AI's deep dive into complex pediatric inguinal hernia issues: a challenge to traditional guidelines?

OBJECTIVE

This study utilized ChatGPT, an artificial intelligence program based on large language models, to explore controversial issues in pediatric inguinal hernia surgery and compare its responses with the guidelines of the European Association of Pediatric Surgeons (EUPSA).

METHODS

Six contentious issues raised by EUPSA were submitted to ChatGPT 4.0 for analysis, for which two independent responses were generated for each issue. These generated answers were subsequently compared with systematic reviews and guidelines. To ensure content accuracy and reliability, a content analysis was conducted, and expert evaluations were solicited for validation. Content analysis evaluated the consistency or discrepancy between ChatGPT 4.0's responses and the guidelines. An expert scoring method assess the quality, reliability, and applicability of responses. The TF-IDF model tested the stability and consistency of the two responses.

RESULTS

The responses generated by ChatGPT 4.0 were mostly consistent with the guidelines. However, some differences and contradictions were noted. The average quality score was 3.33, reliability score was 2.75, and applicability score was 3.46 (out of 5). The average similarity between the two responses was 0.72 (out of 1), Content analysis and expert ratings yielded consistent conclusions, enhancing the credibility of our research.

CONCLUSION

ChatGPT can provide valuable responses to clinical questions, but it has limitations and requires further improvement. It is recommended to combine ChatGPT with other reliable data sources to improve clinical practice and decision-making.

Chronic GvHD NIH Consensus Project Biology Task Force: evolving path to personalized treatment of chronic GvHD

Chronic graft-versus-host disease (cGvHD) remains a prominent barrier to allogeneic hematopoietic stem cell transplantion as the leading cause of nonrelapse mortality and significant morbidity. Tremendous progress has been achieved in both the understanding of pathophysiology and the development of new therapies for cGvHD. Although our field has historically approached treatment from an empiric position, research performed at the bedside and bench has elucidated some of the complex pathophysiology of cGvHD. From the clinical perspective, there is significant variability of disease manifestations between individual patients, pointing to diverse biological underpinnings. Capitalizing on progress made to date, the field is now focused on establishing personalized approaches to treatment. The intent of this article is to concisely review recent knowledge gained and formulate a path toward patient-specific cGvHD therapy.

Donor T cell STAT3 deficiency enables tissue PD-L1-dependent prevention of graft-versus-host disease while preserving graft-versus-leukemia activity

STAT3 deficiency (STAT3-/-) in donor T cells prevents graft-versus-host disease (GVHD), but the impact on graft-versus-leukemia (GVL) activity and mechanisms of GVHD prevention remains unclear. Here, using murine models of GVHD, we show that STAT3-/- donor T cells induced only mild reversible acute GVHD while preserving GVL effects against nonsusceptible acute lymphoblastic leukemia (ALL) cells in a donor T cell dose-dependent manner. GVHD prevention depended on programmed death ligand 1/programmed cell death protein 1 (PD-L1/PD-1) signaling. In GVHD target tissues, STAT3 deficiency amplified PD-L1/PD-1 inhibition of glutathione (GSH)/Myc pathways that regulate metabolic reprogramming in activated T cells, with decreased glycolytic and mitochondrial ATP production and increased mitochondrial ROS production and dysfunction, leading to tissue-specific deletion of host-reactive T cells and prevention of GVHD. Mitochondrial STAT3 deficiency alone did not reduce GSH expression or prevent GVHD. In lymphoid tissues, the lack of host-tissue PD-L1 interaction with PD-1 reduced the inhibition of the GSH/Myc pathway despite reduced GSH production caused by STAT3 deficiency and allowed donor T cell functions that mediate GVL activity. Therefore, STAT3 deficiency in donor T cells augments PD-1 signaling-mediated inhibition of GSH/Myc pathways and augments dysfunction of T cells in GVHD target tissues while sparing T cells in lymphoid tissues, leading to prevention of GVHD while preserving GVL effects.

Donor programmed cell death 1 ligand 1 is required for organ transplant tolerance in major histocompatibility complex-mismatched mixed chimeras although programmed cell death 1 ligand 1 and major histocompatibility complex class II are not required for inducing chimerism

Induction of major histocompatibility complex (MHC) human leukocyte antigen (HLA)-mismatched mixed chimerism is a promising approach for organ transplantation tolerance; however, human leukocyte antigen-mismatched stable mixed chimerism has not been achieved in the clinic. Tolerogenic dendritic cell (DC) expression of MHC class II (MHC II) and programmed cell death 1 ligand 1 (PD-L1) is important for immune tolerance, but whether donor-MHC II or PD-L1 is required for the induction of stable MHC-mismatched mixed chimerism and transplant tolerance is unclear. Here, we show that a clinically applicable radiation-free regimen can establish stable MHC-mismatched mixed chimerism and organ transplant tolerance in murine models. Induction of MHC-mismatched mixed chimerism does not require donor cell expression of MHC II or PD-L1, but donor-type organ transplant tolerance in the mixed chimeras (MC) requires the donor hematopoietic cells and the organ transplants to express PD-L1. The PD-L1 expressed by donor hematopoietic cells and the programmed cell death 1 expressed by host cells augment host-type donor-reactive CD4+ and CD8+ T cell anergy/exhaustion and differentiation into peripheral regulatory T (pTreg) cells in association with the organ transplant tolerance in the MC. Conversely, host-type Treg cells augment the expansion of donor-type tolerogenic CD8+ DCs that express PD-L1. These results indicate that PD-L1 expressed by donor-type tolerogenic DCs and expansion of host-type pTreg cells in MHC-mismatched MCs play critical roles in mediating organ transplant tolerance.

[A semi-supervised network-based tissue-aware contrast enhancement method for CT images]

OBJECTIVE

To propose a tissue- aware contrast enhancement network (T- ACEnet) for CT image enhancement and validate its accuracy in CT image organ segmentation tasks.

METHODS

The original CT images were mapped to generate low dynamic grayscale images with lung and soft tissue window contrasts, and the supervised sub-network learned to recognize the optimal window width and level setting of the lung and abdominal soft tissues via the lung mask. The self-supervised sub-network then used the extreme value suppression loss function to preserve more organ edge structure information. The images generated by the T-ACEnet were fed into the segmentation network to segment multiple abdominal organs.

RESULTS

The images obtained by T-ACEnet were capable of providing more window setting information in a single image, which allowed the physicians to conduct preliminary screening of the lesions. Compared with the suboptimal methods, T-ACE images achieved improvements by 0.51, 0.26, 0.10, and 14.14 in SSIM, QABF, VIFF, and PSNR metrics, respectively, with a reduced MSE by an order of magnitude. When T-ACE images were used as input for segmentation networks, the organ segmentation accuracy could be effectively improved without changing the model as compared with the original CT images. All the 5 segmentation quantitative indices were improved, with the maximum improvement of 4.16%.

CONCLUSION

The T-ACEnet can perceptually improve the contrast of organ tissues and provide more comprehensive and continuous diagnostic information, and the T-ACE images generated using this method can significantly improve the performance of organ segmentation tasks.

Engineering CpG island DNA methylation in pluripotent cells through synthetic CpG-free ssDNA insertion

Cellular differentiation requires global changes to DNA methylation (DNAme), where it functions to regulate transcription factor, chromatin remodeling activity, and genome interpretation. Here, we describe a simple DNAme engineering approach in pluripotent stem cells (PSCs) that stably extends DNAme across target CpG islands (CGIs). Integration of synthetic CpG-free single-stranded DNA (ssDNA) induces a target CpG island methylation response (CIMR) in multiple PSC lines, Nt2d1 embryonal carcinoma cells, and mouse PSCs but not in highly methylated CpG island hypermethylator phenotype (CIMP)+ cancer lines. MLH1 CIMR DNAme spanned the CGI, was precisely maintained through cellular differentiation, suppressed MLH1 expression, and sensitized derived cardiomyocytes and thymic epithelial cells to cisplatin. Guidelines for CIMR editing are provided, and initial CIMR DNAme is characterized at TP53 and ONECUT1 CGIs. Collectively, this resource facilitates CpG island DNAme engineering in pluripotency and the genesis of novel epigenetic models of development and disease.

[A semi-supervised material quantitative intelligent imaging algorithm for spectral CT based on prior information perception learning]

OBJECTIVE

To propose a semi-supervised material quantitative intelligent imaging algorithm based on prior information perception learning (SLMD-Net) to improve the quality and precision of spectral CT imaging.

METHODS

The algorithm includes a supervised and a self- supervised submodule. In the supervised submodule, the mapping relationship between low and high signal-to-noise ratio (SNR) data was constructed through mean square error loss function learning based on a small labeled dataset. In the self- supervised sub-module, an image recovery model was utilized to construct the loss function incorporating the prior information from a large unlabeled low SNR basic material image dataset, and the total variation (TV) model was used to to characterize the prior information of the images. The two submodules were combined to form the SLMD-Net method, and pre-clinical simulation data were used to validate the feasibility and effectiveness of the algorithm.

RESULTS

Compared with the traditional model-driven quantitative imaging methods (FBP-DI, PWLS-PCG, and E3DTV), data-driven supervised-learning-based quantitative imaging methods (SUMD-Net and BFCNN), a material quantitative imaging method based on unsupervised learning (UNTV-Net) and semi-supervised learning-based cycle consistent generative adversarial network (Semi-CycleGAN), the proposed SLMD-Net method had better performance in both visual and quantitative assessments. For quantitative imaging of water and bone materials, the SLMD-Net method had the highest PSNR index (31.82 and 29.06), the highest FSIM index (0.95 and 0.90), and the lowest RMSE index (0.03 and 0.02), respectively) and achieved significantly higher image quality scores than the other 7 material decomposition methods (P < 0.05). The material quantitative imaging performance of SLMD-Net was close to that of the supervised network SUMD-Net trained with labeled data with a doubled size.

CONCLUSIONS

A small labeled dataset and a large unlabeled low SNR material image dataset can be fully used to suppress noise amplification and artifacts in basic material decomposition in spectral CT and reduce the dependence on labeled data-driven network, which considers more realistic scenario in clinics.

Blockade of trans PD-L1 interaction with CD80 augments antitumor immunity

PD-L1 has two receptors: PD-1 and CD80. Previous reports assumed that PD-L1 and CD80 interacted in trans, but recent reports showed that only cis PD-L1/CD80 interactions existed, and prevention of cis PD-L1/CD80 interactions on antigen-presenting cells (APCs) reduced antitumor immunity via augmenting PD-L1/PD-1 and CD80/CTLA4 interactions between T and APCs. Here, using tumor-bearing mice capable of cis and trans or trans only PD-L1/CD80 interactions, we show that trans PD-L1/CD80 interactions do exist between tumor and T cells, and the effects of trans PD-L1/CD80 interactions require tumor cell expression of MHC-I and T cell expression of CD28. The blockade of PD-L1/CD80 interactions in mice with both cis and trans interactions or with only trans interactions augments antitumor immunity by expanding IFN-γ-producing CD8⁺ T cells and IFN-γ-dependent NOS2-expressing tumor-associated macrophages. Our studies indicate that although cis and trans PD-L1/CD80 interactions may have opposite effects on antitumor immunity, the net effect of blocking PD-L1/CD80 interactions in vivo augments CD8⁺ T cell-mediated antitumor immunity.

Prediction of knee pain improvement over two years for knee osteoarthritis using a dynamic nomogram based on MRI-derived radiomics: a proof-of-concept study

OBJECTIVES

To develop and validate a nomogram to detect improved knee pain in osteoarthritis (OA) by integrating magnetic resonance imaging (MRI) radiomics signature of subchondral bone and clinical characteristics.

METHODS

Participants were selected from the Vitamin D Effects on Osteoarthritis (VIDEO) study. The primary outcome was 20% improvement of knee pain score over 2 years in participants administrated either vitamin D or placebo. Radiomics features of subchondral bone and clinical characteristics from 216 participants were extracted and analyzed. The participants were randomly split into the training and validation cohorts at a ratio of 8:2. Least absolute shrinkage and selection operator (LASSO) regression was used to select features and generate radiomics signatures. The optimal radiomics signature and clinical indicators were fitted into a nomogram using multivariable logistic regression model.

RESULTS

The nomogram showed favorable discrimination performance [AUC_training, 0.79 (95% CI: 0.72-0.79), AUC_validation, 0.83 (95% CI: 0.70-0.96)] as well as a good calibration. Additional contributing value of fusion radiomics signature to the nomogram was statistically significant (NRI, 0.23; IDI, 0.14, P < 0.001 in training cohort and NRI, 0.29; IDI, 0.18, P < 0.05 in validating cohort). Decision curve analysis confirmed the clinical usefulness of nomogram.

CONCLUSION

The radiomics-based nomogram comprising the MR radiomics signature and clinical variables achieves a favorable predictive efficacy and accuracy in differentiating improvement in knee pain among OA patients. This proof-of-concept study provides a promising way to predict clinically meaningful outcomes.

Th17 Cell-Derived Amphiregulin Promotes Colitis-Associated Intestinal Fibrosis Through Activation of mTOR and MEK in Intestinal Myofibroblasts

BACKGROUND & AIMS

Intestinal fibrosis is a significant complication of Crohn's disease (CD). Gut microbiota reactive Th17 cells are crucial in the pathogenesis of CD; however, how Th17 cells induce intestinal fibrosis is still not completely understood.

METHODS

In this study, T-cell transfer model with wild-type (WT) and Areg-/- Th17 cells and dextran sulfate sodium (DSS)-induced chronic colitis model in WT and Areg-/- mice were used. CD4+ T-cell expression of AREG was determined by quantitative reverse-transcriptase polymerase chain reaction and enzyme-linked immunosorbent assay. The effect of AREG on proliferation/migration/collagen expression in human intestinal myofibroblasts was determined. AREG expression was assessed in healthy controls and patients with CD with or without intestinal fibrosis.

RESULTS

Although Th1 and Th17 cells induced intestinal inflammation at similar levels when transferred into Tcrβxδ-/- mice, Th17 cells induced more severe intestinal fibrosis. Th17 cells expressed higher levels of AREG than Th1 cells. Areg-/- mice developed less severe intestinal fibrosis compared with WT mice on DSS insults. Transfer of Areg-/- Th17 cells induced less severe fibrosis in Tcrβxδ-/- mice compared with WT Th17 cells. Interleukin (IL)6 and IL21 promoted AREG expression in Th17 cells by activating Stat3. Stat3 inhibitor suppressed Th17-induced intestinal fibrosis. AREG promoted human intestinal myofibroblast proliferation, motility, and collagen I expression, which was mediated by activating mammalian target of rapamycin and MEK. AREG expression was increased in intestinal CD4+ T cells in fibrotic sites compared with nonfibrotic sites from patients with CD.

CONCLUSIONS

These findings reveal that Th17-derived AREG promotes intestinal fibrotic responses in experimental colitis and human patients with CD. Thereby, AREG might serve as a potential therapeutic target for fibrosis in CD.

Trafficking between clonally related peripheral T-helper cells and tissue-resident T-helper cells in chronic GVHD

Chronic graft-versus-host disease (cGVHD) is an autoimmune-like syndrome. CXCR5-PD-1hi peripheral T-helper (Tph) cells have an important pathogenic role in autoimmune diseases, but the role of Tph cells in cGVHD remains unknown. We show that in patients with cGVHD, expansion of Tph cells among blood CD4+ T cells was associated with cGVHD severity. These cells augmented memory B-cell differentiation and production of immunoglobulin G via interleukin 21 (IL-21). Tph cell expansion was also observed in a murine model of cGVHD. This Tph cell expansion in the blood is associated with the expansion of pathogenic tissue-resident T-helper (Trh) cells that form lymphoid aggregates surrounded by collagen in graft-versus-host disease (GVHD) target tissues. Adoptive transfer experiments showed that Trh cells from GVHD target tissues give rise to Tph cells in the blood, and conversely, Tph cells from the blood give rise to Trh cells in GVHD target tissues. Tph cells in the blood and Trh cells in GVHD target tissues had highly overlapping T-cell receptor α and β repertoires. Deficiency of IL-21R, B-cell lymphoma 6 (BCL6), or T-bet in donor T cells markedly reduced the proportions of Tph cells in the blood and Trh cells in GVHD target tissues and reduced T-B interaction in the lymphoid aggregates. These results indicate that clonally related pathogenic Tph cells and Trh cells traffic between the blood and cGVHD target tissues, and that IL-21R-BCL6 signaling and T-bet are required for the development and expansion of Tph and Trh cells in the pathogenesis of cGVHD.

[Association analysis between genetic variants of matrix metalloproteinase enzyme 2 gene and the blood pressure of children and adolescents]

Objective: To explore the association between genetic variants of matrix metalloproteinase enzyme 2 (MMP2) gene and the blood pressure of children and adolescents. Methods: This cross-sectional study was performed in 2016 and included 4 155 children and adolescents in the urban area of Guangzhou. Physical examinations (including body height, weight, and blood pressure), questionnaires (including general characteristics, physical exercise, parental educational level, household income, etc.), and blood sampling were performed. Multivariable linear regression models were used to investigate the associations of MMP2 genetic variations (rs243865, rs7201) and the genetic risk score (GRS) level with standardized blood pressure. Mediating effect of standardized body mass index (BMI) was further assessed by process analysis in the association between GRS level and blood pressure, and potential additive interaction between physical activity and GRS level was analyzed using the product term in the regression model. Results: A total of 4 155 primary and secondary schoolchildren were finally included in the analysis, consisting of 1 401 (33.7%) second grade pupils of primary school, 1 422 (34.2%) first grade pupils of middle school, and 1 332 (32.1%) first-grade students of senior high school. After adjusting for age, sex, parental educational level, and family income, as compared to the rs243865 TT genotype, the CC/CT genotype increased diastolic blood pressure (DBP) by 0.461 standard deviations (SD) (β for dominant model=0.461, 95%CI 0.199-0.723). When compared to the rs7201 CC genotype, the AA/AC genotype showed 0.147 SD higher systolic blood pressure (SBP) (β for recessive model=0.147, 95%CI 0.014-0.279) and 0.171 SD increased DBP (β for recessive model=0.171, 95%CI 0.039-0.304). For each increment of GRS level, SBP and DBP increased by 0.151 SD (β for dominant model=0.151, 95%CI 0.029-0.272) and 0.242 SD (β=0.242, 95%CI 0.120-0.363), respectively. The mediating effect of BMI accounted for 28.3% and 12.6% of the total effect of GRS on SBP and DBP, respectively. After controlling BMI, the direct effect of GRS on DBP remained statistically significant (P<0.001). The insufficient moderate-to-vigorous physical activity (<0.5 h/d) showed a significant interaction with GRS on SBP under additive scale (β for interaction=0.518, 95%CI 0.088-0.949, P=0.018). Conclusions: rs243865 and rs7201 variants in MMP2 gene are associated with the elevated blood pressure of children and adolescents. Obesity may yield a mediation role in the associations, while insufficient physical activity may have a positively additive interaction with MMP2 genetic variants.

MOF-Derived Co3O4 Nanoparticles Catalyzing Hydrothermal Deoxygenation of Fatty Acids for Alkane Production

Designing economical and nonprecious catalysts with a catalytic performance as good as that of noble metals is of great importance in future renewable bioenergy production. In this study, the metal-organic framework (MOF) was applied as a precursor template to synthesize Co₃O₄ nanoparticles with a carbon matrix shell (denoted as M-Co₃O₄). To select the synthesized optimal catalyst, stearic acid was chosen as the model reactant. The effects of catalyst dosage, methanol dosage, water dosage, temperature, and reaction time on catalytic efficiency were examined. Under the designed condition, M-Co₃O₄ exhibited high catalytic performance and the catalyst showed higher conversion of stearic acid (98.7%) and selectivity toward C8-C18 alkanes (92.2%) in comparison with Pt/C (95.8% conversion and 93.2% selectivity toward C8-C18). Furthermore, a series of characterization techniques such as scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption isotherms (Brunauer-Emmett-Teller (BET) method), and thermogravimetric analysis (TGA) was applied to investigate the physicochemical properties of the catalysts. Finally, we proposed that decarbonization (deCO) could be the presumably mechanistic pathway for the production of C8-C18 alkanes from the decomposition of stearic acid.

Retention of Donor T Cells in Lymphohematopoietic Tissue and Augmentation of Tissue PD-L1 Protection for Prevention of GVHD While Preserving GVL Activity

Allogeneic hematopoietic cell transplantation (Allo-HCT) is a curative therapy for hematological malignancies (i.e., leukemia and lymphoma) due to the graft-versus-leukemia (GVL) activity mediated by alloreactive T cells that can eliminate residual malignant cells and prevent relapse. However, the same alloreactive T cells can cause a serious side effect, known as graft-versus-host disease (GVHD). GVHD and GVL occur in distinct organ and tissues, with GVHD occurring in target organs (e.g., the gut, liver, lung, skin, etc.) and GVL in lympho-hematopoietic tissues where hematological cancer cells primarily reside. Currently used immunosuppressive drugs for the treatment of GVHD inhibit donor T cell activation and expansion, resulting in a decrease in both GVHD and GVL activity that is associated with cancer relapse. To prevent GVHD, it is important to allow full activation and expansion of alloreactive T cells in the lympho-hematopoietic tissues, as well as prevent donor T cells from migrating into the GVHD target tissues, and tolerize infiltrating T cells via protective mechanisms, such as PD-L1 interacting with PD-1, in the target tissues. In this review, we will summarize major approaches that prevent donor T cell migration into GVHD target tissues and approaches that augment tolerization of the infiltrating T cells in the GVHD target tissues while preserving strong GVL activity in the lympho-hematopoietic tissues.

Steroid-Refractory Gut Graft-Versus-Host Disease: What We Have Learned From Basic Immunology and Experimental Mouse Model

Intestinal graft-versus-host disease (Gut-GVHD) is one of the major causes of mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). While systemic glucocorticoids (GCs) comprise the first-line treatment option, the response rate for GCs varies from 30% to 50%. The prognosis for patients with steroid-refractory acute Gut-GVHD (SR-Gut-aGVHD) remains dismal. The mechanisms underlying steroid resistance are unclear, and apart from ruxolitinib, there are no approved treatments for SR-Gut-aGVHD. In this review, we provide an overview of the current biological understanding of experimental SR-Gut-aGVHD pathogenesis, the advanced technology that can be applied to the human SR-Gut-aGVHD studies, and the potential novel therapeutic options for patients with SR-Gut-aGVHD.

microRNA-142 guards against autoimmunity by controlling Treg cell homeostasis and function

Regulatory T (Treg) cells are critical in preventing aberrant immune responses. Posttranscriptional control of gene expression by microRNA (miRNA) has recently emerged as an essential genetic element for Treg cell function. Here, we report that mice with Treg cell-specific ablation of miR-142 (hereafter Foxp3CremiR-142fl/fl mice) developed a fatal systemic autoimmune disorder due to a breakdown in peripheral T-cell tolerance. Foxp3CremiR-142fl/fl mice displayed a significant decrease in the abundance and suppressive capacity of Treg cells. Expression profiling of miR-142-deficient Treg cells revealed an up-regulation of multiple genes in the interferon gamma (IFNγ) signaling network. We identified several of these IFNγ-associated genes as direct miR-142-3p targets and observed excessive IFNγ production and signaling in miR-142-deficient Treg cells. Ifng ablation rescued the Treg cell homeostatic defect and alleviated development of autoimmunity in Foxp3CremiR-142fl/fl mice. Thus, our findings implicate miR-142 as an indispensable regulator of Treg cell homeostasis that exerts its function by attenuating IFNγ responses.

Murine Models Provide New Insights Into Pathogenesis of Chronic Graft-Versus-Host Disease in Humans

Allogeneic hematopoietic cell transplantation (allo-HCT) is a curative therapy for hematologic malignancies, but its success is complicated by graft-versus-host disease (GVHD). GVHD can be divided into acute and chronic types. Acute GVHD represents an acute alloimmune inflammatory response initiated by donor T cells that recognize recipient alloantigens. Chronic GVHD has a more complex pathophysiology involving donor-derived T cells that recognize recipient-specific antigens, donor-specific antigens, and antigens shared by the recipient and donor. Antibodies produced by donor B cells contribute to the pathogenesis of chronic GVHD but not acute GVHD. Acute GVHD can often be effectively controlled by treatment with corticosteroids or other immunosuppressant for a period of weeks, but successful control of chronic GVHD requires much longer treatment. Therefore, chronic GVHD remains the major cause of long-term morbidity and mortality after allo-HCT. Murine models of allo-HCT have made great contributions to our understanding pathogenesis of acute and chronic GVHD. In this review, we summarize new mechanistic findings from murine models of chronic GVHD, and we discuss the relevance of these insights to chronic GVHD pathogenesis in humans and their potential impact on clinical prevention and treatment.

Tissue-resident PSGL1loCD4+ T cells promote B cell differentiation and chronic graft-versus-host disease-associated autoimmunity

CD4+ T cell interactions with B cells play a critical role in the pathogenesis of systemic autoimmune diseases such as systemic lupus and chronic graft-versus-host disease (cGVHD). Extrafollicular CD44hiCD62LloPSGL1loCD4+ T cells (PSGL1loCD4+ T cells) are associated with the pathogenesis of lupus and cGVHD, but their causal role has not been established. With murine and humanized MHC-/-HLA-A2+DR4+ murine models of cGVHD, we showed that murine and human PSGL1loCD4+ T cells from GVHD target tissues have features of B cell helpers with upregulated expression of programmed cell death protein 1 (PD1) and inducible T cell costimulator (ICOS) and production of IL-21. They reside in nonlymphoid tissues without circulating in the blood and have features of tissue-resident memory T cells with upregulated expression of CD69. Murine PSGL1loCD4+ T cells from GVHD target tissues augmented B cell differentiation into plasma cells and production of autoantibodies via their PD1 interaction with PD-L2 on B cells. Human PSGL1loCD4+ T cells were apposed with memory B cells in the liver tissues of humanized mice and cGVHD patients. Human PSGL1loCD4+ T cells from humanized GVHD target tissues also augmented autologous memory B cell differentiation into plasma cells and antibody production in a PD1/PD-L2-dependent manner. Further preclinical studies targeting tissue-resident T cells to treat antibody-mediated features of autoimmune diseases are warranted.

Abstract 3180: Blockade of PD-L1 interaction with CD80 in trans augments anti-tumor immunity by increasing NOS2 in tumor-associated macrophages

Programmed death ligand 1(PD-L1) has two receptors: programmed death receptor 1 (PD-1) and CD80. Both PD-L1 and CD80 are expressed by activated T-cells, antigen presenting cells (APCs) and tumor cells. Although the role of PD-L1/PD-1 interaction in regulation of tumor immunity has been well characterized, role of PD-L1/CD80 interaction remains largely unknown. The interaction mode of PD-L1 with CD80 is also controversial. Our previous studies showed that in murine model of acute graft versus host disease, PD-L1 interact with CD80 on different cells (Deng et al: J. Immunol. 2015); but a recent report showed that PD-L1 interacts with CD80 in cis on the same cell (Sugiura et al: Science 2019). In the current studies, we tested the role of PD-L1/CD80 interaction in trans in regulation of tumor immunity. WT, PD-L1-/-, and CD80-/- C57BL/6 mice were inoculated with WT or PD-L1-/- MC38 tumor cells and intraperitoneally injected with 200μg anti-PD-L1(43H12) that specifically block PD-L1/CD80 interactions or control IgG, starting on D7 after tumor inoculation, every 3 days, total of 5 times. Tumor volume was monitored every 3 days for up to D20. Tumor and tumor draining lymph nodes were harvested on D14 or D15 after tumor inoculation for mechanism studies. We observed that administration of 43H12 resulted in inhibition of tumor growth in WT MC38→WT Rec model; as well as in models of WT MC38→PD-L1-/- Rec (no PD-L1 on APCs or T cells), WT MC38→CD80-/- Rec (no CD80 on APCs or T cells), and PD-L1-/-MC38→CD80-/- Rec (no PD-L1 on tumor cells and no CD80 on APCs or T cells, truly PD-L1 interaction with CD80 in trans). These results indicate that blockade of PD-L1 interaction with CD80 in trans inhibits tumor growth. Furthermore, we found that blockade of PD-L1/CD80 interaction by 43H12 mAb increased percentage of CD8+ effector memory T (Tem) that produce IFN-γ and tumor-associated macrophages (TAMs) that express NOS2. Administration of anti-IFN-γ eliminated increase of NOS2 and anti-tumor effect, and administration of NOS2 inhibitor (1400W) also eliminated the anti-tumor effect mediated by injection of 43H12 mAb. Therefore, PD-L1 interaction with CD80 in trans regulate tumor immunity; and blockade of this interaction augments anti-tumor immunity via augmenting CD8+ Tem expansion and their production of IFN-γ, and subsequently augmenting tumoricidal NOS2 expressed in TAMs.

Citation Format: Yuankun Zhang, Qingxiao Song, Michael Lee, Haidong Tang, Kaniel Cassady, Yang-Xin Fu, Dustin E. Schones, Arthur Riggs, Ru Feng, Defu Zeng. Blockade of PD-L1 interaction with CD80 in trans augments anti-tumor immunity by increasing NOS2 in tumor-associated macrophages [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3180.

Tolerogenic anti-IL-2 mAb prevents graft-versus-host disease while preserving strong graft-versus-leukemia activity

Donor T cells mediate both graft-versus-leukemia (GVL) activity and graft-versus-host disease (GVHD) after allogeneic hematopoietic cell transplantation (allo-HCT). Development of methods that preserve GVL activity while preventing GVHD remains a long-sought goal. Tolerogenic anti-interleukin-2 (IL-2) monoclonal antibody (JES6-1) forms anti-IL-2/IL-2 complexes that block IL-2 binding to IL-2Rβ and IL-2Rγ on conventional T cells that have low expression of IL-2Rα. Here, we show that administration of JES6 early after allo-HCT in mice markedly attenuates acute GVHD while preserving GVL activity that is dramatically stronger than observed with tacrolimus (TAC) treatment. The anti-IL-2 treatment downregulated activation of the IL-2-Stat5 pathway and reduced production of granulocyte-macrophage colony-stimulating factor (GM-CSF). In GVHD target tissues, enhanced T-cell programmed cell death protein 1 (PD-1) interaction with tissue-programmed cell death-ligand 1 (PD-L1) led to reduced activation of protein kinase-mammalian target of rapamycin pathway and increased expression of eomesodermin and B-lymphocyte-induced maturation protein-1, increased T-cell anergy/exhaustion, expansion of Foxp3-IL-10-producing type 1 regulatory (Tr1) cells, and depletion of GM-CSF-producing T helper type 1 (Th1)/cytotoxic T cell type 1 (Tc1) cells. In recipient lymphoid tissues, lack of donor T-cell PD-1 interaction with tissue PD-L1 preserved donor PD-1+TCF-1+Ly108+CD8+ T memory progenitors and functional effectors that have strong GVL activity. Anti-IL-2 and TAC treatments have qualitatively distinct effects on donor T cells in the lymphoid tissues, and CD8+ T memory progenitor cells are enriched with anti-IL-2 treatment compared with TAC treatment. We conclude that administration of tolerogenic anti-IL-2 monoclonal antibody early after allo-HCT represents a novel approach for preventing acute GVHD while preserving GVL activity.

IL-22-dependent dysbiosis and mononuclear phagocyte depletion contribute to steroid-resistant gut graft-versus-host disease in mice

Efforts to improve the prognosis of steroid-resistant gut acute graft-versus-host-disease (SR-Gut-aGVHD) have suffered from poor understanding of its pathogenesis. Here we show that the pathogenesis of SR-Gut-aGVHD is associated with reduction of IFN-γ+ Th/Tc1 cells and preferential expansion of IL-17-IL-22+ Th/Tc22 cells. The IL-22 from Th/Tc22 cells causes dysbiosis in a Reg3γ-dependent manner. Transplantation of IFN-γ-deficient donor CD8+ T cells in the absence of CD4+ T cells produces a phenocopy of SR-Gut-aGVHD. IFN-γ deficiency in donor CD8+ T cells also leads to a PD-1-dependent depletion of intestinal protective CX3CR1hi mononuclear phagocytes (MNP), which also augments expansion of Tc22 cells. Supporting the dual regulation, simultaneous dysbiosis induction and depletion of CX3CR1hi MNP results in full-blown Gut-aGVHD. Our results thus provide insights into SR-Gut-aGVHD pathogenesis and suggest the potential efficacy of IL-22 antagonists and IFN-γ agonists in SR-Gut-aGVHD therapy.

Haploidentical mixed chimerism cures autoimmunity in established type 1 diabetic mice

Clinical trials are currently testing whether induction of haploidentical mixed chimerism (Haplo-MC) induces organ transplantation tolerance. Whether Haplo-MC can be used to treat established autoimmune diseases remains unknown. Here, we show that established autoimmunity in euthymic and adult-thymectomized NOD (H-2g7) mice was cured by induction of Haplo-MC under a non-myeloablative anti-thymocyte globulin-based conditioning regimen and infusion of CD4+ T cell-depleted hematopoietic graft from H-2b/g7 F1 donors that expressed autoimmune-resistant H-2b or from H-2s/g7 F1 donors that expressed autoimmune-susceptible H-2s. The cure was associated with enhanced thymic negative selection, increased thymic Treg (tTreg) production, and anergy or exhaustion of residual host-type autoreactive T cells in the periphery. The peripheral tolerance was accompanied by expansion of donor- and host-type CD62L-Helios+ tTregs as well as host-type Helios-Nrp1+ peripheral Tregs (pTregs) and PD-L1hi plasmacytoid DCs (pDCs). Depletion of donor- or host-type Tregs led to reduction of host-type PD-L1hi pDCs and recurrence of autoimmunity, whereas PD-L1 deficiency in host-type DCs led to reduction of host-type pDCs and Helios-Nrp1+ pTregs. Thus, induction of Haplo-MC reestablished both central and peripheral tolerance through mechanisms that depend on allo-MHC+ donor-type DCs, PD-L1hi host-type DCs, and the generation and persistence of donor- and host-type tTregs and pTregs.

[Time-series analysis on the relationship between ambient PM2.5 and daily outpatient visits due to allergic conjunctivitis among children in Shenzhen]

Objective: To explore the short-term effects of ambient PM_2.5 on the outpatient visits of allergic conjunctivitis among children in Shenzhen. Methods: It was a ecological study. Data on daily visits including date of visit, sex and age from children with allergic conjunctivitis were collected from Shenzhen Eye Hospital and Shenzhen Children's Hospital in 2018. Related data on air pollution (PM_2.5, PM₁₀, SO₂, NO₂, CO and O₃) and meteorology (atmospheric pressure, temperature and relative humidity) were also collected. Pearson correlation analysis was used for normal distribution data and Spearman rank correlation analysis was used for non-normal distribution data. Generalized additive model was used to estimate the impact of PM_2.5 pollution on allergic conjunctivitis outpatients and the lagging effects. Results: In 2018, there were 16 133 allergic conjunctivitis outpatients in the two hospitals. The maximum age was 18 years and the minimum age was 2 months. Males accounted for 49.3%. The daily average concentration of PM_2.5 was 22 (15, 31) μg/m³. Changes of the concentration of PM_2.5 had a positive correlation with the amount of allergic conjunctivitis visits, and the Spearman correlation coefficient was 0.150 (P=0.004). The single pollutant model showed that the strongest effect appeared at 3 days (RR=1.111， 95%CI:1.071-1.152). A 10 μg/m³ increase of PM_2.5 would result in an excessive number of allergic conjunctivitis outpatients as much as 11.112% (95%CI：7.011%-15.212%). In the multiple air pollutants models, after the introduction of NO₂, O₃ and CO, the concentration of PM_2.5 showed an enhanced effect on the number of hospital visits due to allergic conjunctivitis on the same day, and the difference was statistically significant (P<0.05). Conclusion: Changes of the concentration of PM_{2.5 h}ad a positive correlation with daily outpatient visits of allergic conjunctivitis among children in Shenzhen. (Chin J Ophthalmol, 2020, 56: 608-614).

MicroRNA-374b accelerates the development of lung cancer through downregulating PTEN expression via activating PI3K/Akt pathway

OBJECTIVE

To elucidate whether microRNA-374b could participate in the development of lung cancer (LC) through downregulating PTEN (gene of phosphate and tensin homolog deleted on chromosome ten) expression via activating PI3K/Akt pathway.

PATIENTS AND METHODS

Expression levels of microRNA-374b and PTEN in LC tissues and adjacent normal tissues were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Moreover, the expression level of microRNA-374b in LC cell lines was detected as well. The microRNA-374b inhibitor was constructed and transfected to downregulate microRNA-374b expression in A549 and H358 cells. The regulatory effects of microRNA-374b on migratory and proliferative capacities of LC cells were explored by wound healing and cell counting kit-8 (CCK-8) assay, respectively. After co-transfection of microRNA-374b inhibitor and si-PTEN in LC cells, expression levels of PTEN/PI3K/Akt were determined by qRT-PCR and Western blot.

RESULTS

QRT-PCR results showed that microRNA-374b expression was higher, while PTEN expression was lower in LC tissues than adjacent tissues. Identically, microRNA-374b was also highly expressed in LC cell lines. PTEN expression was negatively correlated with microRNA-374b expression in LC. The downregulation of microRNA-374b in A549 and H358 cells inhibited their migratory and proliferative potentials. Subsequently, we verified that microRNA-374b could bind to PTEN through dual-luciferase reporter gene assay. MicroRNA-374b could inhibit PTEN expression and activate the PI3K/Akt pathway. Furthermore, PTEN knockdown enhanced migratory and proliferative abilities of LC cells, which were attenuated by co-transfection of microRNA-374b inhibitor.

CONCLUSIONS

MicroRNA-374b promotes the development of LC by downregulating PTEN expression through activating PI3K/Akt pathway.

1144 Actigraphy-defined Sleep And Neurocognitive Decline In Middle-age Hispanic/Latino Adults

Introduction

Few studies have evaluated objective sleep measures and longitudinal neurocognitive decline, particularly in middle-age or Hispanic/Latino adults. We evaluated prospective associations between actigraphy-defined sleep and 7-year neurocognitive change among Hispanic/Latino adults. We hypothesized that sleep duration would be associated with neurocognitive decline.

Methods

We analyzed data from 1,036 adults 45-64 years of age from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a multi-center prospective cohort study of diverse community-dwelling Hispanic/Latino adults. At Visit 1 (2008-2011), participants underwent neurocognitive assessments, 7-days of actigraphy, home sleep testing, and sleep questionnaires (including the Insomnia Severity Index). Seven years later, participants repeated neurocognitive assessments. The neurocognitive battery included the Six-Item Screener, Brief Spanish-English Verbal Learning Test, phonemic word fluency test, and Digit Symbol Subtest. Survey linear regression was used to evaluate prospective associations between actigraphy-defined or self-reported sleep variables and neurocognitive change. Final models adjusted for objectively-defined variables (age, body-mass index, Field Center, and time between neurocognitive assessments), and self-reported variables (sex, education, Hispanic/Latino background, alcohol consumption, physical activity, heart failure, cerebrovascular events, depression and anxiety symptoms, and antidepressant use).

Results

At Visit 1, the sample was 55% female and mean age was 54.9±2.2 years. The mean sleep duration was 402.6±27.6 minutes, mean sleep-onset latency was 11.3±9.7 minutes, mean number of days with naps of ≥ 15 minutes duration was 1.1±0.7, and mean sleep-time per nap was 51±14.1 minutes. Increased sleep-onset latency was associated with 7-year declines in global neurocognitive function (β=-0.0026, p&lt;0.01), verbal learning (β=-0.0028, p&lt;0.001) and verbal memory (β=-0.036, p&lt;0.05). Increased sleep-time per nap predicted better verbal memory (β=0.0038, p&lt;0.05). In contrast, sleep duration, sleep fragmentation, and self-reported sleep measures were not associated with neurocognitive change.

Conclusion

Among middle-age adults, sleep-onset latency and nap duration were associated with neurocognitive change. These findings may serve as targets for intervention of neurocognitive decline.

Support

This work is supported by the National Institute on Aging: R01AG048642, RF1AG054548, R01AG061022, R21AG056952, and R21HL140437 (AR).

Tc17 cells cause gut graft-versus-host disease through induction of dysbiosis and depletion of CX3CR1hi phagocytes

Th/Tc17 but not Th/Tc1 cells are resistant to steroid-induced apoptosis or inhibition of cytokine production, but the role of Th/Tc17 in pathogenesis of steroid-resistant intestinal graft versus host disease (SR-Gut-GVHD) remains controversial. Here, we show a reduction of IFN-g-producing Th/Tc1 cells and expansions of IL-22-producing Th17 and especially Tc17 cells in the gut tissues of mice with SR-Gut-GVHD. IL-22 from Tc17-dervied from IFN-g−/− donor CD8+ T cells augments host-tissue production of RegIIIg, leading to dysbiosis. IL-22 also augments host tissue production of IL-18 that sustains Tc17 expansion. In the absence of donor-derived IFN-g, host-tissue PD-L1 depletes donor-derived CX3CR1hi intestinal mononuclear phagocytes (MNP), leading to increased bacterial translocation and loss of IL-18 binding protein that neutralizes IL-18. Depletion of CX3CR1hi MNP in the colon is also observed in mice with SR-Gut-GVHD. Taken together, our results indicate that depletion of donor-derived CX3CR1hi MNP in the colon plays an important role in Tc17-mediated gut GVHD pathogenesis. These results call for caution in clinical testing of IL-22 agonists or IFN-g antagonist in patients with SR-Gut-GVHD, and they offer a new avenue toward understanding mechanisms that account for SR-Gut-GVHD.

Blockade of CD80 interaction with PD-L1 between T and tumor cells augments effector T expansion and tumor immunity in a PD-1-dependent manner

PD-L1 interactions with PD-1 and CD80 play a critical role in regulating tumor immunity. Blockade of PD-L1 interaction with PD-1 between tumor and T cells augments tumor immunity. Cis-PD-L1/CD80 interactions reduce PD-L1 interaction with PD-1 on T cells and augment tumor immunity. However, whether trans-PD-L1 interaction with CD80 between tumor and T cells play a role in regulating tumor immunity remains unknown. In the current studies, using B16 and MC38 tumor lines in C57BL/6 mice with or without PD-1 or PD-L1 deficiency, we show that administration of anti-PD-L1 (43H12), a monoclonal antibody that specifically blocks PD-L1 interaction with CD80, augments tumor immunity. The effect is tumor PD-L1 interaction with PD-1 on T cells-dependent, because although 43H12 blockade does not augment tumor immunity in PD-1−/− mice or in PD-L1−/− mice with PD-L1 KO tumor lines, 43H12 blockade does augment tumor immunity in PD-L1−/− mice with wild-type tumor lines. Furthermore, consistent with CD28 requirement for augmenting anti-tumor immunity during blocking anti-PD-1 treatment, 43H12 blockade of PD-L1/CD80 interaction does not augment tumor immunity in CD28−/− mice. Finally, 43H12 blockade augments CD8+ T effector expansion in the tumor draining lymph nodes, with increased production of IFN-g and down-regulation of ps21-EZH2. These results indicate that blockade of PD-L1 interaction with CD80 can augment tumor immunity via down-regulating the effect of PD-L1 interaction with PD-1. (This work is supported by DMRI institutional funds and NIH 1R01CA228465-01 to Zeng).

Over-expression of both VEGF-C and Twist predicts poor prognosis in human breast cancer

BACKGROUND

Angiogenesis is an indispensable step in the growth and invasiveness of breast cancers involving a series of exquisite molecular steps. Pro-angiogenic factors, including vascular endothelial growth factor (VEGF), have been recognized as pivotal therapeutic targets in the treatment of breast cancer. More recently, a highly conserved transcription factor Twist has been reported to be involved in tumor angiogenesis and metastasis.

METHODS

The expression of VEGF-C and Twist was immunohistochemically determined in tissue samples of primary tumors from 408 patients undergoing curative surgical resection for breast cancer. The correlations of VEGF-C and Twist expressions with clinicopathologic parameters as well as survival outcomes were evaluated.

RESULTS

Of the 408 patients evaluated, approximately 70% had high expression of VEGF-C which was significantly associated with advanced tumor stages (P = 0.019). Similarly, VEGF-C expression was associated with the proliferation index Ki67, N3 lymph node metastasis, and D2-40-positive lymphatic vessel invasion (LVI) in a univariate analysis. Furthermore, patients with high expressions of VEGF-C and Twist (V + T+) had significantly increased lymph node metastasis, higher clinical stage, and worse disease-free survival, DFS (P = 0.001) and overall survival, OS (P = 0.011).

CONCLUSIONS

Our results suggested that co-expression of VEGF-C and Twist was associated with larger tumor size, higher numbers of lymph node involvement, D2-40-positive LVI, higher risk of distant metastasis, and worse DFS or OS in breast cancer patients.

Neutralization of IL-2 prevents acute GVHD while preserving GVL activity via regulating PD-L1/PD-1 signaling

Acute gut graft versus host disease (GVHD) has a critical impact on the outcome of allogeneic hematopoietic cell transplantation (allo-HCT). Our recent studies indicate that IL-2 from donor CD4+ T cells make infiltrating T cells resistant to host-tissue PD-L1-mediated tolerance (Ni & Song et al: JCI 2017), but the mechanisms remain unclear. To tested whether in vivo neutralization of IL-2 early after allo-HCT differentially regulates PD-L1/PD-1 signaling in GVHD target tissues and lymphoid tissues, spleen and BM cells from C57BL/6 (H-2b) donors were transplanted into lethally irradiated wild-type (WT) or PD-L1−/− BALB/c (H-2d) recipients in the presence or absence of BCL1 leukemia/lymphoma cells. Recipients were treated with neutralizing anti-IL-2 mAb or control IgG. Administration of anti-IL-2 completely prevented gut GVHD while preserving GVL activity in WT recipients but not in PD-L1−/− recipients. This effect was associated with expansion of donor T cells in the lymphoid tissues (i.e. spleen and MLN) but reduction of donor T cells in the GVHD target tissues such as the gut. Prevention of GVHD resulted from increased donor T apoptosis, with increased expression of Fas but reduced expression of Bcl-XL. Residual T cells showed evidence of enhanced anergy/exhaustion and upregulated expression of FR4, CD73, KLRG1 and Eomes. Finally, prevention of GVHD was associated with inhibition of pAKT/mTOR pathway in a donor T cell PD-1-dependent and host tissue PD-L1-dependent manner. These results indicate that neutralizing IL-2 early after allo-HCT augments tolerance-induction through PD-1 signaling mediated by host PD-L1 in GVHD target tissues but not in lymphoid tissues, thereby preventing gut GVHD while preserving GVL effects.

Regulation of GVHD and GVL Activity via PD-L1 Interaction With PD-1 and CD80

Allogeneic hematopoietic cell transplantation (HCT) is a curative therapy for hematological malignancies (i.e. leukemia and lymphoma), because graft-versus-leukemia (GVL) activity mediated by alloreactive T cells can eliminate residual malignant cells and prevent relapse. However, the same alloreactive T cells also mediate a severe side effect, graft-versus-host disease (GVHD), and prevention of GVHD while preserving GVL activity remains an elusive goal. The immune checkpoint molecule PD-L1 and its interaction with PD-1 receptor in regulating cancer immunity is under intensive and wide-spread study, but knowledge about this interaction in regulating GVHD and GVL activity is very limited. In this review, we summarize the literature exploring how PD-L1 interaction with its receptors PD-1 and CD80 regulate GVHD and GVL activities, how PD-L1 signaling regulates T cell metabolic profiles, and how a differential role of PD-L1 interaction with PD-1, CD80 or both may provide a novel avenue to prevent GVHD while preserving strong GVL effects.

Abstract 4515: Lgr5 mediates positive B-cell selection and is critical for initiation and survival of B-cell malignancies

Introduction: In B-cell leukemia and lymphoma, leukemia initiating cells occur at a high frequency (Rehe 2013), are phenotypically diverse (Aoki 2015) and can arise from any stage of B-cell development (Le Viseur 2008). Unlike stem cells, where self-renewal is regulated by a developmental hierarchy, in the B-cell lineage, positive selection events, i.e. induced by antigen-receptor (BCR) signaling dictates their ability to self-renew. Leucine-rich repeat containing G-protein coupled receptor 5 (Lgr5) is a Wnt target gene and through binding to its ligand R-spondin, Lgr5 modulates Wnt signaling strength. Lgr5 is widely used as stem cell marker in multiple epithelial tissues, however the role of Lgr5 in hematopoietic cells was not explored. Results: Upon successful completion of immunoglobulin V(D)J gene recombination and first encounter of antigen represent key events in the life of a B-cell that promote survival and positive selection. Here, we found that both events result in upregulation of Lgr5 expression in B cell precursors in the bone marrow and germinal center B cells. Likewise, engagement of BCR signaling on B-cell lymphomas and oncogenic BCR-signaling mimics in leukemia strongly increased LGR5 expression, which was sensitive to inhibition of SYK and BTK kinases in the BCR pathway.In patients with B-cell leukemia, higher than median mRNA levels of LGR5 at the time of diagnosis were associated with poor clinical outcome and higher likelihood of drug-resistance and relapse. Inducible ablation of Lgr5 during earliest stages of B-cell development resulted in a &gt;100-fold reduction of absolute B-cell numbers. Studies in epithelial cells suggest a role of Lgr5 as potentiator of WNT-signaling. However, deletion of Lgr5 in B cells caused cell death in parallel with massive accumulation of nuclear β-catenin and increased expression of β -catenin target genes. Deletion of Lgr5 abolished colony forming capacity and reduced the ability of leukemia cells to initiate fatal disease in transplant recipients. Likewise, inducible activation of a gain-of-function mutant of β-catenin resulted in rapid cell death in normal and malignant B cells. Conclusion: Lgr5-expression and positive B-cell selection is induced by BCR-engagement by antigen or oncogenic mimics of BCR signaling in B-cell malignancies (e.g. transforming oncogenes that engage the BCR pathway). Unlike in epithelial cells, LGR5 expression in B cells restricts the levels of nuclear β-catenin and enables B-cell survival and transformation through negative regulation of Wnt-signaling. Targeting Lgr5 using a novel Lgr5-ADC seems promising to deplete B-cell leukemia- and lymphoma-initiating cells.

Citation Format: Kadriye Nehir Cosgun, Anna Hecht, Xin Yang, Maurizio Mangolini,, Ali Aghajanirefah, Gang Xiao, Teresa Sadras, Zhengshan Chen, Lars Klemm, Huimin Geng, Chao Hong, Qingxiao Song, Deye Zeng, Hassan Jumaa, Defu Zeng, Hans Clevers, Markus Muschen. Lgr5 mediates positive B-cell selection and is critical for initiation and survival of B-cell malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4515.

Ethanol production from mixtures of sugarcane bagasse and Dioscorea composita extracted residue with high solid loading

Various mixing ratios of alkali pretreated sugarcane bagasse and starch-rich waste Dioscorea composita hemls extracted residue (DER) were evaluated via simultaneous saccharification and fermentation (SSF) with 12% (w/w) solid loading, and the mixture ratio of 1:1 achieved the highest ethanol concentration and yield. When the solid loading was increased from 12% to 32%, the ethanol concentration was increased to 72.04 g/L, whereas the ethanol yield was reduced from 84.40% to 73.71%. With batch feeding and the addition of 0.1% (w/v) Tween 80, the final ethanol concentration and yield of SSF at 34% loading were 82.83 g/L and 77.22%, respectively. Due to the integration with existing starch-based ethanol industry, the co-fermentation is expected to be a competitive alternative form for cellulosic ethanol production.

Induction of Haploidentical Mixed Chimerism Cures Autoimmune Type 1 Diabetes

Type 1 diabetes is an autoimmune disease in association with particular MHC, and induction of MHC-matched mixed chimerism cannot reverse autoimmunity. Haploidentical HCT has gradually become a common practice for treating non-malignant diseases, but it remains unknown whether induction of haploidentical mixed chimerism can reverse autoimmunity.

In the current studies, we induced mixed chimerism in NOD mice (H2-Ag7) by transplanting bone marrow and CD4+ T-depleted spleen cells from haploidentical (B6 × B6g7) F1 donors (H2-Ab/g7). We found that haploidentical mixed chimerism eliminated insulitis as well as prevented in pre-diabetic and cured diabetes in new-onset WT NOD mice. Interestingly, although I-As was thought to be autoimmune susceptible, induction of haploidentical mixed chimerism with I-Ag7/s transplants also effectively eliminate insulitis. Furthermore, the mixed chimerism markedly reduced the percentage of host-type but not donor-type CD4+CD8+ thymocytes and increased CD11c+CD8−SIRPα+CD11b+ migratory DC that can mediate thymic negative selection in the chimeric thymus. In the peripheral, percentage of tetramer+ autoreactive host-type Tcon cells was markedly reduced and part of the residual T cells became PD-1hiIL-7Rαlo anergic/exhausted, while percentage of host-type CD4+Foxp3+ Treg cells significantly increased. Additionally, in the pancreas of mixed chimeric BDC2.5 NOD mice, Treg cells among tetramer+ autoreactive T cells increase 5–10 fold. Taken collectively, haploidentical mixed chimerism reverses autoimmunity and eliminating insulitis in NOD mice by enhancing DC mediated negative selection in thymus and augmenting expansion of Treg, especially antigen specific Treg cells, in the periphery.

MicroRNA-142 guards against autoimmunity by controlling Treg cell development and function

Regulatory T (Treg) cells are critical in preventing aberrant immune responses. Post-transcriptional gene control by microRNA (miRNA), a large class of small regulatory RNA, has recently emerged as a key genetic element required for Treg cell function. Nevertheless, specific miRNA gene(s) that play a vital role in the regulation of Treg cell activity are still unknown. Here we report that mice with Treg cell-specific ablation of miR-142 (hereafter Foxp3CremiR-142fl/fl mice) developed a fatal systemic autoimmune disorder due to a breakdown in peripheral T cell tolerance. Foxp3CremiR-142fl/fl mice displayed a sharp decrease in abundance and suppressive capacity of Treg cells. Analysis of miR-142-deficient Treg cells revealed excessive IFNγ production and dysregulated IFNγ signaling. We have identified several of the derepressed IFNγ-related genes, including Ifngr2 receptor and Hif1a transcription factor, as direct miR-142 targets. Furthermore, lowering the Hif1a gene dose in Treg cells significantly diminished the hyperactivation of peripheral effector T cells in Foxp3CremiR-142fl/flmice. Thus, miR-142 is an indispensable regulator of Treg cell development and function that mediates its control by attenuating IFNg response.

Tc17 cells mediate gut GVHD via IL-22 and dysbiosis

Gut GVHD is critical for determining the outcome of allogenic hematopoietic cell transplantation (HCT). Damage of Paneth cells and loss of RegIIIg can lead to dysregulation of intestinal microbiota and gut GVHD pathogenesis. RegIIIg can be produced by Paneth cells and intestinal epithelial cells, and its secretion is augmented by IL-22. However, the circumstances leading to RegIIIg dysregulation and dysbiosis remain largely unknown. Here we show that, in a MHC-mismatched model of C57BL/6 donor to BALB/c recipient, one injection of depleting anti-CD4 effectively prevents acute gut GVHD in recipients given wild-type (WT) transplants but has no effect in recipients given IFN-g−/− transplants. Interestingly, PD-L1−/−recipients given IFN-g−/− transplants showed spontaneous recovery of the disease. Recipients given IFN-g−/− transplants showed expansion of Tc17, IL-22 but not IL-17 from Tc17 was required for the disease induction. Furthermore, host tissue PD-L1 augmented expansion of Tc17 as well as CX3CR1+ DC, CX3CR1+ DC mediate bacteria clearance and prevent bacteria translocation, at the same time, CX3CR1+ DC produce IL-18 BP, which limit Tc17 expansion through IL-18 signaling. In addition, recipients given IFN-g−/− transplants showed no damage of Paneth cells but markedly increased RegIIIg. Gut GVHD in recipients had significant reduction of Barnesiella in feces and significant increase of E. Coli and Lactobacillus. Taken together, these results indicate that 1) in the absence of donor IFN-g, host-tissue PD-L1 mediates expansion of Tc17 through IL-18 signaling and dysregulation of IL-22 functional effect; 2) Dysregualtion of IL-22 from Tc17 cell can lead to dysbiosis and gut GVHD in the absence of Paneth cell damage.

Appropriate dose of Lactobacillus buchneri supplement improves intestinal microbiota and prevents diarrhoea in weaning Rex rabbits

This study examined the effects on intestinal microbiota and diarrhoea of Lactobacillus buchneri supplementation to the diet of weaning Rex rabbits. To this end, rabbits were treated with L. buchneri at two different doses (LC: 104 cfu/g diet and HC: 105 cfu/g diet) for 4 weeks. PCR-DGGE was used to determine the diversity of the intestinal microbiota, while real-time PCR permitted the detection of individual bacterial species. ELISA and real-time PCR allowed the identification of numerous cytokines in the intestinal tissues. Zonula occludens-1, polymeric immunoglobulin receptor and immunoglobulin A genes were examined to evaluate intestinal barriers. Results showed that the biodiversity of the intestinal microbiota of weaning Rex rabbits improved in the whole tract of the treated groups. The abundance of most detected bacterial species was highly increased in the duodenum, jejunum and ileum after L. buchneri administration. The species abundance in the HC group was more increased than in the LC group when compared to the control. Although the abundance of Enterobacteriaceae exhibited a different pattern, Escherichia coli was inhibited in all treatment groups. Toll-like receptor (TLR)2 and TLR4 genes were down-regulated in all intestinal tissues as the microbiota changed. In the LC group, the secretion of the inflammatory cytokine tumour necrosis factor-α was reduced, the gene expression of the anti-inflammatory cytokine interleukin (IL)-4 was up-regulated and the expression of intestinal-barrier-related genes was enhanced. Conversely, IL-4 expression was increased and the expression of other tested genes did not change in the HC group. The beneficial effects of LC were greater than those of HC or the control in terms of improving the daily weight gain and survival rate of weaning Rex rabbits and reducing their diarrhoea rate. Therefore, 104 cfu/g L. buchneri treatment improved the microbiota of weaning Rex rabbits and prevented diarrhoea in these animals.

Gene expression profiles for a prognostic immunoscore in gastric cancer

Background

Increasing evidence has indicated an association between immune infiltration in gastric cancer and clinical outcome. However, reliable prognostic signatures, based on systematic assessments of the immune landscape inferred from bulk tumour transcriptomes, have not been established. The aim was to develop an immune signature, based on the cellular composition of the immune infiltrate inferred from bulk tumour transcriptomes, to improve the prognostic predictions of gastric cancer.

Methods

Twenty‐two types of immune cell fraction were estimated based on large public gastric cancer cohorts from the Gene Expression Omnibus using CIBERSORT. An immunoscore based on the fraction of immune cell types was then constructed using a least absolute shrinkage and selection operator (LASSO) Cox regression model.

Results

Using the LASSO model, an immunoscore was established consisting of 11 types of immune cell fraction. In the training cohort (490 patients), significant differences were found between high‐ and low‐immunoscore groups in overall survival across and within subpopulations with an identical TNM stage. Multivariable analysis revealed that the immunoscore was an independent prognostic factor (hazard ratio 1·92, 95 per cent c.i. 1·54 to 2·40). The prognostic value of the immunoscore was also confirmed in the validation (210) and entire (700) cohorts.

Conclusion

The proposed immunoscore represents a promising signature for estimating overall survival in patients with gastric cancer.

Immunoscore predicts prognosis

Newly found arsons ignite the fire of gut GVHD

Acute graft-versus-host disease (GVHD) in the gut is common following hematopoetic cell transplantation (HCT) and is associated with high mortality. However, it remains unclear whether Th1 or Th17 CD4+ T cells can initiate acute gut GVHD. In this issue of the JCI, Ullrich and colleagues identified a subset of CD4+ T cells that express high levels of IL-7Rα and granulocyte-macrophage CSF (IL-7RαhiGM-CSF+) cells that are involved in the induction of acute gut GVHD in murine models. The IL-7RαhiGM-CSF+ effector memory cells were BATF dependent, RORγt independent, produced large amounts of GM-CSF and IFN-γ, and released little IL-17. CD4+IL-7RαhiGM-CSF+ cells were not classical Th17 cells but had more of a Th1-like phenotype, despite their dependence on BATF. This work suggests that targeting the IL-7R/BATF/GM-CSF axis has therapeutic potential for treating acute gut GVHD.