ARF6-dependent endocytic trafficking of the Interferon-γ receptor drives adaptive immune resistance in cancer.

Adaptive immune resistance (AIR) is a protective process used by cancer to escape elimination by CD8+ T cells. Inhibition of immune checkpoints PD-1 and CTLA-4 specifically target Interferon-gamma (IFNγ)-driven AIR. AIR begins at the plasma membrane where tumor cell-intrinsic cytokine signaling is initiated. Thus, plasma membrane remodeling by endomembrane trafficking could regulate AIR. Herein we report that the trafficking protein ADP-Ribosylation Factor 6 (ARF6) is critical for IFNγ-driven AIR. ARF6 prevents transport of the receptor to the lysosome, augmenting IFNγR expression, tumor intrinsic IFNγ signaling and downstream expression of immunosuppressive genes. In murine melanoma, loss of ARF6 causes resistance to immune checkpoint blockade (ICB). Likewise, low expression of ARF6 in patient tumors correlates with inferior outcomes with ICB. Our data provide new mechanistic insights into tumor immune escape, defined by ARF6-dependent AIR, and support that ARF6-dependent endomembrane trafficking of the IFNγ receptor influences outcomes of ICB.

Maternal infection causes dysfunctional BCR signaling in male offspring due to aberrant Xist expression.

Infections during pregnancy with pathogens such as helminths correlate with altered immune responses to common childhood immunizations. However, the molecular mechanisms that underlie this remain unknown. Using our murine model of maternal schistosomiasis, when immunized, males from infected mothers had a lower frequency of antigen-specific germinal center B cells and downregulation of transcripts downstream of BCR signaling compared to males from uninfected mothers. This is driven by a reduction in developing B cell populations within the bone marrow of pups from infected mothers. Males from infected mothers were impacted to a greater extent than their female littermate counterparts. We found this defect to be caused by aberrant expression of the long non-coding RNA Xist in males leading to dysregulated Igα expression on developing B cells. This, for the first time, links dysfunctional BCR signaling with Xist expression, while also proposing a detrimental function for Xist expression in males.

Integrated genomic epidemiology and phenotypic profiling of Clostridium difficile across intra-hospital and community populations in Colombia.

Clostridium difficile, the causal agent of antibiotic-associated diarrhea, has a complex epidemiology poorly studied in Latin America. We performed a robust genomic and phenotypic profiling of 53 C. difficile clinical isolates established from diarrheal samples from either intrahospital (IH) or community (CO) populations in central Colombia. In vitro tests were conducted to evaluate the cytopathic effect, the minimum inhibitory concentration of ten antimicrobial agents, the sporulation efficiency and the colony forming ability. Eleven different sequence types (STs) were found, the majority present individually in each sample, however in three samples two different STs were isolated. Interestingly, CO patients were infected with STs associated with hypervirulent strains (ST-1 in Clade-2). Three coexistence events (two STs simultaneously detected in the same sample) were observed always involving ST-8 from Clade-1. A total of 2,502 genes were present in 99% of the isolates with 95% of identity or more, it represents a core genome of 28.6% of the 8,735 total genes identified in the set of genomes. A high cytopathic effect was observed for the isolates positive for the two main toxins but negative for binary toxin (TcdA+/TcdB+/CDT- toxin production type), found only in Clade-1. Molecular markers conferring resistance to fluoroquinolones (cdeA and gyrA) and to sulfonamides (folP) were the most frequent in the analyzed genomes. In addition, 15 other markers were found mostly in Clade-2 isolates. These results highlight the regional differences that C. difficile isolates display, being in this case the CO isolates the ones having a greater number of accessory genes and virulence-associated factors.

Adaptación transcultural al castellano del sistema de evaluación del equilibrio (BESTest) en adultos mayores / Transcultural adaptation to the Spanish language of the Balance Evaluation Systems Test (BESTest) in older adults

Introducción. El riesgo de caídas en adultos mayores se incrementa a consecuencia de la disminución de la fuerza, la flexibilidad, el equilibrio y los cambios sensoriales, que afectan a la funcionalidad y la calidad de vida. Por tal razón se hace necesario un sistema integral de evaluación del equilibrio con fines preventivos o para intervenciones terapéuticas tempranas. Objetivo. Presentar los resultados del proceso de traducción y adaptación transcultural del sistema de evaluación del equilibrio (BESTest) al castellano. Sujetos y métodos. Se tradujo al castellano la versión original del BESTest, siguiendo el proceso de retrotraducción y adaptación cultural y teniendo en cuenta las equivalencias semánticas, idiomáticas, conceptual y experiencial. Posteriormente, la versión fue revisada por un panel de expertos que calificó la claridad, la coherencia, la pertinencia y la suficiencia. En la prueba piloto participaron 32 adultos de 50-80 años. Resultados. Se realizó la traducción completa del instrumento y de las instrucciones para el sujeto y para el evaluador. La mayoría de ítems de la prueba alcanzaron la puntuación máxima de 4 (100%), nueve ítems lograron una calificación media de 3,9 (99%); un ítem, una calificación media de 3,8 (95%), y dos ítems, una calificación media de 3,7 (92,5%). Conclusiones. Con este estudio, la comunidad de habla hispana cuenta con un instrumento pertinente, suficiente, coherente y claro para identificar el sistema del equilibrio afectado, enfocar el tratamiento y obtener mejores resultados funcionales a partir de la evaluación del equilibrio en adultos mayores

Introduction. The risk of falls in older adults increases because of the decrease in strength, flexibility, balance and sensory changes affecting functionality and quality of life. For this reason, an integral system of evaluation of equilibrium is necessary, for preventive purposes or for early therapeutic interventions. Aim. To present the results of the transcultural translation and adaptation process of the Balance Evaluation Systems Test (BESTest) to Spanish language. Subjects and methods. The original version of the BESTest was translated into Spanish, following the process of retrotraduction and cultural adaptation considering the semantic, idiomatic, conceptual and experiential equivalences. Subsequently the version was reviewed by a panel of experts qualifying clarity, coherence, relevance and sufficiency. The pilot test included 32 adults between 50 and 80 years old. Results. It was possible to carry out the complete translation of the instrument, the instructions for the subject and for the evaluator. Most items of the test reached the maximum score of 4.0 (100%), nine items achieved an average score of 3.9 (99%), one item got an average score of 3.8 (95%) and two items achieved an average score of 3.7 (92.5%). Conclusions. With this study the Spanish speakers community has a pertinent sufficient, coherent and clear instrument in order to identify the control postural system altered to focus treatment and to get better functional outcomes from balance evaluation in older adults

Predicción espacio-temporal probabilista de la epidemia de dengue total y grave en Colombia / Probabilistic spatial-temporal prediction of total and severe epidemic of dengue in Colombia / Previsão probabilística espaço-temporal da epidemia de dengue total e grave na Colômbia

RESUMEN Objetivo Establecer una nueva metodología predictiva de la proporción de dengue grave respecto al total anual de infectados de dengue por departamento con base en la teoría de la probabilidad. Métodos Con base en los datos anuales de número de infectados por departamentos en el periodo 2005 -2010, se calculó la proporción entre casos de dengue grave respecto al total para cada año, y se construyeron espacios de probabilidad que evalúan estos eventos en rangos de 0,5 y 0,3. Se determinaron conjuntos de rangos y se calculó probabilidad, desviación media cuadrática y la diferencia entre ellas. Se realizó una predicción del rango de infectados para el 2011 con el promedio aritmético de los valores de los últimos dos años. Resultados Se predijo correctamente el rango en el que se encuentra incluida la proporción de número de infectados de dengue grave sobre el total en cada departamento con una efectividad del 93,3% para el rango de 0,5 y de 86,7% para el de 0,3. Conclusión Se evidenció una autoorganización matemática espacio temporal en la proporción de dengue grave respecto al total que permite establecer predicciones de utilidad para la toma de decisiones de salud pública.(AU)

ABSTRACT Objective To establish a new predictive methodology to determine the proportion of severe dengue with respect to the annual total of dengue infections per department based on the probability theory. Materials and Methods Based on annual data on the number of infected persons by department in the period 2005-2010, the proportion of cases of severe dengue was calculated with respect to the total for each year. Probability spaces were constructed to evaluate these events in the ranges 0.5 and 0.3. Sets of ranges were determined and probability, mean square deviation and the difference between them were estimated. A prediction of the range of infected people for 2011 was made using the arithmetic average of the values of the last two years. Results The range in which the proportion of the number of people infected with severe dengue is included with respect to the total amount in each department was correctly predicted, with an effectiveness of 93.3% for the 0.5 range and 86.7% for the 0.3 range. Conclusion A mathematical spatial-temporal self-organization was found in the proportion of severe dengue with respect to the total, which allows establishing useful predictions for decision-making in public health.(AU)

RESUMO Objetivo Estabelecer uma nova metodologia preditiva para a proporção de dengue grave em relação ao dengue total anual infectado por departamento com base na teoria da probabilidade. Métodos Com base nos dados anuais do número de infectados por departamentos no período 2005-2010, a proporção entre os casos de dengue grave em relação ao total foi calculada para cada ano, e foram construídos espaços de probabilidade que avaliam esses eventos em intervalos de 0, 5 e 0,3. Conjuntos de intervalos foram determinados e a probabilidade, o desvio médio quadrático e a diferença entre eles foram calculados. A previsão da faixa de infectados para 2011 foi feita com a média aritmética dos valores dos últimos dois anos. Resultados A faixa na qual a proporção do número de infectados por dengue grave sobre o total está incluída em cada departamento foi corretamente prevista com uma eficácia de 93,3% para a faixa de 0,5 e 86,7% para aquela de 0,3. Conclusão Evidenciou-se uma auto-organização matemática espaço-temporal na proporção de dengue grave em relação ao total, o que permite estabelecer previsões úteis para a tomada de decisões em saúde pública.(AU)

New Insights into Clostridium difficile (CD) Infection in Latin America: Novel Description of Toxigenic Profiles of Diarrhea-Associated to CD in Bogotá, Colombia.

Clostridium difficile (CD) produces antibiotic associated diarrhea and leads to a broad range of diseases. The source of CD infection (CDI) acquisition and toxigenic profile are factors determining the impact of CD. This study aimed at detecting healthcare facility onset- (HCFO) and community-onset (CO) CDI and describing their toxigenic profiles in Bogotá, Colombia. A total of 217 fecal samples from patients suffering diarrhea were simultaneously submitted to two CDI detection strategies: (i) in vitro culture using selective chromogenic medium (SCM; chromID, bioMérieux), followed verification by colony screening (VCS), and (ii) molecular detection targeting constitutive genes, using two conventional PCR tests (conv.PCR) (conv.16S y conv.gdh) and a quantitative test (qPCR.16s). The CD toxigenic profile identified by any molecular test was described using 6 tests independently for describing PaLoc and CdtLoc organization. High overall CDI frequencies were found by both SCM (52.1%) and conv.PCR (45.6% for conv.16S and 42.4% for conv.gdh), compared to reductions of up to half the frequency by VCS (27.2%) or qPCR.16S (22.6%). Infection frequencies were higher for SCM and conv.16S regarding HCFO but greater for CO concerning conv.gdh, such differences being statistically significant. Heterogeneous toxigenic profiles were found, including amplification with lok1/3 primers simultaneously with other PaLoc markers (tcdA, tcdB or tcdC). These findings correspond the first report regarding the differential detection of CDI using in vitro culture and molecular detection tests in Colombia, the circulation of CD having heterogeneous toxigenic profiles and molecular arrays which could affect the impact of CDI epidemiology.

[Probabilistic spatial-temporal prediction of total and severe epidemic of dengue in Colombia]. / Predicción espacio-temporal probabilista de la epidemia de dengue total y grave en Colombia.

OBJECTIVE: To establish a new predictive methodology to determine the proportion of severe dengue with respect to the annual total of dengue infections per department based on the probability theory. MATERIALS AND METHODS: Based on annual data on the number of infected persons by department in the period 2005-2010, the proportion of cases of severe dengue was calculated with respect to the total for each year. Probability spaces were constructed to evaluate these events in the ranges 0.5 and 0.3. Sets of ranges were determined and probability, mean square deviation and the difference between them were estimated. A prediction of the range of infected people for 2011 was made using the arithmetic average of the values of the last two years. RESULTS: The range in which the proportion of the number of people infected with severe dengue is included with respect to the total amount in each department was correctly predicted, with an effectiveness of 93.3% for the 0.5 range and 86.7% for the 0.3 range. CONCLUSION: A mathematical spatial-temporal self-organization was found in the proportion of severe dengue with respect to the total, which allows establishing useful predictions for decision-making in public health.

OBJETIVO: Establecer una nueva metodología predictiva de la proporción de dengue grave respecto al total anual de infectados de dengue por departamento con base en la teoría de la probabilidad. MÉTODOS: Con base en los datos anuales de número de infectados por departamentos en el periodo 2005 -2010, se calculó la proporción entre casos de dengue grave respecto al total para cada año, y se construyeron espacios de probabilidad que evalúan estos eventos en rangos de 0,5 y 0,3. Se determinaron conjuntos de rangos y se calculó probabilidad, desviación media cuadrática y la diferencia entre ellas. Se realizó una predicción del rango de infectados para el 2011 con el promedio aritmético de los valores de los últimos dos años. RESULTADOS: Se predijo correctamente el rango en el que se encuentra incluida la proporción de número de infectados de dengue grave sobre el total en cada departamento con una efectividad del 93,3% para el rango de 0,5 y de 86,7% para el de 0,3. CONCLUSIÓN: Se evidenció una autoorganización matemática espacio temporal en la proporción de dengue grave respecto al total que permite establecer predicciones de utilidad para la toma de decisiones de salud pública.