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Objectives: Dysregulated RNA alternative splicing is the hallmark of myotonic dystrophy type 1 (DM1). However, the association between RNA mis-splicing and physical function in children with the most severe form of disease, congenital myotonic dystrophy (CDM), is unknown. Methods: 82 participants (42 DM1 adults & 40 CDM children) with muscle biopsies and measures of myotonia, motor function, and strength were combined from five observational studies. Data were normalized and correlated with an aggregate measure of alternative splicing dysregulation, [MBNL] inferred in skeletal muscle biopsies. Multiple linear regression analysis was performed to predict [MBNL] inferred using clinical outcome measures alone. Similar analyses were performed to predict 12-month physical function using baseline metrics. Results: Myotonia (measured via vHOT) was significantly correlated with RNA mis-splicing in our cross-sectional population of all DM1 individuals; CDM participants alone displayed no myotonia despite a similar range of RNA mis-splicing. Measures of motor performance and muscle strength were significantly associated with [MBNL] inferred in our cohort of all DM1 individuals and when assessing CDM children independently. Multiple linear regression analyses yielded two models capable of predicting [MBNL] inferred from select clinical outcome assessments alone in all subjects (adjusted R 2 = 0.6723) or exclusively in CDM children (adjusted R 2 = 0.5875). Interpretation: Our findings establish significant correlations between skeletal muscle performance and a composite measure of alternative splicing dysregulation, [MBNL] inferred, in DM1. The strength of these correlations and the development of the predictive models will assist in designing efficacious clinical trials for individuals with DM1, particularly CDM.
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BACKGROUND AND OBJECTIVES: To describe the neurobehavioral phenotype of congenital myotonic dystrophy. Congenital myotonic dystrophy (CDM) is the most severe form of myotonic dystrophy, characterized by symptom presentation at birth and later, cognitive impairment, autistic features, and disordered sleep. METHODS: The neurobehavioral phenotype was assessed in this cross-sectional study by a neuropsychological battery consisting of the Wechsler Preschool and Primary Scale of Intelligence, Third Edition, Weschler Intelligence Scale for Children, Fourth Edition, Vineland Adaptive Behavior Scale, Second Edition (Vineland-II), Behavior Rating Inventory of Executive Function including preschool and teacher reports, Autism Spectrum Screening Questionnaire, Social Communication Scale, and Repetitive Behavior Scale-Revised. Sleep quality was evaluated with the Pediatric Sleep Questionnaire and Pediatric Daytime Sleepiness Scale. RESULTS: Fifty-five children with CDM, ages 5 weeks to 14 years, were enrolled. The mean age and (CTG)n repeats (±SD) were 6.4 ± 3.8 years and 1,263 ± 432, respectively. The mean IQ was 64.1 ± 14.9 on the Weschler scales with 65.6% of participants falling in the extremely low range for IQ. Adaptive functioning was significantly low for 57.1% of participants (n = 20). Caregiver report of executive functioning indicated 23.1% (9/39) of participants had clinically elevated levels of dysfunction, though teacher report was discrepant and indicated 53.3% of participants with CDM fell in this range (8/15). Spearman correlations were strongly positive (p ≤ 0.05) for estimated full scale IQ, overall adaptive functioning and with daily living and socialization domain standard scores on the Vineland-II ranging from r = 0.719 to r = 0.849 for all ages. Aspects of executive function were directly related to features of autism and sleep quality. Social communication was inversely related to all aspects of daily functioning, except communication, and directly related to aspects of autism behavior. DISCUSSION: Depressed IQ, adaptive skills, and executive functioning, poor sleep quality, and features of autism and altered social functioning individually describe different aspects of the neurobehavioral phenotype in CDM. These neurobehavioral and sleep measures could help quantitatively measure and assess the burden of cognitive impairment in CDM.
Subject(s)
Autism Spectrum Disorder , Autistic Disorder , Myotonic Dystrophy , Child, Preschool , Infant, Newborn , Child , Humans , Myotonic Dystrophy/complications , Cross-Sectional Studies , Autism Spectrum Disorder/psychology , PhenotypeABSTRACT
Objective: This report summarizes the key discussions from the "Early Care (0-3 years) in Duchenne Muscular Dystrophy" meeting, which aimed to address the challenges and opportunities in the diagnosis and care of Duchenne muscular dystrophy (DMD) and female carriers within the 0-3-year age group. Methods: The meeting brought together experts and healthcare providers who shared insights, discussed advancements in DMD care, and identified research needs. Presentations covered diagnostic challenges, approved therapies, clinical trials, identification of young female carriers, and the importance of clinical care and support for families. Results: The meeting highlighted the importance of timely diagnosis and the lack of evidence-based guidelines for the care of children with DMD aged 0-3 years. Diagnostic challenges were discussed, including delays in receiving a DMD diagnosis and disparities based on ethnicity. The potential benefits and process of newborn screening were addressed.Approved therapeutic interventions, such as corticosteroids and exon-skipping drugs, were explored, with studies indicating the potential benefits of early initiation of corticosteroid therapy and the safety of exon-skipping drugs in DMD. Clinical trials involving infants and young boys were discussed, focusing on drugs like ataluren, vamorolone, and gene therapies.The meeting emphasized the importance of clinical care and support for families, including comprehensive information provision, early intervention services, and individualized support. The identification and care of young female carriers were also addressed. Conclusion: The meeting provided a platform for experts and healthcare providers to discuss and identify key aspects of early care for children with DMD aged 0-3 years. The meeting emphasized the need for early diagnosis, evidence-based guidelines, and comprehensive care and support for affected children and their families. Further research, collaboration, and the development of consensus guidelines are needed to improve early diagnosis, treatment, and outcomes in this population.
Subject(s)
Muscular Dystrophy, Duchenne , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Adrenal Cortex Hormones , Muscular Dystrophy, Duchenne/diagnosis , Muscular Dystrophy, Duchenne/therapy , Muscular Dystrophy, Duchenne/genetics , Neonatal ScreeningABSTRACT
BACKGROUND: We aim to describe 12-mo functional and motor outcome performance in a cohort of participants with congenital myotonic dystrophy (CDM). METHODS: CDM participants performed the 6 Minute Walk Test (6MWT), 10 Meter Run, 4 Stair Climb, Grip Strength, and Lip Force at baseline and 12-mo visits. Parents completed the Vineland Adaptive Behavior Scale. RESULTS: Forty-seven participants, aged 0 to 13 y old, with CDM were enrolled. 6MWT, 10 Meter Run, and 4 Stair Climb were completed in >85% of eligible participants. The only significant difference between mean baseline and 12-mo performance was an improvement in 6MWT in children 3-6 y old (P = .008). This age group also had the largest mean % improvement in performance in all other timed functional testing. In children >7 y, the slope of change on timed functional tests decreased or plateaued, with further reductions in performance in children ≥10 y. Participants with CTG repeat lengths <500 did not perform differently than those with repeat lengths >1000. CONCLUSIONS: The 6MWT, 10 Meter Run, and 4 Stair Climb were the most feasible measures. Our findings are consistent with the clinical profile and prior cross-sectional data, helping to establish reasonable expectations of functional trajectories in this population as well as identifying points in which therapeutic interventions may be best studied. Further study of outcomes in children >10 y old and <3 y is warranted, but this new information will assist planning of clinical trials in the CDM population.
Subject(s)
Activities of Daily Living , Motor Skills , Muscle Strength , Myotonic Dystrophy/physiopathology , Adolescent , Child , Child Development , Child, Preschool , Communication , Disease Progression , Female , Humans , Infant , Infant, Newborn , Male , Myotonic Dystrophy/genetics , Myotonin-Protein Kinase/genetics , Social Behavior , Trinucleotide Repeat Expansion , Walk TestABSTRACT
Purpose Verbs with low concreteness are frequent in discourse samples but rarely targeted in aphasia treatments for verbs. These verbs are an important part of functional communication, and recent studies have called for more research regarding aphasia and treatment stimuli with low concreteness. The aim of this study was to pilot the use of verbs with low concreteness in a novel sentence production intervention with persons with aphasia. Method The study took the form of a single-case experimental design with multiple baselines across behaviors and across participants. Three persons with chronic nonfluent aphasia and apraxia of speech participated in the study. Each participant received treatment designed to increase the semantic networks of verbs with high frequency and low concreteness. Sentence production was closely examined over the course of treatment for treated and untreated verbs of varying concreteness levels. Additional measures of language and cognitive functioning were also taken before and after treatment. Results Results indicated improved sentence production with target verbs attributable to the treatment in the 1st phase of 2 phases for 2 of the 3 participants. The increases corresponded with the application of treatment, despite the difference in number of baseline sessions for the participants. Where there were treatment effects, there was also considerable generalization to untreated sets of items during the 1st treatment phase. Word retrieval also improved for 2 participants. Conclusions The results suggest that the novel treatment may improve sentence production and word retrieval in persons with aphasia, even when using target verbs with low concreteness ratings. Future research is warranted into the use of low concreteness verbs. Supplemental Material https://doi.org/10.23641/asha.10870958.
Subject(s)
Aphasia, Broca/therapy , Aphasia/therapy , Language Therapy/methods , Adult , Aphasia/etiology , Female , Humans , Male , Middle Aged , Pilot Projects , Stroke/complications , Stroke/etiology , VocabularyABSTRACT
PURPOSE OF REVIEW: Myotonic dystrophy type 1 is a multisystemic disorder caused by a noncoding triplet repeat. The age of onset is variable across the lifespan, but in its most severe form, the symptoms appear at birth (congenital myotonic dystrophy) or in the pediatric age range (childhood-onset myotonic dystrophy). These children have a range of disabilities that reduce the lifespan and cause significant morbidity. Currently, there are no agreed upon recommendations for caring for these children. RECENT FINDINGS: The Myotonic Dystrophy Foundation recruited 11 international clinicians who are experienced with congenital and childhood-onset myotonic dystrophy to create consensus-based care recommendations. The experts used a 2-step methodology using elements of the single text procedure and nominal group technique. Completion of this process has led to the development of clinical care recommendations for this population. SUMMARY: Children with myotonic dystrophy often require monitoring and interventions to improve the lifespan and quality of life. The resulting recommendations are intended to standardize and improve the care of children with myotonic dystrophy.
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OBJECTIVE: This study explores the use of quantitative data on strength and fatigability of orofacial muscles in patients with facioscapulohumeral muscular dystrophy (FSHD) and assesses the frequency of swallowing and communication difficulties and their relationship to orofacial muscle involvement. METHODS: We included 43 patients with FSHD and 35 healthy controls and used the Iowa Oral Performance Instrument (IOPI) to obtain quantitative measurements of strength and endurance of lip compression, cheek (buccodental) compression, and tongue elevation. For the assessment of swallowing and communication difficulties, we used the dysphagia-specific quality of life (SWAL-QOL) and Communicative Participation Item Bank questionnaires. RESULTS: Cheek compression strength was reduced in patients with FSHD compared to healthy controls. Dysphagia and difficulty with verbal communication were reported by 25% and 35% of patients, respectively, and correlated to cheek compression strength and endurance and to anterior tongue elevation endurance. Prolonged cheek compression or anterior tongue elevation endurance (decreased fatigability) made swallowing or speech problems less likely to occur. CONCLUSION: Cheek compression strength is the most sensitive IOPI measure for orofacial weakness in FSHD. Orofacial weakness contributes to dysphagia and speech difficulties in FSHD, which are both common, though generally mild. Higher endurance of orofacial muscles was associated with a lower chance of dysphagia or speech problems. More research is required for further refinement of the pattern of facial muscle involvement in FSHD and to provide new insights for improvement of speech and language therapy.
Subject(s)
Deglutition Disorders/physiopathology , Facial Muscles/physiopathology , Muscle Weakness/physiopathology , Muscular Dystrophy, Facioscapulohumeral/physiopathology , Speech Disorders/physiopathology , Adult , Aged , Aged, 80 and over , Case-Control Studies , Communication , Deglutition , Deglutition Disorders/etiology , Female , Humans , Male , Middle Aged , Muscle Weakness/etiology , Muscular Dystrophy, Facioscapulohumeral/complications , Quality of Life , Speech , Speech Disorders/etiology , Speech Therapy , Young AdultABSTRACT
PURPOSE OF REVIEW: Myotonic dystrophy type 1 (DM1) is a severe, progressive genetic disease that affects between 1 in 3,000 and 8,000 individuals globally. No evidence-based guideline exists to inform the care of these patients, and most do not have access to multidisciplinary care centers staffed by experienced professionals, creating a clinical care deficit. RECENT FINDINGS: The Myotonic Dystrophy Foundation (MDF) recruited 66 international clinicians experienced in DM1 patient care to develop consensus-based care recommendations. MDF created a 2-step methodology for the project using elements of the Single Text Procedure and the Nominal Group Technique. The process generated a 4-page Quick Reference Guide and a comprehensive, 55-page document that provides clinical care recommendations for 19 discrete body systems and/or care considerations. SUMMARY: The resulting recommendations are intended to help standardize and elevate care for this patient population and reduce variability in clinical trial and study environments.
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INTRODUCTION: Herein we present an exploratory study of orofacial function in children with congenital myotonic dystrophy (CDM) vs. healthy controls. METHODS: We evaluated 41 children with CDM and 29 healthy controls for speech and swallow function and for lingual and labial strength. RESULTS: The Iowa Oral Performance Instrument (IOPI), measuring tongue strength, and a lip force meter (LFM), measuring lip strength, had excellent interrater reliability with intraclass correlation coefficients (ICCs) of 0.75 (n = 19, P < 0.001) and 0.96 (n = 20, P < 0.001), respectively. Mean overall lingual strength was 3.5-fold less and labial strength was about 7-fold less in CDM patients than in healthy controls. Eighteen of 24 children with CDM demonstrated dysarthria and an additional 11 participants were nonverbal. Dysarthria correlated moderately with lingual strength, age, and dysphagia. Strength measures correlated moderately with dysphagia. DISCUSSION: Children with CDM have impaired orofacial functioning that affects communication and swallowing. Reliability of strength measures may be useful for future therapeutic trials. Muscle Nerve 58: 413-417, 2018.
Subject(s)
Deglutition Disorders/physiopathology , Dysarthria/physiopathology , Facial Muscles/physiopathology , Muscle Strength/physiology , Myotonic Dystrophy/physiopathology , Adolescent , Child , Child, Preschool , Deglutition Disorders/diagnosis , Dysarthria/diagnosis , Female , Humans , Infant , Lip/physiopathology , Male , Myotonic Dystrophy/diagnosis , Tongue/physiopathologyABSTRACT
While coagulation often causes pathology during infectious disease, we recently demonstrated that fibrin, a product of the coagulation pathway, performs a critical protective function during acute toxoplasmosis (L. L. Johnson, K. N. Berggren, F. M. Szaba, W. Chen, and S. T. Smiley, J. Exp. Med. 197:801-806, 2003). Here, we investigate the mechanisms regulating the formation of this protective fibrin. Through comparisons of Toxoplasma-infected wild-type and cytokine-deficient mice we dissociate, for the first time, the relative fibrin-regulating capacities of pathogen products, host cytokines, and infection-stimulated hemorrhage. Remarkably, neither the pathogen burden nor hemorrhage is a primary regulator of fibrin levels. Rather, two type 1 cytokines exert dominant and counterregulatory roles: tumor necrosis factor alpha (TNF-alpha), acting via the type 1 TNF-alpha receptor, promotes fibrin deposition, while gamma interferon (IFN-gamma), acting via STAT1 and IFN-gamma receptors expressed on radioresistant cells, suppresses fibrin deposition. These findings have important clinical implications, as they establish that cytokines known to regulate pathological coagulation also dictate levels of protective fibrin deposition. We present a novel model depicting mechanisms by which the immune system can destroy infected tissue while independently restraining hemorrhage and promoting tissue repair through the deliberate deposition of protective fibrin.
Subject(s)
Fibrin/metabolism , Gene Expression Regulation/immunology , Interferon-gamma/metabolism , Toxoplasma/pathogenicity , Toxoplasmosis/immunology , Tumor Necrosis Factor-alpha/metabolism , Acute Disease , Animals , Fibrin/immunology , Hemorrhage/pathology , Humans , Mice , Mice, Inbred C57BL , Toxoplasma/isolation & purification , Toxoplasmosis/parasitology , Toxoplasmosis/pathologyABSTRACT
Pulmonary infection with the bacterium Yersinia pestis causes pneumonic plague, an often-fatal disease for which no vaccine is presently available. Antibody-mediated humoral immunity can protect mice against pulmonary Y. pestis infection, an experimental model of pneumonic plague. Little is known about the protective efficacy of cellular immunity. We investigated the cellular immune response to Y. pestis in B-cell-deficient microMT mice, which lack the capacity to generate antibody responses. To effectively prime pulmonary cellular immunity, we intranasally vaccinated microMT mice with live replicating Y. pestis. Vaccination dramatically increased survival of microMT mice challenged intranasally with a lethal Y. pestis dose and significantly reduced bacterial growth in pulmonary, splenic, and hepatic tissues. Vaccination also increased numbers of pulmonary T cells, and administration of T-cell-depleting monoclonal antibodies at the time of challenge abrogated vaccine-induced survival. Moreover, the transfer of Y. pestis-primed T cells to naive microMT mice protected against lethal intranasal challenge. These findings establish that vaccine-primed cellular immunity can protect against pulmonary Y. pestis infection and suggest that vaccines promoting both humoral and cellular immunity will most effectively combat pneumonic plague.
Subject(s)
Immunity, Cellular/immunology , Plague Vaccine/immunology , Plague/immunology , Plague/prevention & control , Yersinia pestis/immunology , Adoptive Transfer , Animals , Antibodies, Bacterial , B-Lymphocytes , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/cytology , CD8-Positive T-Lymphocytes/immunology , Lung/immunology , Lung/microbiology , Lung/pathology , Lymphocyte Count , Mice , Mice, Inbred C57BL , Plague/microbiology , VaccinationABSTRACT
Bacterial infections are major causes of human mortality. The activation of coagulation pathways leading to the deposition of insoluble fibrin frequently accompanies bacterial infection, and much attention has focused upon the pathological attributes of infection-stimulated fibrin deposition. Nevertheless, here we present conclusive evidence that infection-stimulated fibrin deposition can perform critical protective functions during bacterial infection. Specifically, we demonstrate that coagulation-impaired fibrin(ogen)-deficient mice, in comparison with genetically matched control mice, display increased mortality upon peritoneal infection with the gram-positive facultative intracellular bacterium Listeria monocytogenes. To distinguish effects of fibrinogen from those of fibrin, we treat wild-type mice with warfarin, an anticoagulant that suppresses fibrin formation without impacting fibrinogen levels. Warfarin treatment exacerbates listeriosis, suggesting that fibrin is the key mediator of protection. With regard to the underlying protective mechanisms, we demonstrate that fibrin(ogen) suppresses anemia, reduces hemorrhagic pathology, and limits bacterial growth during listeriosis. Despite confirming a prior report that fibrin(ogen) promotes the peritoneal clearance of the extracellular bacterium Staphylococcal aureus, we demonstrate that fibrin(ogen) plays little role in controlling peritoneal numbers of L. monocytogenes bacteria or the dissemination of L. monocytogenes bacteria from the peritoneal cavity. Rather, fibrin(ogen) primarily limits the growth of these intracellular bacteria within hepatic tissue. While the pathological potential of excessive infection-stimulated fibrin deposition is well appreciated, our findings reveal that fibrin can function protectively, via multiple mechanisms, during bacterial infection.
Subject(s)
Fibrin/physiology , Hemorrhage/prevention & control , Listeria monocytogenes/growth & development , Listeriosis/blood , Liver/microbiology , Animals , Interferon-gamma/genetics , Listeriosis/immunology , Listeriosis/microbiology , Mice , Mice, Inbred C57BL , Nitric Oxide Synthase/genetics , Nitric Oxide Synthase Type II , RNA, Messenger/analysis , Tumor Necrosis Factor-alpha/geneticsABSTRACT
Pneumonic plague, an often-fatal disease for which no vaccine is presently available, results from pulmonary infection by the bacterium Yersinia pestis. The Y. pestis V protein is a promising vaccine candidate, as V protein immunizations confer to mice significant protection against aerosolized Y. pestis. CD4 T cells play central roles during vaccine-primed immune responses, but their functional contributions to Y. pestis vaccines have yet to be evaluated and optimized. Toward that end, we report here the identification of three distinct epitopes within the Y. pestis V protein that activate CD4 T cells in C57BL/6 mice. To our knowledge, these are the first identified CD4 T-cell epitopes in any Y. pestis protein. The epitopes are restricted by the I-A(b) class II major histocompatibility complex molecule and are fully conserved between Y. pestis, Yersinia pseudotuberculosis, and Yersinia enterocolitica. Immunizing mice with a V protein-containing vaccine or with short peptides containing the identified epitopes primes antigen-specific production of interleukin 2 and gamma interferon by CD4 T cells upon their restimulation in vitro. Consistent with prior studies documenting protective roles for CD4 T cells during Y. enterocolitica infection, vaccinating mice with a 16-amino-acid peptide encoding one of the epitopes suffices to protect against an otherwise lethal Y. enterocolitica challenge. The identification of these epitopes will permit quantitative assessments of V-specific CD4 T cells, thereby enabling researchers to evaluate and optimize the contribution of these cells to vaccine-primed protection against pneumonic plague.
Subject(s)
Antigens, Bacterial/immunology , CD4-Positive T-Lymphocytes/immunology , Epitopes, T-Lymphocyte , Yersinia pestis/immunology , Amino Acid Sequence , Animals , Immunization , Interferon-gamma/biosynthesis , Male , Mice , Mice, Inbred C57BL , Molecular Sequence Data , Plague Vaccine/immunology , Pore Forming Cytotoxic Proteins , Yersinia pseudotuberculosis Infections/prevention & controlABSTRACT
Fibrinogen-like protein 2 (Fgl2, fibroleukin) is a leukocyte product that exhibits significant homology to secreted proteins of diverse function, including growth factors, lectins, and components of extracellular matrix. Prior studies found that Fgl2 is IFN gamma-inducible, possesses direct coagulant activity, and inhibits T cell proliferation and dendritic cell maturation in vitro. Here, we demonstrate that Fgl2 expression is up-regulated during type 1 immunity in vivo and establish that such up-regulation is IFN gamma-, signal transducer and activation of transcription protein 1-, and IFN response factor 1-dependent. To investigate functional roles for Fgl2 during type 1 immunity, we generated Fgl2-deficient mice. Those animals are born at predicted Mendelian frequencies, appear overtly healthy, and contain normal numbers and frequencies of lymphoid cells. Although Fgl2 is IFN gamma-inducible and putatively regulates T cell activation/proliferation, we demonstrate that Fgl2-deficient and control mice exhibit similar degrees of T cell expansion, immunopathology, and/or pathogen burdens during protozoan (Toxoplasma gondii), bacterial (Yersinia enterocolitica, Listeria monocytogenes, and Mycobacterium tuberculosis), and viral (murine gamma-herpesvirus-68 and Sendai) infections. Fgl2-deficient mice also reject allografts with similar kinetics as control mice. Moreover, despite prior reports that Fgl2 functions as a procoagulant enzyme, we demonstrate that Fgl2-deficient and control mice produce similar levels of fibrin, a product of the coagulation cascade, during T. gondii infection and allograft rejection. Together, our findings suggest that Fgl2, although highly conserved and IFN gamma-inducible, is not a critical mediator of either type 1 immunity or immune-associated coagulant activity.
Subject(s)
Interferon-gamma/immunology , T-Lymphocytes/immunology , Animals , Bacterial Infections/immunology , Blood Coagulation/immunology , DNA Primers , Disease Models, Animal , Fibrin/immunology , Heart Transplantation/immunology , Lymphocyte Activation , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Knockout , RNA, Messenger/genetics , Toxoplasmosis/immunology , Transplantation, Homologous , Virus Diseases/immunologyABSTRACT
Fibrin, a product of the blood coagulation cascade, accompanies many type 1 immune responses, including delayed-type hypersensitivity, autoimmunity, and graft rejection. In those settings, fibrin is thought to exacerbate inflammation and disease. Here, we evaluate roles for coagulation during infection with Toxoplasma gondii, a pathogen whose control requires robust type 1 immunity. We establish that fibrin prevents infection-stimulated blood loss, thereby performing a protective function that is essential for survival. Remarkably, fibrin does not simply protect against vascular damage caused directly by the infectious agent, but rather, protects against hemorrhage evoked by interferon-gamma, a critical mediator of type 1 immunity. This finding, to our knowledge, is the first to document a beneficial role for coagulation during type 1 immunity, and suggests that fibrin deposition protects host tissue from collateral damage caused by the immune system as it combats infection.
Subject(s)
Blood Coagulation/physiology , Fibrin/metabolism , Immunity/physiology , Toxoplasma/immunology , Toxoplasmosis/immunology , Animals , Fibrin/genetics , Fibrin/immunology , Interferon-gamma/metabolism , Liver/metabolism , Liver/parasitology , Liver/pathology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Survival RateABSTRACT
SYPRO Ruby protein gel stain is compatible with a variety of imaging platforms since it absorbs maximally in the ultraviolet (280 nm) and visible (470 nm) regions of the spectrum. Dye localization is achieved by noncovalent, electrostatic and hydrophobic binding to proteins, with signal being detected at 610 nm. Since proteins are not covalently modified by the dye, compatibility with downstream proteomics techniques such as matrix-assisted laser desorption/ionisation-time of flight mass spectrometry is assured. The principal limitation of the original formulation of SYPRO Ruby protein gel stain, is that it was only compatible with a limited number of gel fixation procedures. Too aggressive a fixation protocol led to diminished signal intensity and poor detection sensitivity. This is particularly apparent when post-staining gels subjected to labeling with other fluorophores such as Schiff's base staining of glycoproteins with fluorescent hydrazides. Consequently, we have developed an improved formulation of SYPRO Ruby protein gel stain that is fully compatible with commonly implemented protein fixation procedures and is suitable for post-staining gels after detection of glycoproteins using the green fluorescent Pro-Q Emerald 300 glycoprotein stain or detection of beta-glucuronidase using the green fluorescent ELF 97 beta-D-glucuronide. The new stain formulation is brighter, making it easier to manually excise spots for peptide mass profiling. An additional benefit of the improved formulation is that it permits staining of proteins in isoelectric focusing gels, without the requirement for caustic acids.