Biology subjects

Urban, J. F.

Publications and source records attributed to Urban, J. F..

9 recordsLinked to original sources

bioRxiv2024

ILC2s navigate tissue redistribution during infection using stage-specific S1P receptors

Lymphocytes can circulate as well as take residence within tissues. While the mechanisms by which circulating populations are recruited to infection sites have been extensively characterized, the molecular basis for the recirculation of tissue-resident cells is less understood. Here, we show that helminth infection- or IL-25-induced redistribution of intestinal group 2 innate lymphoid cells (ILC2s) requires access to the lymphatic vessel network. Although the secondary lymphoid structure is an essential signal hub for adaptive lymphocyte differentiation and dispatch, it is redundant for ILC2 migration and effector function. Upon IL-25 stimulation, a dramatic change in epigenetic landscape occurs in intestinal ILC2s, leading to the expression of sphingosine-1-phosphate receptors (S1PRs). Among the various S1PRs, we found that S1PR5 is critical for ILC2 exit from intestinal tissue to lymph. By contrast, S1PR1 plays a dominant role in ILC2 egress from mesenteric lymph nodes to blood circulation and then to distal tissues including the lung where the redistributed ILC2s contribute to tissue repair. The requirement of two S1PRs for ILC2 migration is largely due to the dynamic expression of the tissue-retention marker CD69, which mediates S1PR1 internalization. Thus, our study demonstrates a stage-specific requirement of different S1P receptors for ILC2 redistribution during infection. We therefore propose a fundamental paradigm that innate and adaptive lymphocytes utilize a shared vascular network frame and specialized navigation cues for migration.

immunology↗

bioRxiv2024

Intestinal helminth infection impairs vaccine-induced T cell responses and protection against SARS-CoV-2

Although vaccines have reduced COVID-19 disease burden, their efficacy in helminth infection endemic areas is not well characterized. We evaluated the impact of infection by Heligmosomoides polygyrus bakeri (Hpb), a murine intestinal hookworm, on the efficacy of an mRNA vaccine targeting the Wuhan-1 spike protein of SARS-CoV-2. Although immunization generated similar B cell responses in Hpb-infected and uninfected mice, polyfunctional CD4+ and CD8+ T cell responses were markedly reduced in Hpb-infected mice. Hpb-infected and mRNA vaccinated mice were protected against the ancestral SARS-CoV-2 strain WA1/2020, but control of lung infection was diminished against an Omicron variant compared to animals immunized without Hpb infection. Helminth mediated suppression of spike-specific CD8+ T cell responses occurred independently of STAT6 signaling, whereas blockade of IL-10 rescued vaccine-induced CD8+ T cell responses. In mice, intestinal helminth infection impairs vaccine induced T cell responses via an IL-10 pathway and compromises protection against antigenically shifted SARS-CoV-2 variants.

immunology↗

bioRxiv2023

Discovery of New Broad-Spectrum Anti-Infectives for Eukaryotic Pathogens Using Bioorganometallic Chemistry

Drug resistance observed with many anti-infectives clearly highlights the need for new broad-spectrum agents to treat especially neglected tropical diseases (NTDs) caused by eukaryotic parasitic pathogens including fungal infections. Since these diseases target the most vulnerable communities who are disadvantaged by health and socio-economic factors, new agents should be, if possible, easy-to-prepare to allow for commercialization based on their low cost. In this study, we show that simple modification of one of the most well-known antifungal drugs, fluconazole, with organometallic moieties not only improves the activity of the parent drug but also broadens the scope of application of the new derivatives. These compounds were highly effective in vivo against pathogenic fungal infections and potent against parasitic worms such as Brugia, which causes lymphatic filariasis and Trichuris, one of the soil-transmitted helminths that infects millions of people globally. Notably, the identified molecular targets indicate a mechanism of action that differs greatly from the parental antifungal drug, including targets involved in biosynthetic pathways that are absent in humans, offering great potential to expand our armamentarium against drug-resistant fungal infections and NTDs targeted for elimination by 2030. Overall, the discovery of these new compounds with broad-spectrum activity opens new avenues for the development of treatments for several current human infections, either caused by fungi or by parasites, including other NTDs, as well as newly emerging diseases. ONE-SENTENCE SUMMARYSimple derivatives of the well-known antifungal drug fluconazole were found to be highly effective in vivo against fungal infections, and also potent against the parasitic nematode Brugia, which causes lymphatic filariasis and against Trichuris, one of the soil-transmitted helminths that infects millions of people globally.

pharmacology and toxicology↗

bioRxiv2022

Intestinal helminth infection impairs oral and parenteral vaccine efficacy

The impact of endemic parasitic infection on vaccine efficacy is an important consideration for vaccine development and deployment. We have examined whether intestinal infection with the natural murine helminth Heligmosomoides polygyrus bakeri alters antigen-specific antibody and cellular immune responses to oral and parenteral vaccination in mice. We found that oral vaccination of mice with a clinically relevant, live, attenuated, recombinant Salmonella vaccine that expresses chicken egg ovalbumin (Salmonella-OVA) disrupts ovalbumin-specific regulatory T cell networks in the gut associated lymphoid tissue and promotes T-effector responses to OVA. Chronic intestinal helminth infection significantly reduced Th1-skewed antibody responses to oral vaccination with Salmonella-OVA. Activated, adoptively-transferred, OVA-specific CD4+ T cells accumulated in draining mesenteric lymph nodes (MLN) of vaccinated mice, irrespective of their helminth-infection status. However, helminth infection increased the frequencies of adoptively-transferred OVA-specific CD4+ T cells producing IL-4 and IL-10 in the MLN. Chronic intestinal helminth infection also significantly reduced Th2-skewed antibody responses to parenteral vaccination with OVA adsorbed to alum. These findings suggest helminth-induced impairment of vaccine antibody responses may be driven by the development of IL-10-secreting CD4+ T regulatory cells. They also underscore the potential need to treat parasitic infection before mass vaccination campaigns in helminth-endemic areas.

immunology↗

bioRxiv2022

Purified cytosolic crystals from Bacillus thuringiensis as a novel active pharmaceutical ingredient (API)

Bacillus thuringiensis or Bt is a Gram-positive soil bacterium, widely and safely applied in the environment as an insecticide for combatting insect pests that damage crops and vector diseases. Dominant active ingredients made by Bt are insect-killing crystal (Cry) proteins released as crystalline inclusions upon bacterial sporulation. Some Bt Cry proteins, e.g., Cry5B, target nematodes (roundworms) and show exceptional promise as anthelmintics (cures for parasitic nematode diseases). We have recently described IBaCC (for Inactivated Bacteria with Cytosolic Crystal(s)) in which bioactive Bt Cry crystals (containing Cry5B) are fully contained within the cytosol of dead bacterial ghosts. Here we demonstrate that these IBaCC-trapped Cry5B crystals can be liberated and purified away from cellular constituents yielding Purified Cytosolic Crystals (PCC). Cry5B PCC contains [~]95% Cry5B protein out of the total protein content. Cry5B PCC is highly bioactive against parasitic nematode larvae and adults in vitro. Cry5B PCC is also highly active in vivo against experimental human hookworm and Ascaris infections in rodents. The process was scaled up to the 100 liter scale to produce PCC for a pilot study to treat two foals infected with the Ascarid, Parascaris spp. Single dose Cry5B PCC brought the fecal egg counts of both foals to zero. These studies describe the process for the scalable production of purified Bt crystals and define a new active pharmaceutical ingredient form of Bt Cry proteins. NON-TECHNICAL IMPORTANCE PARAGRAPHBacillus thuringiensis crystal proteins are widely and safely used as insecticides. Recent studies show they also can cure gastrointestinal parasitic worm (nematode) infections when ingested. However, reproducible, scalable, and practical techniques for purifying these proteins have been lacking. Here, we address this severe limitation and present scalable and practical methods for large-scale purification of potently bioactive B. thuringiensis crystals and crystal proteins. The resultant product, called Purified Cytosolic Crystals (PCC), is highly compatible with ingestible drug delivery and formulation. Furthermore, there are growing applications in agriculture and insect control where access to large quantities of purified crystal proteins are desirable and where these methods will find great utility.

microbiology↗

bioRxiv2022

Resident T cells orchestrate adipose tissue remodeling in a site peripheral to infection

Infection with helminth parasites can affect adiposity, but underlying mechanisms that regulate this process are unclear. We found that fat content of mesenteric adipose tissue (mAT) declined in mice during infection with gut-restricted parasitic worms. This was associated with the accumulation of metabolically activated, immunostimulatory cytokine- and extracellular matrix-secreting multipotent stromal cells, which had potential to differentiate into preadipocytes. Concomitantly, mAT became infiltrated with Th2 lymphocytes that took up long-term residence and responded to signals from stromal cells by producing stromal cell-stimulating cytokines, including Amphiregulin. Signals delivered by Amphiregulin to stromal cells were required for immunity to infection. Our findings reveal intricate intercellular communication between Th2 cells and adipocyte progenitors and link immunity to intestinal infection to T cell-dependent effects on the adipocyte lineage.

immunology↗

bioRxiv2020

Recombinant Paraprobiotics as a New Paradigm for Treating Gastrointestinal Nematode Parasites of Humans

Gastrointestinal nematodes (GINs) of humans, e.g., hookworms, negatively impact childhood growth, cognition, nutrition, educational attainment, income, productivity, and pregnancy. Hundreds of millions of people are targeted with mass drug administration (MDA) of donated benzimidazole (BZ) anthelmintics. However, BZ efficacy against GINs is suboptimal, and reduced/low efficacy has been seen. Developing an anthelmintic for human MDA is daunting: it must be safe, effective, inexpensive, stable without a cold chain, and massively scalable. Bacillus thuringiensis (Bt) crystal protein 5B (Cry5B) has anthelmintic properties that could fill this void. Here we develop an API (Active Pharmaceutical Ingredient) form of Bt Cry5B compatible with MDA. We expressed Cry5B in asporogenous Bt during vegetative phase, forming cytosolic crystals. These Bacteria with Cytosolic Crystals (BaCC) were rendered inviable (inactivated BaCC or IBaCC) with food-grade essential oils. IBaCC potency was validated in vitro against nematodes. IBaCC was also potent in vivo against human hookworm infections in hamsters. IBaCC production was successfully scaled to 350 liters at a contract manufacturing facility. A simple fit-for-purpose formulation to protect against stomach digestion and powdered IBaCC were successfully made and used against GINS in hamsters and mice. A pilot histopathology study and blood chemistry workup showed that five daily consecutive doses of 200 mg/kg Cry5B IBaCC (the curative single dose is 40 mg/kg) was non-toxic and completely safe. IBaCC is a safe, inexpensive, highly effective, easy-to-manufacture, and scalable anthelmintic that is practical for MDA and represents a new paradigm for treating human GINs.

microbiology↗

bioRxiv2019

De novo identification of toxicants that cause irreparable damage to parasitic nematode intestinal cells

Efforts to identify new drugs for therapeutic and preventive treatments against parasitic nematodes have gained increasing interest with expanding pathogen omics databases and drug databases from which new anthelmintic compounds might be identified. Here, a novel approach focused on integrating a pan-Nematoda multi-omics data targeted to a specific nematode organ system (the intestinal tract) with evidence-based filtering and chemogenomic screening was undertaken. Based on de novo computational target prioritization of the 3,564 conserved intestine genes in A. suum, exocytosis was identified as a high priority pathway, and predicted inhibitors of exocytosis were tested using the large roundworm (Ascaris suum larval stages), a filarial worm (Brugia pahangi adult and L3), a whipworm (Trichuris muris adult), and the non-parasitic nematode Caenorhabditis elegans. 10 of 13 inhibitors were found to cause rapid immotility in A. suum L3 larvae, and five inhibitors were effective against the three phylogenetically diverse parasitic nematode species, indicating potential for a broad spectrum anthelmintics. Several distinct pathologic phenotypes were resolved related to molting, motility, or intestinal cell and tissue damage using conventional and novel histologic methods. Pathologic profiles characteristic for each inhibitor will guide future research to uncover mechanisms of the anthelmintic effects and improve on drug designs. This progress firmly validates the focus on intestinal cell biology as a useful resource to develop novel anthelmintic strategies. Author summaryThe intestinal cells of parasitic nematodes are not known to regenerate, therefore disruption of essential processes that cause irreparable damage to intestinal cells is expected to promote worm expulsion. To facilitate improved methods of therapy we need to better understand the basic intestinal cell and tissue functions of this critical organ. To that end have undertaken a comprehensive analysis of multi-omics omics data and identify and prioritize intestinal genes/pathways with essential functions and associated drugs and established a foundational model of the STH intestinal system using the large roundworm Ascaris suum to test and validate inhibitors of these functions. We found 10 inhibitors to impacted motility, and seven of those showed severe pathology and an apparent irreparable damage to intestinal cells. Furthermore, five inhibitors were effective against the three phylogenetically diverse parasitic nematode species, indicating potential for a broad spectrum anthelmintics. Our results firmly validate the focus on intestinal cell biology as a useful resource to develop novel anthelmintic strategies.

pathology↗

bioRxiv2019

Deficiency in Bhlhe40 impairs resistance to H. polygyrus bakeri and reveals novel Csf2rb-dependent regulation of anti-helminth immunity

The cytokines GM-CSF and IL-5 are thought to possess largely divergent functions despite a shared dependence on the common beta ({beta}C) chain to initiate signaling. Although IL-5 is part of the core type 2 cytokine signature and is required for protection against some helminths, it is dispensable for immunity to others, such as Heligmosomoides polygyrus bakeri (H. polygyrus). Whether this is due to compensatory mechanisms is unclear. The transcription factor Bhlhe40 has been shown to control GM-CSF production and is proposed to be a novel regulator of T helper type 2 cells. We have found that Bhlhe40 is required in T cells for a protective memory response to secondary H. polygyrus infection. H. polygyrus rechallenge elicited dramatic Bhlhe40-dependent changes in gene and cytokine expression by lamina propria CD4+ T cells and in vitro-polarized TH2 cells, including induction of GM-CSF and maximal production of type 2 cytokines including IL-5. {beta}C chain-deficient, but not GM-CSF-deficient, mice rechallenged with H. polygyrus had severely impaired protective immunity. Our results demonstrate that Bhlhe40 is an essential regulator of TH2 cell immunity during helminth infection and reveal unexpected redundancy of {beta}C chain-dependent cytokines.

immunology↗