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1.
Nature ; 623(7986): 340-346, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37853124

RESUMEN

Understanding the effects of cash crop expansion on natural forest is of fundamental importance. However, for most crops there are no remotely sensed global maps1, and global deforestation impacts are estimated using models and extrapolations. Natural rubber is an example of a principal commodity for which deforestation impacts have been highly uncertain, with estimates differing more than fivefold1-4. Here we harnessed Earth observation satellite data and cloud computing5 to produce high-resolution maps of rubber (10 m pixel size) and associated deforestation (30 m pixel size) for Southeast Asia. Our maps indicate that rubber-related forest loss has been substantially underestimated in policy, by the public and in recent reports6-8. Our direct remotely sensed observations show that deforestation for rubber is at least twofold to threefold higher than suggested by figures now widely used for setting policy4. With more than 4 million hectares of forest loss for rubber since 1993 (at least 2 million hectares since 2000) and more than 1 million hectares of rubber plantations established in Key Biodiversity Areas, the effects of rubber on biodiversity and ecosystem services in Southeast Asia could be extensive. Thus, rubber deserves more attention in domestic policy, within trade agreements and in incoming due-diligence legislation.


Asunto(s)
Conservación de los Recursos Naturales , Bosques , Mapeo Geográfico , Goma , Imágenes Satelitales , Asia Sudoriental , Biodiversidad , Nube Computacional , Conservación de los Recursos Naturales/estadística & datos numéricos , Conservación de los Recursos Naturales/tendencias
2.
Nat Immunol ; 15(5): 473-81, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24633226

RESUMEN

Regulatory T cells (Treg cells) express members of the tumor-necrosis factor (TNF) receptor superfamily (TNFRSF), but the role of those receptors in the thymic development of Treg cells is undefined. We found here that Treg cell progenitors had high expression of the TNFRSF members GITR, OX40 and TNFR2. Expression of those receptors correlated directly with the signal strength of the T cell antigen receptor (TCR) and required the coreceptor CD28 and the kinase TAK1. The neutralization of ligands that are members of the TNF superfamily (TNFSF) diminished the development of Treg cells. Conversely, TNFRSF agonists enhanced the differentiation of Treg cell progenitors by augmenting responsiveness of the interleukin 2 receptor (IL-2R) and transcription factor STAT5. Costimulation with the ligand of GITR elicited dose-dependent enrichment for cells of lower TCR affinity in the Treg cell repertoire. In vivo, combined inhibition of GITR, OX40 and TNFR2 abrogated the development of Treg cells. Thus, expression of members of the TNFRSF on Treg cell progenitors translated strong TCR signals into molecular parameters that specifically promoted the development of Treg cells and shaped the Treg cell repertoire.


Asunto(s)
Receptor Cross-Talk , Receptores de Antígenos de Linfocitos T/agonistas , Linfocitos T Reguladores/inmunología , Timo/inmunología , Péptidos y Proteínas Asociados a Receptores de Factores de Necrosis Tumoral/metabolismo , Animales , Antígenos CD28/genética , Antígenos CD28/metabolismo , Diferenciación Celular/genética , Células Cultivadas , Proteína Relacionada con TNFR Inducida por Glucocorticoide/genética , Proteína Relacionada con TNFR Inducida por Glucocorticoide/metabolismo , Quinasas Quinasa Quinasa PAM/genética , Quinasas Quinasa Quinasa PAM/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Receptor Cross-Talk/inmunología , Receptores OX40/genética , Receptores OX40/metabolismo , Receptores Tipo II del Factor de Necrosis Tumoral/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/farmacología , Factor de Transcripción STAT5/metabolismo , Transducción de Señal/genética , Péptidos y Proteínas Asociados a Receptores de Factores de Necrosis Tumoral/genética
3.
Proc Natl Acad Sci U S A ; 116(46): 23202-23208, 2019 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-31659031

RESUMEN

Consumption of globally traded agricultural commodities like soy and palm oil is one of the primary causes of deforestation and biodiversity loss in some of the world's most species-rich ecosystems. However, the complexity of global supply chains has confounded efforts to reduce impacts. Companies and governments with sustainability commitments struggle to understand their own sourcing patterns, while the activities of more unscrupulous actors are conveniently masked by the opacity of global trade. We combine state-of-the-art material flow, economic trade, and biodiversity impact models to produce an innovative approach for understanding the impacts of trade on biodiversity loss and the roles of remote markets and actors. We do this for the production of soy in the Brazilian Cerrado, home to more than 5% of the world´s species. Distinct sourcing patterns of consumer countries and trading companies result in substantially different impacts on endemic species. Connections between individual buyers and specific hot spots explain the disproportionate impacts of some actors on endemic species and individual threatened species, such as the particular impact of European Union consumers on the recent habitat losses for the iconic giant anteater (Myrmecophaga tridactyla). In making these linkages explicit, our approach enables commodity buyers and investors to target their efforts much more closely to improve the sustainability of their supply chains in their sourcing regions while also transforming our ability to monitor the impact of such commitments over time.


Asunto(s)
Agricultura , Biodiversidad , Comercio , Glycine max , Modelos Teóricos , Animales , Brasil , Internacionalidad
4.
PLoS Biol ; 13(2): e1002074, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25710450

RESUMEN

How often do people visit the world's protected areas (PAs)? Despite PAs covering one-eighth of the land and being a major focus of nature-based recreation and tourism, we don't know. To address this, we compiled a globally-representative database of visits to PAs and built region-specific models predicting visit rates from PA size, local population size, remoteness, natural attractiveness, and national income. Applying these models to all but the very smallest of the world's terrestrial PAs suggests that together they receive roughly 8 billion (8 x 109) visits/y-of which more than 80% are in Europe and North America. Linking our region-specific visit estimates to valuation studies indicates that these visits generate approximately US $600 billion/y in direct in-country expenditure and US $250 billion/y in consumer surplus. These figures dwarf current, typically inadequate spending on conserving PAs. Thus, even without considering the many other ecosystem services that PAs provide to people, our findings underscore calls for greatly increased investment in their conservation.


Asunto(s)
Conservación de los Recursos Naturales/economía , Modelos Estadísticos , Recreación/economía , Viaje/estadística & datos numéricos , Conservación de los Recursos Naturales/estadística & datos numéricos , Ecosistema , Europa (Continente) , Humanos , América del Norte , Recreación/psicología , Viaje/economía , Viaje/psicología
6.
Cell Immunol ; 319: 28-34, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28711152

RESUMEN

CD28 is the major costimulatory receptor on T cells regulating proliferation, survival and effector function. Acquired mutations in the extracellular domain of CD28 have been identified in patients with cutaneous T cell lymphoma, angioimmunoblastic T cell lymphoma and other T cell neoplasms, suggesting it may contribute to disease pathogenesis. We used a heterologous system in which mutant human CD28 was expressed on primary murine T cells deficient in CD28 to ascertain how specific mutations identified in a genetic screen of patients with cutaneous T cell lymphoma affected normal T cell function. All three mutant CD28 proteins examined enhanced CD28-dependent T cell proliferation and effector function. These data suggest that the mutant CD28 isoforms could accelerate tumor cell growth and increase tumor burden in affected patients. Interruption of CD28:ligand interactions may be an effective, targeted therapy for a subset of patients whose tumors bear the mutant CD28 receptor.


Asunto(s)
Antígenos CD28/genética , Antígeno CTLA-4/genética , Linfoma Cutáneo de Células T/genética , Mutación , Linfocitos T/inmunología , Secuencia de Aminoácidos , Animales , Antígenos CD28/inmunología , Antígeno CTLA-4/inmunología , Proliferación Celular , Supervivencia Celular , ADN Complementario/genética , ADN Complementario/inmunología , Expresión Génica , Humanos , Activación de Linfocitos , Linfoma Cutáneo de Células T/inmunología , Linfoma Cutáneo de Células T/patología , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Proteínas Mutantes Quiméricas/genética , Proteínas Mutantes Quiméricas/inmunología , Cultivo Primario de Células , Linfocitos T/patología , Transfección , Transgenes
7.
J Immunol ; 194(10): 4717-28, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25833397

RESUMEN

In health, long-lived plasma cells (LLPC) are essential for durable protective humoral immunity, and, conversely, in disease are a major source of pathogenic Abs in autoimmunity, graft rejection, and allergy. However, the molecular basis for their longevity is largely unknown. We have recently found that CD28 signaling in plasma cells (PC) is essential for sustaining Ab titers, by supporting the survival of LLPC, but not short-lived PC (SLPC). We now find that, unlike SLPC, CD28 activation in LLPC induces prosurvival downstream Vav signaling. Knockin mice with CD28 cytoplasmic tail mutations that abrogate Vav signaling (CD28-AYAA) had significantly fewer LLPC but unaffected SLPC numbers, whereas mice with mutations that abrogate PI3K signaling (CD28-Y170F) were indistinguishable from wild-type controls. This was consistent with the loss of CD28's prosurvival effect in LLPC from CD28-AYAA, but not CD28-Y170F, mice. Furthermore, the CD28 Vav motif in the B lineage was essential for the long-term maintenance of Ag-specific LLPC populations and Ab titers in vivo. Signaling downstream of the CD28 Vav motif induced previously undescribed transcriptional regulation of B lymphocyte-induced maturation protein-1, a key mediator of PC differentiation and maintenance. These findings suggest CD28 signaling in LLPC modulates the central B lymphocyte-induced maturation protein-1 transcriptional nexus involved in long-term survival and function.


Asunto(s)
Antígenos CD28/metabolismo , Células Plasmáticas/citología , Células Plasmáticas/inmunología , Transducción de Señal/inmunología , Factores de Transcripción/biosíntesis , Secuencias de Aminoácidos , Animales , Formación de Anticuerpos/inmunología , Western Blotting , Antígenos CD28/inmunología , Diferenciación Celular/inmunología , Supervivencia Celular/inmunología , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Inmunoprecipitación , Subgrupos Linfocitarios/citología , Subgrupos Linfocitarios/inmunología , Subgrupos Linfocitarios/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , Células Plasmáticas/metabolismo , Factor 1 de Unión al Dominio 1 de Regulación Positiva , Prolina , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de Transcripción/inmunología , Regulación hacia Arriba
8.
Glob Chang Biol ; 22(8): 2787-800, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-26748590

RESUMEN

Agricultural expansion has resulted in both land use and land cover change (LULCC) across the tropics. However, the spatial and temporal patterns of such change and their resulting impacts are poorly understood, particularly for the presatellite era. Here, we quantify the LULCC history across the 33.9 million ha watershed of Tanzania's Eastern Arc Mountains, using geo-referenced and digitized historical land cover maps (dated 1908, 1923, 1949 and 2000). Our time series from this biodiversity hotspot shows that forest and savanna area both declined, by 74% (2.8 million ha) and 10% (2.9 million ha), respectively, between 1908 and 2000. This vegetation was replaced by a fivefold increase in cropland, from 1.2 million ha to 6.7 million ha. This LULCC implies a committed release of 0.9 Pg C (95% CI: 0.4-1.5) across the watershed for the same period, equivalent to 0.3 Mg C ha(-1)  yr(-1) . This is at least threefold higher than previous estimates from global models for the same study area. We then used the LULCC data from before and after protected area creation, as well as from areas where no protection was established, to analyse the effectiveness of legal protection on land cover change despite the underlying spatial variation in protected areas. We found that, between 1949 and 2000, forest expanded within legally protected areas, resulting in carbon uptake of 4.8 (3.8-5.7) Mg C ha(-1) , compared to a committed loss of 11.9 (7.2-16.6) Mg C ha(-1) within areas lacking such protection. Furthermore, for nine protected areas where LULCC data are available prior to and following establishment, we show that protection reduces deforestation rates by 150% relative to unprotected portions of the watershed. Our results highlight that considerable LULCC occurred prior to the satellite era, thus other data sources are required to better understand long-term land cover trends in the tropics.


Asunto(s)
Biodiversidad , Carbono/análisis , Conservación de los Recursos Naturales , Agricultura , Carbono/efectos adversos , Bosques
9.
J Immunol ; 192(8): 3465-9, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24639356

RESUMEN

CD28 is a critical regulator of T cell function, augmenting proliferation, cytokine secretion, and cell survival. Our previous work using knockin mice expressing point mutations in CD28 demonstrated that the distal proline motif was primarily responsible for much of CD28 function, whereas in marked contrast to prior studies, mutation of the PI3K-binding motif had little discernible effect. In this study, we examined the phenotype of mice in which both motifs are simultaneously mutated. We found that mutation of the PYAP motif unmasks a critical role for the proximal tyrosine motif in regulating T cell proliferation and expression of Bcl-xL but not cytokine secretion. In addition, we demonstrated that, although function is more severely impaired in the double mutant than in either single mutant, there remained residual CD28-dependent responses, definitively establishing that additional motifs can partially mediate CD28 function.


Asunto(s)
Secuencias de Aminoácidos , Antígenos CD28/genética , Antígenos CD28/inmunología , Mutación , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Proteína bcl-X/genética , Secuencia de Aminoácidos , Animales , Antígenos CD28/química , Proliferación Celular , Citocinas/biosíntesis , Activación de Linfocitos , Ratones , Ratones Transgénicos , Proteína bcl-X/metabolismo
10.
Dev Psychopathol ; 28(1): 73-83, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25851172

RESUMEN

Children entering out-of-home (OoH) care have often experienced multiple forms of maltreatment and are at risk of psychiatric disorder and poor long-term outcome. Recent evidence shows high rates of disinhibited attachment disorder (DAD) among maltreated adolescents in U.K. OoH care (Kay & Green, 2013). This study aimed to further understand the mechanisms of outcome in this group through investigation of social cognitive functioning. Patterns of theory of mind (ToM) and social information processing were assessed alongside DAD behavior and psychopathology in 63 adolescents in U.K. OoH care (mean age = 176 months, SD = 22; 48% male; 89% White British) and 69 low-risk comparison adolescents (mean age = 171 months, SD = 17; 46% male; 87% White British). Compared to low risk, OoH adolescents showed a hostile attribution bias and ToM deficit, but this was confounded by language ability. ToM was associated with reduced hostile attribution and responding biases and increased social competence, which was further associated with lower levels of externalizing psychopathology. There was no association between social cognition and core features of DAD. Social cognitive deficits and biases may play a role in the high rates of externalizing psychopathology and relationship functioning difficulties in maltreated samples. Future research should assess alternative cognitive mechanisms for DAD.


Asunto(s)
Maltrato a los Niños/psicología , Trastornos del Conocimiento/psicología , Cuidados en el Hogar de Adopción , Trastorno de Vinculación Reactiva/psicología , Percepción Social , Teoría de la Mente , Adolescente , Estudios de Casos y Controles , Niño , Cognición , Femenino , Hostilidad , Humanos , Masculino , Apego a Objetos , Ajuste Social , Conducta Social , Reino Unido
11.
J Immunol ; 190(10): 5078-85, 2013 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-23585675

RESUMEN

CD43 is a glycosylated surface protein abundantly expressed on lymphocytes. Its role in immune responses has been difficult to clearly establish, with evidence supporting both costimulatory and inhibitory functions. In addition, its contribution to disease pathogenesis remains elusive. Using a well-characterized murine model of elastase-induced abdominal aortic aneurysm (AAA) that recapitulates many key features of the human disease, we established that the presence of CD43 on T cells is required for AAA formation. Moreover, we found that IFN-γ-producing CD8(+) T cells, but not CD4(+) T cells, promote the development of aneurysm by enhancing cellular apoptosis and matrix metalloprotease activity. Reconstitution with IFN-γ-producing CD8(+) T cells or recombinant IFN-γ promotes the aneurysm phenotype in CD43(-/-) mice, whereas IFN-γ antagonism abrogates disease in wild-type animals. Furthermore, we showed that the presence of CD43 with an intact cytoplasmic domain capable of binding to ezrin-radixin-moesin cytoskeletal proteins is essential for optimal in vivo IFN-γ production by T cells and aneurysm formation. We have thus identified a robust physiologic role for CD43 in a relevant animal model and established an important in vivo function for CD43-dependent regulation of IFN-γ production. These results further suggest that IFN-γ antagonism or selective blockade of CD43(+)CD8(+) T cell activities merits further investigation for immunotherapy in AAA.


Asunto(s)
Aneurisma de la Aorta Abdominal/inmunología , Linfocitos T CD8-positivos/metabolismo , Inflamación/inmunología , Interferón gamma/biosíntesis , Leucosialina/metabolismo , Animales , Aneurisma de la Aorta Abdominal/patología , Apoptosis/inmunología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Modelos Animales de Enfermedad , Leucosialina/genética , Activación de Linfocitos/inmunología , Macrófagos/inmunología , Metaloproteinasas de la Matriz/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neurofibromina 2/metabolismo , Neutrófilos/inmunología , Elastasa Pancreática
12.
J Immunol ; 191(6): 3082-9, 2013 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-23956428

RESUMEN

The CD28 costimulatory receptor is a critical regulator of T cell function, making it an attractive therapeutic target for the treatment of immune-mediated diseases. CTLA4Ig, now approved for use in humans, prevents naive T cell activation by binding to B7 proteins and blocking engagement of CD28. However, CTLA4Ig suppresses inflammation even if administered when disease is established, suggesting alternative mechanisms. We identified a novel, CD28-independent mechanism by which CTLA4Ig inhibits activated T cells. We show that in vitro, CTLA4Ig synergizes with NO from bone marrow-derived macrophages to inhibit T cell proliferation. Depletion of regulatory T cells (Tregs) or interference with TGF-ß signaling abrogated the inhibitory effect of CTLA4Ig. Parallel in vivo experiments using an allergic airway inflammation model demonstrated that this novel mechanism required both macrophages and regulatory T cells. Furthermore, CTLA4Ig was ineffective in SMAD3-deficient mice, supporting a requirement for TGF-ß signaling. Thus, in addition to preventing naive T cells from being fully activated, CTLA4Ig can turn off already activated effector T cells by an NO/regulatory T cell/TGF-ß-dependent pathway. This mechanism is similar to cell-extrinsic effects of endogenous CTLA4 and may be particularly important in the ability of CTLA4Ig to treat chronic inflammatory disease.


Asunto(s)
Antiinflamatorios/farmacología , Antígeno CTLA-4/inmunología , Inmunoglobulina G/farmacología , Activación de Linfocitos/efectos de los fármacos , Linfocitos T Reguladores/inmunología , Factor de Crecimiento Transformador beta/inmunología , Traslado Adoptivo , Animales , Técnicas de Cocultivo , Modelos Animales de Enfermedad , Citometría de Flujo , Inmunoconjugados/farmacología , Activación de Linfocitos/inmunología , Macrófagos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Recombinantes de Fusión/farmacología , Hipersensibilidad Respiratoria/inmunología , Linfocitos T Reguladores/efectos de los fármacos
13.
Conserv Biol ; 28(2): 427-37, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24372589

RESUMEN

Much of the biodiversity-related climate change impacts research has focused on the direct effects to species and ecosystems. Far less attention has been paid to the potential ecological consequences of human efforts to address the effects of climate change, which may equal or exceed the direct effects of climate change on biodiversity. One of the most significant human responses is likely to be mediated through changes in the agricultural utility of land. As farmers adapt their practices to changing climates, they may increase pressure on some areas that are important to conserve (conservation lands) whereas lessening it on others. We quantified how the agricultural utility of South African conservation lands may be altered by climate change. We assumed that the probability of an area being farmed is linked to the economic benefits of doing so, using land productivity values to represent production benefit and topographic ruggedness as a proxy for costs associated with mechanical workability. We computed current and future values of maize and wheat production in key conservation lands using the DSSAT4.5 model and 36 crop-climate response scenarios. Most conservation lands had, and were predicted to continue to have, low agricultural utility because of their location in rugged terrain. However, several areas were predicted to maintain or gain high agricultural utility and may therefore be at risk of near-term or future conversion to cropland. Conversely, some areas were predicted to decrease in agricultural utility and may therefore prove easier to protect from conversion. Our study provides an approximate but readily transferable method for incorporating potential human responses to climate change into conservation planning.


Asunto(s)
Agricultura , Cambio Climático , Conservación de los Recursos Naturales , Modelos Teóricos , Biodiversidad , Sudáfrica , Triticum/crecimiento & desarrollo , Zea mays/crecimiento & desarrollo
14.
J Immunol ; 189(6): 2909-17, 2012 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-22896637

RESUMEN

CD28 is required for maximal proliferation of CD4+ T cells stimulated through their TCRs. Two sites within the cytoplasmic tail of CD28, a YMNM sequence that recruits PI3K and activates NF-κB and a PYAP sequence that recruits Lck, are candidates as transducers of the signals responsible for these biological effects. We tested this proposition by tracking polyclonal peptide:MHCII-specific CD4+ T cells in vivo in mice with mutations in these sites. Mice lacking CD28 or its cytoplasmic tail had the same number of naive T cells specific for a peptide:MHCII ligand as wild-type mice. However, the mutant cells produced one tenth as many effector and memory cells as wild-type T cells after infection with bacteria expressing the antigenic peptide. Remarkably, T cells with a mutated PI3K binding site, a mutated PYAP site, or both mutations proliferated to the same extent as wild-type T cells. The only observed defect was that T cells with a mutated PYAP or Y170F site proliferated even more weakly in response to peptide without adjuvant than wild-type T cells. These results show that CD28 enhances T cell proliferation during bacterial infection by signals emanating from undiscovered sites in the cytoplasmic tail.


Asunto(s)
Antígenos CD28/fisiología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/patología , Diferenciación Celular/inmunología , Listeriosis/inmunología , Listeriosis/patología , Secuencias de Aminoácidos/genética , Secuencias de Aminoácidos/inmunología , Animales , Antígenos CD28/química , Antígenos CD28/genética , Linfocitos T CD4-Positivos/microbiología , Diferenciación Celular/genética , Línea Celular Transformada , Células Clonales , Citoplasma/inmunología , Citoplasma/microbiología , Citoplasma/patología , Epítopos de Linfocito T/biosíntesis , Antígenos de Histocompatibilidad Clase II/inmunología , Listeriosis/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Fragmentos de Péptidos/biosíntesis , Fragmentos de Péptidos/genética , Transducción de Señal/genética , Transducción de Señal/inmunología , Regulación hacia Arriba/genética , Regulación hacia Arriba/inmunología
15.
Am J Respir Crit Care Med ; 187(5): 494-501, 2013 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-23292882

RESUMEN

RATIONALE: T lymphocytes are important in the pathogenesis of allergic asthma. Costimulation through CD28 is critical for optimal activation of T cells, and inhibition of this pathway with CTLA4Ig has been shown to be effective in preventing airway inflammation and hyperresponsiveness in animal models of asthma. Abatacept, a humanized version of CTLA4Ig, has been approved for treatment of rheumatoid arthritis, providing the opportunity to test whether inhibition of costimulation is an effective strategy to treat people with asthma. OBJECTIVES: To determine if 3 months of treatment with abatacept reduced allergen-induced airway inflammation in people with mild atopic asthma. METHODS: Randomized, placebo-controlled, double-blinded study. Bronchoscopically directed segmental allergen challenge was performed on 24 subjects followed by bronchoalveolar lavage 48 hours later. Subjects were randomized 1:1 to receive abatacept or placebo, followed by a second allergen challenge protocol after 3 months of study drug. MEASUREMENTS AND MAIN RESULTS: There was no significant reduction in allergen-induced eosinophilic inflammation in the abatacept-treated group compared with placebo (17.71% ± 17.25% vs. 46.39% ± 29.21%; P = 0.26). In addition, we did not detect an effect of abatacept on FEV1, provocative concentration of methacholine sufficient to induce a 20% decline in FEV1, or asthma symptoms. Subjects treated with abatacept had an increased percentage of naive and a corresponding decrease in memory CD4(+) T cells in the blood compared with placebo. CONCLUSIONS: Inhibition of CD28-mediated costimulation with abatacept does not seem to alter the inflammatory response to segmental allergen challenge or clinical measures of asthma symptoms in people with mild atopic asthma. Clinical trial registered with ClinicalTrials.gov (NCT 00784459).


Asunto(s)
Asma/tratamiento farmacológico , Antígenos CD28/antagonistas & inhibidores , Inmunoconjugados/uso terapéutico , Inmunosupresores/uso terapéutico , Abatacept , Adulto , Asma/inmunología , Método Doble Ciego , Eosinófilos/metabolismo , Femenino , Volumen Espiratorio Forzado , Humanos , Inmunoconjugados/efectos adversos , Inmunosupresores/efectos adversos , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Transducción de Señal , Subgrupos de Linfocitos T/metabolismo , Linfocitos T/metabolismo
16.
BMC Psychol ; 12(1): 137, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38475925

RESUMEN

BACKGROUND: 16p11.2 proximal deletion and duplication syndromes (Break points 4-5) (593KB, Chr16; 29.6-30.2mb - HG38) are observed to have highly varied phenotypes, with a known propensity for lifelong psychiatric problems. This study aimed to contribute to a research gap by qualitatively exploring the challenges families with 16p11.2 deletion and duplication face by answering three research questions: (1) What are parents' perceptions of the ongoing support needs of families with children who have 16p11.2 living in the UK?; (2) What are their experiences in trying to access support?; (3) In these regards, do the experiences of parents of children with duplication converge or vary from those of parents of children with 16p11.2 deletion? METHODS: 33 parents with children (aged 7-17 years) with 16p11.2 deletion or duplication participated in structured interviews, including the Autism Diagnostic Interview- Revised (ADI-R). Their answers to the ADI-R question 'what are your current concerns' were transcribed and subsequently analysed using Braun and Clarke's six step reflexive thematic analysis framework. RESULTS: Three themes were identified: (1) Child is Behind Peers (subthemes: developmentally; academically; socially; emotionally); (2) Metabolism and Eating Patterns and; (3) Support (subthemes: insufficient support available; parent has to fight to access support; COVID-19 was a barrier to accessing support; 16p11.2 diagnosis can be a barrier to support, child is well-supported). CONCLUSIONS: Parents of children with either 16p11.2 deletion or duplication shared similar experiences. However, metabolism concerns were specific to parents of children with 16p11.2 deletion. The theme Child is Behind Peers echoed concerns raised in previous Neurodevelopmental Copy Number Variant research. However, there were some key subthemes relating to research question (2) which were specific to this study. This included parents' descriptions of diagnostic overshadowing and the impact of a lack of eponymous name and scant awareness of 16p11.2.


Asunto(s)
Trastorno Autístico , Deleción Cromosómica , Niño , Humanos , Trastorno Autístico/genética , Padres
17.
Crit Care ; 17(3): R85, 2013 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-23663657

RESUMEN

INTRODUCTION: Fungal sepsis is an increasingly common problem in intensive care unit patients.Mortality from fungal sepsis remains high despite antimicrobial therapy that is highly active against most fungal pathogens, a finding consistent with defective host immunity that is present in many patients with disseminated fungemia.One recently recognized immunologic defect that occurs in patients with sepsis is T cell "exhaustion" due to increased expression of programmed cell death -1 (PD-1).This study tested the ability of anti-PD-1 and anti-programmed cell death ligand -1 (anti-PD-L1) antagonistic antibodies to improve survival and reverse sepsis-induced immunosuppression in two mouse models of fungal sepsis. METHODS: Fungal sepsis was induced in mice using two different models of infection, that is, primary fungal sepsis and secondary fungal sepsis occurring after sub-lethal cecal ligation and puncture (CLP).Anti-PD-1 and anti-PD-L1 were administered 24 to 48 h after fungal infection and effects on survival, interferon gamma production, and MHC II expression were examined. RESULTS: Anti-PD-1 and anti-PD-L1 antibodies were highly effective at improving survival in primary and secondary fungal sepsis.Both antibodies reversed sepsis-induced suppression of interferon gamma and increased expression of MHC II on antigen presenting cells.Blockade of cytotoxic T-lymphocyte antigen-4 (CTLA-4), a second negative co-stimulatory molecule that is up-regulated in sepsis and acts like PD-1 to suppress T cell function, also improved survival in fungal sepsis. CONCLUSIONS: Immuno-adjuvant therapy with anti-PD-1, anti-PD-L1 and anti-CTLA-4 antibodies reverse sepsis-induced immunosuppression and improve survival in fungal sepsis.The present results are consistent with previous studies showing that blockade of PD-1 and CTLA-4 improves survival in bacterial sepsis.Thus, immuno-adjuvant therapy represents a novel approach to sepsis and may have broad applicability in the disorder.Given the relative safety of anti-PD-1 antibody in cancer clinical trials to date, therapy with anti-PD-1 in patients with life-threatening sepsis who have demonstrable immunosuppression should be strongly considered.


Asunto(s)
Anticuerpos/uso terapéutico , Antígeno B7-H1/antagonistas & inhibidores , Antígeno CTLA-4/antagonistas & inhibidores , Fungemia/inmunología , Fungemia/terapia , Receptor de Muerte Celular Programada 1/antagonistas & inhibidores , Animales , Antígeno B7-H1/inmunología , Antígeno CTLA-4/inmunología , Candidiasis/inmunología , Candidiasis/terapia , Modelos Animales de Enfermedad , Genes MHC Clase I , Antígenos HLA-DR/biosíntesis , Huésped Inmunocomprometido , Interferón gamma/biosíntesis , Masculino , Ratones Endogámicos C57BL , Receptor de Muerte Celular Programada 1/inmunología , Análisis de Supervivencia
18.
J Clin Transl Sci ; 7(1): e99, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37250991

RESUMEN

Revisions to the Common Rule and NIH policy require the use of a single Institutional Review Board (sIRB) for the review of most federally funded, multisite research, with the intent of streamlining the review process. However, since initial implementation in 2018, many IRBs and institutions continue to struggle with the logistics of implementing this requirement. In this paper, we report the findings of a workshop held in 2022 to examine why sIRB review remains problematic and propose possible solutions. Workshop participants identified several issues as major barriers, including new responsibilities for study teams, persistent duplicative review processes, the lack of harmonization of policies and practices across institutions, the absence of additional guidance from federal agencies, and the need for greater flexibility in policy requirements. Addressing these problems will require providing additional resources and training to research teams, the commitment of institutional leaders to harmonize practice, and policymakers to critically evaluate the requirement and provide flexibility in applicability.

19.
Am J Physiol Lung Cell Mol Physiol ; 302(1): L167-73, 2012 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-22003092

RESUMEN

Organ-specific regulation of immune responses relies on the exchange of information between nonimmune and immune cells. In a primary culture model of the lung airway, we demonstrate that T cell proliferation is potently inhibited by airway epithelial cells (ECs). This is mediated by activation of the IFNγ/STAT1 pathway in the EC and transforming growth factor-ß (TGFß)-dependent suppression of T cell proliferation. In this way, the EC can restrict the expansion of T cells. Given the constant exposure of the airway to inhaled antigen, this may be important in setting a threshold for the initiation of T cell-dependent immune responses and preventing unwanted, chronic inflammation.


Asunto(s)
Células Epiteliales , Interferón gamma , Factor de Transcripción STAT1 , Linfocitos T , Factor de Crecimiento Transformador beta , Animales , Proliferación Celular , Técnicas de Cocultivo , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Interferón gamma/inmunología , Interferón gamma/metabolismo , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos C57BL , Neumonía/inmunología , Neumonía/fisiopatología , Factor de Transcripción STAT1/inmunología , Factor de Transcripción STAT1/metabolismo , Transducción de Señal/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Tráquea/citología , Tráquea/inmunología , Tráquea/metabolismo , Factor de Crecimiento Transformador beta/inmunología , Factor de Crecimiento Transformador beta/metabolismo
20.
J Exp Med ; 203(9): 2121-33, 2006 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-16908623

RESUMEN

Activation of naive T cells requires the integration of signals through the antigen receptor and CD28. Although there is agreement on the importance of CD28, there remains controversy on the mechanism by which CD28 regulates T cell function. We have generated a gene-targeted knockin mouse expressing a mutation in the C-terminal proline-rich region of the cytoplasmic tail of CD28. Our analysis conclusively showed that this motif is essential for CD28-dependent regulation of interleukin 2 secretion and proliferation. In vivo analysis revealed that mutation of this motif-dissociated CD28-dependent regulation of cellular and humoral responses in an allergic airway inflammation model. Furthermore, we find an important gene dosage effect on the phenotype of the mutation and provide a mechanistic explanation for the conflicting data on the significance of this motif in CD28 function.


Asunto(s)
Formación de Anticuerpos , Antígenos CD28/inmunología , Interleucina-2/metabolismo , Prolina/metabolismo , Linfocitos T/inmunología , Secuencia de Aminoácidos , Animales , Hiperreactividad Bronquial/inmunología , Antígenos CD28/química , Antígenos CD28/genética , Antígenos CD28/metabolismo , Comunicación Celular , Proliferación Celular , Relación Dosis-Respuesta Inmunológica , Centro Germinal/citología , Centro Germinal/inmunología , Inmunoglobulina G/metabolismo , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Mutación , Prolina/química , Transducción de Señal , Proteína bcl-X/metabolismo
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