Pancreatic cancer-associated fibroblasts modulate macrophage differentiation via sialic acid-Siglec interactions.

Despite recent advances in cancer immunotherapy, pancreatic ductal adenocarcinoma (PDAC) remains unresponsive due to an immunosuppressive tumor microenvironment, which is characterized by the abundance of cancer-associated fibroblasts (CAFs). Once identified, CAF-mediated immune inhibitory mechanisms could be exploited for cancer immunotherapy. Siglec receptors are increasingly recognized as immune checkpoints, and their ligands, sialic acids, are known to be overexpressed by cancer cells. Here, we unveil a previously unrecognized role of sialic acid-containing glycans on PDAC CAFs as crucial modulators of myeloid cells. Using multiplex immunohistochemistry and transcriptomics, we show that PDAC stroma is enriched in sialic acid-containing glycans compared to tumor cells and normal fibroblasts, and characterized by ST3GAL4 expression. We demonstrate that sialic acids on CAF cell lines serve as ligands for Siglec-7, -9, -10 and -15, distinct from the ligands on tumor cells, and that these receptors are found on myeloid cells in the stroma of PDAC biopsies. Furthermore, we show that CAFs drive the differentiation of monocytes to immunosuppressive tumor-associated macrophages in vitro, and that CAF sialylation plays a dominant role in this process compared to tumor cell sialylation. Collectively, our findings unravel sialic acids as a mechanism of CAF-mediated immunomodulation, which may provide targets for immunotherapy in PDAC.

The transcriptional landscape of glycosylation-related genes in cancer.

Changes in glycosylation patterns have been associated with malignant transformation and clinical outcomes in several cancer types, prompting ongoing research into the mechanisms involved and potential clinical applications. In this study, we performed an extensive transcriptomic analysis of glycosylation-related genes and pathways, using publicly available bulk and single cell transcriptomic datasets from tumor samples and cancer cell lines. We identified genes and pathways strongly associated with different tumor types, which may represent novel diagnostic biomarkers. By using single cell RNA-seq data, we characterized the contribution of different cell types to the overall tumor glycosylation. Transcriptomic analysis of cancer cell lines revealed that they present a simplified landscape of genes compared to tissue. Lastly, we describe the association of different genes and pathways with the clinical outcome of patients. These results can serve as a resource for future research aimed to unravel the role of the glyco-code in cancer.

Unraveling the impact of sialic acids on the immune landscape and immunotherapy efficacy in pancreatic cancer.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers. Despite the successful application of immune checkpoint blockade in a range of human cancers, immunotherapy in PDAC remains unsuccessful. PDAC is characterized by a desmoplastic, hypoxic and highly immunosuppressive tumor microenvironment (TME), where T-cell infiltration is often lacking (immune desert), or where T cells are located distant from the tumor islands (immune excluded). Converting the TME to an immune-inflamed state, allowing T-cell infiltration, could increase the success of immunotherapy in PDAC. METHOD: In this study, we use the KPC3 subcutaneous PDAC mouse model to investigate the role of tumor-derived sialic acids in shaping the tumor immune landscape. A sialic acid deficient KPC3 line was generated by genetic knock-out of the CMAS (cytidine monophosphate N-acetylneuraminic acid synthetase) enzyme, a critical enzyme in the synthesis of sialic acid-containing glycans. The effect of sialic acid-deficiency on immunotherapy efficacy was assessed by treatment with anti-programmed cell death protein 1 (PD-1) and agonistic CD40. RESULT: The absence of sialic acids in KPC3 tumors resulted in increased numbers of CD4+ and CD8+ T cells in the TME, and reduced frequencies of CD4+ regulatory T cells (Tregs) within the T-cell population. Importantly, CD8+ T cells were able to infiltrate the tumor islands in sialic acid-deficient tumors. These favorable alterations in the immune landscape sensitized sialic acid-deficient tumors to immunotherapy, which was ineffective in sialic acid-expressing KPC3 tumors. In addition, high expression of sialylation-related genes in human pancreatic cancer correlated with decreased CD8+ T-cell infiltration, increased presence of Tregs, and poorer survival probability. CONCLUSION: Our results demonstrate that tumor-derived sialic acids mediate T-cell exclusion within the PDAC TME, thereby impairing immunotherapy efficacy. Targeting sialic acids represents a potential strategy to enhance T-cell infiltration and improve immunotherapy outcomes in PDAC.

Spatial immune composition of tumor microenvironment in patients with pancreatic cancer.

This study examined the composition of the immune microenvironment at different sites within resected pancreas specimens from patients with pancreatic ductal adenocarcinoma (PDAC). Therefore, single-cell suspensions were made from fresh tumor and non-tumorous tissue. Fourteen patients were included from whom twelve PDAC and five non-tumorous samples were obtained. These samples were analyzed with a nineteen marker panel on the Aurora spectral flow cytometer. Furthermore, slides from formalin-fixed paraffine PDACs of eight additional patients were stained with eight markers and analyzed by multispectral imaging. These corresponded to central tumor, periphery of the tumor, i.e., invasive front and resected lymph node and were divided into tumor and adjacent tissue. In the single-cell suspension, a decreased ratio between lymphoid and myeloid cells and between M1 and M2 macrophages was observed in the tumor tissue compared to non-tumorous tissue. Furthermore, an increase in CD169 + macrophages in patients undergoing neoadjuvant therapy was found. Using immunofluorescence, more macrophages compared to T cells were observed, as well as a lower ratio of CD8 to M2 macrophage, a higher ratio of CD4-CD8 T cells and a higher ratio of immune-suppressive cells to pro-inflammatory cells in the PDAC area compared to the adjacent non-tumorous tissue. Finally, there were more immune-suppressive cells in the central tumor area compared to the invasive front. In conclusion, we show a gradient in the immune-suppressive environment in PDAC from most suppressive in the central tumor to least suppressive in distant non-tumorous tissue.

Extended interval dosing of ocrelizumab modifies the repopulation of B cells without altering the clinical efficacy in multiple sclerosis.

BACKGROUND: Recent studies suggest that extended interval dosing of ocrelizumab, an anti-B cell therapy, does not affect its clinical effectiveness in most patients with multiple sclerosis (MS). However, it remains to be established whether certain B cell subsets are differentially repopulated after different dosing intervals and whether these subsets relate to clinical efficacy. METHODS: We performed high-dimensional single-cell characterization of the peripheral immune landscape of patients with MS after standard (SID; n = 43) or extended interval dosing (EID; n = 37) of ocrelizumab and in non-ocrelizumab-treated (control group, CG; n = 28) patients with MS, using mass cytometry by time of flight (CyTOF). RESULTS: The first B cells that repopulate after both ocrelizumab dosing schemes were immature, transitional and regulatory CD1d+ CD5+ B cells. In addition, we observed a higher percentage of transitional, naïve and regulatory B cells after EID in comparison with SID, but not of memory B cells or plasmablasts. The majority of repopulated B cell subsets showed an increased migratory phenotype, characterized by higher expression of CD49d, CD11a, CD54 and CD162. Interestingly, after EID, repopulated B cells expressed increased CD20 levels compared to B cells in CG and after SID, which was associated with a delayed repopulation of B cells after a subsequent ocrelizumab infusion. Finally, the number of/changes in B cell subsets after both dosing schemes did not correlate with any relapses nor progression of the disease. CONCLUSIONS: Taken together, our data highlight that extending the dosing interval of ocrelizumab does not lead to increased repopulation of effector B cells. We show that the increase of CD20 expression on B cell subsets in EID might lead to longer depletion or less repopulation of B cells after the next infusion of ocrelizumab. Lastly, even though extending the ocrelizumab interval dosing alters B cell repopulation, it does not affect the clinical efficacy of ocrelizumab in our cohort of patients with MS.

LA SINDEMIA ASOCIADA A COVID-19 Y LOS DERECHOS DE NIÑAS, NIÑOS Y ADOLESCENTES EN LATINOAMÉRICA: ANÁLISIS A PARTIR DE SEIS PAÍSES DE LA REGIÓN, 2023 / The syndemic associated with Covid-19 and the rights of children and adolescents in Latin America: Analysis from six countries in the region, 2023

El presente trabajo constituye un puntal de evidencia científica que queda disponible a los tomadores de decisiones en políticas nacionales y regionales relativas a la población de niñas, niños y adolescentes, y eso por sí solo es una muy buena contribución a la relevancia que debe tener esta población. Este estudio reconoce que vivimos un momento histórico, una ventana de oportunidad para tomar las decisiones adecuadas. Es prioridad contribuir para lograr que las políticas públicas sean eficaces en la garantía de los derechos humanos, esto requiere avanzar en consolidar Estados Sociales de Derecho y Bienestar con sistemas de salud y protección social universales. Asimismo, es fundamental fortalecer las capacidades de trabajo intersectorial y transdisciplinar, la integración regional y la cooperación internacional para hacer realidad la justicia social y ambiental, así como entender que las niñas, niños y adolescentes no son el futuro, son el presente. De lo que hagamos ahora depende el desarrollo y bienestar de nuestros pueblos. En este sentido el análisis se realiza a partir de un marco conceptual que abarca los siguientes aspectos:: Más allá de la pandemia, una sindemia; desigualdades múltiples: una manera de trascender a las desigualdades de ingreso; Derechos Humanos y su operacionalización en el contexto sindémico; Convención sobre los Derechos del Niño; sindemia COVID-19 y los derechos de niñas, niños y adolescentes; sindemia y políticas públicas, sindemia por COVID-19 y un llamado a la acción.

DNA microarrays to identify etiological agents, as sensors of environmental wellbeing.

Background: The epidemiologic transition in Mexico has generated a change of paradigm in public health. Morbidity is characterized by infectious diseases and the mortality is due to chronic degenerative diseases. The three most important infectious diseases in the country are: respiratory infections, diarrhea, and urinary tract infections. Method: The objective of this work was to build a tool to monitor the presence of health risks in the environment in a timely manner and to demonstrate its application in different sicknesses, especially those that are water related. In this study, we analyzed water samples from five cenotes with high tourist flow in the State of Yucatan. We developed a DNA microarray for the adequate and prompt detection of viruses, bacteria, fungi, and parasites. This microarray could be used in samples of different origin including air, water (fresh, brackish and saltwater), food, inert surfaces or wounds. Clinically, it would allow prompt and precise detection of etiological agents of infectious diseases to prevent outbreaks. It would also be useful for the identification of those agents that cannot be detected in our laboratories with the traditional methods. It includes 38,000 probes that detect 252 etiological agents of diseases in humans and antimicrobial resistance genes. Results from DNA samples can be obtained in 24 h, which would be difficult or impossible using other technologies. Results: The results are readily available within 24 h. Samples from five cenotes (sinkholes) with high flow of people, were analyzed with the microarray. The water samples analyzed detected 228 different bacteria, viruses, fungi, and protozoa. They are amongst the most important etiological agents for infectious diseases in Mexico. Conclusions: The microarray provides the opportunity for precise and early detection of various infectious agents in individuals, hospitals and natural environments. This could help reduce the global burden of diseases, the severity of outbreaks, and reduce antibiotic resistance.

Juegos tradicionales para niños con discapacidad visual: un conocimiento necesario en educación médica / Traditional games for visually impaired children: a necessary knowledge in medical education

Fundamento: los juegos tradicionales resultan motivantes y de fácil ejecución para los escolares con necesidades educativas especiales porque favorecen la movilidad y orientación espacial de niños con discapacidad visual. Objetivo: proponer un grupo de juegos tradicionales adaptados para mejorar la movilidad y orientación espacial de niños con discapacidad visual en la Escuela Especial "Fructuoso Rodríguez" de Santa Clara, Villa Clara, Cuba. Métodos: se realizó un estudio descriptivo transversal, entre los meses de mayo-septiembre de 2021. Se emplearon métodos teóricos: analítico-sintético, inductivo-deductivo e histórico-lógico; y empíricos: análisis de documentos, observación, cuestionario y entrevista. Resultados: el diagnóstico realizado corroboró que los sujetos estudiados presentaban dificultades en la movilidad y la orientación espacial; desconfianza, inseguridad y pocas iniciativas relacionadas con la recreación en su cotidianeidad familiar, por lo que se adaptaron 10 juegos tradicionales conocidos, pero poco jugados por los niños con discapacidad visual, con el fin de alcanzar otras vías que contribuyan a mejorar su movilidad y orientación espacial, luego de una etapa de confinamiento provocada por la Covid-19. Conclusiones: la propuesta de juegos tradicionales adaptados responde a la necesidad detectada y potencia la recreación e inclusión de estos infantes en actividades escolares y extraescolares después de la pandemia.

Background: traditional games are motivating and easy to play for schoolchildren with special educational needs because they favor the mobility and spatial orientation of visually impaired children. Objective: to propose a group of traditional games adapted to improve the mobility and spatial orientation of visually impaired children at "Fructuoso Rodríguez" Special School in Santa Clara, Villa Clara, Cuba. Methods: a cross-sectional descriptive study was carried out, from May to September 2021. Theoretical methods were used: analytical-synthetic, inductive-deductive and historical-logical; and empirical ones: document analysis, observation, questionnaire and interview. Results: the diagnosis made corroborated that the subjects studied presented difficulties in mobility and spatial orientation; distrust, insecurity and few initiatives related to recreation in their family daily life, for which 10 known traditional games were adapted, but little played by children with visual disabilities, in order to reach other ways that contribute to improving their mobility and orientation space, after a stage of confinement caused by Covid-19. Conclusions: the proposal of adapted traditional games responds to the detected need and enhances the recreation and inclusion of these infants in school and extracurricular activities after the pandemic.

Single-cell profiling reveals periventricular CD56bright NK cell accumulation in multiple sclerosis.

Multiple sclerosis (MS) is a chronic demyelinating disease characterised by immune cell infiltration resulting in lesions that preferentially affect periventricular areas of the brain. Despite research efforts to define the role of various immune cells in MS pathogenesis, the focus has been on a few immune cell populations while full-spectrum analysis, encompassing others such as natural killer (NK) cells, has not been performed. Here, we used single-cell mass cytometry (CyTOF) to profile the immune landscape of brain periventricular areas - septum and choroid plexus - and of the circulation from donors with MS, dementia and controls without neurological disease. Using a 37-marker panel, we revealed the infiltration of T cells and antibody-secreting cells in periventricular brain regions and identified a novel NK cell signature specific to MS. CD56bright NK cells were accumulated in the septum of MS donors and displayed an activated and migratory phenotype, similar to that of CD56bright NK cells in the circulation. We validated this signature by multiplex immunohistochemistry and found that the number of NK cells with high expression of granzyme K, typical of the CD56bright subset, was increased in both periventricular lesions and the choroid plexus of donors with MS. Together, our multi-tissue single-cell data shows that CD56bright NK cells accumulate in the periventricular brain regions of MS patients, bringing NK cells back to the spotlight of MS pathology.

Actualización diagnóstica y terapéutica sobre la úlcera corneal / Diagnostic and therapeutic updating about the corneal ulcer

Se realizó una revisión bibliográfica exhaustiva sobre la anatomía de la córnea, a fin de profundizar en los principales factores predisponentes de la úlcera corneal, sus causas, cuadro clínico, evolución, complicaciones y tratamiento. Se analizó conceptualmente la enfermedad y se propuso incluir en su concepto el método clínico como premisa. Actualmente, en la provincia de Santiago de Cuba, la curación de estas úlceras constituye un problema de salud a resolver, puesto que los tratamientos convencionales no siempre permiten una evolución estable de los pacientes diagnosticados, razón por la cual surge la necesidad de buscar medicamentos y alternativas terapéuticas para tratar a dichos pacientes.

An exhaustive literature review on the cornea anatomy was carried out in order to deepen in the main predisposing factors of the corneal ulcer, their causes, clinical picture, clinical course, complications and treatment. The disease was conceptually analyzed and it was suggested to include in its concept the clinical method as premise. At the moment, in Santiago de Cuba province, the cure of these ulcers constitutes a health problem to solve, since the conventional treatments not always allow a stable clinical course of the diagnosed patients, reason why there is a necessity of searching medicines and therapeutic alternatives to treat them.

Caracterización de pacientes con úlcera grave de la córnea y queratoplastia terapéutica

RESUMEN Introducción: La queratoplastia ha sido la técnica más empleada para el tratamiento de las alteraciones corneales. Objetivo: Describir las características clínico-epidemiológicas de la queratoplastia terapéutica en pacientes con úlcera grave de la córnea. Método: Se realizó un estudio observacional descriptivo y transversal a 17 ojos de 16 pacientes operados de queratoplastia terapéutica que presentaron úlcera grave de la córnea, ingresados en el servicio de Oftalmología del Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" de Santiago de Cuba en el periodo de enero de 2018 a diciembre de 2019. Se estudiaron las variables edad, sexo, procedencia, ocupación, factores predisponentes, tiempo de evolución previo al ingreso, tratamiento tópico previo y germen causal. En el análisis estadístico se utilizó la frecuencia absoluta y el porcentaje para las variables cualitativas y para las cuantitativas, la media y la desviación estándar. Resultados: Predominaron los pacientes del sexo masculino, jubilados con más de 60 años. Prevaleció el trauma ocular no quirúrgico como factor predisponente. Previo al ingreso se aplicó con mayor frecuencia el colirio antibiótico y el tiempo de evolución promedio fue de 12,2 días. El grupo de gérmenes más preponderante fue el de las bacterias. Conclusiones: El vínculo entre el germen causal y la aplicación de medicamentos tópicos previos de manera prolongada propicia que la enfermedad evolucione tórpidamente hacia formas graves de úlcera corneal. Lo que ofrece una respuesta deficiente y prolongada a los esquemas convencionales de tratamiento, que en ocasiones llevan a una queratoplastia terapéutica-tectónica.

ABSTRACT Introduction: Keratoplasty has been the most used technique for the treatment of corneal alterations. Objective: To describe the clinical-epidemiological characteristics of therapeutic keratoplasty in patients with severe corneal ulcer. Method: A descriptive and cross-sectional observational study was carried out on 17 eyes of 16 patients operated on for therapeutic keratoplasty who presented severe corneal ulcer, admitted to the Ophthalmology service of the Hospital "Dr. Juan Bruno Zayas Alfonso" in Santiago de Cuba, in the period from January 2018 to December 2019. The variables studied were: age, gender, origin, occupation, predisposing factors, time of evolution prior to admission, previous topical treatment and causal germ. In the statistical analysis, the absolute frequency and the percentage were used for the qualitative variables, and for the quantitative ones, the mean and the standard deviation. Results: Male patients predominated, retired with more than 60 years. Non-surgical ocular trauma prevailed as a predisposing factor. Prior to admission, antibiotic eye drops were applied more frequently, and the average evolution time was 12.2 days. The most preponderant group of germs was bacteria. Conclusions: The link between the causal germ and the application of previous topical medications in a prolonged manner favors the torpid evolution of the disease towards severe forms of corneal ulcer. This evolution offers a poor and prolonged response to conventional treatment schemes, which sometimes lead to a therapeutic-tectonic keratoplasty.

RESUMO Introdução: A ceratoplastia tem sido a técnica mais utilizada para o tratamento das alterações corneanas. Objetivo: Descrever as características clínico-epidemiológicas da ceratoplastia terapêutica em pacientes com úlcera de córnea grave. Método: Estudo observacional descritivo e transversal em 17 olhos de 16 pacientes operados de ceratoplastia terapêutica que apresentavam úlcera de córnea grave, internados no serviço de Oftalmologia do Hospital General Docente "Dr. Juan Bruno Zayas Alfonso" em Santiago de Cuba no período de janeiro de 2018 a dezembro de 2019. Foram estudadas as variáveis idade, sexo, procedência, ocupação, fatores predisponentes, tempo de evolução antes da admissão, tratamento tópico prévio e germe causal. Na análise estatística, utilizou-se a frequência absoluta e o percentual para as variáveis qualitativas e para as quantitativas, a média e o desvio padrão. Resultados: Predominou pacientes do sexo masculino, aposentados com mais de 60 anos. O trauma ocular não cirúrgico prevaleceu como fator predisponente. Antes da internação, colírios antibióticos foram aplicados com maior frequência e o tempo médio de evolução foi de 12,2 dias. O grupo de germes mais preponderante foi o de bactérias. Conclusões: A ligação entre o germe causal e a aplicação de medicações tópicas prévias de forma prolongada favorece a evolução entorpecida da doença para formas graves de úlcera de córnea. O que oferece uma resposta pobre e prolongada aos esquemas de tratamento convencionais, que por vezes conduzem a uma queratoplastia tectónica terapêutico.

Analysis of the glyco-code in pancreatic ductal adenocarcinoma identifies glycan-mediated immune regulatory circuits.

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most aggressive malignancies with a 5-year survival rate of only 9%. Despite the fact that changes in glycosylation patterns during tumour progression have been reported, no systematic approach has been conducted to evaluate its potential for patient stratification. By analysing publicly available transcriptomic data of patient samples and cell lines, we identified here two specific glycan profiles in PDAC that correlated with progression, clinical outcome and epithelial to mesenchymal transition (EMT) status. These different glycan profiles, confirmed by glycomics, can be distinguished by the expression of O-glycan fucosylated structures, present only in epithelial cells and regulated by the expression of GALNT3. Moreover, these fucosylated glycans can serve as ligands for DC-SIGN positive tumour-associated macrophages, modulating their activation and inducing the production of IL-10. Our results show mechanisms by which the glyco-code contributes to the tolerogenic microenvironment in PDAC.

Las desigualdades matan. Informe de Oxfam / Inequalities kill. Oxfam Report

Webinar N° 103 del ORAS-CONHU, realizado el 27 de enero de 2022, Oxfam presentó el informe "Las desigualdades matan. Se requieren medidas sin precedentes para acabar con el inaceptable aumento de las desigualdades por la COVID-19". Conferencistas del webinar: Carlos Mejía, Director Ejecutivo Oxfam Colombia, Gloria García, Directora Regional de Programas e Influencia Oxfam en América Latina y Ernesto Rodríguez, Consultor ORAS-CONHU, Director del Centro Latinoamericano sobre Juventud.

Curso teórico-práctico para preparación metodológica de profesores universitarios sobre educación a distancia / Theoretical-practical course for the methodological preparation of university professors on distance learning

RESUMEN Fundamento: constituye una necesidad la preparación metodológica de los profesores desde la superación posgraduada para utilizar la educación a distancia en las condiciones de la pandemia COVID-19. Objetivo: diseñar un curso de preparación metodológica para orientar a los profesores en la adecuación de los programas y tareas, que los capaciten en la concepción de las etapas, la realización de las acciones básicas y el conocimiento que requieren sobre la educación a distancia. Métodos: se realizó un estudio descriptivo transversal, en la Universidad Central "Marta Abreu" de Las Villas, entre los meses enero-abril 2021. Se emplearon métodos teóricos: analítico-sintético e inductivo-deductivo; empíricos: análisis de documentos, observación científica, encuesta, triangulación, criterio de especialistas para la valoración del curso diseñado y la distribución empírica de frecuencias. Resultados: se constataron las necesidades de preparación metodológica para asumir la modalidad de educación a distancia, por lo que se diseñó un curso que sirvió como modelo, el cual contiene el análisis de los principios, las principales etapas y acciones a considerar en su elaboración, además muestra las herramientas que la plataforma Moodle ofrece para su diseño; de modo que los profesores dispusieran de una orientación didáctica general a implementar en sus disciplina. Conclusiones: el curso fue valorado por los especialistas como adecuado para ser aplicado, por su pertinencia, factibilidad, cientificidad y su estructura metodológica.

ABSTRACT Background: the methodological preparation of teachers from postgraduate training to use distance education in the conditions of the COVID 19 pandemic is a necessity. Objective: to design a methodological preparation course to guide teachers in the adaptation of programs and tasks, to train them in the conception of the stages, the performance of basic actions and the knowledge they require about distance learning. Methods: a cross-sectional descriptive study was carried out at "Marta Abreu" Central University of Las Villas, from January to April 2021. Theoretical methods were used: analytical-synthetic and inductive-deductive; empirical ones: document analysis, scientific observation, survey, information contrasting, specialist criteria for the evaluation of the designed course and the empirical distribution of frequencies. Results: the methodological preparation needs to assume the distance-learning modality were verified, that´s whya course was designed that served as a model, which contains the analysis of the principles, the main stages and actions to be considered in its elaboration. It also shows the tools that the Moodle platform offers for its design; so that teachers had a general didactic orientation to implement in their disciplines. Conclusions: the course was valued by the specialists as adequate to be applied, due to its relevance, feasibility, scientificity and its methodological structure.

CD169 Defines Activated CD14+ Monocytes With Enhanced CD8+ T Cell Activation Capacity.

Monocytes are antigen-presenting cells (APCs) that play diverse roles in promoting or regulating inflammatory responses, but their role in T cell stimulation is not well defined. In inflammatory conditions, monocytes frequently show increased expression of CD169/Siglec-1, a type-I interferon (IFN-I)-regulated protein. However, little is known about the phenotype and function of these CD169+ monocytes. Here, we have investigated the phenotype of human CD169+ monocytes in different diseases, their capacity to activate CD8+ T cells, and the potential for a targeted-vaccination approach. Using spectral flow cytometry, we detected CD169 expression by CD14+ CD16- classical and CD14+ CD16+ intermediate monocytes and unbiased analysis showed that they were distinct from dendritic cells, including the recently described CD14-expressing DC3. CD169+ monocytes expressed higher levels of co-stimulatory and HLA molecules, suggesting an increased activation state. IFNα treatment highly upregulated CD169 expression on CD14+ monocytes and boosted their capacity to cross-present antigen to CD8+ T cells. Furthermore, we observed CD169+ monocytes in virally-infected patients, including in the blood and bronchoalveolar lavage fluid of COVID-19 patients, as well as in the blood of patients with different types of cancers. Finally, we evaluated two CD169-targeting nanovaccine platforms, antibody-based and liposome-based, and we showed that CD169+ monocytes efficiently presented tumor-associated peptides gp100 and WT1 to antigen-specific CD8+ T cells. In conclusion, our data indicate that CD169+ monocytes are activated monocytes with enhanced CD8+ T cell stimulatory capacity and that they emerge as an interesting target in nanovaccine strategies, because of their presence in health and different diseases.

Human hydatid cyst fluid-induced therapeutic anti-cancer immune responses via NK1.1+ cell activation in mice.

Echinococcus granulosus is a cestode parasite which causes cystic echinococcosis disease. Previously we observed that vaccination with E. granulosus antigens from human hydatid cyst fluid (HCF) significantly inhibits colon cancer growth. In the present work, we evaluate the anti-tumor immune response induced by human HCF against LL/2 lung cancer in mice. HCF vaccination protected from tumor growth, both in prophylactic and therapeutic settings, and significantly increased mouse survival compared to control mice. Considering that tumor-associated carbohydrate antigens are expressed in E. granulosus, we oxidized terminal carbohydrates in HCF with sodium periodate. This treatment abrogates the anti-tumor activity induced by HCF vaccination. We found that HCF vaccination-induced IgG antibodies that recognize LL/2 tumor cells by flow cytometry. An antigen-specific immune response is induced with HCF vaccination in the tumor-draining lymph nodes and spleen characterized by the production of IL-5 and, in less extent, IFNÉ£. In the tumor microenvironment, we found that NK1.1 positive cells from HCF-treated mice showed higher expression of CD69 than control mice ones, indicating a higher level of activation. When we depleted these cells by administrating the NK-specific antibody NK1.1, a significantly decreased survival was observed in HCF-induced mice, suggesting that NK1.1+ cells mediate the anti-tumor protection induced by HCF. These results suggest that HCF can evoke an integrated anti-tumor immune response involving both, the innate and adaptive components, and provide novel insights into the understanding of the intricate relationship between HCF vaccination and tumor growth.

Quantitative Phosphoproteomic Analysis Reveals Dendritic Cell- Specific STAT Signaling After α2-3-Linked Sialic Acid Ligand Binding.

Dendritic cells (DCs) are key initiators of the adaptive immunity, and upon recognition of pathogens are able to skew T cell differentiation to elicit appropriate responses. DCs possess this extraordinary capacity to discern external signals using receptors that recognize pathogen-associated molecular patterns. These can be glycan-binding receptors that recognize carbohydrate structures on pathogens or pathogen-associated patterns that additionally bind receptors, such as Toll-like receptors (TLRs). This study explores the early signaling events in DCs upon binding of α2-3 sialic acid (α2-3sia) that are recognized by Immune inhibitory Sialic acid binding immunoglobulin type lectins. α2-3sias are commonly found on bacteria, e.g. Group B Streptococcus, but can also be expressed by tumor cells. We investigated whether α2-3sia conjugated to a dendrimeric core alters DC signaling properties. Through phosphoproteomic analysis, we found differential signaling profiles in DCs after α2-3sia binding alone or in combination with LPS/TLR4 co-stimulation. α2-3sia was able to modulate the TLR4 signaling cascade, resulting in 109 altered phosphoproteins. These phosphoproteins were annotated to seven biological processes, including the regulation of the IL-12 cytokine pathway. Secretion of IL-10, the inhibitory regulator of IL-12 production, by DCs was found upregulated after overnight stimulation with the α2-3sia dendrimer. Analysis of kinase activity revealed altered signatures in the JAK-STAT signaling pathway. PhosphoSTAT3 (Ser727) and phosphoSTAT5A (Ser780), involved in the regulation of the IL-12 pathway, were both downregulated. Flow cytometric quantification indeed revealed de- phosphorylation over time upon stimulation with α2-3sia, but no α2-6sia. Inhibition of both STAT3 and -5A in moDCs resulted in a similar cytokine secretion profile as α-3sia triggered DCs. Conclusively, this study revealed a specific alteration of the JAK-STAT pathway in DCs upon simultaneous α2-3sia and LPS stimulation, altering the IL10:IL-12 cytokine secretion profile associated with reduction of inflammation. Targeted control of the STAT phosphorylation status is therefore an interesting lead for the abrogation of immune escape that bacteria or tumors impose on the host.

Sialic acids in pancreatic cancer cells drive tumour-associated macrophage differentiation via the Siglec receptors Siglec-7 and Siglec-9.

Changes in glycosylation during tumour progression are a key hallmark of cancer. One of the glycan moieties generally overexpressed in cancer are sialic acids, which can induce immunomodulatory properties via binding to Siglec receptors. We here show that Pancreatic Ductal Adenocarcinoma (PDAC) tumour cells present an increased sialylation that can be recognized by Siglec-7 and Siglec-9 on myeloid cells. We identified the expression of the α2,3 sialyltransferases ST3GAL1 and ST3GAL4 as main contributor to the synthesis of ligands for Siglec-7 and Siglec-9 in tumour cells. Analysing the myeloid composition in PDAC, using single cell and bulk transcriptomics data, we identified monocyte-derived macrophages as contributors to the poor clinical outcome. Tumour-derived sialic acids dictate monocyte to macrophage differentiation via signalling through Siglec-7 and Siglec-9. Moreover, triggering of Siglec-9 in macrophages reduce inflammatory programmes, while increasing PD-L1 and IL-10 expression, illustrating that sialic acids modulate different myeloid cells. This work highlights a critical role for sialylated glycans in controlling immune suppression and provides new potential targets for cancer immunotherapy in PDAC.

[Corynebacterium pyruviciproducens and Corynebacterium amycolatum mastitis in immunocompetent no breastfeeding women]. / Mastitis por Corynebacterium pyruviciproducens y Corynebacterium amycolatum en mujeres inmunocompetentes no lactantes.

Corynebacterium species, other than Corynebacterium diphteriae, are usually dismissed as contaminants when recovered from patient's samples. It is often difficult to decide whether these bacteria have clinical relevance or not. The Corynebacterium genus has been implicated in a wide variety of human infections. In this brief report, two cases of mastitis caused by Corynebacterium pyruviciproducens and Corynebacterium amycolatum are described in not breastfeeding women. These patients were immunocompetent with no evidence of ongoing risk factors for mastitis. This report seeks to give importance to this genus by always ranking cultures, starting with a thorough sample collection up until a complete evaluation of lab results and clinical presentation.