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1.
Front Psychol ; 12: 782433, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34819904

RESUMEN

This manuscript builds on research about how university students felt affected by the Covid19 pandemic and, especially, by the irruption of non-face-to-face classes and mixed teaching methods in this context. How have young people experienced this situation? How has it affected their wellbeing and the learning strategies should develop have had to incorporate into their virtual relationships? their virtual relationships? How have they related and relate to virtual tools for a task that they have always experienced face-to-face? To answer these questions, the TRAY-AP project that investigates how university students learn collected 89 scenes that show the effects of the Covid 19 on their lives and the university. We grouped these scenes into seven key concepts to detect how students were emotionally affected, especially by moving from face-to-face to virtual learning. From this analysis, although primarily negative, the emotional effects have also allowed them to generate positive strategies for readaptation and collaboration with other colleagues. All of which opens the way to rethink the predominant pedagogical and knowledge relations in the university.

2.
Transplant Proc ; 53(9): 2724-2727, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34598808

RESUMEN

BACKGROUND: With improvements in survival rates, health-related quality of life is an important outcome parameter to evaluate the effectiveness of transplantation. We aimed to identify potential immunologic abnormalities as factors associated with poorer health-related quality of life at distinct scales of the 36-Item Short Form Health Survey in heart transplant recipients long term after transplantation. METHODS: One hundred heart transplant recipients were evaluated in a single center. Short-form 36 questionnaires were sent by mail to participants. All patients were clinically and immunologically evaluated after the first year of heart transplantation. RESULTS: A high prevalence of several immunologic abnormalities persisted even after the first year of transplantation, including IgG hypogammaglobulinemia, low IgG-specific antipneumococcal antibodies, C4 hypocomplementemia, CD8 T-cell lymphocytopenia, and CD19 B-cell lymphocytopenia. Older recipients (>55 years), posttransplant diabetes, digestive complications, and posttransplant infections were associated with lower physical functioning scores (scale < 60). Older recipients (>55 years), pretransplant diabetes, pretransplant arterial hypertension, posttransplant digestive complications, and lower CD8 counts were associated with lower physical role scores (scale <25). CONCLUSION: In a single center study, lower CD8 cell counts were found to be associated with poorer health status in heart recipients after the first year of transplantation.


Asunto(s)
Trasplante de Corazón , Trasplante de Pulmón , Trasplante de Corazón/efectos adversos , Humanos , Calidad de Vida , Encuestas y Cuestionarios , Tasa de Supervivencia
3.
Immun Ageing ; 17: 22, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32802142

RESUMEN

BACKGROUND: The SARS-CoV-2 infection has widely spread to become the greatest public health challenge to date, the COVID-19 pandemic. Different fatality rates among countries are probably due to non-standardized records being carried out by local health authorities. The Spanish case-fatality rate is 11.22%, far higher than those reported in Asia or by other European countries. A multicentre retrospective study of demographic, clinical, laboratory and immunological features of 584 Spanish COVID-19 hospitalized patients and their outcomes was performed. The use of renin-angiotensin system blockers was also analysed as a risk factor. RESULTS: In this study, 27.4% of cases presented a mild course, 42.1% a moderate one and for 30.5% of cases, the course was severe. Ages ranged from 18 to 98 (average 63). Almost 60 % (59.8%) of patients were male. Interleukin 6 was higher as severity increased. On the other hand, CD8 lymphocyte count was significantly lower as severity grew and subpopulations CD4, CD8, CD19, and NK showed concordant lowering trends. Severity-related natural killer percent descents were evidenced just within aged cases. A significant severity-related decrease of CD4 lymphocytes was found in males. The use of angiotensin-converting enzyme inhibitors was associated with a better prognosis. The angiotensin II receptor blocker use was associated with a more severe course. CONCLUSIONS: Age and age-related comorbidities, such as dyslipidaemia, hypertension or diabetes, determined more frequent severe forms of the disease in this study than in previous literature cohorts. Our cases are older than those so far reported and the clinical course of the disease is found to be impaired by age. Immunosenescence might be therefore a suitable explanation for the hampering of immune system effectors. The adaptive immunity would become exhausted and a strong but ineffective and almost deleterious innate response would account for COVID-19 severity. Angiotensin-converting enzyme inhibitors used by hypertensive patients have a protective effect in regards to COVID-19 severity in our series. Conversely, patients on angiotensin II receptor blockers showed a severer disease.

4.
Movimento (Porto Alegre) ; 22(2): 471-484, abr.-jun. 2016. tab, ilus
Artículo en Español | LILACS | ID: biblio-835034

RESUMEN

El estudio acerca de la construcción de la identidad del profesor en los últimos 20 años ha mostrado la importancia de la formación y de las primeras experiencias docentes para el proceso de aprender a ser profesor. Las evidencias recogidas mediante el análisis de 23 microetnografías y 13 grupos focales, en que han participado un total de 88 profesores, siete de ellos especialistas en Educación Física, nos ha permitido explorar los componentes macro, meso y microsistemas en que los profesores interactúan y dan sentido a su aprender a enseñar. La discusión y contextualización de las experiencias de los docentes en relación a: (a) el ingreso a la formación, (b) la experiencia de la formación inicial y permanente, (c) el concepto de conocimiento y aprendizaje y (d) cómo han aprendido a enseñar, pone de manifiesto la complejidad de ser docente en los días actuales y nos posibilita elaborar recomendaciones para la mejora de la formación y de la inserción en las escuelas.


Studies on the construction of teacher identity in the past 20 years showed the importance of professional development and early teaching experiences for the process of learning how to be a teacher. Evidence was collected by conducting 23 micro-ethnographies and 13 focus groups, in which a total of 88 teachers participated, seven of whom were specialists in Physical Education. It allowed us to explore the components of the ‘macro’, ‘meso’ and ‘micro’ systems in which teachers interact and ascribe meaning to their learning of how to become teachers, and to how they have been constructed as teachers. The complexity involved in learning to be a teacher today was shown by discussion and contextualization of teachers’ experiences regarding: (a) starting their development; (b) experience with initial and continued training; (c) the notion of knowledge and learning; and (d) how they have been learning to teach, allowing us to make recommendations to improve teachers’ training and their placement in schools.


O estudo sobre a construção da identidade do professor nos últimos vinte anos destacou a importância da formação e das primeiras experiências docentes para o processo de aprender a ser professor. As evidências identificadas por meio da análise de 23 microetnografías e de 13 grupos focais, nos quais participaram um total de 88 professores, sete deles especialistas em Educação Física, nos permitiram explorar os componentes dos macro, meso e microsistemas em que os professores interagem e atribuem sentido ao seu aprender a ensinar e a como eles têm se constituído como professores. A discussão e a contextualização das experiências dos professores em relação a: (a) a entrada em formação, (b) a experiência da formação inicial e continuada, (c) o conceito de conhecimento e aprendizagem e (d) como eles têm aprendido a ensinar colocam em evidência a complexidade que implica ser docente hoje e nos possibilita elaborar recomendações para a melhoraria da formação e da inserção nas escolas.


Asunto(s)
Humanos , Crianza del Niño , Educación Primaria y Secundaria , Docentes , Aprendizaje Basado en Problemas
6.
Am J Reprod Immunol ; 71(5): 458-66, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24612159

RESUMEN

PROBLEM: Recurrent reproductive failure (RRF) has been associated with expansion of circulating NK cells, key cells for maternal tolerance, decidual vasculogenesis and embryo growth. This study reports our experience in intravenous immunoglobulin (IVIg) therapy of a large cohort of women with RRF with expanded circulating NK and/or NKT-like cells (blood NKT cells are a heterogeneous subset of T cells that share properties of both T cells and NK cells). METHOD OF STUDY: Observational study of RRF women with NK or NKT-like expansion (>12% or 10% cutoff levels of total lymphocytes, respectively), treated with IVIg for the next gestation. RESULTS: By multivariant logistic regression analysis after adjusting for age, NK cells subsets and other therapies, IVIg significantly improved the live birth rate to 96.3% in women with recurrent miscarriage (RM) compared with 30.6% in case not receiving IVIg (P < 0.0001). In women with recurrent implantation failure (RIF), in comparison with women not receiving IVIg, treatment increased the pregnancy rate from 26.2 to 93.8% (P ≤ 0.0001) and the live birth rate from 17.9 to 80.0% in RIF (P ≤ 0.0001). CONCLUSIONS: Immunomodulation with IVIg in our selected group of RRF patients with immunologic alterations enhanced clinical pregnancy and live birth rates. Our results may facilitate the design of future clinical trials of IVIg in this pathology.


Asunto(s)
Aborto Habitual/tratamiento farmacológico , Inmunoglobulinas Intravenosas/uso terapéutico , Factores Inmunológicos/uso terapéutico , Células Asesinas Naturales/efectos de los fármacos , Células T Asesinas Naturales/efectos de los fármacos , Aborto Habitual/inmunología , Aborto Habitual/patología , Adulto , Femenino , Fertilización In Vitro , Humanos , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/patología , Nacimiento Vivo , Modelos Logísticos , Recuento de Linfocitos , Células T Asesinas Naturales/inmunología , Células T Asesinas Naturales/patología , Embarazo , Insuficiencia del Tratamiento
8.
Am J Reprod Immunol ; 70(1): 59-68, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23480226

RESUMEN

PROBLEM: Natural killer (NK) cells play a key role in embryo implantation and pregnancy success, whereas blood and uterine NK expansions have been involved in the pathophysiology of reproductive failure (RF). Our main goal was to design in a large observational study a tree-model decision for interpretation of risk factors for RF. METHODS OF STUDY: A hierarchical multivariate decision model based on a classification and regression tree was developed. NK and NKT-like cell subsets were analyzed by flow cytometry. RESULTS: By multivariate analysis, blood NK cells expansion was an independent risk factor for RF (both recurrent miscarriages and implantation failures). We propose a new decision-tree model for the risk interpretation of women with RF based on a combination of main risk factors. CONCLUSIONS: Women with age above 35 years and >13% CD56⁺CD16⁺ NK cells showed the highest risk of further pregnancy loss (100%).


Asunto(s)
Aborto Habitual/inmunología , Antígeno CD56/inmunología , Técnicas de Apoyo para la Decisión , Pérdida del Embrión/inmunología , Células Asesinas Naturales/inmunología , Receptores de IgG/inmunología , Adulto , Femenino , Proteínas Ligadas a GPI/inmunología , Humanos , Embarazo , Factores de Riesgo
9.
Am J Reprod Immunol ; 68(1): 75-84, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22509929

RESUMEN

PROBLEM: Natural killer (NK, CD3(-)CD56(+)/CD16(+)) and NKT-like cells (CD3(+)CD56(+)/CD16(+)) activity is considered among the key factors for reproductive success. In the absence of immunological screening, beneficial effects of intravenous immunoglobulin (IVIG) in preventing recurrent reproductive failure (RRF) have not been reported. Here, we analyse the IVIG influence on pregnancy success in women with RRF and circulating NK or/and NKT-like cells expansion. METHOD OF STUDY: One hundred fifty-seven women with previous recurrent miscarriage and/or recurrent implantation failure after in vitro fertilization were consecutively studied. Sixty-four patients with CD56(+) cell expansion, no apparent underlying disease and who maintained their desire to conceive were selected. Forty of them received IVIG during pregnancy. RESULTS: Overall, the clinical pregnancy rate for the women under IVIG therapy was 92.5% and the live birth rate was 82.5%. Significantly lower pregnancy and live birth rates (25% and 12.5%, respectively) were observed for the patients with recurrent pregnancy loss and NK/NKT-like cells expansion without IVIG. After three cycles of IVIG, NK cell percentages decreased significantly and these values persisted throughout gestation. CONCLUSION: Intravenous immunoglobulin therapy for women with RRF and NK or NKT-like cell expansion was a safe and beneficial therapeutic strategy that associated with high clinical pregnancy and live birth rates.


Asunto(s)
Aborto Habitual/prevención & control , Inmunoglobulinas Intravenosas/administración & dosificación , Factores Inmunológicos/administración & dosificación , Células Asesinas Naturales/inmunología , Nacimiento Vivo , Células T Asesinas Naturales/inmunología , Aborto Habitual/sangre , Aborto Habitual/inmunología , Adulto , Femenino , Humanos , Células Asesinas Naturales/metabolismo , Recuento de Linfocitos , Células T Asesinas Naturales/metabolismo , Embarazo , Estudios Retrospectivos , España
10.
Inmunología (1987) ; 31(1): 13-20, ene.-mar. 2012. ilus, tab
Artículo en Inglés | IBECS | ID: ibc-108930

RESUMEN

Aim: Haemophagocytic lymphohistiocytosis (HLH) is characterised by T cell and macrophage activation and excessive production of inflammatory cytokines. Genetic diagnosis is required to discriminate between primary forms (familial HLH, FHL), due to mutations in genes involved in cytolysis, and secondary forms. We aimed to analyse the genes coding for Munc13-4 (UNC13D) and syntaxin-11 (STX11) proteins in search of mutations that might explain HLH in 5 patients without perforin defects. Materials and methods: Perforin expression was evaluated by flow cytometry, sCD25 was measured by ELISA and NK activity was investigated by the conventional functional assay. Coding regions and exons surroundings were sequenced for PRF1, UNC13D and STX11 genes. Results: P1 and P2 developed severe early-onset HLH, P1 died at 6 months. P3, with a sister who died after HLH, responded well to treatment (HLH-2004), and had a second HLH episode two years later. P2 developed HLH at year 7 while in complete remission after lymphoblastic leukaemia. P4 and P5 were brothers who died at 5 and 6 years old due to an HLH and EBV mononucleosis infection. XLP was discarded because P4 was a girl. P1 and P3 showed mutations in UNC13D previously described as pathogenic. There were no changes in STX11.Conclusions: UNC13D mutations were found in 50% of the HLH families without perforin defects and STX11 defects were not detected. These results agree with published series in which mutations in UNC13D explain up to 50% of FHL without PRF1 mutations, supporting a heterogeneous genetic background for this disease (AU)


Objetivo: La linfohistiocitosis hemofagocítica (HLH) se caracteriza por la activación incontrolada de células T y macrófagos y producción excesiva de citoquinas inflamatorias. El diagnóstico genético es necesario para distinguir entre formas primarias (HLH familiar, FHL),debidas a mutaciones en genes implicados en citolisis, y secundarias. Nuestro objetivo es analizar la presencia de mutaciones en los genes que codifican para Munc13-4 (UNC13D) ysintaxina-11 (STX11) en cinco pacientes con HLH no asociado a defecto de perforina. Materiales y métodos: Se evaluó la expresión de perforina por citometría, CD25s por ELISA y la actividad NK con un ensayo funcional. Se secuenciaron los exones y regiones flanqueantes de los genes PRF1, UNC13D y STX11.Resultados: P1 y P2 desarrollaron HLH severo de inicio temprano, P1 falleció con 6 meses. P3,con una hermana fallecida tras HLH, respondió adecuadamente al tratamiento (HLH-2004),presentando un segundo episodio dos años después. P2 desarrolló HLH a los 7 años de edad estando en remisión completa de una leucemia linfoblástica previa. P4 y P5 son hermanos que fallecieron con 5 y 6 años tras HLH y mononucleosis por infección EBV. Se descartó XLP ya que uno de los pacientes era niña. P1 y P3 presentaron mutaciones en UNC13D previamente descritas como patogénicas. No se encontraron alteraciones en STX11.Conclusiones: Se encontraron mutaciones en UNC13D en el 50% de las familias con HLH sin defectos de perforina y no se detectaron defectos en STX11. Este resultado concuerda con series publicadas en las que mutaciones en UNC13D explican hasta el 50% de la FLH sin mutaciones en PRF1, y apoyan una base genética muy heterogénea para esta enfermedad (AU)


Asunto(s)
Humanos , Masculino , Femenino , Perforina/genética , Linfohistiocitosis Hemofagocítica/genética , Citometría de Imagen/métodos , Mutación/genética
11.
J Clin Invest ; 121(10): 3872-6, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21926461

RESUMEN

T cells recognize antigens via their cell surface TCR and are classified as either αß or γδ depending on the variable chains in their TCR, α and ß or γ and δ, respectively. Both αß and γδ TCRs also contain several invariant chains, including CD3δ, which support surface TCR expression and transduce the TCR signal. Mutations in variable chains would be expected to affect a single T cell lineage, while mutations in the invariant chains would affect all T cells. Consistent with this, all CD3δ-deficient patients described to date showed a complete block in T cell development. However, CD3δ-KO mice have an αß T cell-specific defect. Here, we report 2 unrelated cases of SCID with a selective block in αß but not in γδ T cell development, associated with a new splicing mutation in the CD3D gene. The patients' T cells showed reduced CD3D transcripts, CD3δ proteins, surface TCR, and early TCR signaling. Their lymph nodes showed severe T cell depletion, recent thymus emigrants in peripheral blood were strongly decreased, and the scant αß T cells were oligoclonal. T cell-dependent B cell functions were also impaired, despite the presence of normal B cell numbers. Strikingly, despite the specific loss of αß T cells, surface TCR expression was more reduced in γδ than in αß T cells. Analysis of individuals with this CD3D mutation thus demonstrates the contrasting CD3δ requirements for αß versus γδ T cell development and TCR expression in humans and highlights the diagnostic and clinical relevance of studying both TCR isotypes when a T cell defect is suspected.


Asunto(s)
Complejo CD3/genética , Mutación , Inmunodeficiencia Combinada Grave/genética , Inmunodeficiencia Combinada Grave/inmunología , Subgrupos de Linfocitos T/inmunología , Animales , Linfocitos B/inmunología , Secuencia de Bases , Análisis Mutacional de ADN , Femenino , Humanos , Lactante , Células Asesinas Naturales/inmunología , Masculino , Ratones , Linaje , Sitios de Empalme de ARN/genética , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Receptores de Antígenos de Linfocitos T gamma-delta/metabolismo , Inmunodeficiencia Combinada Grave/etiología
12.
J Allergy Clin Immunol ; 128(5): 1050-7, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21757226

RESUMEN

BACKGROUND: CD3δ deficiency is a fatal form of severe combined immunodeficiency that can be cured by hematopoietic stem cell transplantation (HSCT). The presence of a thymus loaded with T-cell progenitors in patients with CD3δ deficiency may require special considerations in choosing the regimen of conditioning and the type of HSCT. OBJECTIVES: To study the outcome of CD3δ deficiency by using various modalities of stem cell transplantation. METHODS: We analyzed data on 13 patients with CD3δ deficiency who underwent HSCT in 7 centers. HSCT was performed by using different sources of donor stem cells as well as various conditioning regimens. RESULTS: One patient received stem cells from a matched related donor and survived after a second transplant, needing substantial conditioning in order to engraft. Only 2 of 7 other patients who received a mismatched related donor transplant survived; 2 of them had no conditioning, whereas the others received various combinations of conditioning regimens. Engraftment of T cells in the survivors appears incomplete. Three other patients who received stem cells from a matched unrelated donor survived and enjoyed full immune reconstitution. Two patients received unrelated cord blood without conditioning. One of them has had a partial but stable engraftment, whereas the other engrafted well but is only 12 months after HSCT. We also report here for the first time that patients with CD3δ deficiency can present with typical features of Omenn syndrome. CONCLUSIONS: HSCT is a successful treatment for patients with CD3δ deficiency. The small number of patients in this report prevents definitive statements on the importance of survival factors, but several are suggested: (1) HLA-matched donor transplants are associated with superior reconstitution and survival than are mismatched donor transplants; (2) substantial conditioning appears necessary; and (3) early diagnosis and absence of opportunistic infections may affect outcome.


Asunto(s)
Complejo CD3/inmunología , Trasplante de Células Madre Hematopoyéticas/métodos , Inmunodeficiencia Combinada Grave/inmunología , Inmunodeficiencia Combinada Grave/cirugía , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Complicaciones Posoperatorias/epidemiología , Acondicionamiento Pretrasplante/métodos
14.
Invest New Drugs ; 29(6): 1156-63, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-20524037

RESUMEN

B-cell chronic lymphocytic leukemia (B-CLL) is an abnormal neoplasic proliferation of B cells, which accumulate mainly in the bone marrow and blood preventing both B cells development in the lymph nodes and the ability to fight against infection. The antitumor agents used in chemotherapy are aimed at inducing malignant cell death, thus limiting the growth and spreading of these cells. However, the lack of specificity for tumor cells exhibited by these agents causes undesirable side effects that have led to the investigation of new therapeutic strategies designed to specifically target malignant cells and thus trigger selective cell destruction. Dequalinium (DQA) is an antitumoral agent that selectively accumulates in the mitochondria and has been shown to display anticancer activity in cells from different malignancies. In the present study, the DQA-induced cytotoxicity in B-CLL cells was analyzed by measuring cell viability and cell death, either by necrosis or apoptosis. Our results support the importance of DQA as a selective and potential antileukemic drug with a higher cytotoxic effect on peripheral blood mononuclear cells from B-CLL patients than in those from healthy donors and encourage the performance of further studies in combination with other agents.


Asunto(s)
Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Decualinio/farmacología , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Antineoplásicos/toxicidad , Supervivencia Celular/efectos de los fármacos , Decualinio/toxicidad , Humanos , Técnicas In Vitro , Leucemia Linfocítica Crónica de Células B/patología , Leucocitos Mononucleares/efectos de los fármacos , Necrosis/inducido químicamente
16.
Transplantation ; 88(3 Suppl): S54-61, 2009 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-19667963

RESUMEN

BACKGROUND: Fully human leukocyte antigens (HLA)-mismatched liver grafts are well accepted, but the HLA influence on acceptance or rejection is unclear and much less so the impact of HLA-C, which may be conditioned by the fact that HLA-C-encode molecules are the major ligands for killer cell immunoglobulin-like receptors (KIR). METHODS: The HLA-C allele compatibility and the effect of donor and recipient HLA-C genotype on early liver graft acceptance and on CD8KIR T-cells recuperation were analyzed in a series of 431 primary liver transplants. Standard polymerase chain reaction PCR-SSO was used for HLA-C typing and flow cytometry to identify T cells KIR positives. Transplants were classified into two groups: acute rejection and nonacute rejection, and individual HLA-C genotypes as C1/C1, C2/C2, and C1/C2. RESULTS: A favorable effect of HLA-C allelic compatibility on early liver graft acceptance was found because acute rejection significantly increased in transplants performed with 2 HLA-C allele mismatches (P=0.02). Considering the HLA-C groups, it was observed that C1/C2 heterozygous donors were best accepted in C1/C1 patients than in C2/C2 recipients, who experienced a high rate of acute rejection (P<0.004 and P<0.005, respectively). In addition, after transplantation CD3CD8KIR2D T-cells repertoires significantly increased in C1/C1 and C1/C2, but not in C2/C2 patients. CONCLUSIONS: This study confirms the benefit of HLA-C allele matching on early liver transplant outcome and shows that donor HLA-C heterozygosis influences the alloresponse of C1 and C2 homozygous patients and the recuperation of CD3CD8KIR2D T cells, suggesting an involvement in liver graft tolerance.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Antígenos HLA-C/inmunología , Trasplante de Hígado/inmunología , Receptores KIR/inmunología , Donantes de Tejidos/estadística & datos numéricos , Estudios de Cohortes , ADN/genética , ADN/aislamiento & purificación , Citometría de Flujo , Tamización de Portadores Genéticos , Genotipo , Rechazo de Injerto/genética , Rechazo de Injerto/inmunología , Supervivencia de Injerto/genética , Supervivencia de Injerto/inmunología , Antígenos HLA/inmunología , Antígenos HLA-C/genética , Prueba de Histocompatibilidad/métodos , Humanos , Inmunosupresores/uso terapéutico
18.
Blood ; 113(2): 338-46, 2009 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-18927437

RESUMEN

Perforin-mediated lymphocyte cytotoxicity is critical for pathogen elimination and immune homeostasis. Perforin disruption of target cell membranes is hypothesized to require binding of a calcium-dependent, lipid-inserting, C2 domain. In a family affected by hemophagocytic lymphohistiocytosis, a severe inflammatory disorder caused by perforin deficiency, we identified 2 amino acid substitutions in the perforin C2 domain: T435M, a previously identified mutant with disputed pathogenicity, and Y438C, a novel substitution. Using biophysical modeling, we predicted that the T435M substitution, but not Y438C, would interfere with calcium binding and thus cytotoxic function. The capacity for cytotoxic function was tested after expression of the variant perforins in rat basophilic leukemia cells and murine cytotoxic T lymphocytes. As predicted, cells transduced with perforin-T435M lacked cytotoxicity, but those expressing perforin-Y438C displayed intact cytotoxic function. Using novel antibody-capture and liposome-binding assays, we found that both mutant perforins were secreted; however, only nonmutated and Y438C-substituted perforins were capable of calcium-dependent lipid binding. In addition, we found that perforin-Y438C was capable of mediating cytotoxicity without apparent proteolytic maturation. This study clearly demonstrates the pathogenicity of the T435M mutation and illustrates, for the first time, the critical role of the human perforin C2 domain for calcium-dependent, cytotoxic function.


Asunto(s)
Calcio/inmunología , Membrana Celular/inmunología , Lípidos de la Membrana/inmunología , Mutación Missense/inmunología , Perforina/inmunología , Linfocitos T Citotóxicos/inmunología , Sustitución de Aminoácidos/inmunología , Animales , Línea Celular Tumoral , Membrana Celular/genética , Homeostasis/inmunología , Humanos , Inmunidad Celular/genética , Inmunidad Celular/inmunología , Ratones , Perforina/genética , Estructura Terciaria de Proteína/genética , Ratas
19.
Leuk Lymphoma ; 49(1): 95-101, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18203018

RESUMEN

Follicular lymphomas (FLs) usually carry BCL2 translocations although BCL6 translocations are also present. We explored relationships between translocations status and clinical or histological parameters at diagnosis in 182 patients stratified in four groups: BCL2-/BCL6-, BCL2+/BCL6-, BCL2-/BCL6+ and BCL2+/BCL6+. BCL2-/BCL6- and BCL2+/BCL6-. Double negative cases were ascribed to lower histological grades. In contrast, BCL2-/BCL6+ cases corresponded to higher grades. However, a majority of BCL2+/BCL6+ tumours were classified as lower grades. These results were reinforced by the finding that double positive patients had lower LDH levels and PS than those with solitary BCL6 rearrangements. Bone marrow involvement was more frequent in BCL2+/BCL6+ compared with BCL2-/BCL6+ tumours. Our data confirm the presence of a relationship between histological grade and translocation status, suggesting that FLs carrying BCL6 translocations probably constitute a special biological subtype. Clinical and histological differences between BCL2-/BCL6+ and BCL2+/BCL6+ tumours could reflect an interplay between both translocations.


Asunto(s)
Genes bcl-2/genética , Linfoma Folicular/diagnóstico , Linfoma Folicular/genética , Proteínas Proto-Oncogénicas c-bcl-6/genética , Translocación Genética , Adulto , Anciano , Médula Ósea , Análisis Citogenético , Frecuencia de los Genes , Humanos , Hibridación Fluorescente in Situ , Persona de Mediana Edad , Análisis de Supervivencia
20.
Haematologica ; 91(9): 1257-60, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16956828

RESUMEN

Perforin gene (PRF1) mutations have been reported in 20-30% of patients with familial hemophagocytic lymphohistiocytosis (FHL), an autosomal recessive disorder of infancy and early childhood that impairs or abolishes lymphocyte cytotoxicity. We report the first case of FHL in an adult patient homozygous for A91V in PRF1 with tuberculosis. The monozygotic twin of the patient is healthy. A91V confers genetic susceptibility for the development of FHL, but is not enough to trigger the disease on its own. We discuss the role of the A91V change together with M. tuberculosis infection as synergistic factors in the late onset of FHL.


Asunto(s)
Linfohistiocitosis Hemofagocítica/etiología , Glicoproteínas de Membrana/genética , Mutación Missense , Tuberculosis/complicaciones , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Perforina , Proteínas Citotóxicas Formadoras de Poros , Gemelos Monocigóticos
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