Genetic ablation of neuronal mitochondrial calcium uptake halts Alzheimer's disease progression.

Alzheimer's disease (AD) is characterized by the extracellular deposition of amyloid beta, intracellular neurofibrillary tangles, synaptic dysfunction, and neuronal cell death. These phenotypes correlate with and are linked to elevated neuronal intracellular calcium ( i Ca 2+ ) levels. Recently, our group reported that mitochondrial calcium ( m Ca 2+ ) overload, due to loss of m Ca 2+ efflux capacity, contributes to AD development and progression. We also noted proteomic remodeling of the mitochondrial calcium uniporter channel (mtCU) in sporadic AD brain samples, suggestive of altered m Ca 2+ uptake in AD. Since the mtCU is the primary mechanism for Ca 2+ uptake into the mitochondrial matrix, inhibition of the mtCU has the potential to reduce or prevent m Ca 2+ overload in AD. Here, we report that neuronal-specific loss of mtCU-dependent m Ca 2+ uptake in the 3xTg-AD mouse model of AD reduced Aß and tau-pathology, synaptic dysfunction, and cognitive decline. Knockdown of Mcu in a cellular model of AD significantly decreased matrix Ca 2+ content, oxidative stress, and cell death. These results suggest that inhibition of neuronal m Ca 2+ uptake is a novel therapeutic target to impede AD progression.

TMEM65 regulates NCLX-dependent mitochondrial calcium efflux.

The balance between mitochondrial calcium (mCa2+) uptake and efflux regulates ATP production, but if perturbed causes energy starvation or mCa2+ overload and cell death. The mitochondrial sodium-calcium exchanger, NCLX, is a critical route of mCa2+ efflux in excitable tissues, such as the heart and brain, and animal models support NCLX as a promising therapeutic target to limit pathogenic mCa2+ overload. However, the mechanisms that regulate NCLX activity remain largely unknown. We used proximity biotinylation proteomic screening to identify the NCLX interactome and define novel regulators of NCLX function. Here, we discover the mitochondrial inner membrane protein, TMEM65, as an NCLX-proximal protein that potently enhances sodium (Na+)-dependent mCa2+ efflux. Mechanistically, acute pharmacologic NCLX inhibition or genetic deletion of NCLX ablates the TMEM65-dependent increase in mCa2+ efflux. Further, loss-of-function studies show that TMEM65 is required for Na+-dependent mCa2+ efflux. Co-fractionation and in silico structural modeling of TMEM65 and NCLX suggest these two proteins exist in a common macromolecular complex in which TMEM65 directly stimulates NCLX function. In line with these findings, knockdown of Tmem65 in mice promotes mCa2+ overload in the heart and skeletal muscle and impairs both cardiac and neuromuscular function. We further demonstrate that TMEM65 deletion causes excessive mitochondrial permeability transition, whereas TMEM65 overexpression protects against necrotic cell death during cellular Ca2+ stress. Collectively, our results show that loss of TMEM65 function in excitable tissue disrupts NCLX-dependent mCa2+ efflux, causing pathogenic mCa2+ overload, cell death and organ-level dysfunction, and that gain of TMEM65 function mitigates these effects. These findings demonstrate the essential role of TMEM65 in regulating NCLX-dependent mCa2+ efflux and suggest modulation of TMEM65 as a novel strategy for the therapeutic control of mCa2+ homeostasis.

Signaling pathways regulating mitochondrial calcium efflux - a commentary on Rozenfeld et al. "Essential role of the mitochondrial Na+/Ca2+ exchanger NCLX in mediating PDE2-dependent neuronal survival and learning".

Mitochondrial calcium (mCa2+) is a critical regulator of neuronal cell death, bioenergetics, and signaling pathways. Although the regulatory machinery governing mCa2+ uptake via the mitochondrial calcium uniporter (mtCU) has been identified and functionally characterized, regulation of the mitochondrial Na+/Ca2+ exchanger (NCLX), the primary means of mCa2+ efflux, is poorly understood. Rozenfeld et al. report that inhibition of phosphodiesterase 2 (PDE2) enhances mCa2+efflux via increased NCLX phosphorylation by protein kinase A (PKA) [1]. The authors demonstrate that enhancing NCLX activity by pharmacologic inhibition of PDE2 improves neuronal survival in response to excitotoxic insult in vitro and enhances cognitive performance. Here we contextualize this discovery within existing literature and provide conjecture to add clarity to the proposed novel regulatory mechanism.

Neuronal loss of NCLX-dependent mitochondrial calcium efflux mediates age-associated cognitive decline.

Mitochondrial calcium overload contributes to neurodegenerative disease development and progression. We recently reported that loss of the mitochondrial sodium/calcium exchanger (NCLX), the primary mechanism of mCa2+ efflux, promotes mCa2+ overload, metabolic derangement, redox stress, and cognitive decline in models of Alzheimer's disease (AD). However, whether disrupted mCa2+ signaling contributes to neuronal pathology and cognitive decline independent of pre-existing amyloid or tau pathology remains unknown. Here, we generated mice with neuronal deletion of the mitochondrial sodium/calcium exchanger (NCLX, Slc8b1 gene), and evaluated age-associated changes in cognitive function and neuropathology. Neuronal loss of NCLX resulted in an age-dependent decline in spatial and cued recall memory, moderate amyloid deposition, mild tau pathology, synaptic remodeling, and indications of cell death. These results demonstrate that loss of NCLX-dependent mCa2+ efflux alone is sufficient to induce an Alzheimer's disease-like pathology and highlights the promise of therapies targeting mCa2+ exchange.

Helicobacter pylori World Gastroenterology Organization Global Guideline.

Helicobacter pylori remains a major health problem worldwide, causing considerable morbidity and mortality due to peptic ulcer disease and gastric cancer. The burden of disease falls disproportionally on less well-resourced populations. As with most infectious diseases, the largest impact on reducing this burden comes from improvement in socioeconomic status, which interrupts transmission. This has been observed in many regions of the world, but the prevalence of infection remains high in many regions where improvements in living standards are slow to occur. Meanwhile, the optimal clinical management and treatment pathways remain unsettled and are evolving with changing antimicrobial resistance patterns. Despite decades of research and clinical practice, major challenges remain. The quest for the most effective, safe, and simple therapy remains the major issue for clinicians. The search for an effective vaccine appears to be elusive still. Clinical guidelines do not infrequently proffer discordant advice. A major challenge for guidelines is for relevance across a variety of populations with a varying spectrum of disease, antimicrobial resistance rates, and vastly different resources. As local factors are central to determining the impact and management strategies for H. pylori infection, it is important that pathways are based on the best available local knowledge rather than solely extrapolating from guidelines formulated in other regions, which may be less applicable. To this end, this revision of the World Gastroenterology Organisation (WGO) H. pylori guideline uses a "Cascades" approach that seeks to summarize the principles of management and offer advice for pragmatic, relevant and achievable diagnostic and treatment pathways based on established key treatment principles and using local knowledge and available resources to guide regional practice.

De novo construction of T cell compartment in humanized mice engrafted with iPSC-derived thymus organoids.

Hematopoietic humanized (hu) mice are powerful tools for modeling the action of human immune system and are widely used for preclinical studies and drug discovery. However, generating a functional human T cell compartment in hu mice remains challenging, primarily due to the species-related differences between human and mouse thymus. While engrafting human fetal thymic tissues can support robust T cell development in hu mice, tissue scarcity and ethical concerns limit their wide use. Here, we describe the tissue engineering of human thymus organoids from inducible pluripotent stem cells (iPSC-thymus) that can support the de novo generation of a diverse population of functional human T cells. T cells of iPSC-thymus-engrafted hu mice could mediate both cellular and humoral immune responses, including mounting robust proinflammatory responses on T cell receptor engagement, inhibiting allogeneic tumor graft growth and facilitating efficient Ig class switching. Our findings indicate that hu mice engrafted with iPSC-thymus can serve as a new animal model to study human T cell-mediated immunity and accelerate the translation of findings from animal studies into the clinic.

Saccharomyces boulardii CNCM I-745 supplementation modifies the fecal resistome during Helicobacter pylori eradication therapy.

BACKGROUND: The gut microbiota is a significant reservoir of antimicrobial resistance genes (ARGs). The use and misuse of antimicrobials can select multi-resistant bacteria and modify the repertoire of ARGs in the gut. Developing effective interventions to manipulate the intestinal resistome would allow us to modify the antimicrobial resistance risk. MATERIALS AND METHODS: Applying shotgun metagenomics, we compared the composition of fecal resistome from individuals treated with triple therapy for Helicobacter pylori plus Saccharomyces boulardii CNCM-I 745 (Sb) versus triple antibiotherapy without S. boulardii (control) before, after, and one month after treatments. DNA samples were sequenced on an Illumina NovaSeq 6000 platform. Reads were trimmed and filtered for quality, and the reads classified as host genome were removed from further analysis. We used the ResFinder database for resistome analysis and the web-based tool ResistoXplorer and RStudio for graphical representation and statistical analysis. RESULTS: We identified 641 unique ARGs in all fecal samples, conferring resistance to 18 classes of antibiotics. The most prevalent ARGs found in at least 90% of the samples before the treatments were against tetracyclines, MLS-B (macrolide, lincosamide, and streptogramin B), beta-lactams, and aminoglycosides. Differential abundance analysis allowed the identification of ARGs significantly different between treatment groups. Thus, immediately after the treatments, the abundance of ARGs that confer resistance to lincosamides, tetracyclines, MLS-B, and two genes in the beta-lactam class (cfxA2 and cfxA3) was significantly lower in the group that received Sb than in the control group (edgeR, FDR <0.05). CONCLUSION: Our study demonstrated that the addition of S. boulardii CNCM-I 745 to the conventional antibiotic eradication therapy for H. pylori reduced the abundance of ARGs, particularly those genes that confer resistance to lincosamides, tetracyclines, MLS-B, and a few genes in the beta-lactams class.

Physician Perceptions on the Use of Antibiotics and Probiotics in Adults: An International Survey in the Asia-Pacific Area.

Background and Aims: The over-prescription of antibiotics is thought to represent a major threat to public health worldwide and is more frequently observed in some low- and middle-income countries. In the Asia-Pacific region, economic development, health care organization and population demographics are very heterogenous. The objective of this survey was to investigate antibiotic use and probiotic co-prescription among adult patients in this area. Methods: An online survey of physicians from seven countries of the Asia-Pacific region (Australia, Japan, Indonesia, India, China, Singapore and South Korea) was performed in 2018. The questionnaire explored current practices of physicians concerning antibiotics and probiotics and factors related to prescribing decisions. Results: A total of 387 general practitioners and 350 gastroenterologists completed the questionnaire. Physicians in Australia, Japan and South-Korea were low prescribers of antibiotics (11% to 19% of visits resulted in an antibiotic prescription), while physicians in Indonesia, India, China and Singapore were high prescribers (41% to 61%). A large majority (85%) of physicians agreed that antibiotics disrupted intestinal microbiota. The rates of co-prescription of probiotics varied from 16% in Japan to 39% in Singapore (overall, 27%). Conditions considered by physicians to be prevented by probiotics were mostly antibiotic-associated diarrhea (62%) and Clostridium difficile colitis (43%). Conclusions: Rates of probiotic co-prescription remain low in many countries although the negative effects of antibiotics on the gut microbiota and the benefits of co-prescribing probiotics are generally known.

Antibiotics as Major Disruptors of Gut Microbiota.

Advances in culture-independent research techniques have led to an increased understanding of the gut microbiota and the role it plays in health and disease. The intestine is populated by a complex microbial community that is organized around a network of metabolic interdependencies. It is now understood that the gut microbiota is vital for normal development and functioning of the human body, especially for the priming and maturation of the adaptive immune system. Antibiotic use can have several negative effects on the gut microbiota, including reduced species diversity, altered metabolic activity, and the selection of antibiotic-resistant organisms, which in turn can lead to antibiotic-associated diarrhea and recurrent Clostridioides difficile infections. There is also evidence that early childhood exposure to antibiotics can lead to several gastrointestinal, immunologic, and neurocognitive conditions. The increase in the use of antibiotics in recent years suggests that these problems are likely to become more acute or more prevalent in the future. Continued research into the structure and function of the gut microbiota is required to address this challenge.

Duodenal microbiome in patients with or without Helicobacter pylori infection.

BACKGROUND: Intestinal microbiota are recognized as an organ with important physiological functions whose alterations have been associated with common diseases including inflammatory intestinal conditions, malnutrition, type-2 diabetes, and cardiovascular diseases. The composition and function of the microbiota in the distal part of the intestine has been mainly described, while there is limited information on the small intestine microbiota. The objective of the present study was to describe the duodenal microbiome in individuals with dyspepsia in the presence or absence of Helicobacter pylori gastric infection. MATERIALS AND METHODS: Thirty-eight biopsies from the proximal duodenum of uninfected and 37 from H pylori-infected individuals were analyzed. Microbiota composition was assessed by PCR amplification and sequencing of 16S rRNA and ITS genes; sequences were analyzed with QIIME2. RESULTS AND CONCLUSIONS: At the phyla level, Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, and Fusobacteria were predominant in the mucosal associated duodenal microbiota (MAM); at the genera level, we observed the predominance of Ralstonia, Streptococcus, Pseudomonas, Haemophilus, Herbaspirillum, Neisseria, and Veillonella. Microbiota α-diversity was higher in H pylori-infected individuals than in non-infected ones. In terms of ß-diversity metrics, there was a statistically significant difference between groups. Also, relative abundance of Haemophilus, Neisseria, Prevotella pallens, Prevotella 7, and Streptococcus was greater in H pylori-infected patients. In infected patients, several types of H pylori were present in duodenal MAM. Finally, the majority of duodenal samples had fungi sequences; the most common taxa observed were Recurvomyces followed by Ascomycota and Basidiomycota.

Irritable bowel syndrome in celiac disease - relationships to celiac disease antibodies and levels of pro-inflammatory cytokines.

BACKGROUND: Evidence indicates that low-grade inflammation can alter gastrointestinal motor and sensory function and might contribute to the genesis of symptoms in IBS. OBJECTIVE: To examine relationships between IBS, disease antibodies and cytokine titers in celiac patients and a control group. MATERIALS AND METHODS: IBS, CD activity and serum levels of IL-6, IL-8 and IL12/23p40 were determined in celiac patients and controls. RESULTS: 123 celiac patients were included, 89% were female. 59% demonstrated disease activity and 32% met IBS criteria. Prevalence of IBS was not different between patients who adhered or did not adhere to GFD as well as between patients with or without positive antibodies. Celiac patients had increased levels of IL-6, IL-8 and IL12/23p40 as compared to controls. Higher levels of cytokines were found in celiac patients with IBS than in those without IBS. No difference in levels of cytokines was found between patients with and without CD positive antibodies. A significant negative correlation between the mental component of QoL and IL-6 and IL12/23p40 levels was found, but not with IL-8. CONCLUSION: Higher levels of inflammatory cytokines were found in CD patients with IBS than in either those without IBS or controls, indicating that IBS symptoms are associated with an increase in the inflammatory response and a decrease in quality of life of CD patients. These differences in cytokine levels were not related to CD antibodies status suggesting that IBS, in CD, is related to a different inflammatory process than that which is relevant to CD.

"It ain't over till it's over!" Risk-mitigation strategies for patients with gastrointestinal diseases in the aftermath of the COVID-19 pandemic.

The available COVID-19 literature has focused on specific disease manifestations, infection control, and delivery or prioritization of services for specific patient groups in the setting of the acute COVID-19 pandemic. Local health systems aim to contain the COVID-19 pandemic and hospitals and health-care providers rush to provide the capacity for a surge of COVID-19 patients. However, the short, medium-term, and long-term outcomes of patients with gastrointestinal (GI) diseases without COVID-19 will be affected by the ability to develop locally adapted strategies to meet their service needs in the COVID-19 setting. To mitigate risks for patients with GI diseases, it is useful to differentiate three phases: (i) the acute phase, (ii) the adaptation phase, and (iii) the consolidation phase. During the acute phase, service delivery for patients with GI disease will be curtailed to meet competing health-care needs of COVID-19 patients. During the adaptation phase, GI services are calibrated towards a "new normal," and the consolidation phase is characterized by rapid introduction and ongoing refinement of services. Proactive planning with engagement of relevant stakeholders including consumer representatives is required to be prepared for a variety of scenarios that are dictated by thus far undefined long-term economic and societal impacts of the pandemic. Because substantial changes to the delivery of services are likely to occur, it is important that these changes are embedded into quality and research frameworks to ensure that data are generated that support evidence-based decision-making during the adaptation and consolidation phases.

Irritable bowel syndrome in celiac disease - relationships to celiac disease antibodies and levels of pro-inflammatory cytokines / Síndrome del intestino irritable en la enfermedad celíaca: relaciones con los anticuerpos contra la enfermedad celíaca y los niveles de citocinas proinflamatorias

ABSTRACT Background: Evidence indicates that low-grade inflammation can alter gastrointestinal motor and sensory function and might contribute to the genesis of symptoms in IBS. Objective: To examine relationships between IBS, disease antibodies and cytokine titers in celiac patients and a control group. Materials and methods: IBS, CD activity and serum levels of IL-6, IL-8 and IL12/23p40 were determined in celiac patients and controls. Results: 123 celiac patients were included, 89% were female. 59% demonstrated disease activity and 32% met IBS criteria. Prevalence of IBS was not different between patients who adhered or did not adhere to GFD as well as between patients with or without positive antibodies. Celiac patients had increased levels of IL-6, IL-8 and IL12/23p40 as compared to controls. Higher levels of cytokines were found in celiac patients with IBS than in those without IBS. No difference in levels of cytokines was found between patients with and without CD positive antibodies. A significant negative correlation between the mental component of QoL and IL-6 and IL12/23p40 levels was found, but not with IL-8. Conclusion: Higher levels of inflammatory cytokines were found in CD patients with IBS than in either those without IBS or controls, indicating that IBS symptoms are associated with an increase in the inflammatory response and a decrease in quality of life of CD patients. These differences in cytokine levels were not related to CD antibodies status suggesting that IBS, in CD, is related to a different inflammatory process than that which is relevant to CD.

RESUMEN Antecedentes: la evidencia indica que la inflamación de bajo grado puede alterar la función motora y sensorial gastrointestinal y puede contribuir a la aparición de síntomas en el SII. Objetivo: Examinar la relación entre SII, anticuerpos contra enfermedades y títulos de citocinas en pacientes celíacos y un grupo de control. Materiales y métodos: se determinaron los síntomas de SII, actividad de CD y niveles séricos de IL-6, IL-8 e IL12 / 23p40 en pacientes celíacos y controles. Resultados: se incluyeron 123 pacientes celíacos, el 89% eran mujeres. El 59% demostró actividad de la enfermedad y el 32% cumplió con los criterios del SII. La prevalencia del SII no fue diferente entre los pacientes que se adhirieron o no se adhirieron a GFD, así como entre los pacientes con o sin anticuerpos positivos. Los pacientes celíacos tenían niveles aumentados de IL-6, IL-8 e IL12 / 23p40 en comparación con los controles. Se encontraron niveles más altos de citocinas en pacientes celíacos con SII que en aquellos sin SII. No se encontraron diferencias en los niveles de citocinas entre pacientes con y sin anticuerpos CD positivos. Se encontró una correlación negativa significativa entre el componente mental de la calidad de vida y los niveles de IL-6 e IL12 / 23p40, pero no con IL-8. Conclusión: Se encontraron niveles más altos de citocinas inflamatorias en pacientes con EC con SII que en aquellos sin SII o controles, lo que indica que los síntomas del SII están asociados con un aumento en la respuesta inflamatoria y una disminución en la calidad de vida de los pacientes con CD. Estas diferencias en los niveles de citocinas no estaban relacionadas con el estado de los anticuerpos contra la CD, lo que sugiere que el SII, en la CD, está relacionado con un proceso inflamatorio diferente al que es relevante para la CD.

Effect of Saccharomyces boulardii CNCM I-745 as complementary treatment of Helicobacter pylori infection on gut microbiome.

Conventional therapy for H. pylori infection includes the combination of antibiotics and a proton-pump inhibitor. Addition of probiotics as adjuvants for H. pylori antibiotic treatment can increase eradication rate and decrease treatment side effects. Although many studies show the benefits of S. boulardii CNCM I-745 in the treatment of H. pylori infection, the mechanism by which those benefits are achieved is unknown. Here, we report clinical characteristics and fecal microbiota changes comparing conventional anti-H. pylori therapy versus conventional therapy supplemented with S. boulardii CNCM I-745. A total of 74 patients were included in the current study; patients positive for H. pylori (n = 63) were randomly assigned to 2 groups: 34 patients received conventional therapy and 29 antibiotic therapy plus 750 mg of S. boulardii CNCM I-745 daily, for 2 weeks. Eleven patients negative for H. pylori infection were also studied. Patients provided 3 fecal samples: before initiating the antibiotic treatment, upon its completion, and 1 month after treatment. Patients were contacted every 72 h to inquire about side effects and compliance. DNA was extracted, and 16S rRNA was amplified and sequenced on Illumina MiSeq. Bioinformatic analysis was performed using QIIME2. Patients who received the probiotic had a significantly lower frequency of associated gastrointestinal symptoms (P = 0.028); higher number of bacterial diversity evenness (P = 0.0156); higher abundance of Enterobacteria; and lower abundance of Bacteroides and Clostridia upon treatment completion. Addition of S. boulardii CNCM I-745 induced a lower frequency of gastrointestinal symptoms that could be related to changes in gut microbiota.

A Comparison of Adjusted Versus Unadjusted Doses of Polymyxin B Based on Renal Function and Incidence of Acute Kidney Injury.

PURPOSE: To determine whether or not polymyxin B needs dose adjustments based on renal function by comparing the incidence of acute kidney injury (AKI) in patients whose polymyxin B doses were adjusted versus not adjusted according to renal function. METHODS: This was a single-center, prospective study with a retrospective cohort taking place in an acute care community hospital. Forty-two patients treated with polymyxin B were evaluated between April 2012 and December 2015. The primary outcome was incidence of AKI at day 7 after initiation of polymyxin B therapy with secondary outcomes including microbiological cure, clinical cure, and 30-day mortality. RESULTS: There was no difference in the incidence of AKI at day 7 in patients with polymyxin B doses adjusted according to renal function versus patients without polymyxin B dose adjustment (20.0% vs 18.2%; P = .882). There were no differences between groups in occurrence of microbiological cure, clinical cure, or 30-day mortality (27.8% vs 57.1%; P = .065, 70.0% vs 72.7%; P = .845, 40.0% vs 31.8%; P = .581, respectively). CONCLUSION: The results from this study support the use of polymyxin B without any dose adjustment in the setting of renal impairment.

Extension for Community Healthcare Outcomes Uruguay: A New Strategy to Promote Best Primary Care Practice for Autism.

Introduction. In Uruguay, the special care required for children with neurodevelopmental disorders presents difficulties including lack of access to specialists and rehabilitation services. Project ECHO (Extension for Community Healthcare Outcomes) connects primary care clinicians from remote areas to specialists to enable them to treat complex conditions through ongoing education and mentoring. Objective. To share the experience of the ECHO Autism program during the first 2 years of implementation. Methods. Analysis of ECHO Autism clinics from June 2015 to June 2017 including clinical cases presented participants' self-perception of changes in skills and competences. Results. Twenty clinical cases were presented: mean age 4.5 years; 15 were males; and 17 with medical and psychiatric comorbidities. After ECHO Autism implementation, a statistically significant improvement in participants' self-perception of skills and competences was observed. Conclusions. ECHO Autism in Uruguay is a meaningful approach to autism care and offers improved access to best practice care.

A genetically engineered Fc-binding amphiphilic polypeptide for congregating antibodies in vivo.

We report herein an affinity-based hydrogel used in creating subcutaneous depots of antibodies in vivo. The biomaterials design centered on pG_EAK, a polypeptide we designed and expressed in E. coli. The sequence consists of a truncated protein G (pG) genetically fused with repeats of the amphiphilic sequence AEAEAKAK ("EAK"). Capture of IgG was demonstrated in vitro in gels prepared from admixing pG_EAK and EAK ("pG_EAK/EAK gel"). The binding affinities and kinetics of pG for IgG were recapitulated in the pG_EAK polypeptide. Injecting IgG antibodies formulated with pG_EAK/EAK gel into subcutaneous space resulted in retention of the antibodies at the site for at least six days, whereas only signal at background levels was detected in grafts injected with IgG formulated in saline or diffusion-driven gel. The local retention of IgG in pG_EAK/EAK gel was correlated with limited distribution of the antibody in liver, spleen and lymph nodes, in contrast to those injected with antibodies formulated in saline or non-Fc binding EAK gel. In addition, antibodies formulated with pG_EAK/EAK gel and injected in mouse footpads were found to retain at the site for 19 days. As a demonstration of potential bioengineering applications, thymic epithelial cells (TECs), the primary population of thymic stromal cells that are critical for the development of T-lymphocytes, were mixed with pG_EAK/EAK gel formulated with TEC-specific anti-EpCAM antibodies and injected subcutaneously into athymic nude mice. The injected TECs congregated into functional thymic units in vivo, supporting the development of both CD4+ and CD8+ T cells as well as Foxp3+ regulatory T cells in the mice. In conclusion, pG_EAK/EAK gel can be used to retain IgG locally in vivo, and can be tailored as scaffolds for controlling deposition of molecular and/or cellular therapeutics. STATEMENT OF SIGNIFICANCE: The unique concept of the work centers on the genetic fusion of an Fc-binding domain and a self-assembling domain into a single polypeptide. To our knowledge, such bi-functional peptide has not been reported in the literature. The impact of the work lies in the ability to display IgG antibodies and Fc-fusion proteins of any specificity. The data shown demonstrate the platform can be used to localize IgG in vivo, and can be tailored for controlling deposition of primary thymic epithelial cells (TECs). The results support a biomaterials-based strategy by which TECs can be delivered as functional units to support T-lymphocyte development in vivo. The platform described in the study may serve as an important tool for immune engineering.

The role of the microbiome and the use of probiotics in gastrointestinal disorders in adults in the Asia-Pacific region - background and recommendations of a regional consensus meeting.

The Asia-Pacific region is diverse, with regard to ethnicity, culture, and economic development incorporating some of the world's least and most developed nations. Gastrointestinal diseases are common in the Asia-Pacific region, and their prevalence, presentation, and management vary considerably within the region. There is growing evidence for an important role for the human gut microbiota in gastrointestinal health. As a consequence, geographic variations in the composition of the gut microbiota may contribute to variations in both the prevalence and response to therapy of specific diseases. Probiotics have been proposed as a valuable option in the prevention and treatment of a number of gastrointestinal illnesses, but the quality of available evidence to support their efficacy is variable. A meeting of international experts in adult and pediatric gastroenterology was held at the Sorbonne University, Paris, France, on April 11 and 12, 2016, to discuss current evidence supporting the use of probiotics in gastrointestinal disorders in the Asia-Pacific region. This article provides an overview of the discussions held at this meeting and recommends the formation of an Asia-Pacific Consortium on Gut Microbiota similar to those established in Europe and North America.