (cluster 1) expressing ...
Microbial pathogens use proteases for their infections, such as digestion of proteins for nutrients and activation of their virulence factors. As an obligate intracellular parasite, Toxoplasma gondii must invade host cells to establish its intracellular propagation. To facilitate invasion, the parasites secrete invasion effectors from microneme and ...
Background: Canine heartworm disease (CHD) caused by Dirofilaria immitis remains a common preventable disease with increasing incidence in some parts of the USA. The treatment guidelines of the American Heartworm Society (AHS) currently recommend monthly macrocyclic lactone administration, 28 days of doxycycline given orally every 12 ...
Trachoma, caused by ocular Chlamydia trachomatis infection, is targeted for global elimination as a public health problem by 2030. To provide evidence for use of antibodies to monitor C. trachomatis transmission, we collated IgG responses to Pgp3 antigen, PCR positivity, and clinical observations from 19,811 ...
Biomolecular condensation underlies the biogenesis of an expanding array of membraneless assemblies, including stress granules (SGs), which form under a variety of cellular stresses. Advances have been made in understanding the molecular grammar of a few scaffold proteins that make up these phases, but how ...
The genomes of kinetoplastids are organized into polycistronic transcription units that are flanked by a modified DNA base (base J, beta-D-glucosyl-hydroxymethyluracil). Previous work established a role of base J in promoting RNA polymerase II (Pol II) termination in Leishmania major and Trypanosoma brucei. We recently ...
The Chagas field has gone >50 years without tangible progress toward new therapies. My colleagues and I have recently reported on a benzoxaborole compound that achieves consistent parasitological cure in experimentally infected mice and in naturally infected non-human primates (NHPs). While these results do not ...
Acanthamoeba species, Naegleria fowleri, and Balamuthia mandrillaris are opportunistic pathogens that cause a range of brain, skin, eye, and disseminated diseases in humans and animals. These pathogenic free-living amoebae (pFLA) are commonly misdiagnosed and have sub-optimal treatment regimens which contribute to the extremely high mortality rates (>90%) when they ...
Malaria is a deadly disease caused by the parasite Plasmodium and is transmitted through the bite of female Anopheles mosquitoes. The sporozoite stage of Plasmodium deposited by mosquitoes in the skin of vertebrate hosts undergoes a phase of mandatory development in the liver before initiating ...
Background: Mosquitoes serve as the vector of canine heartworm (Dirofilaria immitis), which represents a significant and persistent threat to canine health. A reduction in the longevity and/or reproductive success of mosquitoes that take a blood meal from fluralaner-treated dogs may consequently reduce the local transmission of ...
Trypanosoma cruzi naturally infects a broad range of mammalian species and frequently results in the pathology that has been most extensively characterized in human Chagas disease. Currently employed treatment regimens fail to achieve parasitological cure of T. cruzi infection in the majority of cases. In ...
Cripowellins from Crinum erubescens are known pesticidal and have potent antiplasmodial activity. To gain mechanistic insights to this class of natural products, studies to determine the timing of action of cripowellins within the asexual intraerythrocytic cycle of Plasmodium falciparum were performed and led to the observation that this class ...
Toxoplasma gondii is an obligate intracellular apicomplexan that causes toxoplasmosis in humans and animals. Central to its dissemination and pathogenicity is the ability to rapidly divide in the tachyzoite stage and infect any type of nucleated cell. Adaptation to different cell contexts requires high plasticity in ...