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1.
Clin Pract Cases Emerg Med ; 8(3): 254-258, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39158244

RESUMEN

Introduction: Diagnosing deep venous thromboses and venous thromboemboli (DVT/VTE) in pregnant patients presents a unique challenge for emergency physicians. The risk of DVT/VTE increases during pregnancy, and the potential consequences of misdiagnoses are severe. Point-of-care ultrasonography (POCUS) is frequently a first-line diagnostic imaging modality. However, recent studies have shown a high incidence of thromboses proximal to the common femoral vein during pregnancy, and these would not be visualized using compressive ultrasonography, which traditionally can only visualize thromboses distal to the femoral vein. Case Report: A 38-year-old female, 25-weeks primiparous, presented to the emergency department with a three-day history of left lower extremity swelling. Point-of-care three-point compression testing was used to evaluate for a DVT; however, no thrombus was visualized. Given high clinical suspicion, color and spectral Doppler testing were performed and demonstrated turbulent flow and reduced respiratory variation in the common femoral vein. This prompted further additional testing for a proximal DVT using magnetic resonance venography, which revealed an occlusive left external iliac thrombus. The patient was subsequently started on daily subcutaneous enoxaparin and discharged home with close follow-up. Conclusion: Emergency physicians play a critical role in evaluations for the presence of DVT/VTE, particularly in pregnant patients. We endorse the use of POCUS with three-point compression testing, as well as color and spectral Doppler imaging, to help identify proximal DVTs in this patient population. This case report can aid physicians in the diagnosis of this pathological condition that if left untreated can have severe consequences.

2.
J Am Coll Emerg Physicians Open ; 5(4): e13228, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38975017

RESUMEN

Background: In emergency department (ED) patients with renal impairment, troponin concentrations can be positive without myocardial ischemia. When there is clinical concern for acute coronary syndrome (ACS), guidelines recommend obtaining a delta troponin measurement to identify acute myocardial injury. However, evidence supporting the use of delta troponin to rule in or out ACS in patients with renal impairment and initial elevated troponin levels is limited. Methods: This retrospective, observational study assessed the diagnostic value of a 20% delta troponin cutoff in the prediction of ACS events in ED patients (estimated glomerular filtration rate [eGFR] <60 mL/min/1.72 m2) with renal impairment, clinical concern for ACS, and an initial positive troponin concentration using either conventional troponin (cTnT) or high-sensitivity troponin (hsTnT). Clinical concern for ACS was based on initial ED physician-reported diagnoses. Patients with an initial diagnosis of ST-elevation myocardial infarction were not included. A positive initial troponin was identified at a threshold of ≥0.06 ng/mL for cTnT and ≥52 ng/L for hsTnT, and delta troponin measurements were obtained within 24 h of the initial troponin. The primary composite outcome, termed ACS event, included (1) cardiac-related mortality, (2) coronary revascularization (or its recommendation), or a (3) clinically diagnosed type-1 myocardial infarction within 6 weeks of the ED presentation. Sensitivities, specificities, negative predictive values, positive predictive values, and negative and positive likelihood ratios were calculated for these 6-week ACS events. Results: A total of 608 ED patients with renal impairment, an initial positive troponin, and clinical concern for ACS were included in the study. Of these patients, 234 had an initial positive cTnT (median eGFR 18 mL/min/1.72 m2) and 374 had an initial positive hsTnT (median eGFR 25 mL/min/1.72 m2). The overall ACS event rate was 38% in the cTnT group and 33% in the hsTnT group. In those with a negative delta, the 6-week ACS event rate was 32% when using cTnT, compared to 24% using hsTnT. Conversely, a positive delta was associated with an ACS event rate of 47% when cTnT was utilized versus 61% when hsTnT was utilized. Conclusion: In this study, approximately one-third of ED patients with renal impairment who had an initial positive troponin and clinical concern for ACS developed ACS events at 6 weeks. A delta troponin did not appear to provide clinically meaningful assistance in the prediction or exclusion of 6-week ACS events in this cohort.

3.
4.
Front Immunol ; 14: 1227633, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37727784

RESUMEN

Restoration of immunological tolerance to self antigens has been a major drive in understanding the mechanisms of, and developing new treatments for, autoimmune and autoinflammatory disease. Sessile dendritic cells (DC) are considered the main instruments underpinning immunological tolerance particularly the CD205+ (DEC205+) cDC1 subset in contrast to DCIR2+ cDC2 which mediate immunogenicity. Targeting DC using autoantigen peptide-antibody fusion proteins has been a well explored methodology for inducing tolerance. Here we show that subcutaneous (s.c.) inoculation of hen-egg lysozyme (HEL)-DEC205 Ig fusion prevents the development of spontaneous uveoretinitis (experimental autoimmune uveoretinitis, EAU) in a transgenic mouse model generated by crossing interphotoreceptor retinol binding protein (IRBP)-HEL (sTg HEL) with HEL specific TCR (sTg TCR) mice. Prolonged suppression of EAU required injections of HEL-DEC205 Ig once weekly, reflecting the half life of s.c. DC. Interestingly, HEL-DCIR2 Ig also had a suppressive effect on development of EAU but less so than DEC205 Ig while it had minimal effect on preventing the retinal atrophy associated with EAU. In addition, HEL-DEC205 Ig was only effective when administered s.c. rather than systemically and had no effect on EAU induced by adoptive transfer of HEL-activated T cells. These data demonstrate the importance of systemic (lymph node) rather than local (eye) antigen presentation in the development of EAU as well as suggest a potential therapeutic approach to controlling sight-threatening immune-mediated uveitis provided relevant antigen(s) can be identified.


Asunto(s)
Anticuerpos , Autoantígenos , Animales , Ratones , Traslado Adoptivo , Células Dendríticas , Receptores de Antígenos de Linfocitos T
5.
Am J Ophthalmol ; 246: 31-41, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36087765

RESUMEN

PURPOSE: To compare antigen-specific intraocular immune responses between different clinical phenotypes of tuberculin skin test (TST)-positive and TST-negative uveitis. DESIGN: Single center, retrospective cross-sectional study. METHODS: Patients requiring diagnostic or therapeutic vitrectomy for the management of intraocular inflammation were divided into 3 groups based on Standardization of Uveitis Nomenclature (SUN) classification criteria for tubercular uveitis. Group 1 included patients with ocular tuberculosis (OTB; n = 23) who were TST-positive patients, met the SUN criteria, and/or had a polymerase chain reaction (PCR)-positive test for TB. Group 2 included patients with uveitis of unknown origin (UNK; n = 24) who were undifferentiated TST-positive patients who had not met SUN criteria. Group 3 included non-TB uveitis patients (n = 24) who were TST-negative either with or without a well-defined non-TB diagnosis. Total vitreous cells were activated with Mycobacterium tuberculosis-specific Early Secreted Antigenic Target-6 (ESAT-6) or the retinal autoantigen, interphotoreceptor retinoid-binding protein peptide (pIRBP 1-20), stained for intracellular interferon gamma (IFNγ), tumor necrosis factor-alfa (TNFα), and interleukin 17 (IL-17), and analyzed by flow cytometry. Antigen-specific single and dual (polyfunctional) cytokine responses to ESAT-6 and IRBP were compared between the 3 groups. RESULTS: All cytokine responses to ESAT-6 were higher in the UNK group compared with the non-TB control subjects, while all except IL-17 were comparable between the OTB and non-TB groups. Polyfunctional responses-IFNγ/IL-17 (P = .002), TNFα/IL-17 (P = .02), and TNFα/IFNγ (P = .01)-were significantly greater for UNK than the OTB group. Polyfunctional cells also produced more cytokine per cell than respective monofunctional cells. IRBP cytokine responses were comparable between different groups and were not affected by the clinical phenotype or duration of disease. CONCLUSION: The intraocular polyfunctional cytokine response is stronger in undifferentiated TST-positive uveitis than in OTB patients, likely representing an exaggerated anti-TB immune response rather than active infection.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Ocular , Tuberculosis , Uveítis , Humanos , Citocinas/metabolismo , Factor de Necrosis Tumoral alfa , Tuberculosis Ocular/diagnóstico , Interleucina-17 , Estudios Retrospectivos , Estudios Transversales , Tuberculosis/diagnóstico , Uveítis/diagnóstico , Prueba de Tuberculina
6.
Front Immunol ; 13: 1054260, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36518752

RESUMEN

Herpes stromal keratitis (HSK) is a blinding corneal disease caused by herpes simplex virus-1 (HSV-1), a common pathogen infecting most of the world's population. Inflammation in HSK is chemokine-dependent, particularly CXCL10 and less so the CC chemokines. The atypical chemokine receptor-2 (ACKR2) is a decoy receptor predominantly for pro-inflammatory CC chemokines, which regulates the inflammatory response by scavenging inflammatory chemokines thereby modulating leukocyte infiltration. Deletion of ACKR2 exacerbates and delays the resolution of the inflammatory response in most models. ACKR2 also regulates lymphangiogenesis and mammary duct development through the recruitment of tissue-remodeling macrophages. Here, we demonstrate a dose-dependent upregulation of ACKR2 during corneal HSV-1 infection. At an HSV inoculum dose of 5.4 x 105 pfu, but not at higher dose, ACKR2 deficient mice showed prolonged clinical signs of HSK, increased infiltration of leukocytes and persistent corneal neovascularization. Viral clearance and T cell activation were similar in ACKR2-/- and wild type mice, despite a transient diminished expression of CD40 and CD86 in dendritic cells. The data suggest that ACKR2 fine-tunes the inflammatory response and the level of neovascularization in the HSK.


Asunto(s)
Queratitis Herpética , Receptores de Quimiocina , Animales , Ratones , Quimiocina CXCL10 , Quimiocinas CC , Activación de Linfocitos , Ratones Endogámicos C57BL , Receptores de Quimiocina/metabolismo , Queratitis Herpética/inmunología , Neovascularización de la Córnea/inmunología , Neovascularización de la Córnea/virología
7.
Artículo en Inglés | MEDLINE | ID: mdl-38983514

RESUMEN

The microenvironment of the CNS (eye and brain) is fertile ground for infection if the barriers are breached. The result of pathogen invasion is often devastating destruction of tissues. In the eye, inflammation is broadly classified either as "infectious" (i.e. caused by infection) or "non-infectious". However, increasingly, forms of intraocular inflammation (IOI), which clinically appear to be "non-infectious" turn out to be initiated by infectious agents, suggesting that pathogens have been retained in latent or persistent form within ocular tissues and have reactivated to cause overt disease. A similar pathogenesis applies to latent infections in the brain. Not all CNS tissues provide an equally protective niche while different pathogens escape detection using different strategies. This review summarises how immune privilege (IP) in the CNS may be permissive for latent infection and allow the eye and the brain to act as a reservoir of pathogens which often remain undetected for the lifetime of the host but in states of immune deficiency may be activated to cause sight- and life-threatening inflammation.

8.
BMJ Paediatr Open ; 5(1): e001116, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34660912

RESUMEN

Direct risk from infection from COVID-19 for children and young people (CYP) is low, but impact on services, education and mental health (so-called collateral damage) appears to have been more significant. In North Central London (NCL) during the first wave of the pandemic, in response to the needs and demands for adults with COVID-19, general paediatric wards in acute hospitals and some paediatric emergency departments were closed. Paediatric mental health services in NCL mental health services were reconfigured. Here we describe process and lessons learnt from a collaboration between physical and mental health services to provide care for CYP presenting in mental health crisis. Two new 'hubs' were created to coordinate crisis presentations in the region and to link community mental health teams with emergency departments. All CYP requiring a paediatric admission in the first wave were diverted to Great Ormond Street Hospital, a specialist children's hospital in NCL, and a new ward for CYP mental health crisis admissions was created. This brought together a multidisciplinary team of mental health and physical health professionals. The most common reason for admission to the ward was following a suicide attempt (n=17, 43%). Patients were of higher acute mental health complexity than usually admitted to the hospital, with some CYP needing an extended period of assessment. In this review, we describe the challenges and key lessons learnt for the development of this new ward setting that involved such factors as leadership, training and also new governance processes. We also report some personal perspectives from the professionals involved. Our review provides perspective and experience that can inform how CYP with mental health admissions can be managed in paediatric medical settings.


Asunto(s)
COVID-19 , Pandemias , Adolescente , Adulto , Niño , Humanos , Londres/epidemiología , Salud Mental , Pandemias/prevención & control , SARS-CoV-2
9.
J Immunol Res ; 2021: 9998200, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34104654

RESUMEN

The microbiome exerts considerable control over immune homeostasis and influences susceptibility to autoimmune and autoinflammatory disease (AD/AID) such as inflammatory bowel disease (IBD), multiple sclerosis (MS), type 1 diabetes (T1D), psoriasis, and uveitis. In part, this is due to direct effects of the microbiome on gastrointestinal (GI) physiology and nutrient transport, but also to indirect effects on immunoregulatory controls, including induction and stabilization of T regulatory cells (T reg). Secreted bacterial metabolites such as short-chain fatty acids (SCFA) are under intense investigation as mediators of these effects. In contrast, folate (vitamin B9), an essential micronutrient, has attracted less attention, possibly because it exerts global physiological effects which are difficult to differentiate from specific effects on the immune system. Here, we review the role of folate in AD/AID with some emphasis on sight-threatening autoimmune uveitis. Since folate is required for the generation and maintenance of T reg , we propose that one mechanism for microbiome-based control of AD/AID is via folate-dependent induction of GI tract T reg , particularly colonic T reg, via anergic T cells (T an). Hence, folate supplementation has potential prophylactic and/or therapeutic benefit in AID/AD.


Asunto(s)
Enfermedades Autoinmunes/inmunología , Autoinmunidad , Ácido Fólico/metabolismo , Microbioma Gastrointestinal/inmunología , Inflamación/inmunología , Animales , Enfermedades Autoinmunes/dietoterapia , Enfermedades Autoinmunes/metabolismo , Enfermedades Autoinmunes/microbiología , Modelos Animales de Enfermedad , Ácido Fólico/administración & dosificación , Humanos , Inflamación/dietoterapia , Inflamación/metabolismo , Inflamación/microbiología , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiología , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo
10.
Cells ; 10(1)2020 12 25.
Artículo en Inglés | MEDLINE | ID: mdl-33375578

RESUMEN

Non-infectious uveitis is considered an autoimmune disease responsible for a significant burden of blindness in developed countries and recent studies have linked its pathogenesis to dysregulation of the gut microbiota. We tested the immunomodulatory properties of two probiotics, Escherichia coli Nissle 1917 (EcN) and E. coli O83:K24:H31 (EcO), in a model of experimental autoimmune uveitis (EAU). To determine the importance of bacterial viability and treatment timing, mice were orally treated with live or autoclaved bacteria in both preventive and therapeutic schedules. Disease severity was assessed by ophthalmoscopy and histology, immune phenotypes in mesenteric and cervical lymph nodes were analyzed by flow cytometry and the gut immune environment was analyzed by RT-PCR and/or gut tissue culture. EcN, but not EcO, protected against EAU but only as a live organism and only when administered before or at the time of disease induction. Successful prevention of EAU was accompanied by a decrease in IRBP-specific T cell response in the lymph nodes draining the site of immunization as early as 7 days after the immunization and eye-draining cervical lymph nodes when the eye inflammation became apparent. Furthermore, EcN promoted an anti-inflammatory response in Peyer's patches, increased gut antimicrobial peptide expression and decreased production of inducible nitric oxide synthase in macrophages. In summary, we show here that EcN controls inflammation in EAU and suggest that probiotics may have a role in regulating the gut-eye axis.


Asunto(s)
Enfermedades Autoinmunes/terapia , Escherichia coli , Inflamación/terapia , Probióticos , Uveítis/terapia , Animales , Modelos Animales de Enfermedad , Femenino , Mucosa Intestinal/patología , Ratones , Ratones Endogámicos C57BL , Probióticos/administración & dosificación , Probióticos/farmacología
11.
Front Immunol ; 11: 583687, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33240272

RESUMEN

Inflammation is central to pathogenic processes in diabetes mellitus and the metabolic syndrome and particularly implicates innate immunity in the development of complications. Inflammation is a primary event in Type 1 diabetes where infectious (viral) and/or autoimmune processes initiate disease; in contrast, chronic inflammation is typical in Type 2 diabetes and is considered a sequel to increasing insulin resistance and disturbed glucose metabolism. Diabetic retinopathy (DR) is perceived as a vascular and neurodegenerative disease which occurs after some years of poorly controlled diabetes. However, many of the clinical features of DR are late events and reflect the nature of the retinal architecture and its cellular composition. Retinal microvascular disease is, in fact, an early event pathogenetically, induced by low grade, persistent leukocyte activation which causes repeated episodes of capillary occlusion and, progressive, attritional retinal ischemia. The later, overt clinical signs of DR are a consequence of the retinal ischemia. Metabolic dysregulation involving both lipid and glucose metabolism may lead to leukocyte activation. On a molecular level, we have shown that macrophage-restricted protein tyrosine phosphatase 1B (PTP1B) is a key regulator of inflammation in the metabolic syndrome involving insulin resistance and it is possible that PTP1B dysregulation may underlie retinal microvascular disease. We have also shown that adherent CCR5+CD11b+ monocyte macrophages appear to be selectively involved in retinal microvascular occlusion. In this review, we discuss the relationship between early leukocyte activation and the later features of DR, common pathogenetic processes between diabetic microvascular disease and other vascular retinopathies, the mechanisms whereby leukocyte activation is induced in hyperglycemia and dyslipidemia, the signaling mechanisms involved in diabetic microvascular disease, and possible interventions which may prevent these retinopathies. We also address a possible role for adaptive immunity in DR. Although significant improvements in treatment of DR have been made with intravitreal anti-VEGF therapy, a sizeable proportion of patients, particularly with sight-threatening macular edema, fail to respond. Alternative therapies targeting inflammatory processes may offer an advantage.


Asunto(s)
Retinopatía Diabética/patología , Inflamación/patología , Animales , Humanos , Leucocitos/patología , Macrófagos/patología , Monocitos/patología , Retina/patología
12.
Front Immunol ; 11: 2071, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33013877

RESUMEN

We specify the clinical features of a spontaneous experimental autoimmune uveitis (EAU) model, in which foreign hen-egg lysozyme (HEL) is expressed in the retina, controlled by the promoter for interphotoreceptor retinol binding protein (IRBP). We previously reported 100% P21 (post-partum day) IRBP:HEL single transgenic (sTg) mice, when crossed to transgenic T cell receptor mice (3A9) generating the double transgenic (dTg) genotype, develop EAU despite profound lymphopenia (thymic HEL-specific T cell deletion). In this work, we characterized the immune component of this model and found conventional dTg CD4+ T cells were less anergic than those from 3A9 controls. Furthermore, prior in vitro HEL-activation of 3A9 anergic T cells (Tan) rendered them uveitogenic upon adoptive transfer (Tx) to sTg mice, while antigen-experienced (AgX, dTg), but not naïve (3A9) T cells halted disease in P21 dTg mice. Flow cytometric analysis of the AgX cells elucidated the underlying pathology: FoxP3+CD25hiCD4+ T regulatory cells (Treg) comprised ∼18%, while FR4+CD73+FoxP3-CD25lo/-CD4+ Tan comprised ∼1.2% of total cells. Further Treg-enrichment (∼80%) of the AgX population indicated FoxP3+CD25hiCD4+ Treg played a key role in EAU-suppression while FoxP3-CD25lo/-CD4+ T cells did not. Here we present the novel concept of dual immunological tolerance where spontaneous EAU is due to escape from anergy with consequent failure of Treg induction and subsequent imbalance in the [Treg:Teffector] cell ratio. The reduced numbers of Tan, normally sustaining Treg to prevent autoimmunity, are the trigger for disease, while immune homeostasis can be restored by supplementation with AgX, but not naïve, antigen-specific Treg.


Asunto(s)
Enfermedades Autoinmunes/inmunología , Inmunoterapia Adoptiva/métodos , Retina/patología , Linfocitos T Reguladores/inmunología , Uveítis/inmunología , Animales , Células Cultivadas , Modelos Animales de Enfermedad , Proteínas del Ojo/inmunología , Factores de Transcripción Forkhead/metabolismo , Humanos , Tolerancia Inmunológica , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Ratones , Ratones Transgénicos , Proteínas de Unión al Retinol/inmunología , Linfocitos T Reguladores/trasplante
13.
J Vis Exp ; (160)2020 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-32597855

RESUMEN

Electrocardiography (ECG) has long been relied upon as an effective and reliable method of assessing cardiovascular (and cardiopulmonary) function in both human and animal models of disease. Individual heart rate, rhythm, and regularity, combined with quantitative parameters collected from ECG, serve to assess the integrity of the cardiac conduction system as well as the integrated physiology of the cardiac cycle. This article provides a comprehensive description of the methods and techniques used to perform a noninvasive ECG on perinatal and neonatal mouse pups as early as the first postnatal day, without requiring the use of anesthetics. This protocol was designed to directly address a need for a standardized and repeatable method for obtaining ECG in newborn mice. From a translational perspective, this protocol proves to be entirely effective for characterization of congenital cardiopulmonary defects generated using transgenic mouse lines, and particularly for analysis of defects causing lethality at or during the first postnatal days. This protocol also aims to directly address a gap in the scientific literature to characterize and provide normative data associated with maturation of the early postnatal cardiac conduction system. This method is not limited to a specific postnatal timepoint, but rather allows for ECG data collection in neonatal mouse pups from birth to postnatal day 10 (P10), a window that is of critical importance for modeling human diseases in vivo, with particular emphasis on congenital heart disease (CHD).


Asunto(s)
Electrocardiografía , Animales , Animales Recién Nacidos , Electrodos , Extremidades/fisiología , Femenino , Cardiopatías Congénitas/diagnóstico por imagen , Cardiopatías Congénitas/fisiopatología , Frecuencia Cardíaca , Ratones Transgénicos , Mutación/genética , Embarazo
14.
Front Immunol ; 11: 608377, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33569055

RESUMEN

Immune privilege (IP), a term introduced to explain the unpredicted acceptance of allogeneic grafts by the eye and the brain, is considered a unique property of these tissues. However, immune responses are modified by the tissue in which they occur, most of which possess IP to some degree. The eye therefore displays a spectrum of IP because it comprises several tissues. IP as originally conceived can only apply to the retina as it contains few tissue-resident bone-marrow derived myeloid cells and is immunologically shielded by a sophisticated barrier - an inner vascular and an outer epithelial barrier at the retinal pigment epithelium. The vascular barrier comprises the vascular endothelium and the glia limitans. Immune cells do not cross the blood-retinal barrier (BRB) despite two-way transport of interstitial fluid, governed by tissue oncotic pressure. The BRB, and the blood-brain barrier (BBB) mature in the neonatal period under signals from the expanding microbiome and by 18 months are fully established. However, the adult eye is susceptible to intraocular inflammation (uveitis; frequency ~200/100,000 population). Uveitis involving the retinal parenchyma (posterior uveitis, PU) breaches IP, while IP is essentially irrelevant in inflammation involving the ocular chambers, uveal tract and ocular coats (anterior/intermediate uveitis/sclerouveitis, AU). Infections cause ~50% cases of AU and PU but infection may also underlie the pathogenesis of immune-mediated "non-infectious" uveitis. Dysbiosis accompanies the commonest form, HLA-B27-associated AU, while latent infections underlie BRB breakdown in PU. This review considers the pathogenesis of uveitis in the context of IP, infection, environment, and the microbiome.


Asunto(s)
Bacterias/inmunología , Microbioma Gastrointestinal , Privilegio Inmunológico , Intestinos/microbiología , Úvea/inmunología , Uveítis/inmunología , Animales , Bacterias/metabolismo , Barrera Hematoencefálica/inmunología , Barrera Hematoencefálica/metabolismo , Disbiosis , Predisposición Genética a la Enfermedad , Antígeno HLA-B27/genética , Antígeno HLA-B27/inmunología , Humanos , Factores de Riesgo , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Linfocitos T Reguladores/microbiología , Úvea/metabolismo , Uveítis/genética , Uveítis/metabolismo , Uveítis/microbiología
15.
J Tissue Eng Regen Med ; 13(9): 1528-1543, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31144475

RESUMEN

Activated T cells are known to promote fibrosis, a major complication limiting the range of polymeric hydrogels as artificial corneal implants. As T cells are activated by dendritic cells (DC), minimally activating hydrogels would be optimal. In this study, we evaluated the ability of a series of engineered (manufactured/fabricated) and natural collagen matrices to either activate DC or conversely induce DC apoptosis in vitro. Bone marrow DC were cultured on a series of singly and doubly crosslinked hydrogels (made from recombinant human collagen III [RHCIII] or collagen mimetic peptide [CMP]) or on natural collagen-containing matrices, MatrigelTM and de-cellularised mouse corneal stroma. DC surface expression of major histocompatibility complex Class II and CD86 as well as apoptosis markers were examined. Natural matrices induced low levels of DC activation and maintained a "tolerogenic" phenotype. The same applied to singly crosslinked CMP-PEG gels. RHCIII gels singly crosslinked using either N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide with the coinitiator N-hydroxy succinimide (EDC-NHS) or N-cyclohexyl-N-(2-morpholinoethyl)carbodiimide metho-p-toulenesulfonate with NHS (CMC-NHS) induced varying levels of DC activation. In contrast, however, RHCIII hydrogels incorporating an additional polymeric network of 2-methacryloyloxyethyl phosphorylcholine did not activate DC but instead induced DC apoptosis, a phenomenon observed in natural matrices. This correlated with increased DC expression of leukocyte-associated immunoglobulin-like receptor-1. Despite low immunogenic potential, viable tolerogenic DC migrated into and through both natural and manufactured RHCIII gels. These data show that the immunogenic potential of RHCIII gels varies with the nature and composition of the gel. Preclinical evaluation of hydrogel immunogenic/fibrogenic potential is recommended.


Asunto(s)
Colágeno/farmacología , Córnea/efectos de los fármacos , Reactivos de Enlaces Cruzados/farmacología , Células Dendríticas/metabolismo , Hidrogeles/farmacología , Prótesis e Implantes , Animales , Apoptosis/efectos de los fármacos , Materiales Biocompatibles/farmacología , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Células Cultivadas , Células Dendríticas/efectos de los fármacos , Ratones Endogámicos C57BL , Fenotipo , Proteínas Recombinantes/farmacología , Ingeniería de Tejidos
16.
J Tissue Eng Regen Med ; 13(9): 1507-1517, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-30938102

RESUMEN

We showed previously that 1-ethyl-3-(3-dimethylamino-propyl)-carbodiimide hydrochloride (EDC) cross-linked recombinant human collagen III hydrogels promoted stable regeneration of the human cornea (continued nerve and stromal cell repopulation) for over 4 years. However, as EDC cross linking kinetics were difficult to control, we additionally tested a sterically bulky carbodiimide. Here, we compared the effects of two carbodiimide cross linkers-bulky, aromatic N-cyclohexyl-N0-(2-morpholinoethyl)-carbodiimide (CMC), and nonbulky EDC-in a mouse corneal graft model. Murine corneas undergoing full-thickness implantation with these gels became opaque due to dense retro-corneal membranes (RCM). Corneal epithelial cytokeratin 12 and alpha smooth muscle actin indicative of functional tissue regeneration and wound contraction were observed in RCM surrounding both hydrogel types. However, quantitatively different levels of infiltrating CD11c+ dendritic cells (DC) were found, suggesting a hydrogel-specific innate immune response. More DC infiltrated the stroma surrounding EDC-N-hydroxysuccinimide (NHS) hydrogels concurrently with higher fibrosis-associated tenascin c expression. The opposite was true for CMC-NHS gels that had previously been shown to be more tolerising to DC. In vitro studies showed that DC cultured with transforming growth factor ß1 (TGF-ß1) induced fibroblasts to secrete more tenascin c than those cultured with lipopolysaccharide and this effect was blocked by TGF-ß1 neutralisation. Furthermore, tenascin c staining was found in 40- to 50µm long membrane nanotubes formed in fibroblast/DC cocultures. We suggest that TGF-ß1 alternatively activated (tolerising) DC regulate fibroblast-mediated tenascin c secretion, possibly via local production of TGF-ß1 in early wound contraction, and that this is indirectly modulated by different hydrogel chemistries.


Asunto(s)
Córnea/patología , Trasplante de Córnea , Células Dendríticas/metabolismo , Fibroblastos/metabolismo , Hidrogeles/farmacología , Tenascina/metabolismo , Factor de Crecimiento Transformador beta1/farmacología , Cicatrización de Heridas , Animales , Técnicas de Cocultivo , Células Dendríticas/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Imidas , Membranas , Ratones , Ratones Endogámicos BALB C , Células 3T3 NIH , Nanotubos/química , Fosforilación/efectos de los fármacos , Propilaminas , Repitelización/efectos de los fármacos , Proteínas Smad/metabolismo , Cicatrización de Heridas/efectos de los fármacos
17.
EMBO Rep ; 20(5)2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30894405

RESUMEN

Regulatory T (Treg) cells help to maintain tolerance and prevent the development of autoimmune diseases. Retinoic acid (RA) can promote peripheral conversion of naïve T cells into Foxp3+ Treg cells. Here, we show that RA can act as an adjuvant to induce antigen-specific type 1 Treg (Tr1) cells, which is augmented by co-administration of IL-2. Immunization of mice with the model antigen KLH in the presence of RA and IL-2 induces T cells that secrete IL-10, but not IL-17 or IFN-γ, and express LAG-3, CD49b and PD-1 but not Foxp3, a phenotype typical of Tr1 cells. Furthermore, immunization of mice with the autoantigen MOG in the presence of RA and IL-2 induces Tr1 cells, which suppress pathogenic Th1 and Th17 cells that mediate the development of experimental autoimmune encephalomyelitis (EAE), an autoimmune disease of the CNS. Furthermore, immunization with a surrogate autoantigen, RA and IL-2 prevents development of spontaneous autoimmune uveitis. Our findings demonstrate that the induction of autoantigen-specific Tr1 cells can prevent the development of autoimmunity.


Asunto(s)
Autoantígenos/inmunología , Autoinmunidad/inmunología , Linfocitos T Reguladores/inmunología , Tretinoina/inmunología , Animales , Encefalomielitis Autoinmune Experimental/inmunología , Femenino , Factores de Transcripción Forkhead/inmunología , Interleucina-10/inmunología , Interleucina-17/inmunología , Ratones , Ratones Endogámicos C57BL , Células TH1/inmunología , Células Th17/inmunología
18.
Data Brief ; 22: 140-144, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30581918

RESUMEN

Histology (H&E) and transmission electron microscopy (TEM) data are provided showing age-related changes in the retinal structure of sTg-IRBP:HEL mice. These include substantial photoreceptor loss, atrophy of the retinal pigment epithelium, Bruch׳s membrane disruption and thickening, along with the presence of drusenoid deposits and changes in basal laminar infoldings. These features resemble some of those key characteristics found in the course of human dry (atrophic) age-related macular degeneration (AMD), particularly with regard to drusen. Hence, we believe the sTg-IRBP:HEL mouse model represents a useful and promising archetype for future study of the mechanism of drusen formation in AMD.

19.
Nat Rev Neurosci ; 19(11): 655-671, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30310148

RESUMEN

Classically, the CNS is described as displaying immune privilege, as it shows attenuated responses to challenge by alloantigen. However, the CNS does show local inflammation in response to infection. Although pathogen access to the brain parenchyma and retina is generally restricted by physiological and immunological barriers, certain pathogens may breach these barriers. In the CNS, such pathogens may either cause devastating inflammation or benefit from immune privilege in the CNS, where they are largely protected from the peripheral immune system. Thus, some pathogens can persist as latent infections and later be reactivated. We review the consequences of immune privilege in the context of CNS infections and ask whether immune privilege may provide protection for certain pathogens and promote their latency.


Asunto(s)
Encéfalo/inmunología , Infecciones del Sistema Nervioso Central/inmunología , Privilegio Inmunológico , Animales , Sistema Nervioso Central/inmunología , Infecciones del Sistema Nervioso Central/complicaciones , Encefalitis/complicaciones , Encefalitis/inmunología , Humanos , Microglía/inmunología
20.
World Dev ; 109: 197-205, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30177865

RESUMEN

Resilience has attracted criticism for its failure to address social vulnerability and to engage with issues of equity and power. Here, we ask: what is equitable resilience? Our focus is on what resilience does on the ground in relation to development, adaptation and disaster management, and on identifying critical issues for engaging with equity in resilience practice. Using techniques from systematic reviews, with variants of equitable resilience as our key search terms, we carried out an analytical literature review which reveals four interconnected themes: subjectivities, inclusion, cross-scale interactions, and transformation. Drawing on this analysis, we find that 'equitable resilience' is increasingly likely when resilience practice takes into account issues of social vulnerability and differential access to power, knowledge, and resources; it requires starting from people's own perception of their position within their human-environmental system, and it accounts for their realities and for their need for a change of circumstance to avoid imbalances of power into the future. Our approach moves beyond debates that focus on the ontological disconnect between resilience and social theory, to provide a definition that can be used in practice alongside resilience indicators to drive ground level interventions towards equitable outcomes. Defined in this way, equitable resilience is able to support the development of social-ecological systems that are contextually rooted, responsive to change and socially just, and thus relevant to global sustainability challenges.

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