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1.
Biochemistry ; 2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39189508

ABSTRACT

As part of its pathogenesis, Salmonella enterica serovar Typhimurium delivers effector proteins into host cells. One effector is SspH2, a member of the so-called novel E3 ubiquitin ligase family, that interacts with and enhances, NOD1 pro-inflammatory signaling, though the underlying mechanisms are unclear. Here, we report that SspH2 interacts with multiple members of the NLRC family to enhance pro-inflammatory signaling by targeted ubiquitination. We show that SspH2 modulates host innate immunity by interacting with both NOD1 and NOD2 in mammalian epithelial cell culture via the NF-κB pathway. Moreover, purified SspH2 and NOD1 directly interact, where NOD1 potentiates SspH2 E3 ubiquitin ligase activity. Mass spectrometry and mutational analyses identified four key lysine residues in NOD1 that are required for its enhanced activation by SspH2, but not its basal activity. These critical lysine residues are positioned in the same region of NOD1 and define a surface on the receptor that appears to be targeted by SspH2. Overall, this work provides evidence for post-translational modification of NOD1 by ubiquitin and uncovers a unique mechanism of spatially selective ubiquitination to enhance the activation of an archetypal NLR.

2.
BMC Health Serv Res ; 24(1): 881, 2024 Aug 02.
Article in English | MEDLINE | ID: mdl-39095800

ABSTRACT

BACKGROUND: People with acquired brain injury (ABI) may experience concurrent conditions such as, mental health and substance use concerns, that require specialized care. There are services that aim to support people with ABI and these conditions separately; however, little is known about the facilitators and barriers of these services. Therefore, the purpose of this study was to engage stakeholders to investigate the facilitators and barriers of healthcare services for ABI and concurrent issues. METHODS: Semi-structured focus groups were conducted in-person and virtually with people with ABI, caregivers, healthcare professionals, and policy makers during a one-day event in British Columbia, Canada. Manifest content analysis was used with a constructivist perspective to analyze data. RESULTS: 90 participants (including 34 people with ABI) provided insights during 15 simultaneous focus groups. Three categories were identified: (1) complexity of ABI, (2) supports, (3) structure of care. Complexity of ABI outlined the ongoing basic needs after ABI and highlighted the need for public awareness of ABI. Supports outlined healthcare professional and community-based supports. Structure of care described people with ABI needing to meet criteria for support, experiences of navigating through the system and necessity of integrated services. CONCLUSIONS: These findings highlight the facilitators and barriers of healthcare services for ABI and concurrent conditions and provide insights into the changes that may be needed. Doing so can improve the accessibility and quality of ABI healthcare services.


Subject(s)
Brain Injuries , Focus Groups , Health Services Accessibility , Qualitative Research , Substance-Related Disorders , Humans , Substance-Related Disorders/therapy , Female , Male , British Columbia , Middle Aged , Adult , Brain Injuries/therapy , Mental Disorders/therapy , Aged
3.
Health Expect ; 27(4): e14136, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38990165

ABSTRACT

OBJECTIVES: The purpose of this study was to engage key stakeholders in a health research priority-setting process to identify, prioritize and produce a community-driven list of research questions addressing intersectional issues on mental health and addictions (MHA) in acquired brain injury (ABI). METHODS: A multiphasic health research priority-setting process was co-designed and executed with community-based stakeholders, including researchers, health professionals, clinicians, service providers, representatives from brain injury associations, policy makers and people with lived experience of ABI and MHA, including patients and their family members. Stakeholders' ideas led to the generation of research questions, which were prioritized at a 1-day workshop. RESULTS: Fifty-nine stakeholders participated in the priority-setting activity during the workshop, which resulted in a rank-ordered list of the top 10 questions for research addressing the intersections of ABI and MHA. Questions identified touched on several pressing issues (e.g., opioid crisis, homelessness), encompassed multiple subtypes of ABI (e.g., hypoxic-ischaemic, mild traumatic), and involved different domains (e.g., identification, intervention) of health research. CONCLUSIONS: This community-driven health research priority-setting study identified and prioritized research questions addressing the intersections of ABI and MHA. Researchers and funding agencies should use this list to inform their agendas and address stakeholders' most urgent needs, fostering meaningful improvements to clinical services. PATIENT OR PUBLIC CONTRIBUTION: An 11-person working group comprised of people with lived experience, service providers, researchers, healthcare professionals and other key stakeholders collaboratively developed and informed the scope, design, methodology and interpretation of this study. Over 50 community-based stakeholders contributed to the research priority-setting activity. One co-author is a person with lived experience.


Subject(s)
Brain Injuries , Stakeholder Participation , Humans , Brain Injuries/therapy , Substance-Related Disorders/therapy , Mental Health , Health Priorities
4.
Dev Comp Immunol ; 159: 105219, 2024 Oct.
Article in English | MEDLINE | ID: mdl-38925431

ABSTRACT

An infection induces the migration of immune cells called hemocytes to the insect heart, where they aggregate around heart valves called ostia and phagocytose pathogens in areas of high hemolymph flow. Here, we investigated whether the cardiac extracellular matrix proteins, Pericardin (Prc) and Lonely heart (Loh), regulate the infection-induced aggregation of periostial hemocytes in the mosquito, An. gambiae. We discovered that RNAi-based post-transcriptional silencing of Prc or Loh did not affect the resident population of periostial hemocytes in uninfected mosquitoes, but that knocking down these genes decreases the infection-induced migration of hemocytes to the heart. Knocking down Prc or Loh did not affect the proportional distribution of periostial hemocytes along the periostial regions. Moreover, knocking down Prc or Loh did not affect the number of sessile hemocytes outside the periostial regions, suggesting that the role of these proteins is cardiac-specific. Finally, knocking down Prc or Loh did not affect the amount of melanin at the periostial regions, or the intensity of an infection at 24 h after challenge. Overall, we demonstrate that Prc and Loh are positive regulators of the infection-induced migration of hemocytes to the heart of mosquitoes.


Subject(s)
Anopheles , Hemocytes , Insect Proteins , Animals , Hemocytes/metabolism , Hemocytes/physiology , Hemocytes/immunology , Insect Proteins/metabolism , Insect Proteins/genetics , Anopheles/immunology , Extracellular Matrix Proteins/metabolism , Extracellular Matrix Proteins/genetics , Cell Movement , RNA Interference , Cell Aggregation/immunology , Phagocytosis , Melanins/metabolism
6.
Aging Cell ; 23(6): e14115, 2024 06.
Article in English | MEDLINE | ID: mdl-38831622

ABSTRACT

With aging skeletal muscle fibers undergo repeating cycles of denervation and reinnervation. In approximately the 8th decade of life reinnervation no longer keeps pace, resulting in the accumulation of persistently denervated muscle fibers that in turn cause an acceleration of muscle dysfunction. The significance of denervation in important clinical outcomes with aging is poorly studied. The Study of Muscle, Mobility, and Aging (SOMMA) is a large cohort study with the primary objective to assess how aging muscle biology impacts clinically important traits. Using transcriptomics data from vastus lateralis muscle biopsies in 575 participants we have selected 49 denervation-responsive genes to provide insights to the burden of denervation in SOMMA, to test the hypothesis that greater expression of denervation-responsive genes negatively associates with SOMMA participant traits that included time to walk 400 meters, fitness (VO2peak), maximal mitochondrial respiration, muscle mass and volume, and leg muscle strength and power. Consistent with our hypothesis, increased transcript levels of: a calciumdependent intercellular adhesion glycoprotein (CDH15), acetylcholine receptor subunits (CHRNA1, CHRND, CHRNE), a glycoprotein promoting reinnervation (NCAM1), a transcription factor regulating aspects of muscle organization (RUNX1), and a sodium channel (SCN5A) were each negatively associated with at least 3 of these traits. VO2peak and maximal respiration had the strongest negative associations with 15 and 19 denervation-responsive genes, respectively. In conclusion, the abundance of denervationresponsive gene transcripts is a significant determinant of muscle and mobility outcomes in aging humans, supporting the imperative to identify new treatment strategies to restore innervation in advanced age.


Subject(s)
Aging , Muscle, Skeletal , Humans , Aging/genetics , Male , Muscle, Skeletal/metabolism , Muscle, Skeletal/innervation , Aged , Female , Middle Aged , Cohort Studies , Adult
7.
Phys Rev Lett ; 132(19): 195001, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38804956

ABSTRACT

Experiments were performed on laser wakefield acceleration in the highly nonlinear regime. With laser powers P<250 TW and using an initial spot size larger than the matched spot size for guiding, we were able to accelerate electrons to energies E_{max}>2.5 GeV, in fields exceeding 500 GV m^{-1}, with more than 80 pC of charge at energies E>1 GeV. Three-dimensional particle-in-cell simulations show that using an oversized spot delays injection, avoiding beam loss as the wakefield undergoes length oscillation. This enables injected electrons to remain in the regions of highest accelerating fields and leads to a doubling of energy gain as compared to results from using half the focal length with the same laser.

8.
Dis Model Mech ; 17(4)2024 Apr 01.
Article in English | MEDLINE | ID: mdl-38691001

ABSTRACT

Ankyrin repeat and LEM domain-containing 2 (ANKLE2) is a scaffolding protein with established roles in cell division and development, the dysfunction of which is increasingly implicated in human disease. ANKLE2 regulates nuclear envelope disassembly at the onset of mitosis and its reassembly after chromosome segregation. ANKLE2 dysfunction is associated with abnormal nuclear morphology and cell division. It regulates the nuclear envelope by mediating protein-protein interactions with barrier to autointegration factor (BANF1; also known as BAF) and with the kinase and phosphatase that modulate the phosphorylation state of BAF. In brain development, ANKLE2 is crucial for proper asymmetric division of neural progenitor cells. In humans, pathogenic loss-of-function mutations in ANKLE2 are associated with primary congenital microcephaly, a condition in which the brain is not properly developed at birth. ANKLE2 is also linked to other disease pathologies, including congenital Zika syndrome, cancer and tauopathy. Here, we review the molecular roles of ANKLE2 and the recent literature on human diseases caused by its dysfunction.


Subject(s)
Nuclear Proteins , Humans , Nuclear Proteins/metabolism , Animals , Disease , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Mutation/genetics
9.
J Imaging Inform Med ; 2024 Apr 08.
Article in English | MEDLINE | ID: mdl-38587766

ABSTRACT

Automated segmentation tools often encounter accuracy and adaptability issues when applied to images of different pathology. The purpose of this study is to explore the feasibility of building a workflow to efficiently route images to specifically trained segmentation models. By implementing a deep learning classifier to automatically classify the images and route them to appropriate segmentation models, we hope that our workflow can segment the images with different pathology accurately. The data we used in this study are 350 CT images from patients affected by polycystic liver disease and 350 CT images from patients presenting with liver metastases from colorectal cancer. All images had the liver manually segmented by trained imaging analysts. Our proposed adaptive segmentation workflow achieved a statistically significant improvement for the task of total liver segmentation compared to the generic single-segmentation model (non-parametric Wilcoxon signed rank test, n = 100, p-value << 0.001). This approach is applicable in a wide range of scenarios and should prove useful in clinical implementations of segmentation pipelines.

10.
Int J Pharm ; 656: 124076, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38569976

ABSTRACT

Vaccines represent a pivotal health advancement for preventing infection. However, because carrier systems with repeated administration can invoke carrier-targeted immune responses that diminish subsequent immune responses (e.g., PEG antibodies), there is a continual need to develop novel vaccine platforms. Zinc carnosine microparticles (ZnCar MPs), which are composed of a one-dimensional coordination polymer formed between carnosine and the metal ion zinc, have exhibited efficacy in inducing an immune response against influenza. However, ZnCar MPs' limited suspendability hinders clinical application. In this study, we address this issue by mixing mannan, a polysaccharide derived from yeast, with ZnCar MPs. We show that the addition of mannan increases the suspendability of this promising vaccine formulation. Additionally, since mannan is an adjuvant, we illustrate that the addition of mannan increases the antibody response and T cell response when mixed with ZnCar MPs. Mice vaccinated with mannan + OVA/ZnCar MPs had elevated serum IgG and IgG1 levels in comparison to vaccination without mannan. Moreover, in the mannan + OVA/ZnCar MPs vaccinated group, mucosal washes demonstrated increased IgG, IgG1, and IgG2c titers, and antigen recall assays showed enhanced IFN-γ production in response to MHC-I and MHC-II immunodominant peptide restimulation, compared to the vaccination without mannan. These findings suggest that the use of mannan mixed with ZnCar MPs holds potential for subunit vaccination and its improved suspendability further promotes clinical translation.


Subject(s)
Carnosine , Mannans , Vaccines, Subunit , Zinc , Mannans/chemistry , Mannans/administration & dosage , Mannans/immunology , Animals , Vaccines, Subunit/administration & dosage , Vaccines, Subunit/immunology , Zinc/chemistry , Zinc/administration & dosage , Carnosine/administration & dosage , Carnosine/chemistry , Female , Immunoglobulin G/blood , Mice , Adjuvants, Immunologic/administration & dosage , Adjuvants, Immunologic/chemistry , Ovalbumin/immunology , Ovalbumin/administration & dosage , Mice, Inbred C57BL , Polymers/chemistry , Polymers/administration & dosage , Mice, Inbred BALB C , Drug Carriers/chemistry
11.
Clin Ther ; 46(4): 368-373, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38508915

ABSTRACT

PURPOSE: Hypertrophic cardiomyopathy (HCM) is an under-recognized genetic cardiac disorder affecting the muscles and contractility of the heart, which in turn can result in heart failure symptoms, arrhythmia, and sudden cardiac death. Previously, pharmacotherapy options for HCM were not disease-specific, often poorly tolerated, and overall inadequate for optimal management. This narrative review discusses the pharmacology of the novel drug mavacamten, the clinical trials supporting its use, and considerations for its use in clinical practice. METHODS: PubMed and ClinicalTrials.gov were searched for the key words mavacamten and Camzyos to identify currently active clinical trials and clinical trials published between January 2015 and March 2023. Data from EXPLORER-HCM were included, as EXPLORER-HCM led to approval by the US Food and Drug Administration of the use of mavacamten, along with data from VALOR-HCM, which provided additional evidence for use. Publications that were not randomized, controlled trials were not included in this review. FINDINGS: The findings from this review suggest that mavacamten is an effective treatment for patients with persistently symptomatic obstructive HCM and may decrease the need for septal reduction therapy. Mavacamten use was associated with improved exercise capacity, left ventricular outflow tract obstruction, and New York Heart Association functional class, and with a decreased frequency of septal reduction therapy. IMPLICATIONS: HCM is associated with significant morbidity and mortality, independent of other disease states. Mavacamten is a novel treatment option for patients with HCM and offers an additional option for patients with persistent symptoms who previously had limited treatment options. The use of mavacamten in patients with obstructive HCM may improve exercise capacity, and decrease symptoms and the need for septal reduction therapy. There is potential for mavacamten to be indicated for use in patients with nonobstructive HCM in the future, pending findings from Phase III trials in this population.


Subject(s)
Cardiomyopathy, Hypertrophic , Humans , Cardiomyopathy, Hypertrophic/drug therapy , Cardiomyopathy, Hypertrophic/physiopathology , Treatment Outcome , Clinical Trials as Topic , Benzylamines , Uracil/analogs & derivatives
12.
Neuroimage Clin ; 42: 103596, 2024.
Article in English | MEDLINE | ID: mdl-38554485

ABSTRACT

INTRODUCTION: Parkinson's disease (PD) and Dementia with Lewy bodies (DLB) show heterogeneous brain atrophy patterns which group-average analyses fail to capture. Neuroanatomical normative modelling overcomes this by comparing individuals to a large reference cohort. Patient-specific atrophy patterns are measured objectively and summarised to index overall neurodegeneration (the 'total outlier count'). We aimed to quantify patterns of neurodegenerative dissimilarity in participants with PD and DLB and evaluate the potential clinical relevance of total outlier count by testing its association with key clinical measures in PD and DLB. MATERIALS AND METHODS: We included 108 participants with PD and 61 with DLB. PD participants were subclassified into high and low visual performers as this has previously been shown to stratify those at increased dementia risk. We generated z-scores from T1w-MRI scans for each participant relative to normative regional cortical thickness and subcortical volumes, modelled in a reference cohort (n = 58,836). Outliers (z < -1.96) were aggregated across 169 brain regions per participant. To measure dissimilarity, individuals' Hamming distance scores were calculated. We also examined total outlier counts between high versus low visual performance in PD; and PD versus DLB; and tested associations between these and cognition. RESULTS: There was significantly greater inter-individual dissimilarity in brain-outlier patterns in PD poor compared to high visual performers (W = 522.5; p < 0.01) and in DLB compared to PD (W = 5649; p < 0.01). PD poor visual performers had significantly greater total outlier counts compared to high (ß = -4.73 (SE = 1.30); t = -3.64; p < 0.01) whereas a conventional group-level GLM failed to identify differences. Higher total outlier counts were associated with poorer MoCA (ß = -0.55 (SE = 0.27), t = -2.04, p = 0.05) and composite cognitive scores (ß = -2.01 (SE = 0.79); t = -2.54; p = 0.02) in DLB, and visuoperception (ß = -0.67 (SE = 0.19); t = -3.59; p < 0.01), in PD. CONCLUSIONS: Neuroanatomical normative modelling shows promise as a clinically informative technique in PD and DLB, where patterns of atrophy are variable.


Subject(s)
Atrophy , Lewy Body Disease , Magnetic Resonance Imaging , Neuroimaging , Parkinson Disease , Humans , Lewy Body Disease/diagnostic imaging , Lewy Body Disease/pathology , Parkinson Disease/diagnostic imaging , Parkinson Disease/pathology , Parkinson Disease/complications , Female , Male , Aged , Atrophy/pathology , Magnetic Resonance Imaging/methods , Middle Aged , Neuroimaging/methods , Aged, 80 and over , Brain/diagnostic imaging , Brain/pathology
13.
PLoS Biol ; 22(3): e3002573, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38547237

ABSTRACT

The rising interest and success in deploying inherited microorganisms and cytoplasmic incompatibility (CI) for vector control strategies necessitate an explanation of the CI mechanism. Wolbachia-induced CI manifests in the form of embryonic lethality when sperm from Wolbachia-bearing testes fertilize eggs from uninfected females. Embryos from infected females however survive to sustain the maternally inherited symbiont. Previously in Drosophila melanogaster flies, we demonstrated that CI modifies chromatin integrity in developing sperm to bestow the embryonic lethality. Here, we validate these findings using wMel-transinfected Aedes aegypti mosquitoes released to control vector-borne diseases. Once again, the prophage WO CI proteins, CifA and CifB, target male gametic nuclei to modify chromatin integrity via an aberrant histone-to-protamine transition. Cifs are not detected in the embryo, and thus elicit CI via the nucleoprotein modifications established pre-fertilization. The rescue protein CifA in oogenesis localizes to stem cell, nurse cell, and oocyte nuclei, as well as embryonic DNA during embryogenesis. Discovery of the nuclear targeting Cifs and altered histone-to-protamine transition in both Aedes aegypti mosquitoes and D. melanogaster flies affirm the Host Modification Model of CI is conserved across these host species. The study also newly uncovers the cell biology of Cif proteins in the ovaries, CifA localization in the embryos, and an impaired histone-to-protamine transition during spermiogenesis of any mosquito species. Overall, these sperm modification findings may enable future optimization of CI efficacy in vectors or pests that are refractory to Wolbachia transinfections.


Subject(s)
Aedes , Arboviruses , Wolbachia , Animals , Female , Male , Drosophila melanogaster/genetics , Histones/genetics , Mosquito Vectors , Semen , Drosophila/genetics , Chromatin , Protamines/genetics
14.
bioRxiv ; 2024 Mar 03.
Article in English | MEDLINE | ID: mdl-38463950

ABSTRACT

mRNA therapeutics offer a potentially universal strategy for the efficient development and delivery of therapeutic proteins. Current mRNA vaccines include chemically modified nucleotides to reduce cellular immunogenicity. Here, we develop an efficient, high-throughput method to measure human translation initiation on therapeutically modified as well as endogenous RNAs. Using systems-level biochemistry, we quantify ribosome recruitment to tens of thousands of human 5' untranslated regions and identify sequences that mediate 250-fold effects. We observe widespread effects of coding sequences on translation initiation and identify small regulatory elements of 3-6 nucleotides that are sufficient to potently affect translational output. Incorporation of N1-methylpseudouridine (m1Ψ) selectively enhances translation by specific 5' UTRs that we demonstrate surpass those of current mRNA vaccines. Our approach is broadly applicable to dissect mechanisms of human translation initiation and engineer more potent therapeutic mRNAs. Highlights: Measurement of >30,000 human 5' UTRs reveals a 250-fold range of translation outputSystematic mutagenesis demonstrates the causality of short (3-6nt) regulatory elementsN1-methylpseudouridine alters translation initiation in a sequence-specific mannerOptimal modified 5' UTRs outperform those in the current class of mRNA vaccines.

15.
Neuropsychol Rev ; 2024 Feb 26.
Article in English | MEDLINE | ID: mdl-38403731

ABSTRACT

Over the past decade, research using virtual reality and serious game-based instruments for assessing spatial navigation and spatial memory in at-risk and AD populations has risen. We systematically reviewed the literature since 2012 to identify and evaluate the methodological quality and risk of bias in the analyses of the psychometric properties of VRSG-based instruments. The search was conducted primarily in July-December 2022 and updated in November 2023 in eight major databases. The quality of instrument development and study design were analyzed in all studies. Measurement properties were defined and analyzed according to COSMIN guidelines. A total of 1078 unique records were screened, and following selection criteria, thirty-seven studies were analyzed. From these studies, 30 instruments were identified. Construct and criterion validity were the most reported measurement properties, while structural validity and internal consistency evidence were the least reported. Nineteen studies were deemed very good in construct validity, whereas 11 studies reporting diagnostic accuracy were deemed very good in quality. Limitations regarding theoretical framework and research design requirements were found in most of the studies. VRSG-based instruments are valuable additions to the current diagnostic toolkit for AD. Further research is required to establish the psychometric performance and clinical utility of VRSG-based instruments, particularly the instrument development, content validity, and diagnostic accuracy for preclinical AD screening scenarios. This review provides a straightforward synthesis of the state of the art of VRSG-based instruments and suggests future directions for research.

16.
Cytoskeleton (Hoboken) ; 81(8): 310-317, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38326972

ABSTRACT

Although diverse actin network architectures found inside the cell have been individually reconstituted outside of the cell, how different types of actin architectures reorganize under applied forces is not entirely understood. Recently, bottom-up reconstitution has enabled studies where dynamic and phenotypic characteristics of various actin networks can be recreated in an isolated cell-like environment. Here, by creating a giant unilamellar vesicle (GUV)-based cell model encapsulating actin networks, we investigate how actin networks rearrange in response to localized stresses applied by micropipette aspiration. We reconstitute actin bundles and branched bundles in GUVs separately and mechanically perturb them. Interestingly, we find that, when aspirated, protrusive actin bundles that are otherwise randomly oriented in the GUV lumen collapse and align along the axis of the micropipette. However, when branched bundles are aspirated, the network remains intact and outside of the pipette while the GUV membrane is aspirated into the micropipette. These results reveal distinct responses in the rearrangement of actin networks in a network architecture-dependent manner when subjected to physical forces.


Subject(s)
Actins , Unilamellar Liposomes , Actins/metabolism , Unilamellar Liposomes/metabolism , Actin Cytoskeleton/metabolism , Animals
17.
bioRxiv ; 2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38352492

ABSTRACT

Granulomas are defined by the presence of organized layers of immune cells that include macrophages. Granulomas are often characterized as a way for the immune system to contain an infection and prevent its dissemination. We recently established a mouse infection model where Chromobacterium violaceum induces the innate immune system to form granulomas in the liver. This response successfully eradicates the bacteria and returns the liver to homeostasis. Here, we sought to characterize the chemokines involved in directing immune cells to form the distinct layers of a granuloma. We use spatial transcriptomics to investigate the spatial and temporal expression of all CC and CXC chemokines and their receptors within this granuloma response. The expression profiles change dynamically over space and time as the granuloma matures and then resolves. To investigate the importance of monocyte-derived macrophages in this immune response, we studied the role of CCR2 during C. violaceum infection. Ccr2 -/- mice had negligible numbers of macrophages, but large numbers of neutrophils, in the C. violaceum-infected lesions. In addition, lesions had abnormal architecture resulting in loss of bacterial containment. Without CCR2, bacteria disseminated and the mice succumbed to the infection. This indicates that macrophages are critical to form a successful innate granuloma in response to C. violaceum.

18.
Microbiol Spectr ; 12(3): e0289723, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38294230

ABSTRACT

The rise in the frequency of antibiotic resistance has made bacterial infections, specifically Pseudomonas aeruginosa, a cause for greater concern. Phage therapy is a promising solution that uses naturally isolated phages to treat bacterial infections. Ecological limitations, which stipulate a discrete host range and the inevitable evolution of resistance, may be overcome through a better understanding of phage biology and the utilization of engineered phages. In this study, we developed a synthetic biology approach to construct tailed phages that naturally target clinically relevant strains of Pseudomonas aeruginosa. As proof of concept, we successfully cloned and assembled the JG024 and DMS3 phage genomes in yeast using transformation-associated recombination cloning and rebooted these two phage genomes in two different strains of P. aeruginosa. We identified factors that affected phage reboot efficiency like the phage species or the presence of antiviral defense systems in the bacterial strain. We have successfully extended this method to two other phage species and observed that the method enables the reboot of phages that are naturally unable to infect the strain used for reboot. This research represents a critical step toward the construction of clinically relevant, engineered P. aeruginosa phages.IMPORTANCEPseudomonas aeruginosa is a bacterium responsible for severe infections and a common major complication in cystic fibrosis. The use of antibiotics to treat bacterial infections has become increasingly difficult as antibiotic resistance has become more prevalent. Phage therapy is an alternative solution that is already being used in some European countries, but its use is limited by the narrow host range due to the phage receptor specificity, the presence of antiviral defense systems in the bacterial strain, and the possible emergence of phage resistance. In this study, we demonstrate the use of a synthetic biology approach to construct and reboot clinically relevant P. aeruginosa tailed phages. This method enables a significant expansion of possibilities through the construction of engineered phages for therapy applications.


Subject(s)
Bacterial Infections , Bacteriophages , Pseudomonas Infections , Pseudomonas Phages , Humans , Pseudomonas aeruginosa , Pseudomonas Phages/genetics , Synthetic Biology , Bacteriophages/genetics , Antiviral Agents
19.
Ocul Surf ; 32: 81-90, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38224775

ABSTRACT

Meibomian gland dysfunction (MGD) is a leading cause of dry eye disease and one of the most common ophthalmic conditions encountered in eye clinics worldwide. These holocrine glands are situated in the eyelid, where they produce specialized lipids, or meibum, needed to lubricate the eye surface and slow tear film evaporation - functions which are critical to preserving high-resolution vision. MGD results in tear instability, rapid tear evaporation, changes in local microflora, and dry eye disease, amongst other pathological entities. While studies identifying the mechanisms of MGD have generally focused on gland obstruction, we now know that age is a major risk factor for MGD that is associated with abnormal cell differentiation and renewal. It is also now appreciated that immune-inflammatory disorders, such as certain autoimmune diseases and atopy, may trigger MGD, as demonstrated through a T cell-driven neutrophil response. Here, we independently discuss the underlying roles of gland and immune related factors in MGD, as well as the integration of these two distinct mechanisms into a unified perspective that may aid future studies. From this unique standpoint, we propose a revised model in which glandular dysfunction and immunopathogenic pathways are not primary versus secondary contributors in MGD, but are fluid, interactive, and dynamic, which we likened to the Yin and Yang of MGD.


Subject(s)
Meibomian Gland Dysfunction , Meibomian Glands , Tears , Humans , Dry Eye Syndromes/immunology , Dry Eye Syndromes/physiopathology , Meibomian Gland Dysfunction/immunology , Meibomian Glands/immunology , Meibomian Glands/pathology , Meibomian Glands/metabolism , Tears/metabolism
20.
Int J Pharm ; 652: 123836, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38266940

ABSTRACT

The most common influenza vaccines are inactivated viruses produced in chicken eggs, which is a time-consuming production method with variable efficacy due to mismatches of the vaccine strains to the dominant circulating strains. Subunit-based vaccines provide faster production times in comparison to the traditional egg-produced vaccines but often require the use of an adjuvant to elicit a highly protective immune response. However, the current FDA approved adjuvant for influenza vaccines (MF59) elicits a primarily helper T-cell type 2 (Th2)-biased humoral immune response. Adjuvants that can stimulate a Th1 cellular response are correlated to have more robust protection against influenza. The cyclic dinucleotide cGAMP has been shown to provide a potent Th1 response but requires the use of a delivery vehicle to best initiate its signalling pathway in the cytosol. Herein, acetalated dextran (Ace-DEX) was used as the polymer to fabricate microparticles (MPs) via double-emulsion, electrospray, and spray drying methods to encapsulate cGAMP. This study compared each fabrication method's ability to encapsulate and retain the hydrophilic adjuvant cGAMP. We compared their therapeutic efficacy to Addavax, an MF59-like adjuvant, and cGAMP Ace-DEX MPs provided a stronger Th1 response in vaccinated BALB/c mice. Furthermore, we compared Ace-DEX MPs to spray dried MPs composed from a commonly used polymer for drug delivery, poly(lactic-co-glycolic acid) (PLGA). We observed that all Ace-DEX MPs elicited similar humoral and cellular responses to the PLGA MPs. Overall, the results shown here indicate Ace-DEX can perform similarly to PLGA as a polymer for drug delivery and that spray drying can provide an efficient way to produce MPs to encapsulate cGAMP and stimulate the immune system.


Subject(s)
Influenza Vaccines , Influenza, Human , Squalene , Animals , Mice , Humans , Dextrans , Polysorbates , Vaccines, Subunit , Adjuvants, Immunologic , Adjuvants, Pharmaceutic
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