Modulating extracellular TCR-CD3 interaction to identify new immunotherapy targets against cancer

T cell recognition of antigen and resulting proximal signaling are key steps in the initiation of the adaptive immune response. Previous studies targeting antigen binding site for enhancing T-cell responses to tumor antigens often lead to off-target effects and toxicity. Recently, we used nuclear magnetic resonance (NMR) spectroscopy, mutational analysis and computational docking to derive a 3D structure of the extracellular TCR-CD3 assembly. Further, biomolecular force probe (BFP) measurements allowed us to determine how 2D affinity and force-modulated TCR-pMHC kinetics depend on TCR-CD3 interaction sites and affect transduction of extracellular pMHC-TCR ligation into T cell function. Based on our TCR-CD3 structural model and binding data, we generated TCR libraries for a melanoma-specific TCR (DMF5) using site-specific mutagenesis in the Cbhelix 3 and helix 4-F strand regions of the TCR to optimize the TCR-CD3 interaction and to select for mutants with enhanced T-cell effector function. One Cb helix 4-F strand mutant, NP202203AA showed increased T cell response to antigen and showed enhanced TCR-pMHC bond lifetime (catch-bonds) in BFP assays leading to prolonged T cell signaling. In the future, DMF5 TCR with reengineered CD3 binding regions will be used in tumor rejection in pre-clinical mouse melanoma models for efficacy and toxicity to develop more effective T cell therapies for human targets.

Blood-based Genomic Profiling of Circulating Tumor DNA from Patients with Advanced Pancreatic Cancer and its Value to Guide Clinical Treatment

Objective: Pancreatic cancer (PC) is a malignant tumor with limited therapeutic choices and extremely poor prognosis. Personalized therapy based on gene alternations is a promising choice. Considering tumor heterogeneity, the practice of ctDNA analysis has drawn the attention. Here, we try to assess the applicability of ctDNA in PC.

Methods and materials: Next generation sequencing (NGS) was performed from blood samples of 223 PC patients and tissue sample of 564 PC patients. Genomic data from the TCGA database were also utilized. In addition, two cases received personalized treatment based on ctDNA sequencing results were reported.

Results: Based on ctDNA sequencing, the genomic features of PC was revealed. Totally, 68.2% of patients detected at least one reportable genomic alteration (GA) from ctDNA. The frequently altered genes were KRAS (53.5%), followed by TP53 (52.8%), and CDKN2A (15.1%). Cell cycle control (8%) and DNA damage response (8%) pathways enriched the most mutated genes. Compared with mutations from tissue samples and a tissue-genomic database, similar frequencies of GAs were detected from ctDNA. The first two highest frequent mutation of genes were the same, but some of mutated genes were inclined to be observed in ctDNA, like AR. And two cases who received personalized therapy achieved better clinical benefit.

Conclusion: Blood-source ctDNA sequencing could be regarded as a meaningful complement to tissue testing, and might guide clinically therapeutic regimen.

Towed Overhauser marine magnetometer for weak magnetic anomaly detection in severe ocean conditions

A towed Overhauser marine geomagnetic magnetometer used for weak magnetic anomaly detection in severe ocean conditions is studied to investigate means to reduce the negative effect of dynamic behavior and magnetic noise associated with ocean waves. For the dynamic effect, a continuous polarization workflow is proposed to enhance the free-induction-decay signal, and then, a multi-angle pickup coil and a self-tracking programmable amplifier are used to further reduce the adverse effect caused by uncontrollable changes in the towfish attitude on the signal quality. Furthermore, to achieve adaptive suppression of magnetic noise in different ocean conditions and areas, a modified adaptive Kalman algorithm is assessed. In addition, an optimized Overhauser sensor and a towfish were developed. Overall, the experimental results show that the sensor can effectively suppress the dynamic effect and magnetic noise. Regarding the magnetic sensitivity, uncertainty and range are 12 pT/Hz^1/2@1Hz and 0.21 nT and 20 000 nT-100 000 nT, respectively. Moreover, underwater testing was performed to verify the function and the detection of the magnetic anomaly.

Erythrocyte count is associated with prognosis in Chinese patients with primary biliary cholangitis

Erythroid parameters have been indicated to be important prognostic factors for liver diseases. The present study aimed to evaluate the prognostic value of the erythrocyte count in Chinese patients with primary biliary cholangitis (PBC) and develop a prognostic model. The clinical data of 301 patients with PBC were retrospectively reviewed. Univariate and multivariate Cox regression analysis was performed to identify potential prognostic risk factors. Bivariate correlation analysis was used to determine the correlation coefficient of the erythrocyte count and biochemical indices. The prognostic values of different factors were compared by receiver operating characteristic (ROC) curve analysis. A novel prognostic model was constructed using multivariate logistic regression. Multivariate regression analysis suggested that the erythrocyte count was an independent risk factor/prognostic index (P=0.042). The erythrocyte count in peripheral blood decreased as the histological stage progressed (P<0.001). The erythrocyte count was correlated with albumin, liver stiffness and Fibrosis-4. Compared with that of platelets, the area under the ROC curve of the erythrocyte count was significantly greater. A similar area under the ROC curve was determined for the erythrocyte count, albumin and total bilirubin (P>0.05). A novel prognostic model was established as follows: P=1/{1 + e-[6.140-3.193 × Ln(erythrocyte count) -0.184 × albumin + 0.827 × Ln(total bilirubin)]}. The novel model had a comparable prognostic value to that of the GLOBE score and UK-PBC risk score, and had a better performance than the Mayo risk score at baseline (0.838 vs. 0.787). In conclusion, the erythrocyte count is an independent risk factor/prognostic index in Chinese patients with PBC. It was correlated with liver function and fibrosis in Chinese patients. The novel model incorporating the erythrocyte count and biochemical indices at baseline may serve as a prognostic tool in Chinese patients with PBC (Trial registration number, ChiCTR-ONRC-10002070; date of registration, 2010-05-10).

Mechanotransduction in T Cell Development, Differentiation and Function

Cells in the body are actively engaging with their environments that include both biochemical and biophysical aspects. The process by which cells convert mechanical stimuli from their environment to intracellular biochemical signals is known as mechanotransduction. Exemplifying the reliance on mechanotransduction for their development, differentiation and function are T cells, which are central to adaptive immune responses. T cell mechanoimmunology is an emerging field that studies how T cells sense, respond and adapt to the mechanical cues that they encounter throughout their life cycle. Here we review different stages of the T cell's life cycle where existing studies have shown important effects of mechanical force or matrix stiffness on a T cell as sensed through its surface molecules, including modulating receptor-ligand interactions, inducing protein conformational changes, triggering signal transduction, amplifying antigen discrimination and ensuring directed targeted cell killing. We suggest that including mechanical considerations in the immunological studies of T cells would inform a more holistic understanding of their development, differentiation and function.

Quasi Fourier-Mellin Transform for Affine Invariant Features

Fourier-Mellin transform (FMT) has been widely used for the extraction of rotation- and scale-invariant features. However, affine transform is a more reasonable approximation model for real viewpoint change. Due to shearing, the integral along the angular direction in the calculation of FMT cannot be used to extract the inherent features of an image undergoing affine transform. To eliminate the effect of shearing, whitening transform should be conducted on the integral along the radial direction. FMT can hardly be modified by conventional whitening-based methods with low computational cost due to additional processes. In this paper, two factors are constructed and embedded into FMT. Quasi Fourier-Mellin transform (QFMT) is proposed. The embedding of these factors is equivalent to whitening transform and can eliminate the effect of shearing in the affine transform. In particular, QFMT can also be calculated by integrating along the radial direction followed by integrating along the angular direction, as in FMT. Based on QFMT, the quasi Fourier-Mellin descriptor (QFMD) is constructed for the extraction of affine invariant features. Some experiments have also been conducted to test the performance of the proposed method.

LncRNA HOTAIR participates in the development and progression of adrenocortical carcinoma via regulating cell cycle

OBJECTIVE

To explore the role of HOTAIR in the pathogenesis of adrenocortical carcinoma (ACC) and its underlying mechanism.

PATIENTS AND METHODS

Differentially expressed lncRNA (HOTAIR) in ACC was screened out from the GEO database. The survival analysis and ROC curve were performed according to HOTAIR expressions in ACC patients. The correlation between HOTAIR expression and clinical information of ACC patients was analyzed by chi-square test. The univariate and multivariate COX regression analysis was carried out to analyze the relationship between HOTAIR expression, disease-free survival (DFS) and overall survival (OS) of ACC patients. We then detected HOTAIR expression in 77 ACC tissues and 30 normal tissues by qRT-PCR (quantitative Real-time polymerase chain reaction). ACC cell lines were further screened out for the following in vitro experiments. After altering HOTAIR expression in ACC cells by plasmid transfection, proliferation and cell cycle were detected by Cell Counting Kit-8 (CCK-8) and colony formation assay, respectively. Finally, Western blot was utilized to detect expressions of cell cycle-related genes in ACC cells.

RESULTS

HOTAIR was overexpressed in ACC tissues than that of normal tissues. HOTAIR expression was remarkably increased in ACC with T3 and T4 stage than that of T1 and T2 stage. Moreover, HOTAIR expression was remarkably increased in ACC with stage III and IV than that of stage I and II. HOTAIR was an independent prognostic factor for DFS and OS of ACC patients. For in vitro experiments, inhibited proliferation and arrested cell cycle were observed in H295R cells transfected with si-HOTAIR. Opposite results were obtained after SW-13 cells were transfected with HOTAIR overexpression plasmid. Furthermore, expressions of cell cycle-related genes, including Cyclin D1, p-Rb and p-GSK3β were remarkably decreased after HOTAIR knockdown.

CONCLUSIONS

We demonstrated for the first time that HOTAIR is overexpressed in ACC and is a prognostic risk factor in ACC patients. HOTAIR participates in the development and progression of ACC via shortening cell cycle and promoting proliferation of ACC cells.

The use of external fixation for the management of acute and chronic Monteggia fractures in children

PURPOSE

The main objective of this study was to retrospectively evaluate the clinical and radiological outcomes of acute (AMF) and chronic Monteggia fractures (CMF) in children treated by closed or open reduction and external fixation (EF).

METHODS

This is a retrospective review of 26 patients with Monteggia fracture. Patients with AMF (time between trauma and surgery less than two weeks) were treated by closed reduction and EF of the ulna (Group A; 15 patients) while those with CMF (time between trauma and surgery more than three weeks) were managed by closed or open reduction and EF of the ulna (Group B; 11 patients). Clinical outcome was evaluated with radiography and the short version of the Disabilities of the Arm, Shoulder and Hand outcome questionnaire (Quick DASH). Complications were recorded in both groups.

RESULTS

No secondary displacement, wire migration, consolidation delays, nonunion, malunion or re-fracture was noted. However, one patient in Group A (6.7%) developed heterotopic ossification of the ulna; the final functional outcome was good (Quick DASH score: 18.2). One case of postoperative redislocation of the radial head was detected in Group B (9.1%). Two patients (7.6%) developed transient pin tract infection. Despite the fact that 16 out of 26 patients (six in Group A and ten in Group B) complained of the clinical appearance and/or had intermittent residual pain on the injured side, the results were essentially the same between the two groups of patients (p > 0.05).

CONCLUSION

EF is an alternative for the management of acute and chronic paediatric Monteggia fractures. It provides satisfactory radiological and clinical outcomes with relatively low rates of complications.

LEVEL OF EVIDENCE

IV.

Identification of key pathways and genes changes in pancreatic cancer cells (BXPC-3) after cross-talk with primary pancreatic stellate cells using bioinformatics analysis

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors with poor prognosis, and the interaction between activated pancreatic stellate cells (PSCs) and PDAC cells plays an important role in the development of PDAC. The aim of this study was to identify gene changes in BXPC-3 after cross-talk with PSCs and reveal their potential mechanisms. The gene expression profiling analysis of BXPC-3 was completed after co-culture with primary PSCs for 48 h. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX software. In total, 3657 DEGs were identified in BXPC-3, including 1881 up-regulated genes and 1776 downregulated genes. GO analysis results showed that upregulated DEGs were significantly enriched in biological processes (BP), including peptide metabolic process, response to stress and electron transport chain; the downregulated DEGs were significantly enriched in biological processes, including signaling, multicellular organism development and anatomical structure development. KEGG pathway analysis revealed that 19 pathways were upregulated and 32 pathways were downregulated, and that upregulated DEGs were enriched in protein export and glutathione metabolism, while the downregulated DEGs were enriched in axon guidance and focal adhesion. The top 10 upregulated genes and the top 10 downregulated genes were identified. By constructing PPI network, we selected out 10 key genes (TP53, SRC, IL6, JUN, ISG15, CAD, STAT1, OAS3, OAS1, VIM) and significant pathways. The associated survival analysis was performed and the SRC, IL-6, ISG15, STAT1, OAS3, OAS1 and VIM were proved to be related to worse overall survival time of PDAC patients. In conclusion, the present study indicated that the identified DEGs promote our understanding of the molecular mechanisms underlying the interaction between pancreatic cancer cells and PSCs and might be used as molecular targets in the future to study the role of tumor microenvironment in the progression of PDAC.

Identification of key pathways and genes changes in pancreatic cancer cells (BXPC-3) after cross-talked with primary pancreatic stellate cells using bioinformatics analysis

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors with poor prognosis, and the interaction between activated pancreatic stellate cells (PSCs) and PDAC cells plays an important role in the development of PDAC. The aim of this study was to identify gene changes in BXPC-3 after cross-talked with PSCs and reveal their potential mechanisms. The gene expression profiling analysis of BXPC-3 was completed after co-cultured with primary PSCs for 48 h. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX software. In total, 3657 DEGs were identified in BXPC-3, including 1881 up-regulated genes and 1776 downregulated genes. GO analysis results showed that up-regulated DEGs were significantly enriched in biological processes (BP), including peptide metabolic process, response to stress, and electron transport chain; the down-regulated DEGs were significantly enriched in biological processes, including signaling, multicellular organismal development, and anatomical structure development. KEGG pathway analysis revealed that 19 pathways were upregulated and 32 pathways were downregulated, and that up-regulated DEGs were enriched in protein export and glutathione metabolism, while the down-regulated DEGs were enriched in axon guidance and focal adhesion. The top 10 up-regulated genes, and the top 10 down-regulated genes were identified. By constructing PPI network, we selected out 10 key genes (TP53, SRC, IL6, JUN, ISG15, CAD, STAT1, OAS3, OAS1, VIM) and significant pathways. The associated survival analysis was performed and the SRC, IL-6, ISG15, STAT1, OAS3, OAS1 and VIM were proved to be related to worse overall survival time of PDAC patients. In conclusion, the present study indicated that the identified DEGs promote our understanding of the molecular mechanisms underlying the interaction between pancreatic cancer cells and PSCs and might be used as molecular targets in the future to study the role of tumor microenvironment in the progression of PDAC.

Identification of key pathways and gene changes in primary pancreatic stellate cells after cross-talk with pancreatic cancer cells (BXPC-3) using bioinformatics analysis

It is well known that as the king of cancer, pancreatic ductal adenocarcinoma (PDAC) has relatively malignant biological behavior and poor prognosis. The interaction between pancreatic stellate cells and PDAC cells promotes the development of PDAC. The aim of this study was to describe gene characteristics in pancreatic stellate cell (PSCs) after cross-talked with BXPC-3 and unravel their underlying mechanisms. The expression profiling analysis of genes in PSCs was completed after co-cultured with primary BXPC-3 for 48h. The Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analysis and gene ontology (GO) analysis were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX program. In total, 1804 DEGs were filtered out in PSCs, including 958 up-regulated genes and 846 downregulated genes. GO analysis showed that the up-regulated DEGs were significantly enriched in biological processes (BP) such as defense response, immune system process and immune response; the down-regulated DEGs were significantly enriched in biological regulation and cytoskeleton organization. KEGG pathway analysis showed that 28 pathways were upregulated and 5 were downregulated. By constructing PPI network, we selected out 10 key genes (IL6，IL8, IL1B, BCL2, CCL2, CSF2, KIT, ICAM1, PTPRC and IGF1) and significant enriched pathways. In conclusion, the current study suggests that the filtered DEGs contribute to our understanding of the molecular mechanisms underlying the interaction between PSCs and pancreatic cancer cells, and might be used as molecular targets to further the study the role of tumor microenvironment in the progression of PDAC.

T-Cell Intrinsic Mechanisms of Resistance to PD-1 Checkpoint Blockade

Although much clinical progress has been made in harnessing the immune system to recognize and target cancer, there is still a significant lack of an understanding of how tumors evade immune recognition and the mechanisms that drive tumor resistance to both T cell and checkpoint blockade immunotherapy. Our objective is to understand how tumor-mediated signaling through inhibitory receptors, including PD-1, combine to affect the process of T cell recognition of tumor antigen and activation signaling. Our goal is to understand the basis of resistance to PD-1 blockade and potentially identify new molecular targets to enable T cells to overcome dysfunction mediated by multiple inhibitory receptors. Biomembrane Force Probe(BFP) measurements show that that the activities of TCR-proximal signaling components affect T cell mechanosensing and sensitivity at the earliest stages of antigen recognition and are influenced by PD-1 and other inhibitory receptors via Shp-1/2 by targeting CD28 and Lckto directly suppress TCR-pMHC-CD8 binding. Phospho-proteomics and flow cytometry-based analysis of patient-derived T cells from PD-1 responders and non-responders identified additional mediators, signaling components and pathways associated with PD-1 checkpoint blockade resistance. CRISPR/Cas9 mediated genome editing was utilized to determine if resistance is mediated by the continued signaling of multiple IRs by perturbing IR signaling in mouse models of PD-1 blockade. Targeting these interactions and understanding the basis of resistance to PD-1 blockade would potentially allow identification of novel biomarkers of resistance or new molecular targets to enable T cells to overcome dysfunction during PD-1 checkpoint blockade.

[Effect of different crystalloids on internal environment in patients with septic shock receiving early fluid resuscitation: a prospective randomized controlled trial]

OBJECTIVE

To compare the effect of 0.9% NaCl solution, Ringer solution, and acetate sodium potassium magnesium calcium glucose solution (ASPMCG solution) on internal environment in patients with septic shock receiving early fluid resuscitation.

METHODS

A prospective randomized controlled trial was conducted. From June 2016 to January 2018, a total of 280 patients with septic shock admitted to intensive care unit (ICU) of Northern Jiangsu People's Hospital were enrolled. All eligible patients were randomly divided into 0.9% NaCl solution group (group N), Ringer solution group (group L) and ASPMCG solution group (group P) with random number table. In all patients, catheters were placed in the right internal jugular vein or subclavian vein and were infused with 30 mL/kg of corresponding crystalloid within 3 hours after admission. According to fluid responsiveness, the rehydration rate and fluid volume were determined by the researcher within 6 hours. Other treatments were based on the 2012 Surviving Sepsis Campaign (SSC) guidelines during the study. In this study, 6-hour or 24-hour fluid volume and 7-day exogenous insulin use were recorded. The changes in arterial blood pH, base excess (BE), blood glucose (Glu), lactic acid (Lac), and serum Na⁺, K⁺, Cl^-, Ca²⁺ were observed at 0, 3, 6, 24 hours, and 3 days and 7 days of resuscitation.

RESULTS

In this study, a total of 1 082 patients were admitted to the ICU, and patients who did not meet the diagnostic criteria for septic shock, death or discharge within 24 hours of ICU admission were excluded. Finally, 280 patients with septic shock were enrolled in the analysis, with 94 patients in group N, 94 patients in group L and 92 patients in group P. There was no significant difference in the amount of crystalloid, colloidal fluid, total fluid within 6 hours or 24 hours or exogenous insulin dose within 7 days among the three groups. After fluid resuscitation, blood Cl^- concentration in the three groups was increased in different degrees, peaked at 24 hours, but it in group N was significantly higher than that in group L and group P (mmol/L: 107.5±5.6 vs. 106.1±4.8, 105.1±4.2, both P < 0.05). Moreover, blood Ca²⁺ concentration also showed an increased tendency, it was significantly lower at 3 hours and 6 hours in group N than that in group L and group P (mmol/L: 1.10±0.08 vs. 1.15±0.09, 1.12±0.10 at 3 hours, 1.12±0.10 vs. 1.16±0.08, 1.15±0.09 at 6 hours, all P < 0.05). There was no significant difference in blood Cl^- or Ca²⁺ between groups L and P (both P > 0.05). Arterial blood pH, BE, Glu, Lac, Na⁺, or K⁺ at each time point during fluid resuscitation also showed no difference among the three groups.

CONCLUSIONS

Among patients with septic shock receiving early fluid resuscitation, compared with Ringer solution and ASPMCG solution, 0.9% NaCl solution may cause hyperchloremia and hypocalcemia, but has no significant effect on acid-base balance.

Clinical Trial Registration

Chinese Clinical Trial Registry, ChiCTR-IOR-16009176.

Role of multi-modality functional imaging in differentiation between benign and malignant thyroid 18F-fluorodeoxyglucose incidentaloma

PURPOSE

To evaluate the diagnostic performance of multi-modality functional imaging in differentiating malignant and benign thyroid ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) incidentaloma.

METHODS

This study included 87 patients with thyroid ¹⁸F-FDG incidentalomas detected by ¹⁸F-FDG- positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) and diagnosed at surgery or biopsy, who received ¹⁸F-FDG-PET/CT, diffusion-weighted MR imaging (DWI) and ultrasound elastography (USE). The metabolic tumor volume (MTV), total lesion glycolysis (TLG), apparent diffusion coefficient (ADC) values and ultrasound elasticity scores of thyroid ¹⁸F-FDG incidentalomas were measured and compared in benign and malignant thyroid incidentalomas. The differences of malignant and benign thyroid incidentalomas were tested by χ² test, Fisher's exact test, t test, or Mann-Whitney U test. The diagnostic performance was evaluated and optimal cut-off values were determined in distinguishing malignant from benign thyroid incidentalomas by receiver operating characteristic curve analysis.

RESULTS

MTV, TLG and USE scores of malignant thyroid incidentalomas were significantly higher than benign; but ADC value was significantly lower. We defined the functional imaging parameters TLG < 2.48, ADC > 1.80 × 10^-3mm²/s, and USE score of 1 as markers of benign thyroid incidentalomas and each scored -1 point; TLG ≥ 2.48, ADC ≤ 1.80 × 10^-3mm²/s, and USE score of 4 as markers of malignancy and each scored 1 point. Combined multi-functional imaging parameters achieved the highest performance (84.6% sensitivity and 97.1% specificity) for distinguish malignant from benign thyroid incidentaloma with AUC 0.957 (95% CI 0.917, 0.997).

CONCLUSIONS

Functional imaging might help to distinguishing malignant from benign thyroid ¹⁸F-FDG incidentalomas, and combined multi-functional imaging parameters could improve it.

Abstract PR08: Mechanisms of primary resistance to PD-1 checkpoint blockade

Although much clinical progress has been made in harnessing the immune system to recognize and target cancer, there is still a significant lack of an understanding of how tumors evade immune recognition and the mechanisms that drive tumor resistance to both T-cell and checkpoint blockade immunotherapy. Our objective is to understand how tumor-mediated signaling through inhibitory receptors, including PD-1, combines to affect the process of T-cell recognition of tumor antigen and activation signaling. This has the goal of understanding the basis of resistance to PD-1 blockade and potentially identifying new molecular targets to enable T-cells to overcome dysfunction mediated by multiple inhibitory receptors. Biomembrane Force Probe (BFP) measurements show that that the activities of TCR-proximal signaling components affect T-cell mechanosensing and sensitivity at the earliest stages of antigen recognition and are influenced by PD-1 and other inhibitory receptors via Shp-1/2 by targeting CD28 and Lck to directly suppress TCR-pMHC-CD8 binding. Phospho-proteomics and flow cytometry-based analysis of patient-derived T-cells from PD-1 responders and nonresponders identified additional mediators, signaling components and pathways associated with PD-1 checkpoint blockade resistance. Targeting these interactions and understanding the basis of resistance to PD-1 blockade would potentially allow identification of novel biomarkers of resistance or new molecular targets to enable T-cells to overcome dysfunction during PD-1 checkpoint blockade.

Citation Format: Michelle Krogsgaard, Duane Moogk, Kaitao Li, Zhou Yuan, Iman Osman, Jeffrey S Weber, Cheng Zhu. Mechanisms of primary resistance to PD-1 checkpoint blockade [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr PR08.

Application of DNA methylation in early diagnosis and treatment of pancreatic cancer

Pancreatic cancer (PC) is one of the most malignant gastrointestinal tumors, characterized by a poor prognosis. Most of the patients have an advanced disease at the time of diagnosis and lose the opportunity of radical surgery, resulting in a 5-year survival rate of less than 5%. Circulating tumor DNA, whose concentration in plasma of patients with pancreatic adenocarcinoma is higher than that in health controls, carries specific gene mutation and aberrant DNA methylation. Epigenetic change is one of the important characteristics of cell carcinogenesis. DNA methylation is an early event in tumorigenesis, which is more helpful for early diagnosis than gene mutation and can be observed in each stage of PC. Therefore, the detection of aberrant DNA methylation in the promoter region in patients with PC may be a non-invasive method for early cancer detection, predicting prognosis, and monitoring recurrence. In the present review, we discuss the recent advances in the study of DNA methylation in the early diagnosis of PC, and the potential application value in the treatment of PC.

Fast Force Loading Disrupts Molecular Binding Stability in Human and Mouse Cell Adhesions

Force plays critical roles in cell adhesion and mechano-signaling, partially by regulating the dissociation rate, i.e., off-rate, of receptor-ligand bonds. However, the mechanism of such regulation still remains elusive. As a controversial topic of the field, when measuring the "off-rate vs. force" relation of the same molecular system, different dynamic force spectroscopy (DFS) assays (namely, force-clamp and force-ramp assays) often yield contradictive results. Such discrepancies hurdled our further understanding of molecular binding, and casted doubt on the existing theoretical models. In this work, we used a live-cell DFS technique, biomembrane force probe, to measure the single-bond dissociation in three receptor-ligand systems which respectively have important functions in vascular and immune systems: human platelet GPIbα-VWF, mouse T cell receptor-OVA peptide:MHC, and mouse platelet integrin α_IIbβ₃-fibrinogen. Using force-clamp and force-ramp assays in parallel, we identified that the force loading disrupted the stability of molecular bonds in a rate-dependent manner. This disruptive effect was achieved by the transitioning of bonds between two dissociation states: faster force loading induces more bonds to adopt the fast-dissociating state (and less to adopt the slow-dissociating state). Based on this mechanism, a new biophysical model of bond dissociation was established which took into account the effects of both force magnitude and loading rate. Remarkably, this model reconciled the results from the two assays in all three molecular systems under study. Our discoveries provided a new paradigm for understanding how force regulates receptor-ligand interactions and a guideline for the proper use of DFS technologies. Furthermore, our work highlighted the opportunity of using different DFS assays to answer specific biological questions in the field of cell adhesion and mechano-signaling.

A TCR mechanotransduction signaling loop induces negative selection in the thymus

The T cell antigen receptor (TCR) expressed on thymocytes interacts with self-peptide major histocompatibility complex (pMHC) ligands to signal apoptosis or survival. Here, we found that negative-selection ligands induced thymocytes to exert forces on the TCR and the co-receptor CD8 and formed cooperative TCR-pMHC-CD8 trimolecular 'catch bonds', whereas positive-selection ligands induced less sustained thymocyte forces on TCR and CD8 and formed shorter-lived, independent TCR-pMHC and pMHC-CD8 bimolecular 'slip bonds'. Catch bonds were not intrinsic to either the TCR-pMHC or the pMHC-CD8 arm of the trans (cross-junctional) heterodimer but resulted from coupling of the extracellular pMHC-CD8 interaction to the intracellular interaction of CD8 with TCR-CD3 via associated kinases to form a cis (lateral) heterodimer capable of inside-out signaling. We suggest that the coupled trans-cis heterodimeric interactions form a mechanotransduction loop that reinforces negative-selection signaling that is distinct from positive-selection signaling in the thymus.

Epigallocatechin-3-gallate protected vanadium-induced eggshell depigmentation via P38MAPK-Nrf2/HO-1 signaling pathway in laying hens

It has been demonstrated that tea polyphenol (TP) epigallocatechin-3-gallate (EGCG) can confer protection against vanadium (V) toxicity in laying hens; however, our understanding of the molecular mechanisms beyond this effect are still limited. In this study, 360 hens were randomly assigned to the 3 groups to study whether the potential mechanism P38MAPK-Nrf2/HO-1 signaling pathway is involved in the protective effect of EGCG on eggshell pigmentation in vanadium challenged laying hens. Treatments included a control group, a 10 mg/kg V (V10), and a V10 plus 130 mg/kg of EGCG group (V10+EGCG130). Both eggshell color and protoporphyrin IX were decreased in the V10 group compared with the control diet, while EGCG130 treatment partially improved shell color and protoporphyrin IX (P < 0.05). The V10 exposure induced higher cell apoptosis rate and oxidative stress in birds as evidenced by the histological apoptosis status, decreased uterine glutathione-S transferase (GST) and high abundance of malondialdehyde (MDA) compared with the control group, whereas EGCG130 markedly alleviated oxidative stress via reducing MDA generation (P < 0.05). Dietary vanadium reduced ferrochelatase, NF-E2-related factor 2 (Nrf2), and heme oxygenase (HO-1) mRNA expression, while EGCG up-regulated Nrf2 and HO-1 expression (P < 0.05). Protein levels of Nrf2, HO-1 and phospho-p38 (P-P38) MAPK were reduced in V10 group, while dietary supplementation with 130 mg/kg EGCG markedly increased Nrf2, HO-1 and P-P38 MAPK protein levels in the uterus compared with the V10 group (P < 0.01). In conclusion, EGCG improved eggshell color and antioxidant system in V10-challenged hens, which seems to be associated with P38MAPK-Nrf2/HO-1 signaling pathway.

Effects of high pressure on the ferromagnetism and in-plane electrical transport of (Ba0.904K0.096)(Zn0.805Mn0.195)2As2 single crystal

Pressure technique is an effective way to modify magnetic properties of diluted magnetic semiconductors (DMS). Based on single crystal, in-plane electrical transport properties of a new generation DMS (Ba_0.904K_0.096)(Zn_0.805Mn_0.195)₂As₂ have been measured with hydrostatic pressure up to 1.8 GPa. Magnetic properties of the single crystal sample are effectively tuned by pressure. Upon compression, the in-plane resistivity initially decreases but then increases when pressure is higher than 1.2 GPa. First principle calculations suggest that decrease of the resistivity is due to enhancement of density of state at Femi energy while increase of the resistivity under higher pressure is caused by distorted MnAs₄ tetrahedra. We reveal that the configuration of the MnAs₄ tetrahedra and strength of interlayer As-As bonding are of importance to ferromagnetic coupling of (Ba,K)(Zn,Mn)₂As₂.

Calhm2 governs astrocytic ATP releasing in the development of depression-like behaviors

Extracellular ATP is a widespread cell-to-cell signaling molecule in the brain, where it functions as a neuromodulator by activating glia and neurons. Although ATP exerts multiple effects on synaptic plasticity and neuro-glia interactions, as well as in mood disorders, the source and regulation of ATP release remain to be elaborated. Here, we define Calhm2 as an ATP-releasing channel protein based on in vitro and in vivo models. Conventional knockout and conditional astrocyte knockout of Calhm2 both lead to significantly reduced ATP concentrations, loss of hippocampal spine number, neural dysfunction and depression-like behaviors in mice, which can be significantly rescued by ATP replenishment. Our findings identify Calhm2 as a critical ATP-releasing channel that modulates neural activity and as a potential risk factor of depression.

Kinsenoside: A Promising Bioactive Compound from Anoectochilus Species

Kinsenoside is a main active component isolated from plants of the genus Anoectochilus, and exhibits many biological activities and pharmacological effects, including hepatoprotective, anti-hyperglycemic, anti-hyperliposis, anti-inflammatory, vascular protective and anti-osteoporosis effects and so on, which is contributing to its promising potency in disease treatments. This review aims to recapitulate the pharmacological functions of kinsenoside, as well as its source, extraction, identification, quantitative analysis, pharmacokinetics, synthesis and patent information. The data reported in this work can confirm the therapeutic potential of kinsenoside and provide useful information for further new drug development.

Optimization of free nitrous acid pre-treatment on waste activated sludge

The effectiveness of the Free Nitrous Acid (FNA) sludge treatment was tested in the range from 0 to 3.0 mg N-HNO₂/L with acidified and neutral pH. 4 h pre-treatment times were used and the specific methane production (SMP) investigated. Results show that between 50 and 100 mg/L of N-NO₂^-/L disappeared during the FNA pre-treatment, reducing its effectiveness. A minimum level of nitrite (174 mg N-NO₂^-/L tested in this study), independently of pH/FNA, was necessary to assure the presence of the chemical throughout the duration of the pre-treatment. Sludge viability was compromised while WAS solubilization and SMP were enhanced with nitrite concentrations of 174 mg N-NO₂^-/L or higher, even at low FNA levels (<0.15 mg N-HNO₂/L). Results show that acidified pH is not needed to enhance methane production, making the pretreatment more economically and environmentally attractive.

Engineering a protein-based nanoplatform as an antibacterial agent for light activated dual-modal photothermal and photodynamic therapy of infection in both the NIR I and II windows

Ultra-small protein-based nanoparticles with absorption in both the NIR I and II biological windows were designed as new photoactivatable antibacterial agents.

Numerical Simulation of Supercritical Carbon Dioxide Critical Flow in the Nozzle Tube

The supercritical carbon dioxide (S-CO2) Brayton gas turbine cycle has been studied as an efficient and cost-effective option for advanced power systems. One major safety issue for any power cycle is a pipe break and the associated discharge of the working fluid and subsequent decrease in system pressure. In this paper, an S-CO2 critical flow in the nozzle tube is analyzed numerically with fluent 15.0. The Redlich–Kwong real gas equation is selected to calculate carbon dioxide density and the standard k-epsilon turbulence model is selected. Experimental data are used as a benchmark to examine the capability of the current approach. Compared with experimental data, the simulation results overestimate the critical mass flux; the error range is between 15% and 25%. The simulation results show that as L/D increases, critical mass flow decreases. As stagnation temperature increases, critical mass flow decreases. The complex thermal hydraulic behavior in the nozzle tubes is analyzed. Three flow patterns in the nozzle tube during transient critical flow are obtained and discussed. From inlet to outlet of the tube, CO2 may undergo the following phases in turn: (1) supercritical phase; (2) supercritical phase—gas phase; (3) supercritical phase—gas phase—liquid phase. The simulation results are also helpful for further experimental and theoretical research.

Exploring alternatives to reduce economical costs associated with FNA pre-treatment of waste activated sludge

Recent studies have shown the effectiveness of Free Nitrous Acid (FNA) pre-treatment in enhancing sludge biodegradability and improving its methane production potential. FNA is regarded as an environmental friendly pre-treatment which can be easily applied when a source of nitrite is present in wastewater treatment plants. However, when nitrite is not available and needs to be purchased, this treatment can become less attractive due to the costs associated to nitrite. In order to overcome this possible limitation, two different strategies to optimize the use of nitrite during FNA treatment were investigated: i) Recovering NO₂^- after the pre-treatment is completed; and ii) Concentrating the sludge before FNA pre-treatment. Results show that recovering NO₂^- from the pre-treated sludge is not suitable due to the loss of soluble organic matter present in the supernatant after the pre-treatment. However, concentrating the sludge before the pre-treatment seems a good strategy to optimize the use of nitrite.

Dual Biomembrane Force Probe enables single-cell mechanical analysis of signal crosstalk between multiple molecular species

Conventional approaches for studying receptor-mediated cell signaling, such as the western blot and flow cytometry, are limited in three aspects: 1) The perturbing preparation procedures often alter the molecules from their native state on the cell; 2) Long processing time before the final readout makes it difficult to capture transient signaling events (<1 min); 3) The experimental environments are force-free, therefore unable to visualize mechanical signals in real time. In contrast to these methods in biochemistry and cell biology that are usually population-averaged and non-real-time, here we introduce a novel single-cell based nanotool termed dual biomembrane force probe (dBFP). The dBFP provides precise controls and quantitative readouts in both mechanical and chemical terms, which is particularly suited for juxtacrine signaling and mechanosensing studies. Specifically, the dBFP allows us to analyze dual receptor crosstalk by quantifying the spatiotemporal requirements and functional consequences of the up- and down-stream signaling events. In this work, the utility and power of the dBFP has been demonstrated in four important dual receptor systems that play key roles in immunological synapse formation, shear-dependent thrombus formation, and agonist-driven blood clotting.

TNFα-YAP/p65-HK2 axis mediates breast cancer cell migration

Clinical and experimental evidence indicates that macrophages could promote solid-tumor progression and metastasis. However, the mechanisms underlying this process remain unclear. Here we show that yes-associated protein 1 (YAP1), a transcriptional regulator that controls tissue growth and regeneration, has an important role in tumor necrosis factor α (TNF α)-induced breast cancer migration. Mechanistically, macrophage conditioned medium (CM) or TNFα triggers IκB kinases (IKKs)-mediated YAP phosphorylation and activation in breast cancer cells. We further found that TNFα or macrophage CM treatment increases the interaction between p65 and YAP. Chromatin immunoprecipitation (ChIP) assay shows that YAP/TEAD (TEA domain family member) and p65 proteins synergistically regulate the transcription of hexokinase 2 (HK2), a speed-limiting enzyme in glycolysis, and promotes TNFα-induced or macrophage CM-induced cell migration. Together, our findings indicate an important role of TNFα-IKK-YAP/p65-HK2 signaling axis in the process of inflammation-driven migration in breast cancer cells, which reveals a new molecular link between inflammation and breast cancer metastasis.

Tannerella forsythia and coating color on the tongue dorsum, and fatty food liking associate with fat accumulation and insulin resistance in adult catch-up fat

BACKGROUND/OBJECTIVES

We aimed to determine the alteration of Tannerella forsythia and coating color on the dorsal tongue, and fatty food liking in catch-up fat in adult (CUFA), as well as the probable associations between fat accumulation, insulin resistance (IR) and these changes.

SUBJECTS/METHODS

T. forsythia on the tongue dorsum, fatty food liking, fat accumulation and insulin sensitivity were investigated in CUFA humans and rats, and tongue-coating color was observed in CUFA individuals. We further determined the changes of fatty food liking, fat accumulation and IR in T. forsythia-infected rodents by oral lavage.

RESULTS

Increases in fat accumulation, IR, percentage of subjects with yellow tongue coating and that with T. forsythia detected were observed in CUFA individuals. Additionally, the fat ranking scores were significantly lower and the hedonic ratings of low-fat options of sampled food were lower, while the ratings of high-fat options were remarkably higher in CUFA subjects. Additionally, T. forsythia level elevated in CUFA rats, and fatty food liking, fat accumulation and IR increased in CUFA and T. forsythia-infected animals, with the increases in T. forsythia infection and fatty food liking preceding the occurrence of fat accumulation and IR.

CONCLUSIONS

T. forsythia and yellow coating on the dorsal tongue and fatty food liking associate fat accumulation and IR in CUFA. Moreover, we tentatively put forward that T. forsythia, which is very important in yellow tongue-coating microbiota, and its consequent increases in fatty food liking, might be crucial in the development of fat accumulation and IR in CUFA.

[Effects of geranylgeranyltransferaseⅠsilencing on the proliferation of tongue squamous cancer cells]

Objective This study aims to investigate the effect of geranylgeranyltransferaseⅠ (GGTase-Ⅰ) on the proliferation and growth of tongue squamous cancer cells. Methods Three small interfering RNAs (siRNAs) were designed on the basis of the GGTase-Ⅰ sequence in GeneBank. These siRNAs were then transfected into tongue squamous cancer cells Cal-27. The mRNA and protein expression of GGTase-Ⅰ and RhoA were examined by real-time quantitative polymerase chain reaction and Western blotting, respectively. The expression of Cyclin D1 and p21 were examined by Western blotting. The proliferation and growth ability were analyzed by cell counting kit-8 assay and flow cytometry. Results The mRNA and protein expression of GGTase-Ⅰ in Cal-27 was reduced significantly after the GGTase-Ⅰ siRNAs were transfected (P<0.05). No significant difference in RhoA mRNA and protein expression was detected (P>0.05). Cyclin D1 expression decreased, whereas p21 expression increased significantly. The cell cycle was altered, and the growth-proliferative activity was inhibited (P<0.05). Conclusion GGTase-Ⅰ siRNA can inhibit the expression of GGTase-Ⅰ and the proliferative activity of tongue squamous cancer cells. GGTase-Ⅰ may be a potential target for gene therapy in tongue squamous cell cancer.

Pharmacokinetic and pharmacodynamic integration and modeling of acetylkitasamycin in swine for Clostridium perfringens

The aim of this study was to establish an integrated pharmacokinetic/pharmacodynamic (PK/PD) modeling approach of acetylkitasamycin for designing dosage regimens and decreasing the emergence of drug-resistant bacteria. After oral administration of acetylkitasamycin to healthy and infected pigs at the dose of 50 mg/kg body weights (bw), a rapid and sensitive LC-MS/MS method was developed and validated for determining the concentration change of the major components of acetylkitasamycin and its possible metabolite kitasamycin in the intestinal samples taken from the T-shape ileal cannula. The PK parameters, including the integrated peak concentration (C_max ), the time when the maximum concentration reached (T_max ) and the area under the concentration-time curve (AUC), were calculated by WinNonlin software. The minimum inhibitory concentration (MIC) of 60 C. perfringens strains was determined following CLSI guideline. The in vitro and ex vivo activities of acetylkitasamycin in intestinal tract against a pathogenic strain of C. perfringens type A (CPFK122995) were established by the killing curve. Our PK data showed that the integrated C_max , T_max , and AUC were 14.57-15.81 μg/ml, 0.78-2.52 hR, and 123.84-152.32 μg hr/ml, respectively. The PD data show that MIC₅₀ and MIC₉₀ of the 60 C. perfringens isolates were 3.85 and 26.45 μg/ml, respectively. The ex vivo growth inhibition data were fitted to the inhibitory sigmoid E_max equation to provide the values of AUC/MIC to produce bacteriostasis (4.84 hr), bactericidal activity (15.46 hr), and bacterial eradication (24.99 hr). A dosage regimen of 18.63 mg/kg bw every 12 hr could be sufficient in the prevention of C. perfringens infection. The therapeutic dosage regimen for C. perfringens infection was at the dose of 51.36 mg/kg bw every 12 hr for 3 days. In summary, the dosage regimen for the treatment of C. perfringens in pigs administered with acetylkitasamycin was designed using PK/PD integrate model. The designed dose regimen could to some extent decrease the risk for emergence of macrolide resistance.

Neutron Generation by Laser-Driven Spherically Convergent Plasma Fusion

We investigate a new laser-driven spherically convergent plasma fusion scheme (SCPF) that can produce thermonuclear neutrons stably and efficiently. In the SCPF scheme, laser beams of nanosecond pulse duration and 10^{14}-10^{15}  W/cm^{2} intensity uniformly irradiate the fuel layer lined inside a spherical hohlraum. The fuel layer is ablated and heated to expand inwards. Eventually, the hot fuel plasmas converge, collide, merge, and stagnate at the central region, converting most of their kinetic energy to internal energy, forming a thermonuclear fusion fireball. With the assumptions of steady ablation and adiabatic expansion, we theoretically predict the neutron yield Y_{n} to be related to the laser energy E_{L}, the hohlraum radius R_{h}, and the pulse duration τ through a scaling law of Y_{n}∝(E_{L}/R_{h}^{1.2}τ^{0.2})^{2.5}. We have done experiments at the ShengGuangIII-prototype facility to demonstrate the principle of the SCPF scheme. Some important implications are discussed.

The metabolic impact of extracellular nitrite on aerobic metabolism of Paracoccus denitrificans

Nitrite, in equilibrium with free nitrous acid (FNA), can inhibit both aerobic and anaerobic growth of microbial communities through bactericidal activities that have considerable potential for control of microbial growth in a range of water systems. There has been much focus on the effect of nitrite/FNA on anaerobic metabolism and so, to enhance understanding of the metabolic impact of nitrite/FNA on aerobic metabolism, a study was undertaken with a model denitrifying bacterium Paracoccus denitrificans PD1222. Extracellular nitrite inhibits aerobic growth of P. denitrificans in a pH-dependent manner that is likely to be a result of both nitrite and free nitrous acid (pK_a = 3.25) and subsequent reactive nitrogen oxides generated from the intracellular passage of FNA into P. denitrificans. Increased expression of a gene encoding a flavohemoglobin protein (Fhp) (Pden_1689) was observed in response to extracellular nitrite. Construction and analysis of a deletion mutant established Fhp to be involved in endowing nitrite/FNA resistance at high extracellular nitrite concentrations. Global transcriptional analysis confirmed nitrite-dependent expression of fhp and indicated that P. denitrificans expressed a number of stress response systems associated with protein, DNA and lipid repair. It is therefore suggested that nitrite causes a pH-dependent stress response that is due to the production of associated reactive nitrogen species, such as nitric oxide from the internalisation of FNA.

[Effects of RhoA silencing on proliferation of tongue squamous cancer cells]

OBJECTIVE

This study investigated the effect of RhoA silencing through RNA interference on proliferation and growth of tongue cancer cells, as well as explored the possible mechanisms of this effect.

METHODS

SSC-4 tongue cancer cells were cultured in vitro and then transfected with small interfering RNA to knock down RhoA expression. The tested cells were divided into three groups: experimental group (experimental group 1: transfected with RhoA-siRNA-1; experi-mental group 2: transfected with RhoA-siRNA-2), negative control group (transfected by random sequence NC-siRNA), and blank control group (transfected with Lipofectamine). The expression levels of RhoA mRNA were respectively measured by quantitative real-time polymerase chain reaction and western blot assay. Moreover, the expression levels of cyclin D1, p21, and p27 and RhoA protein were evaluated by Western blot assay. Proliferation and growth potentiality were analyzed through evaluation of doubling times and methyl thiazolyl tetrazolium assessment.

RESULTS

The expression levels of RhoA gene and protein of experimental groups significantly decreased following siRNA transfection compared with those in the negative and blank control groups. The expression of cyclin D1 decreased significantly and that of p21 and p27 increased significantly. The doubling time was extended and the growth potentiality decreased.

CONCLUSIONS

The results indicated that RhoA silencing can inhibit proliferation of tongue cancer cells, whereas RhoA affects cell proliferation by regulating the cell cycle pathway. Thus, RhoA is a potential target in gene therapy for tongue cancer.