RESUMEN
Cancer remains one of the leading causes of mortality worldwide, leading to increased interest in utilizing immunotherapy strategies for better cancer treatments. In the past decade, CD103+ T cells have been associated with better clinical prognosis in patients with cancer. However, the specific immune mechanisms contributing toward CD103-mediated protective immunity remain unclear. Here, we show an unexpected and transient CD61 expression, which is paired with CD103 at the synaptic microclusters of T cells. CD61 colocalization with the T cell antigen receptor further modulates downstream T cell antigen receptor signaling, improving antitumor cytotoxicity and promoting physiological control of tumor growth. Clinically, the presence of CD61+ tumor-infiltrating T lymphocytes is associated with improved clinical outcomes, mediated through enhanced effector functions and phenotype with limited evidence of cellular exhaustion. In conclusion, this study identified an unconventional and transient CD61 expression and pairing with CD103 on human immune cells, which potentiates a new target for immune-based cellular therapies.
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Antígenos CD , Apirasa , Cadenas alfa de Integrinas , Receptores de Antígenos de Linfocitos T , Transducción de Señal , Animales , Humanos , Ratones , Antígenos CD/metabolismo , Antígenos CD/inmunología , Línea Celular Tumoral , Citotoxicidad Inmunológica , Cadenas alfa de Integrinas/metabolismo , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Neoplasias/inmunología , Neoplasias/terapia , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores de Antígenos de Linfocitos T/inmunología , Transducción de Señal/inmunología , Linfocitos T Citotóxicos/inmunologíaRESUMEN
NP105-113-B*07:02-specific CD8+ T cell responses are considered among the most dominant in SARS-CoV-2-infected individuals. We found strong association of this response with mild disease. Analysis of NP105-113-B*07:02-specific T cell clones and single-cell sequencing were performed concurrently, with functional avidity and antiviral efficacy assessed using an in vitro SARS-CoV-2 infection system, and were correlated with T cell receptor usage, transcriptome signature and disease severity (acute n = 77, convalescent n = 52). We demonstrated a beneficial association of NP105-113-B*07:02-specific T cells in COVID-19 disease progression, linked with expansion of T cell precursors, high functional avidity and antiviral effector function. Broad immune memory pools were narrowed postinfection but NP105-113-B*07:02-specific T cells were maintained 6 months after infection with preserved antiviral efficacy to the SARS-CoV-2 Victoria strain, as well as Alpha, Beta, Gamma and Delta variants. Our data show that NP105-113-B*07:02-specific T cell responses associate with mild disease and high antiviral efficacy, pointing to inclusion for future vaccine design.
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Antígeno HLA-B7/inmunología , Epítopos Inmunodominantes/inmunología , Proteínas de la Nucleocápside/inmunología , SARS-CoV-2/inmunología , Linfocitos T Citotóxicos/inmunología , Anciano , Secuencia de Aminoácidos , Anticuerpos Antivirales/inmunología , Afinidad de Anticuerpos/inmunología , COVID-19/inmunología , COVID-19/patología , Línea Celular Transformada , Femenino , Perfilación de la Expresión Génica , Humanos , Memoria Inmunológica/inmunología , Masculino , Persona de Mediana Edad , Receptores de Antígenos de Linfocitos T/inmunología , Índice de Severidad de la Enfermedad , Virus Vaccinia/genética , Virus Vaccinia/inmunología , Virus Vaccinia/metabolismoRESUMEN
Increased permeability of the intestinal epithelial layer is linked to the pathogenesis and perpetuation of a wide range of intestinal and extra-intestinal diseases. Infecting humans with controlled doses of helminths, such as human hookworm (termed hookworm therapy), is proposed as a treatment for many of the same diseases. Helminths induce immunoregulatory changes in their host which could decrease epithelial permeability, which is highlighted as a potential mechanism through which helminths treat disease. Despite this, the influence of a chronic helminth infection on epithelial permeability remains unclear. This study uses the chronically infecting intestinal helminth Heligmosomoides polygyrus to reveal alterations in the expression of intestinal tight junction proteins and epithelial permeability during the infection course. In the acute infection phase (1 week postinfection), an increase in intestinal epithelial permeability is observed. Consistent with this finding, jejunal claudin-2 is upregulated and tricellulin is downregulated. By contrast, in the chronic infection phase (6 weeks postinfection), colonic claudin-1 is upregulated and epithelial permeability decreases. Importantly, this study also investigates changes in epithelial permeability in a small human cohort experimentally challenged with the human hookworm, Necator americanus. It demonstrates a trend toward small intestinal permeability increasing in the acute infection phase (8 weeks postinfection), and colonic and whole gut permeability decreasing in the chronic infection phase (24 weeks postinfection), suggesting a conserved epithelial response between humans and mice. In summary, our findings demonstrate dynamic changes in epithelial permeability during a chronic helminth infection and provide another plausible mechanism by which chronic helminth infections could be utilized to treat disease.
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Mucosa Intestinal , Permeabilidad , Animales , Humanos , Mucosa Intestinal/parasitología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/inmunología , Enfermedad Crónica , Nematospiroides dubius/inmunología , Ratones , Necator americanus , Parasitosis Intestinales/inmunología , Uniones Estrechas/metabolismo , Proteínas de Uniones Estrechas/metabolismo , Intestino Delgado/parasitología , Intestino Delgado/inmunología , Femenino , Ratones Endogámicos C57BL , Masculino , Helmintiasis/inmunología , Helmintiasis/parasitología , Necatoriasis/inmunología , Proteína 2 con Dominio MARVEL/metabolismoRESUMEN
BACKGROUND: Surveys suggest most people would prefer to die in their own home. AIM: To examine predictors of place of death over an 11-year period between 2000 and 2010 in Dumfries and Galloway, south west Scotland. DESIGN: Retrospective cohort study. SETTING/PARTICIPANTS: 19,697 Dumfries and Galloway residents who died in the region or elsewhere in Scotland. We explored the relation between age, gender, cause of death (cancer, respiratory, ischaemic heart disease, stroke and dementia) and place of death (acute hospital, cottage hospital, residential care and home) using regression models to show differences and trends. The main acute hospital in the region had a specialist palliative care unit. RESULTS: Fewer people died in their own homes (23.2% vs 29.6%) in 2010 than in 2000. Between 2007 and 2010, men were more likely to die at home than women (p < 0.001), while both sexes were less likely to die at home as they became older (p < 0.001) and in successive calendar years (p < 0.003). Older people with dementia as the cause of death were particularly unlikely to die in an acute hospital and very likely to die in a residential home (p < 0.001). Between 2007 and 2010, an increasing proportion of acute hospital deaths occurred in the specialist palliative care unit (6% vs 11% of all deaths in the study). CONCLUSION: The proportion of people dying at home fell during our survey. Place of death was strongly associated with age, calendar year and cause of death. A mismatch remains between stated preference for place of death and where death occurs.
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Actitud Frente a la Muerte , Hospitales/estadística & datos numéricos , Prioridad del Paciente , Instituciones Residenciales/estadística & datos numéricos , Cuidado Terminal/estadística & datos numéricos , Factores de Edad , Anciano , Anciano de 80 o más Años , Causas de Muerte , Femenino , Hospitales/tendencias , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Instituciones Residenciales/tendencias , Estudios Retrospectivos , Escocia , Factores SexualesRESUMEN
BACKGROUND: The Mexican healthcare system is under increasing strain due to the rising prevalence of non-communicable diseases (especially type 2 diabetes), mounting costs, and a reactive curative approach focused on treating existing diseases and their complications rather than preventing them. Casalud is a comprehensive primary healthcare model that enables proactive prevention and disease management throughout the continuum of care, using innovative technologies and a patient-centred approach. METHODS: Data were collected over a 2-year period in eight primary health clinics (PHCs) in two states in central Mexico to identify and assess enablers and inhibitors of the implementation process of Casalud. We used mixed quantitative and qualitative data collection tools: surveys, in-depth interviews, and participant and non-participant observations. Transcripts and field notes were analyzed and coded using Framework Analysis, focusing on defining and describing enablers and inhibitors of the implementation process. RESULTS: We identified seven recurring topics in the analyzed textual data. Four topics were categorized as enablers: political support for the Casalud model, alignment with current healthcare trends, ongoing technical improvements (to ease adoption and support), and capacity building. Three topics were categorized as inhibitors: administrative practices, health clinic human resources, and the lack of a shared vision of the model. CONCLUSIONS: Enablers are located at PHCs and across all levels of government, and include political support for, and the technological validity of, the model. The main inhibitor is the persistence of obsolete administrative practices at both state and PHC levels, which puts the administrative feasibility of the model's implementation in jeopardy. Constructing a shared vision around the model could facilitate the implementation of Casalud as well as circumvent administrative inhibitors. In order to overcome PHC-level barriers, it is crucial to have an efficient and straightforward adaptation and updating process for technological tools. One of the key lessons learned from the implementation of the Casalud model is that a degree of uncertainty must be tolerated when quickly scaling up a healthcare intervention. Similar patient-centred technology-based models must remain open to change and be able to quickly adapt to changing circumstances.
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Atención a la Salud , Diabetes Mellitus Tipo 2/terapia , Difusión de Innovaciones , Personal de Salud , Servicios de Salud , Instituciones de Atención Ambulatoria , Continuidad de la Atención al Paciente , Diabetes Mellitus Tipo 2/prevención & control , Manejo de la Enfermedad , Administración de los Servicios de Salud , Humanos , México , Modelos Biológicos , Atención Dirigida al Paciente , Atención Primaria de Salud , Investigación CualitativaRESUMEN
Understanding the pattern of gene expression during erythropoiesis is crucial for a synthesis of erythroid developmental biology. Here, we isolated 4 distinct populations at successive erythropoietin-dependent stages of erythropoiesis, including the terminal, pyknotic stage. The transcriptome was determined using Affymetrix arrays. First, we demonstrated the importance of using defined cell populations to identify lineage and temporally specific patterns of gene expression. Cells sorted by surface expression profile not only express significantly fewer genes than unsorted cells but also demonstrate significantly greater differences in the expression levels of particular genes between stages than unsorted cells. Second, using standard software, we identified more than 1000 transcripts not previously observed to be differentially expressed during erythroid maturation, 13 of which are highly significantly terminally regulated, including RFXAP and SMARCA4. Third, using matched filtering, we identified 12 transcripts not previously reported to be continuously up-regulated in maturing human primary erythroblasts. Finally, using transcription factor binding site analysis, we identified potential transcription factors that may regulate gene expression during terminal erythropoiesis. Our stringent lists of differentially regulated and continuously expressed transcripts containing many genes with undiscovered functions in erythroblasts are a resource for future functional studies of erythropoiesis. Our Human Erythroid Maturation database is available at https://cellline.molbiol.ox.ac.uk/eryth/index.html. [corrected].
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Células Precursoras Eritroides/metabolismo , Células Precursoras Eritroides/fisiología , Eritropoyesis/genética , Perfilación de la Expresión Génica , Análisis por Micromatrices , Diferenciación Celular/genética , Células Cultivadas , Análisis por Conglomerados , Eritroblastos/metabolismo , Eritroblastos/fisiología , Células Precursoras Eritroides/química , Eritropoyesis/fisiología , Citometría de Flujo , Perfilación de la Expresión Génica/métodos , Regulación del Desarrollo de la Expresión Génica , Humanos , Análisis por Micromatrices/métodos , Reacción en Cadena de la PolimerasaRESUMEN
Most existing studies characterizing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cell responses are peptide based. This does not allow evaluation of whether tested peptides are processed and presented canonically. In this study, we use recombinant vaccinia virus (rVACV)-mediated expression of SARS-CoV-2 spike protein and SARS-CoV-2 infection of angiotensin-converting enzyme (ACE)-2-transduced B cell lines to evaluate overall T cell responses in a small cohort of recovered COVID-19 patients and uninfected donors vaccinated with ChAdOx1 nCoV-19. We show that rVACV expression of SARS-CoV-2 antigen can be used as an alternative to SARS-CoV-2 infection to evaluate T cell responses to naturally processed spike antigens. In addition, the rVACV system can be used to evaluate the cross-reactivity of memory T cells to variants of concern (VOCs) and to identify epitope escape mutants. Finally, our data show that both natural infection and vaccination could induce multi-functional T cell responses with overall T cell responses remaining despite the identification of escape mutations.
Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , ChAdOx1 nCoV-19 , Vacunación , Anticuerpos AntiviralesRESUMEN
Saxitoxin and its derivatives, the paralytic shellfish toxins (PSTs), are well known to be toxic to humans, and maximum permitted levels in seafood have been established by regulatory authorities in many countries. Monitoring of PSTs is typically performed using chemical methods which quantify the concentration of the individual PST analogues, of which there are many. However, since the toxicities of analogues are different, they do not equally contribute to the overall toxicity of the sample. To account for these differences, toxicity equivalency factors (TEFs) need to be determined for each analogue and applied. Currently there are no established TEFs for decarbamoyl gonyautoxin 1&4 (dcGTX1&4), which occurs in some clam species such as Mactra chinensis contaminated with PSTs due to metabolism within the shellfish. In this study the median lethal dose of purified, equilibrated epimeric mixture of dcGTX1&4 has been determined by intraperitoneal injection (i.p.) (4.75 µmol/kg) and by feeding (34.9 µmol/kg). The most relevant route of exposure is orally with feeding being more representative of human consumption and more reliable than gavage. Based on the median lethal dose by feeding, a TEF of 0.1 is recommended for dcGTX1&4. Receptor binding activity and i.p. toxicity results showed dcGTX1&4 to be much less toxic than STX (140-170-fold). However, by feeding a much smaller difference in toxicity was observed with dcGTX1&4 being only 11-fold less toxic than STX. Analysis of the gut contents of mice dosed with dcGTX1&4 showed the presence of decarbamoyl gonyautoxin 2&3, decarbamoyl saxitoxin and decarbamoyl neosaxitoxin, all of which are of greater toxicity. This conversion of dcGTX1&4 within the digestive track to more toxic congeners may explain the high relative toxicity of dcGTX1&4 by feeding compared to that determined by i.p. and by sodium channel activity.
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Bivalvos , Intoxicación por Mariscos , Animales , Ratones , Saxitoxina/análogos & derivados , Saxitoxina/toxicidad , Mariscos/análisisRESUMEN
Interferon gamma (IFNγ) supports effector responses of CD8+ cytotoxic T lymphocytes (CTLs) and is a surrogate marker for detection of antigen-specific T cells. Here, we show that tumor-specific CTL clones have impaired IFNγ expression and production upon activation. Assessment of the relationship between IFNγ production and the 5'methylcytosine-guanine (CpG) dinucleotide methylation of the IFNγ promoter using bisulfite treatment has shown that IFNγ- CTL clones accumulates CpG hypermethylation within the promoter at key transcription factor binding sites (-186 and -54), known to be vital for transcription. We confirmed these findings using ex vivo isolated and short-term expanded bulk tumor-specific CTL lines from four cancer patients and demonstrated that IFNγ methylation inversely correlates with transcription, protein level, and cytotoxicity. Altogether, we propose that a sizeable portion of human tumor-specific CTLs are deficient in IFNγ response, contributed by CpG hypermethylation of the IFNγ promoter. Our findings have important implications for immunotherapy strategies and for methods to detect human antigen-specific T cells.
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Antígenos de Neoplasias/inmunología , Linfocitos T CD8-positivos/inmunología , Islas de CpG/genética , Metilación de ADN , Interferón gamma/biosíntesis , Humanos , Interferón gamma/genética , Regiones Promotoras GenéticasRESUMEN
Enrichment of CD103+ tumor-infiltrating T lymphocytes (TIL) is associated with improved outcomes in patients. However, the characteristics of human CD103+ cytotoxic CD8+ T cells (CTL) and their role in tumor control remain unclear. We investigated the features and antitumor mechanisms of CD103+ CTLs by assessing T-cell receptor (TCR)-matched CD103+ and CD103- cancer-specific CTL immunity in vitro and its immunophenotype ex vivo Interestingly, we found that differentiated CD103+ cancer-specific CTLs expressed the active form of TGFß1 to continually self-regulate CD103 expression, without relying on external TGFß1-producing cells. The presence of CD103 on CTLs improved TCR antigen sensitivity, which enabled faster cancer recognition and rapid antitumor cytotoxicity. These CD103+ CTLs had elevated energetic potential and faster migration capacity. However, they had increased inhibitory receptor coexpression and elevated T-cell apoptosis following prolonged cancer exposure. Our data provide fundamental insights into the properties of matured human CD103+ cancer-specific CTLs, which could have important implications for future designs of tissue-localized cancer immunotherapy strategies.
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Antígenos CD/metabolismo , Linfocitos T CD8-positivos/inmunología , Cadenas alfa de Integrinas/metabolismo , Neoplasias Pulmonares/inmunología , Linfocitos Infiltrantes de Tumor/inmunología , Neoplasias/inmunología , Linfocitos T Citotóxicos/inmunología , Antígenos CD/inmunología , Humanos , Inmunofenotipificación/métodos , Cadenas alfa de Integrinas/inmunología , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Neoplasias/metabolismo , Neoplasias/patología , Pronóstico , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/inmunología , Factor de Crecimiento Transformador beta1/inmunología , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
Immunotherapy treatments with anti-PD-1 boost recovery in less than 30% of treated cancer patients, indicating the complexity of the tumor microenvironment. Expression of HLA-E is linked to poor clinical outcomes in mice and human patients. However, the contributions to immune evasion of HLA-E, a ligand for the inhibitory CD94/NKG2A receptor, when expressed on tumors, compared with adjacent tissue and peripheral blood mononuclear cells, remains unclear. In this study, we report that epithelial-derived cancer cells, tumor macrophages, and CD141+ conventional dendritic cells (cDC) contributed to HLA-E enrichment in carcinomas. Different cancer types showed a similar pattern of enrichment. Enrichment correlated to NKG2A upregulation on CD8+ tumor-infiltrating T lymphocytes (TIL) but not on CD4+ TILs. CD94/NKG2A is exclusively expressed on PD-1high TILs while lacking intratumoral CD103 expression. We also found that the presence of CD94/NKG2A on human tumor-specific T cells impairs IL2 receptor-dependent proliferation, which affects IFNγ-mediated responses and antitumor cytotoxicity. These functionalities recover following antibody-mediated blockade in vitro and ex vivo Our results suggest that enriched HLA-E:CD94/NKG2A inhibitory interaction can impair survival of PD-1high TILs in the tumor microenvironment.
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Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Antígenos de Histocompatibilidad Clase I/inmunología , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Subfamília C de Receptores Similares a Lectina de Células NK/metabolismo , Subfamília D de Receptores Similares a Lectina de las Células NK/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Linfocitos T CD8-positivos/patología , Línea Celular Tumoral , Citocinas/metabolismo , Citometría de Flujo , Expresión Génica , Antígenos de Histocompatibilidad Clase I/genética , Humanos , Cadenas alfa de Integrinas/genética , Cadenas alfa de Integrinas/metabolismo , Ligandos , Linfocitos Infiltrantes de Tumor/patología , Microambiente Tumoral/inmunología , Antígenos HLA-ERESUMEN
Multiple myeloma is an incurable, bone marrow-dwelling malignancy that disrupts bone homeostasis causing skeletal damage and pain. Mechanisms underlying myeloma-induced bone destruction are poorly understood and current therapies do not restore lost bone mass. Using transcriptomic profiling of isolated bone lining cell subtypes from a murine myeloma model, we find that bone morphogenetic protein (BMP) signalling is upregulated in stromal progenitor cells. BMP signalling has not previously been reported to be dysregulated in myeloma bone disease. Inhibition of BMP signalling in vivo using either a small molecule BMP receptor antagonist or a solubilized BMPR1a-FC receptor ligand trap prevents trabecular and cortical bone volume loss caused by myeloma, without increasing tumour burden. BMP inhibition directly reduces osteoclastogenesis, increases osteoblasts and bone formation, and suppresses bone marrow sclerostin levels. In summary we describe a novel role for the BMP pathway in myeloma-induced bone disease that can be therapeutically targeted.
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Enfermedades Óseas/tratamiento farmacológico , Proteínas Morfogenéticas Óseas/metabolismo , Mieloma Múltiple/complicaciones , Pirazoles/farmacología , Pirimidinas/farmacología , Células Madre/efectos de los fármacos , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Densidad Ósea/efectos de los fármacos , Enfermedades Óseas/etiología , Enfermedades Óseas/patología , Médula Ósea/patología , Receptores de Proteínas Morfogenéticas Óseas/antagonistas & inhibidores , Receptores de Proteínas Morfogenéticas Óseas/metabolismo , Línea Celular Tumoral , Modelos Animales de Enfermedad , Fémur/citología , Fémur/efectos de los fármacos , Fémur/patología , Perfilación de la Expresión Génica , Regulación de la Expresión Génica , Humanos , Inyecciones Intraperitoneales , Ratones , Ratones Endogámicos , Mieloma Múltiple/patología , Osteoclastos/efectos de los fármacos , Osteoclastos/metabolismo , Osteogénesis/efectos de los fármacos , Pirazoles/uso terapéutico , Pirimidinas/uso terapéutico , RNA-Seq , Transducción de Señal/efectos de los fármacos , Células Madre/patología , Tibia/citología , Tibia/efectos de los fármacos , Tibia/patología , Resultado del Tratamiento , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Background: Cancer patients often display dysfunctional antitumor T-cell responses. Because noteworthy benefits of immune checkpoint pathway blockade, such as programmed cell death protein 1 (PD-1) inhibitors, have been achieved in multiple advanced cancers, the next critical question is which mono-blockade or combinatorial blockade regimens may reinvigorate antitumor T-cell immunity in those cancer patients while limiting immune-related adverse effects. Method: This study recruited, in total, 172 primary cancer patients (131 were blood-tumor-matched patients) who were treatment-naïve prior to the surgeries or biopsies covering the eight most prevalent types of cancer. With access to fresh surgical samples, this study simultaneously investigated the ex vivo expression level of eight known immune checkpoint receptors [PD-1, cytotoxic T-lymphocyte antigen-4 [CTLA-4], T-cell immunoglobulin and mucin-domain containing-3 [Tim-3], 2B4, killer cell lectin like receptor G1 [KLRG-1], TIGIT, B- and T-lymphocyte attenuator [BTLA], and CD160] on tumor-infiltrating T cells (TILs) and paired circulating T cells in blood from a 131-patient cohort. Results: We found increased an expression of PD-1 and Tim-3 but a decreased expression of BTLA on TILs when compared with peripheral blood from multiple types of cancer. Moreover, our co-expression analysis of key immune checkpoint receptors delineates "shared" subsets as PD-1+Tim-3+TIGIT+2B4+KLRG-1-CTLA-4- and PD-1+TIGIT+2B4+Tim-3-KLRG-1-CTLA-4- from bulk CD8 TILs. Furthermore, we found that a higher frequency of advanced differentiation stage T cells (CD27-CCR7-CD45RA-) among the "shared" subset (PD-1+Tim-3+TIGIT+2B4+KLRG-1-CTLA-4-) in bulk CD8 TILs was associated with poorly differentiated cancer type in cervical cancer patients. Conclusions: To our knowledge, our study is the first comprehensive analysis of key immune checkpoint receptors on T cells in treatment-naïve, primary cancer patients from the eight most prevalent types of cancer. These findings might provide useful information for future design of mono-blockade/combinatorial blockades and/or genetically modified T-cell immunotherapy.
RESUMEN
Paralytic shellfish poisoning results from consumption of seafood naturally contaminated by saxitoxin and its congeners, the paralytic shellfish toxins (PSTs). The levels of such toxins are regulated internationally, and maximum permitted concentrations in seafood have been established in many countries. A mouse bioassay is an approved method for estimating the levels of PSTs in seafood, but this is now being superseded in many countries by instrumental methods of analysis. Such analyses provide data on the levels of many PSTs in seafood, but for risk assessment, knowledge of the relative toxicities of the congeners is required. These are expressed as "Toxicity Equivalence Factors" (TEFs). At present, TEFs are largely based on relative specific activities following intraperitoneal injection in a mouse bioassay rather than on acute toxicity determinations. A more relevant parameter for comparison would be median lethal doses via oral administration, since this is the route through which humans are exposed to PSTs. In the present study, the median lethal doses of gonyautoxin 5, gonyautoxin 6, decarbamoyl neosaxitoxin and of equilibrium mixtures of decarbamoyl gonyautoxins 2&3, C1&2 and C3&4 by oral administration to mice have been determined and compared with toxicities via intraperitoneal injection. The results indicate that the TEFs of several of these substances require revision in order to more accurately reflect the risk these toxins present to human health.
Asunto(s)
Saxitoxina/análogos & derivados , Administración Oral , Animales , Femenino , Inyecciones Intraperitoneales , Dosificación Letal Mediana , Ratones , Nivel sin Efectos Adversos Observados , Saxitoxina/administración & dosificación , Saxitoxina/toxicidadRESUMEN
Mexico, like many low- and middle-income countries (LMICs), faces an epidemic of chronic non-communicable diseases (NCDs), specifically diabetes, hypertension, obesity, and lipid disorders. Many people with these NCDs may not be aware that they have a disease, pointing to the need for broader screening programs. The traditional prevention policy in Mexico was based on screening with a paper-based risk factor questionnaire. However, this was used to screen patients already seeking healthcare services at facilities, and screening goals were set as a function of the number of questionnaires applied, not number of individuals screened. Due to this, Fundación Carlos Slim developed Medición Integrada para la Detección Oportuna (MIDOTM), or Integrated Measurement for Early Detection, an NCD screening and proactive prevention policy. This document is a policy analysis based on early learnings from the initial implementation of MIDO in eight primary healthcare centers in two central Mexican states. MIDO was found to expand screening programs beyond clinic walls, systematize community screening strategies, emphasize the detection of pre-disease phases, incorporate lifestyle counseling, and propose screening goals based on population targets. In collaboration with the Mexican Ministry of Health, MIDO has successfully screened over 500 000 individuals-about 40% of whom would not have been screened under previous policies. Of these more than 500 000 screened individuals, 13.4% had pre-diabetes (fasting glucose between 100 and 125 mg/dL), and 5.8% had undiagnosed diabetes (defined as fasting glucose above 126 mg/dL or random glucose above 200 mg/dL). However, there is still room for improvement in linking positive results from screening with disease confirmation and with patient incorporation into disease management. The experience of implementing MIDO in Mexico suggests that primary and secondary prevention programs in other parts of the world should consider the need for population-based screening targets, a greater focus on pre-disease stages, and the streamlining of the transition between screening, confirmation of diagnosis, and incorporation of patients into the healthcare system.
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Enfermedad Crónica/prevención & control , Prestación Integrada de Atención de Salud/organización & administración , Política de Salud , Tamizaje Masivo/organización & administración , Enfermedades no Transmisibles/prevención & control , Servicios Preventivos de Salud/organización & administración , Diagnóstico Precoz , Humanos , México , Formulación de PolíticasRESUMEN
For the first time wild-caught Tasmanian abalone, Haliotis rubra, have been reported to contain paralytic shellfish toxins (PSTs). This observation followed blooms of the toxic dinoflagellate Gymnodinium catenatum. No illnesses were reported, but harvesting restrictions were enforced in commercial areas. Abalone were assayed using HPLC-FLD methodology based on AOAC official method 2005.06. An uncommon congener, deoxydecarbamoyl-STX (doSTX), was observed in addition to regulated PSTs as unassigned chromatographic peaks. A quantitative reference material was prepared from contaminated Tasmanian abalone viscera and ampouled at 54.2 µmol/L. The LD50 of doSTX via intraperitoneal injection was 1069 nmol/kg (95% confidence limits 983-1100 nmol/kg), indicating it is nearly 40 times less toxic than STX. A toxicity equivalence factor of 0.042 was generated using the mouse bioassay. Levels of PSTs varied among individuals from the same site, although the toxin profile remained relatively consistent. In the foot tissue, STX, decarbamoyl-STX and doSTX were identified. On a molar basis doSTX was the dominant congener in both foot and viscera samples. The viscera toxin profile was more complex, with other less toxic PST congeners observed and was similar to mussels from the same site. This finding implicates localised dinoflagellate blooms as the PST source in Tasmanian abalone.