T-cell commitment inheritance-an agent-based multi-scale model.

T-cell development provides an excellent model system for studying lineage commitment from a multipotent progenitor. The intrathymic development process has been thoroughly studied. The molecular circuitry controlling it has been dissected and the necessary steps like programmed shut off of progenitor genes and T-cell genes upregulation have been revealed. However, the exact timing between decision-making and commitment stage remains unexplored. To this end, we implemented an agent-based multi-scale model to investigate inheritance in early T-cell development. Treating each cell as an agent provides a powerful tool as it tracks each individual cell of a simulated T-cell colony, enabling the construction of lineage trees. Based on the lineage trees, we introduce the concept of the last common ancestors (LCA) of committed cells and analyse their relations, both at single-cell level and population level. In addition to simulating wild-type development, we also conduct knockdown analysis. Our simulations predicted that the commitment is a three-step process that occurs on average over several cell generations once a cell is first prepared by a transcriptional switch. This is followed by the loss of the Bcl11b-opposing function approximately two to three generations later. This is when our LCA analysis indicates that the decision to commit is taken even though in general another one to two generations elapse before the cell actually becomes committed by transitioning to the DN2b state. Our results showed that there is decision inheritance in the commitment mechanism.

Durability of neutralizing antibodies and T-cell response post SARS-CoV-2 infection / 医学前沿

The ongoing pandemic of Coronavirus disease 19 (COVID-19) is caused by a newly discovered β Coronavirus named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). How long the adaptive immunity triggered by SARS-CoV-2 can last is of critical clinical relevance in assessing the probability of second infection and efficacy of vaccination. Here we examined, using ELISA, the IgG antibodies in serum specimens collected from 17 COVID-19 patients at 6-7 months after diagnosis and the results were compared to those from cases investigated 2 weeks to 2 months post-infection. All samples were positive for IgGs against the S- and N-proteins of SARS-CoV-2. Notably, 14 samples available at 6-7 months post-infection all showed significant neutralizing activities in a pseudovirus assay, with no difference in blocking the cell-entry of the 614D and 614G variants of SARS-CoV-2. Furthermore, in 10 blood samples from cases at 6-7 months post-infection used for memory T-cell tests, we found that interferon γ-producing CD4

Microdeletion 22q11.2 syndrome: Does thymus incidental surgical resection affect its immunological profile?

Background: The del22q11 syndrome patients present immunological abnormalities associated to thymus alterations. Up to 75% of them present cardiopathies and thymus is frequently removed during surgery. The thymectomy per se has a deleterious effect concerning lymphocyte subpopulations, and T cell function. When compared to healthy controls, these patients have higher infections propensity of variable severity. The factors behind these variations are unknown. We compared immunological profiles of del22q11.2 Syndrome patients with and without thymectomy to establish its effect in the immune profile. Methods: Forty-six del22q11.2 syndrome patients from 1 to 16 years old, 19 of them with partial or total thymectomy were included. Heart disease type, heart surgery, infections events and thymus resection were identified. Immunoglobulin levels, flow cytometry for lymphocytes subpopulations and TREC levels were determined, and statistical analyses were performed. Results: The thymectomy group had a lower lymphocyte index, both regarding total cell count and when comparing age-adjusted Z scores. Also, CD3+, CD4+ and CD8+ lower levels were observed in this group, the lowest count in those patients who had undergone thymus resection during the first year of life. Their TREC level median was 23.6/μL vs 16.1 miL in the non-thymus group (p = 0.22). No differences were identified regarding immunoglobulin levels or infection events frequencies over the previous year. Conclusion: Patients with del22q11.2 syndrome subjected to thymus resection present lower lymphocyte and TREC indexes when compared to patients without thymectomy. This situation may be influenced by the age at the surgery and the time elapsed since the procedure

No disponible

Evaluation of immunological parameters in pregnant women: low levels of B and NK cells / Avaliação dos parâmetros imunológicos em mulheres gestantes: baixos níveis de células B e NK

Abstract Objective To describe the immunological and hematological reference intervals of low-risk pregnant women. Methods A cross-sectional retrospective database analysis of a basic and translational study analyzing the hematological evaluation blood counts and immunophenotyping of TCD3 + , TCD4 + , TCD8 + , B, and natural killer (NK) cells of the peripheral blood in 79 low-risk pregnant women and of 30 control women from the state of Pernambuco, Brazil, was performed. Results No significant differences were detected between the hematological profiles of the 2nd and 3rd trimesters. Nevertheless, the median level of B cells decreased significantly in the 2nd (174 x 103 μL; p < 0.002) and 3rd trimesters (160 x 103 μL; p < 0.001), compared with the control group (296 x 103 μL). Similarly, the median level of NK cells was lower in the 2nd (134 x 103 μL; p < 0.0004) and 3rd trimesters (100 x 103 μL, p < 0.0004), compared with the control group (183 x 103 μL). In contrast, relative TCD4+ and TCD8+ levels increased in the 2nd and 3rd trimesters compared with the controls (TCD4 + : 2nd trimester = 59%; p < 0.001; 3rd trimester = 57%; p < 0.01; control = 50%; and TCD8 + : 2nd trimester = 31%; p < 0.001; 3rd trimester = 36%; p < 0.01; control = 24%). Conclusion Low-risk pregnant women have ~ 40% less B and NK cells in the peripheral blood, compared with non-pregnant women. These parameters may improve health assistance for mothers and contribute to define reference values for normal pregnancies.

Resumo Objetivo Descrever o intervalo de referência imunológico e hematológico de gestantes de baixo risco. Métodos Realizou-se uma análise retrospectiva, de um estudo básico e translacional, analisando o perfil hematológico e a imunofenotipagem das células TCD3 + , TCD4 + , TCD8 + , B e natural killer (NK) do sangue periférico de 79 gestantes de baixo risco e de 30 mulheres (controles) do estado de Pernambuco, Brasil. Resultados Não observamos diferenças significativas entre os perfis hematológicos do 2° e 3° trimestres. No entanto, houve redução das células B no 2° (média = 174 x 103 μL; p < 0,002) e no 3° trimestres (160 x 103 μL; p < 0,001), comparado como grupo controle (296 x 103 μL). A mediana das células NK foi menor no 2° (134 x 103 μL; p < 0,0004) e no 3° trimestres (100 x 103 μL; p < 0,0004), comparado com o grupo controle (183 x 103 μL). Porém, o percentual de TCD4+ e de TCD8+ aumentou no 2° e 3° trimestres em relação aos controles (TCD4 + : 2° trimestre = 59%; p < 0,001; 3° trimestre = 57%; p < 0,01; controle = 50%; e TCD8 + : 2° trimestre = 31%; p < 0,001; 3° trimestre = 36%; p < 0,01; controle = 24%). Conclusão Mulheres grávidas de baixo risco têm ~ 40% menos células B e NK no sangue periférico em comparação com mulheres não grávidas. Estes parâmetros podem melhorar a assistência à saúde das mães e contribuir para a definição de valores de referência para gestações normais.

Immunosenescence: participation of T lymphocytes and myeloid-derived suppressor cells in aging-related immune response changes / Imunosenescência: participação de linfócitos T e células mieloides supressoras nas alterações da resposta imune relacionadas ao envelhecimento

ABSTRACT Healthy aging is partly related to appropriate function of the immune system. As already reported, some changes in this system are observed, including reduced number and repertoire of T cells due to thymic involution, accumulation of memory T cells by chronic infections, homeostatic proliferation compensating for the number of naïve T cells, decreased proliferation of T cells against a stimulus, telomere shortening, replicative senescence of the T cells, and inflammaging, besides the accumulation of myeloid-derived suppressor cells. The purpose of this article is to clarify each of these changes, aiming to minimize limitations of immunosenescence. If such associations can be established, these cells may be used as early and less invasive markers of aging-related diseases, as well as to indicate interventions, evaluate the efficacy of interventions and be a tool to achieve longevity with quality of life.

RESUMO O envelhecimento saudável está relacionado, pelo menos em parte, com a função adequada do sistema imunológico. Isso porque já foi relatado que, com o envelhecimento, algumas mudanças desse sistema são observadas, como a diminuição da percentagem e do repertório de células T pela involução tímica, acúmulo de células T de memória por infecções crônicas, compensação do número de células T naïve por proliferação homeostática, diminuição da capacidade de proliferação das células T frente a um estímulo, encurtamento dos telômeros, senescência replicativa das células T, e inflammaging, além do acúmulo de células mieloides supressoras. Este artigo visa esclarecer cada uma das mudanças, mencionadas, com o intuito de buscar meios de minimizar as limitações da imunosenescência. Caso seja possível estabelecer tais relações, essas células podem ser utilizadas como marcadores precoces e pouco invasivos de doenças relacionadas ao envelhecimento, além da possibilidade de serem utilizadas para indicar intervenções, avaliar a eficácia das intervenções e como ferramenta para alcance da longevidade com qualidade de vida.

Immune System Dysfunction in the Elderly

ABSTRACT Human aging is characterized by both physical and physiological frailty that profoundly affects the immune system. In this context aging is associated with declines in adaptive and innate immunity established as immunosenescence. Immunosenescence is a new concept that reflects the age-associated restructuring changes of innate and adaptive immune functions. Thus elderly individuals usually present chronic low-level inflammation, higher infection rates and chronic diseases. A study of alterations in the immune system during aging could provide a potentially useful biomarker for the evaluation of immune senescence treatment. The immune system is the result of the interplay between innate and adaptive immunity, yet the impact of aging on this function is unclear. In this article the function of the immune system during aging is explored.

Inmunoterapia genética con células dendríticas para el tratamiento del cáncer / Dendritic cells in cancer immunotherapy

Desde comienzos del siglo XX, los científicos han intentado aprovechar las actividades naturales del sistema inmunológico para curar el cáncer. Sin embargo, las inmunoterapias no han dado el resultado clínico que podría haberse esperado. De hecho, lo tratamientos anti-neoplásicos clásicos como la cirugía, la radioterapia y la quimioterapia siguen consistiendo en la primera línea de tratamiento. Aun así, existe un gran número de evidencias experimentales sobre la inmunogenicidad de las células cancerosas. Sin embargo, la activación efectiva de las respuestas T anti-cancerosas depende estrechamente de la presentación eficiente de antígenos tumorales por parte de células presentadoras de antígeno profesionales, como las células dendríticas (dendritic cells, DC). Aunque se han desarrollado un gran número de estrategias para reforzar las funciones de presentación de antígeno de las DC, la inmunoterapia como tratamiento anti-neoplásico todavía no es tan efectiva como esperaríamos de acuerdo con los resultados obtenidos en modelos preclínicos durante las últimas décadas. En este trabajo no pretendemos revisar exhaustivamente la inmunoterapia con DC, un campo ampliamente extenso y tratado en otras revisiones especializadas. Aquí se exponen la experiencias que nuestro grupo ha llevado a cabo durante la última década modificando genéticamente a las DC para mejorar su eficacia anti-tumoral (AU)

Since the beginning of the 20th century, biomedical scientists have tried to take advantage of the natural anti-cancer activities of the immune system. However, all the scientific and medical efforts dedicated to this have not resulted in the expected success. In fact, classical antineoplastic treatments such as surgery, radio and chemotherapy are still first line treatments. Even so, there is a quantity of experimental evidence demonstrating that cancer cells are immunogenic. However, the effective activation of anti-cancer T cell responses closely depends on an efficient antigen presentation carried out by professional antigen presenting cells such as DC. Although there are a number of strategies to strengthen antigen presentation by DC, anti-cancer immunotherapy is not as effective as we would expect according to preclinical data accumulated in recent decades. We do not aim to make an exhaustive review of DC immunotherapy here, which is an extensive research subject already dealt with in many specialised reviews. Instead, we present the experimental approaches undertaken by our group over the last decade, by modifying DC to improve their antitumour capacities (AU)

Caracterización del infiltrado linfocitario (CD, CD4, CD8, CD45RO y FOXP3) e inestabilidad microsatelital en pacientes con cáncer colorrectal / Lymphocyte infiltration and microsatellite instability in colorectal cancer patients

Background: In colorectal cancer (CRC) patients, lymphocyte infiltration (LI) and microsatellite instability (MSI) have been associated with better prognosis. Aim: To analyze the association between components of LI (CD3/CD4/CD8/CD45R0/FoxP3) and MSI status with metastatic stages in CRC patients. Material and Methods: Prospective study of 109 patients diagnosed with CRC. The expression of CD3, CD4, CD8, CD45R0 and FoxP3 markers, was evaluated by immunohistochemical analysis, and tumors were classified into negative, low and intense expression. The MSI was assessed with seven markers amplified by PCR from normal and tumoral DNA. Tumors were grouped in MSS (stable)/MSI-low and MSI-high. Statistical analysis was performed with Fischer's exact test. Results: 29 percent, 28 percent, 12 percent and 86 percent of tumors exhibits intense expression of CD3+, CD4+, CD8+ and CD45RO+ lymphocytes, respectively. 84 percent of the tumors presented MSS/ MSI-low and 16 percent had MSI-high. Tumors that show a high density of T cells (CD3+, CD4+ y CD45R0+) are associated with early stage tumors (I and II) (p = 0.023; p = 0.030 and p = 0.003, respectively). Additionally, there was a significant association between the MSS/MSI-low tumors and a reduced ability to recruit CD8+ cytotoxic T lymphocytes (p = 0.037) and CD3+ (p = 0.064). Conclusion: There is an association between high densities of CD3+, CD4+ and CD45RO+ lymphocytes and non-metastatic tumors. In addition, MSS/ MSI-low tumors are associated with a lower recruitment of CD8+ and CD3+ lymphocytes.

Introducción: En el cáncer colorrectal (CCR), se sugiere que un mejor pronóstico podría asociarse a una respuesta inmune antitumoral (del huésped) y/o a la presencia de una alta inestabilidad microsatelital (MSI). Objetivo: Determinar si los niveles de expresión de los marcadores de linfocitos T (CD3/CD4/CD8/ CD45RO/FoxP3) y el estado de MSI se asocian a estadios metastásicos en pacientes con CCR. Material y Método: Estudio prospectivo de 109 pacientes con diagnóstico de CCR. El análisis de expresión de los marcadores CD3/CD4/CD8/CD45RO/FoxP3 fue realizado por inmunohistoquímica; los tumores fueron clasificados en negativo, débil e intenso. La MSI fue evaluada con siete marcadores amplificados desde ADN normal y tumoral; los tumores fueron agrupados en: MSS (estable)/MSI-baja y MSI-alta. El análisis estadístico fue realizado con el test exacto de Fischer. Resultados: Una intensa expresión de los marcadores CD3+, CD4+, CD8+ y CD45RO+, fue observada en el 29 por ciento, 28 por ciento, 12 por ciento y 86 por ciento de los tumores, respectivamente. El 16 por ciento de los tumores presentó MSI-alta. Los tumores que presentan una alta densidad de linfocitos T (CD3+, CD4+ y CD45RO+) se asocian a estadios tempranos I-II (p = 0,023; p = 0,030 y p = 0,003, respectivamente). Adicionalmente, se identificó una asociación estadística significativa entre los tumores con MSS/MSI-baja y una menor capacidad de reclutar linfocitos T citotóxicos CD8+ (p = 0,037) y totales CD3+ (p = 0,064). Conclusión: Existe una asociación entre altas densidades de linfocitos T CD3+, CD4+ y CD45RO+ y tumores con estadios no metastásicos. Además, tumores con MSS/MSI-baja se asocian a un menor reclutamiento de linfocitos T CD8+ y CD3+.

Aggressive Multilocular Osteoblastoma in the Mandible: A Rare and Difficult Case to Diagnose

Osteoblastoma is a benign neoplasia and is uncommon in the jaws. In some cases, this lesion presents extremely aggressive local characteristics and is termed aggressive osteoblastoma. Because the clinical, radiographic and histopathologic characteristics are similar to those of a variety of benign and malignant tumors, it poses a diagnostic dilemma. This report presents a case of an aggressive osteoblastoma in the mandible and discusses the differential diagnosis of this lesion. A 13-year-old white male sought the Stomatology Clinic at the State University of Paraíba, Campina Grande, PB, Brazil, complaining of asymptomatic swelling on the left side of his face. Cone-beam computerized tomography showed a multilocular, hypodense bone lesion, located in the body of the left mandible and lower third of the ascending ramus. The initial diagnostic hypothesis was juvenile ossifying fibroma or osteosarcoma. After histopathologic examination, the final diagnosis was aggressive osteoblastoma. Surgical resection with a safety margin was performed. There was no evidence of recurrence after a follow-up period of 4 years.

O osteoblastoma é uma neoplasia benigna e incomum nos maxilares. Em alguns casos esta lesão apresenta características locais extremamente agressivas, sendo denominada osteoblastoma agressivo. Devido às características clínicas, radiográficas e histopatológicas serem similares a uma variedade de tumores benignos e malignos, o seu diagnóstico é um dilema. Este relato apresenta o caso de um osteoblastoma agressivo na mandíbula e discute o diagnóstico diferencial desta lesão. Paciente, branco, 13 anos de idade, foi atendido na Clínica de Estomatologia da Universidade Estadual da Paraíba, Campina Grande, PB, Brasil, queixando-se de aumento de volume assintomático do lado esquerdo de sua face. A tomografia computadorizada de feixe cônico revelou uma lesão óssea hipodensa multilocular, localizada no corpo do lado esquerdo da mandíbula e no terço inferior do ramo ascendente da mandíbula. A hipótese diagnóstica foi de fibroma ossificante juvenil e osteosarcoma. Após exame histopatológico, o diagnóstico final foi osteoblastoma agressivo. Foi realizada ressecção cirúrgica com margem de segurança. Não houve sinais de recorrência após 4 anos de acompanhamento.

Los linfocitos Th1 no son exclusivos de la inmunidad celular / Lymphocytes Th1 are not exclusive of cellular immunity

Los linfocitos T cooperadores CD4+ (Th de “helper”) se dividen en subpoblaciones, entre lasque se destacan Th1 y Th2. A lo largo de mi vida profesional he observado que muchos investigadores asocian a la subpoblación Th1 exclusivamente con la inmunidad celular, incluso aquellos que trabajan en vacunología; criterio citadoen presentaciones de eventos, artículos científicos, trabajos de diploma, tesis de especialidad o para grados científicos. Al igual ocurre con diversos librosde texto. Pretendemos polemizar y mostrar que esta subpoblación no está limitada a esta vertiente de lainmunidad, y que es vital para la respuesta humoral(AU)

Papel del factor de crecimiento transformador-beta (TGF) en la fisiopatología de la artritis reumatoide / Role of transforming growth factor-beta (TGF) beta in the physiopathology of rheumatoid arthritis

El factor de crecimiento transformador-beta (TGF) es una citocina implicada en procesos celulares como hematopoyesis, proliferación, angiogénesis, diferenciación, migración y apoptosis celular. Aunque su papel en la artritis reumatoide no está bien definido, está considerada como una citocina inmunomoduladora según las condiciones del entorno. Numerosos trabajos han tratado de definir el papel del TGF en el desarrollo de la artritis murina en diferentes modelos de enfermedad, con resultados discordantes. De hecho, resultados recientemente publicados indican que TGF no desempeña un papel relevante en el modelo murino de artritis inducida con colágeno. Su implicación en la diferencación y la funcionalidad de las diferentes poblaciones de células T también ha mostrado resultados dispares sobre su papel como inhibidor o promotor de la respuesta inflamatoria. En este trabajo se presenta una revisión sobre el papel de TGF en modelos animales de artritis (AU)

Transforming growth factor-beta (TGF) is a cytokine with pleiotropic functions in hematopoiesis, angiogenesis, cell proliferation, differentiation, migration and apoptosis. Although its role in rheumatoid arthritis is not well defined, TGF activation leads to functional immunomodulatory effects according to environmental conditions. The function of TGF in the development of arthritis in murine models has been extensively studied with controversial results. Recent findings point to a non-relevant role for TGF in a mice model of collagen-induced arthritis. The study of TGF on T-cell responses has shown controversial results as an inhibitor or promoter of the inflammatory response. This paper presents a review of the role of TGF in animal models of arthritis (AU)

Cellular heterogeneity in superficial and deep subcutaneous adipose tissues in overweight patients

Human abdominal adipose tissue (AAT) can be divided into two compartments according to anatomical location to dermis layer, i.e. superficial and deep compartments (sAAT and dAAT). In morbidly obese patients, dAAT mass has been linked to obesity-associated pathologies. In the present study, we characterized in overweight healthy individuals human sAAT and dAAT cellular composition and adipogenic potential. Twelve paired sAAT and dAAT samples were collected. sAAT compared to dAAT adipocytes are larger. In agreement with increased size, real-time PCR analyses performed on isolated adipocytes showed that sAAT adipocytes exhibited higher leptin transcript levels but also higher expression of genes involved in metabolism including hormone-sensitive lipase compared to dAAT adipocytes. Flow cytometry analyses performed on stroma-vascular fraction (SVF) showed no difference in the numbers of progenitor cells, endothelial cells and macrophages between sAAT and dAAT. Macrophage phenotypes were not distinct between both AAT compartments. However, CD3+ T lymphocyte number was higher in dAAT than in sAAT. Adipogenic potential of dAAT SVF was lower than sAAT SVF whereas the one of isolated progenitor cells was not distinct whatever the AAT compartments. Therefore, in overweight patients, both sAAT and dAAT compartments exhibit differences in terms of adipocytes and T lymphocyte accumulation. dAAT is characterized by higher T lymphocyte accumulation together with smaller less metabolically active adipocytes. The lower adipogenic potential of dAAT SVF is not due to intrinsic progenitor cell properties but more likely to the increased T lymphocyte accumulation (AU)

Visión panorámica del sistema inmune / Panoramic vision of the inmune system

El sistema inmune media numerosas patologías, por lo que es importante conocer su estructura y funcionamiento. Se clasifica en innato y adquirido. El sistema inmune innato brinda una temprana e inespecífica respuesta contra los microorganismos. El sistema inmune adquirido humoral y celular nos brinda una respuesta específica para diferentes moléculas, posee memoria frente a los antígenos y diversidad para reaccionar a una gran variedad de antígenos.

The immune system mediates numerous pathologies functions por functioning it is important to know its structure and functioning. The immune system is classified into innate and adaptive immunity. The innate immunity provides early and non-specific response against microbes. The adaptive humoral and cellular immunity gives specificy for distinct molecules and has memory to enhance response to antigen and diversity to responde to large variety of antigen

Inmunología del embarazo / Immunology of pregnancy

Uno de los fenómenos que abre más interrogantes en la Inmunología es ¿Por qué el embrión, comportándose como un injerto semialogénico, no es rechazado por la madre? Se sabe que la madre produce una activa respuesta inmunológica frente al feto y sin embargo, en condiciones normales, el rechazo inmunológico no se produce. En el presente trabajo de revisión, se describen algunos mecanismos por medio de los cuales se genera la tolerancia inmunológica específica de la madre hacia el embrión. Todos estos mecanismos son interdependientes, y en conjunto constituyen una trama para evitar el rechazo fetal. Aquí se detalla la acción de las hormonas sexuales femeninas sobre el sistema inmunológico, el cambio del perfil de citoquinas, la generación de proteínas inmunomoduladoras y de anticuerpos bloqueantes, el efecto de la expresión de los HLA-G y el papel de algunas células inmunocompetentes como los linfocitos T reguladores, las células dendríticas y las células asesinas naturales o Natural Killer. Asimismo se detallan otras vías por las cuales el embrión se defiende del ataque inmunológico materno como la inducción de la apoptosis en el endometrio y en los leucocitos, el metabolismo de hierro y triptofano, la inhibición del sistema del complemento y la expresión de anexinas.

One of the phenomena that offers more questions in Immunology is: Why the embryo, behaving like a semialogenic graft, is not rejected by the mother? It is known that the mother produces an active immunological response against the fetus and, nevertheless, in normal conditions, the immunological rejection does not take place. In the present work of revision, some mechanisms are described by means of which the specific immunological tolerance of the mother is generated towards the embryo. All these mechanisms are interdependent and altogether they constitute a safety network to avoid the fetal rejection. Here the effects of female sex hormones on the immunological system, the change of the profile of cytokines, the generation of immunomodulating proteins and blocking antibodies, the effect of the expression of the HLA-G and the paper of some cells, like Regulatory T lymphocytes, dendritic and Natural Killer cells, are detailed. Also other routes by which the embryo defends itself of the maternal immunological attack are described, like the induction of apoptosis in the endometrium and leukocytes, the tryptophan and iron metabolisms, the inhibition of the complement system and the expression of annexins.

El sistema inmunológico también envejece / The immune system ages too

El sistema inmunológico envejece con el paso del tiempo al igual que otras funciones del organismo. Contrariamente a lo que se creía, la respuesta inmune es una de las funciones corporales que más profundamente se ve afectada por el envejecimiento (Ruiz Fernández NA, Solano L, 2001). Esto nos obliga a tomar ciertos recaudos antes de proceder a efectuar alguna técnica invasiva en personas mayores, aún aparentemente sanas, ya que en algunos casos los riesgos son grandes. La mortalidad debida a infecciones es cinco veces mayor en los ancianos. En este artículo se describen cuáles son los cambios encontrados y cómo tratar de evitar sus consecuencias.

NFAT regulates CSF-1 gene transcription triggered by L-selectin crosslinking

L-selectin is a member of the selectin family that play an important role both in mediating the initial capture and subsequent rolling of leukocytes along the endothelial cells. Furthermore, L-selectin can function as a signal molecule. In our previous studies, we reported that L-selectin ligation could regulate CSF-1 (colony-stimulating factor-1) gene transcription, in which AP-1 acts as a crucial transcriptional factor. Here we investigated the function of the NFAT in the CSF-1 gene transcriptional events. We found that overexpression of WT NFAT induce CSF-1 gene transcription greatly in the activated Jurkat cells. Furthermore, we found that NFAT can be recruited to the nucleus after L-selectin ligation, and the nuclear NFAT interacts with the CSF-1 promoter region to regulate CSF-1 gene transcription in the L-s electin ligation activated Jurkat cells. These results indicate that nuclear NFAT can activate CSF-1 gene transcription by connecting with the CSF-1 promoter in the signaling events induced by L-selectin ligation.

NFAT regulates CSF-1 gene transcription triggered by L-selectin crosslinking

L-selectin is a member of the selectin family that play an important role both in mediating the initial capture and subsequent rolling of leukocytes along the endothelial cells. Furthermore, L-selectin can function as a signal molecule. In our previous studies, we reported that L-selectin ligation could regulate CSF-1 (colony-stimulating factor-1) gene transcription, in which AP-1 acts as a crucial transcriptional factor. Here we investigated the function of the NFAT in the CSF-1 gene transcriptional events. We found that overexpression of WT NFAT induce CSF-1 gene transcription greatly in the activated Jurkat cells. Furthermore, we found that NFAT can be recruited to the nucleus after L-selectin ligation, and the nuclear NFAT interacts with the CSF-1 promoter region to regulate CSF-1 gene transcription in the L-s electin ligation activated Jurkat cells. These results indicate that nuclear NFAT can activate CSF-1 gene transcription by connecting with the CSF-1 promoter in the signaling events induced by L-selectin ligation.(AU)

Infección por el virus de la inmunodeficiencia humana y geriatría, una nueva realidad / No disponible

Desde 1996, momento en que se generalizó el uso del tratamiento antirretroviral de alta eficacia, se ha producido un cambio pronóstico importante para los pacientes con infección por el virus de la inmunodeficiencia humana, cronificando la infección y presentando expectativas de vida similar, en algunos casos, a la población general no infectada. Por otro lado, los factores de riesgo para la adquisición de la infección están cambiando, siendo actualmente la vía sexual la principal vía de contagio. Los pacientes ancianos han sido considerados tradicionalmente un grupo de bajo riesgo para la infección, pero las mejoras en el tratamiento de la disfunción eréctil y una falsa sensación de seguridad que conlleva a un bajo uso de métodos anticonceptivos de barrera comportan que los pacientes ancianos presenten un riesgo no despreciable para infectarse. El personal sanitario también infraestima el riesgo en estos pacientes, llevando a retrasos diagnósticos y en el inicio del tratamiento, que empeoran el pronóstico de estos pacientes (AU)

Since 1996, with the widespread use of highly active antiretroviral treatment, a shift has important prognostic for patients infected with the human immunodeficiency virus, becoming a chronic infection and presenting life expectancy similar, in some cases, to not infected general population. Moreover, risk factors for acquisition of infection are changing, sexual intercourse is the main risk factor for HIV. Elderly patients have traditionally been considered a low risk group for infection, but improvements in the treatment of erectile dysfunction and a false sense of security that leads to a low use of barrier methods behave that elderly patients present a non-negligible risk to be infected. Health staff also under estimates the risk in these patients, leading to delays in diagnosis and initiation of treatment, which worsen the prognosis of those patients (AU)

Bone Marrow T Cells are Superior to Splenic T Cells to Induce Chimeric Conversion After Non-Myeloablative Bone Marrow Transplantation

BACKGROUND/AIMS: The bone marrow functions not only as the primary B-lymphocyte-producing organ but also as a secondary lymphoid organ for CD4 and CD8 cell responses and a site of preferential homing and persistence for memory T cells. Bone marrow T (BM-T) cells are distinguished from peripheral blood T cells by surface phenotype, cytokine secretion profile, and immune functions. In this study, we evaluated the alloreactive potential of donor lymphocyte infusion (DLI) using BM-T cells in mixed chimerism compared to that using spleen T (SP-T) cells. METHODS: Cells were prepared using established procedures. BM-T cells were obtained as a by-product of T-cell depletion in BM grafting and then cryopreserved for subsequent DLI. We performed DLI using BM-T cells in allogeneic mixed chimera mice on post-BMT day 21. RESULTS: When the same dose of T cells, 5-10x10(5) (Thy1.2+), fractionated from BM and spleen were administered into mixed chimeras, the BM-T group showed complete chimeric conversion, with self-limited graft-versus-host disease (GVHD) and no pathological changes. However, the SP-T group showed persistent mixed chimerism, with pathological signs of GVHD in the liver and intestine. CONCLUSIONS: Our results suggest that DLI using BM-T cells, even in small numbers, is more potent at inducing chimeric conversion in mixed chimerism than DLI using SP-T cells. Further study is needed to determine whether cryopreserved BM-T cells are an effective cell source for DLI to consolidate donor-dominant chimerism in clinical practice without concerns about GVHD.