CD4+ CAR-T cell exhaustion associated with early relapse of multiple myeloma after BCMA CAR-T cell therapy

Multiple myeloma is characterized by frequent clinical relapses following conventional therapy. Recently, chimeric antigen receptor T (CAR-T) cells targeting B-cell maturation antigen (BCMA) has been established as a treatment option for patients with relapsed or refractory disease. However, while >70% of patients initially respond to this treatment, clinical relapse and disease progression occur in most cases. Recent studies showed persistent expression of BCMA at the time of relapse, indicating that immune intrinsic mechanisms may contribute to this resistance. While there were no pre-existing T cell features associated with clinical outcomes, we found that patients with a durable response to CAR-T cell treatment had greater persistence of their CAR-T cells compared to patients with transient clinical responses. They also possessed a significantly higher proportion of CD8+ T effector memory cells. In contrast, patients with short-lived responses to treatment have increased frequencies of cytotoxic CD4+ CAR-T cells. These cells expand in vivo early after infusion but express exhaustion markers (HAVCR2 and TIGIT) and remain polyclonal. Finally, we demonstrate that non-classical monocytes are enriched in the myeloma niche and may induce CAR-T cell dysfunction through mechanisms that include TGFβ. These findings shed new light on the role of cytotoxic CD4+ T cells in disease progression after CAR-T cell therapy.

Seedlings of Poncirus trifoliata exhibit tissue-specific detoxification in response to NH4 + toxicity

Ammonium nitrogen (NH4 +-N) is essential for fruit tree growth, but the impact of excess NH4 +-N from fertilizer on evergreen citrus trees is unclear. In a climate chamber, 8-month-old citrus plants were exposed to five different hydroponic NH4 +-N concentrations (0, 5, 10, 15 and 20 mm) for 1 month to study effects of NH4 +-N on growth characteristics, N uptake, metabolism, antioxidant enzymes and osmotic regulatory substances. Application of 10 mm NH4 +-N adversely affected root plasma membrane integrity, root physiological functions, and plant biomass. MDA, CAT, POD, APX and SOD content were significantly correlated with leaf N metabolic enzyme activity (GOGAT, GDH, GS and NR). GDH was the primary enzyme involved in NH4 +-N assimilation in leaves, while the primary pathway involved in roots was GS-GOGAT. Under comparatively high NH4 + addition, roots were the main organs involved in NH4 + utilization in citrus seedlings. Our results demonstrated that variations in NH4 + concentration and enzyme activity in various organs are associated with more effective N metabolism in roots than in leaves to prevent NH4 + toxicity in evergreen woody citrus plants. These results provide insight into the N forms used by citrus plants that are important for N fertilizer management.

Fibulin-1 Regulates Initiation of Successional Dental Lamina

In humans, teeth are replaced only once, and the successional dental lamina (SDL) of the permanent tooth is maintained in a quiescent state until adolescence. Recently, we showed that biomechanical stress generated by the rapid growth of the deciduous tooth inhibits SDL development via integrin β1-RUNX2 signaling at embryonic day 60 (E60) in miniature pigs. However, the mechanism by which RUNX2 regulates SDL initiation within the SDL stem cell niche remains unclear. In the current study, we transcriptionally profiled single cells from SDL and surrounding mesenchyme at E60 and identified the landscape of cellular heterogeneity. We then identified a specific fibroblast subtype in the dental follicle mesenchyme between the deciduous tooth and the SDL of the permanent tooth (DFDP), which constitutes the inner part of the niche (deciduous tooth side). Compared with traditional dental follicle cells, the specific expression profile of DFDP was identified and found to be related to biomechanical stress. Subsequently, we found that RUNX2 could bind to the enhancer regions of Fbln1 (gene of fibulin-1), one of the marker genes for DFDP. Through gain- and loss-of-function experiments, we proved that the biomechanical stress-mediated RUNX2-fibulin-1 axis inhibits the initiation of SDL by maintaining SDL niche homeostasis.

Contouring Analysis on Synthetic Contrast-Enhanced MR from GRMM-GAN and Implications on MR-Guide Radiation Therapy

PURPOSE/OBJECTIVE(S)

MR-guided linear accelerators have been commercialized making MR-only planning and adaptation an appealing alternative circumventing MR-CT registration. However, obtaining daily contrast-enhanced MR images can be prohibitive due to the increased risk of side effects from repeated contrast injections. In this work, we evaluate the quality of contrast-enhanced multi-modal MR image synthesis network GRMM-GAN (gradient regularized multi-modal multi-discrimination sparse-attention fusion generative adversarial network) for MR-guided radiation therapy.

MATERIALS/METHODS

With IRB approval, we trained the GRMM-GAN based on 165 abdominal MR studies from 65 patients. Each study included T2, T1 pre-contrast (T1pre), and T1 contrast enhanced (T1ce) images. The two pre-contrast MR modalities, T2 and T1pre images were adopted as inputs for GRMM-GAN, and the T1ce image at the portal venous phase was used as an output. Ten MR scans containing 21 liver tumors were selected for contouring analysis. A Turing test was first given to six radiation oncologists, in which 100 real T1ce and synthetic T1ce image slices are randomly given to the radiation oncologists to determine the authenticity of the synthesis. We then invited two radiation oncologists (RadOnc 1 and RadOnc2) to manually contour the 21 liver tumors independently on the real T1ce images. RadOnc2 then performed contouring on the respective synthetic T1ce MRs. DICE coefficient (defined as the intersection over the average of two volumes) and Hausdorff distance (HD, measuring how far two volumes are from each other) were used as analysis metrics. The DICE coefficients were calculated from the two radiation oncologists' contours on the real T1ce MR for each tumor. The DICE coefficients were also calculated from RadOnc 2's contours on real and synthetic MRs. Besides, tumor center shifts were extracted. The tumor center of mass coordinates was extracted from real and synthetic volumes. The difference in the coordinates indicated the shifts in the superior-inferior (SI), right-left (RL), and anterior-posterior (AP) directions between real and synthetic tumor volumes.

RESULTS

An average of 52.3% test score was achieved from the six radiation oncologists, which is close to random guessing. RadOnc 1 and RadOnc 2, who had participated in the contouring analysis, achieved an average DICE of 0.91±0.02 from tumor volumes drawn on the real T1ce MRs. This result sets the inter-operator uncertainty baseline in the real clinical setting. RadOnc 2 achieved an average DICE (real vs. synth) of 0.90±0.04 and HD of 4.76±1.82 mm. Only sub-millimeter (SI: 0.67 mm, RL: 0.41 mm, AP: 0.39 mm) tumor center shifts were observed in all three directions.

CONCLUSION

The GRMM-GAN method has the potential for MR-guided liver radiation when contrast agents cannot be administered daily and provide synthetic contrast-enhanced MR for better tumor targeting. The network can produce synthetic MR images with satisfactory contour agreement and geometric integrity.

NAIR: Network Analysis of Immune Repertoire

T cells represent a crucial component of the adaptive immune system and mediate anti-tumoral immunity as well as protection against infections, including respiratory viruses such as SARS-CoV-2. Next-generation sequencing of the T-cell receptors (TCRs) can be used to profile the T-cell repertoire. We developed a customized pipeline for Network Analysis of Immune Repertoire (NAIR) with advanced statistical methods to characterize and investigate changes in the landscape of TCR sequences. We first performed network analysis on the TCR sequence data based on sequence similarity. We then quantified the repertoire network by network properties and correlated it with clinical outcomes of interest. In addition, we identified (1) disease-specific/associated clusters and (2) shared clusters across samples based on our customized search algorithms and assessed their relationship with clinical outcomes such as recovery from COVID-19 infection. Furthermore, to identify disease-specific TCRs, we introduced a new metric that incorporates the clonal generation probability and the clonal abundance by using the Bayes factor to filter out the false positives. TCR-seq data from COVID-19 subjects and healthy donors were used to illustrate that the proposed approach to analyzing the network architecture of the immune repertoire can reveal potential disease-specific TCRs responsible for the immune response to infection.

Abstract 6420: Harnessing immune responses in prostate MMRd tumors treated with immune checkpoint blockade

There is increasing evidence correlating tumor mutational burden with response to immunotherapy in many different types of cancer. Some tumors show high microsatellite instability (MSI-H) as a consequence of the loss of function of mismatch repair (MMR) genes, which would resolve DNA damage in normal conditions. MSH2 plays a critical role in MMR, and several studies have identified mutations in MSH2 as key drivers of MSI in tumors. In preclinical mouse models, MMR deficiency and high microsatellite instability have been previously shown to translate into higher sensitivity to anti-PD-1 treatment. Despite the advances led by the recent tumor-agnostic approval of checkpoint inhibitors for highly mutated tumors, response rates among MMR-deficient (MMRd) tumors in humans are variable, and the mechanisms behind such heterogeneity are still poorly understood. We successfully knocked out the MSH2 gene in the murine prostate adenocarcinoma TRAMP-C2 cell line by CRISPR gene editing. By sequential passaging, we generated a MSH2-KO subclonal population that presents MSI and MMR deficiency, validated by increased tumor mutational burden (TMB) observed by exome sequencing. In studies where we challenged immunodeficient and immunocompetent mice with MMR-proficient (MMRp) and MMRd tumors, the latter showed increase immunogenicity, which led us to interrogate and better characterize such immune responses in the context of immune checkpoint blockade by anti-PD-1.In our studies, MMRd tumor-infiltrating T cells presented significantly enhanced effector and cytotoxic profiles, which likely led to improved tumor control with or without anti-PD-1. We observed an intriguingly lower frequency of SPAS-1 (a well-known TRAMP-C2 immunodominant epitope) antigen-specific T cells in the tumor-reactive fraction of MMRd infiltrates compared to MMRp, which prompted us to interrogate tumor-infiltrate gene expression, TCR repertoire and the potential expansion of multiple antigen-reactive subsets against MMRd tumors in successful immune responses by single cell RNA sequencing and functional ex vivo studies. We also interrogated TCR repertoire data from patients harboring MMRd tumors to add translatability to our findings in mice.Our results constitute a relevant addition to the understanding of immune responses in MMRd tumors and the potential features that could be exploited to improve response rates in immunotherapeutic strategies targeting such malignancies.

Citation Format: Marcel Arias Badia, Zenghua Fan, Yee May Lwin, PeiXi Chen, Aahir Srinath, Lawrence Fong. Harnessing immune responses in prostate MMRd tumors treated with immune checkpoint blockade [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6420.

Abstract 1120: Dissecting tumor cell programs through group biology estimation in clinical single-cell transcriptomics

Translational oncology studies increasingly emphasize deriving hypotheses from single-cell datasets by evaluating groups of patients (e.g., treated vs. untreated, responders vs. non-responders, early vs. late-stage tumors) for differences in gene signatures/pathways to guide subsequent investigations. However, when evaluating these questions using tumor single-cell data, current statistical methods for this task are limited in two major aspects: (i) They are not representative of the hierarchical nature of tumor single-cell datasets (where cells are more similar within the patient than between patients); and (ii) They often do not contextualize statistical significance (p-values) in the context of variability that is expected biologically between patients. This can lead to molecular hypotheses that are skewed by patient-specific biology with high false positive rates. To address these challenges, we developed a nonparametric statistical method, BEANIE (group Biology EstimAtioN in sIngle cEll), for estimating group biology in single-cell transcriptomic datasets. BEANIE uses monte carlo simulations to estimate the p-value distribution for the gene signature of interest and normalizes with respect to a background distribution of the expected patient-to-patient variability. The method then performs leave-one-out cross-validation to infer robustness of the gene signatures to patient exclusion. We applied our method to public cancer single-cell datasets to evaluate candidate differences in tumor cell populations between known groups. When comparing tumor cell programs derived from treatment-naive vs. chemotherapy-treated Triple-Negative Breast Cancer (TNBC) patients, BEANIE identified upregulation of hallmark gene signatures for fatty acid metabolism and hypoxia to be statistically significant and robust in the treatment-naive group, indicative of response to chemotherapy treatment. We also compared BEANIE to conventional methods like Mann-Whitney U (MWU) test followed by Benjamini-Hochberg (BH) correction and Generalized Linear Models (GLM). MWU test and GLM also identified these signatures to be upregulated, but they additionally identified other immune cell gene signatures like T-cell markers, B-cell markers and NK cell markers, to also be upregulated, which was not expected since we were comparing between tumor cells. Similarly, BEANIE identified candidate tumor cell intrinsic programs relevant to hypotheses in lung cancer patients (early vs. late-stage) and melanoma patients (Immune Checkpoint Blockade (ICB)-naive vs. ICB-treated). Therefore, BEANIE greatly increased the specificity of analysis, and reduced false positive rates. This method is publicly available and may overcome existing methodological limitations to guide tumor-intrinsic hypothesis generation in rapidly growing clinical cancer single-cell cohorts.

Citation Format: Shreya Johri, Kevin Bi, Breanna M. Titchen, Jingxin Fu, Jake Conway, Jett Crowdis, Natalie I. Volkes, Zenghua Fan, Lawrence Fong, Jihye Park, David Liu, Meng Xiao He, Eliezer M. Van Allen. Dissecting tumor cell programs through group biology estimation in clinical single-cell transcriptomics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1120.

A Predictive Model of Capillary Forces and Contact Diameters between Two Plates Based on Artificial Neural Network

Many efforts have been devoted to the forecasting of the capillary force generated by capillary adsorption between solids, which is fundamental and essential in the fields of micro-object manipulation and particle wetting. In this paper, an artificial neural network (ANN) model optimized by a genetic algorithm (GA-ANN) was proposed to predict the capillary force and contact diameter of the liquid bridge between two plates. The mean square error (MSE) and correlation coefficient (R²) were employed to evaluate the prediction accuracy of the GA-ANN model, theoretical solution method of the Young-Laplace equation and simulation approach based on the minimum energy method. The results showed that the values of MSE of capillary force and contact diameter using GA-ANN were 10.3 and 0.0001, respectively. The values of R² were 0.9989 and 0.9977 for capillary force and contact diameter in regression analysis, respectively, demonstrating the accuracy of the proposed predictive model. The sensitivity analysis was conducted to investigate the influence of input parameters, including liquid volume and separation distance, on the capillary force and contact diameter. The liquid volume and separation distance played dominant roles in affecting the capillary force and contact diameter.

A study on prenucleation and heterogeneous nucleation in liquid Pb on solid Al using molecular dynamics simulations

In this paper, we investigate prenucleation and heterogeneous nucleation in the liquid Pb/solid Al system as an example of systems with large lattice misfit using molecular dynamics simulation. Solid Pb and Al have a large positive lattice misfit (f) of 18.2% along the densely packed [110] direction. This study reveals that prenucleation occurs at 600 K (an undercooling of 15 K), and a 2-dimensional (2D) ordered structure forms at the interface with a coincidence site lattice (CSL) between the first Pb and first Al layers. The CSL accommodates the major part of the f, and only a small residual lattice misfit (f_r) of 1.9% remains. The formation of the CSL transforms the original substrate into a considerably potent nucleant, where the first Pb layer becomes the new surface layer of the substrate. At an undercooling of about 22 K, nucleation proceeds by merging 2D ordered structure through structural templating: the second Pb layer is epitaxial to the CSL Pb layer, the third Pb layer largely accommodates the f_r, and the fourth Pb layer is a nearly perfect crystalline plane. Further analysis indicates that the interface with the CSL has a lower interfacial energy than with a cube-to-cube orientation relationship. For the first time, we established that the CSL was an effective mechanism to accommodate the f for systems with a large positive misfits. Heterogeneous nucleation is governed not by a single mechanism (misfit dislocations in Turnbull's model), but instead by various mechanisms depending on f. This study sheds new light on the atomistic mechanism of heterogeneous nucleation.

Mid-infrared frequency combs and staggered spectral patterns in χ(2) microresonators

The potential of frequency comb spectroscopy has aroused great interest in generating mid-infrared frequency combs in the integrated photonic setting. However, despite remarkable progress in microresonators and quantum cascade lasers, the availability of suitable mid-IR comb sources remains scarce. Here, we generate mid-IR microcombs relying on cascaded three-wave-mixing for the first time. By pumping a CdSiP₂ microresonator at 1.55 µm wavelength with a low power continuous wave laser, we generate χ⁽²⁾ frequency combs at 3.1 µm wavelength, with a span of about 30 nm. We observe ordinary combs states with a line spacing of the free spectral range of the resonator, and combs where the sideband numbers around the pump and half-harmonic alternate, forming staggered patterns of spectral lines. Our scheme for mid-IR microcomb generation is compatible with integrated telecom lasers. Therefore, it has the potential to be used as a simple and fully integrated mid-IR comb source, relying on only one single material.

Plant-specific features of respiratory supercomplex I + III2 from Vigna radiata

The last steps of cellular respiration-an essential metabolic process in plants-are carried out by mitochondrial oxidative phosphorylation. This process involves a chain of multi-subunit membrane protein complexes (complexes I-V) that form higher-order assemblies called supercomplexes. Although supercomplexes are the most physiologically relevant form of the oxidative phosphorylation complexes, their functions and structures remain mostly unknown. Here we present the cryogenic electron microscopy structure of the supercomplex I + III₂ from Vigna radiata (mung bean). The structure contains the full subunit complement of complex I, including a newly assigned, plant-specific subunit. It also shows differences in the mitochondrial processing peptidase domain of complex III₂ relative to a previously determined supercomplex with complex IV. The supercomplex interface, while reminiscent of that in other organisms, is plant specific, with a major interface involving complex III₂'s mitochondrial processing peptidase domain and no participation of complex I's bridge domain. The complex I structure suggests that the bridge domain sets the angle between the enzyme's two arms, limiting large-scale conformational changes. Moreover, complex I's catalytic loops and its response in active-to-deactive assays suggest that, in V. radiata, the resting complex adopts a non-canonical state and can sample deactive- or open-like conformations even in the presence of substrate. This study widens our understanding of the possible conformations and behaviour of complex I and supercomplex I + III₂. Further studies of complex I and its supercomplexes in diverse organisms are needed to determine the universal and clade-specific mechanisms of respiration.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Circulating monocytes associated with anti-PD-1 resistance in human biliary cancer induce T cell paralysis

Suppressive myeloid cells can contribute to immunotherapy resistance, but their role in response to checkpoint inhibition (CPI) in anti-PD-1 refractory cancers, such as biliary tract cancer (BTC), remains elusive. We use multiplexed single-cell transcriptomic and epitope sequencing to profile greater than 200,000 peripheral blood mononuclear cells from advanced BTC patients (n = 9) and matched healthy donors (n = 8). Following anti-PD-1 treatment, CD14+ monocytes expressing high levels of immunosuppressive cytokines and chemotactic molecules (CD14CTX) increase in the circulation of patients with BTC tumors that are CPI resistant. CD14CTX can directly suppress CD4+ T cells and induce SOCS3 expression in CD4+ T cells, rendering them functionally unresponsive. The CD14CTX gene signature associates with worse survival in patients with BTC as well as in other anti-PD-1 refractory cancers. These results demonstrate that monocytes arising after anti-PD-1 treatment can induce T cell paralysis as a distinct mode of tumor-mediated immunosuppression leading to CPI resistance.

Flexible Magnetic Micropartners for Micromanipulation at Interfaces

Microrobots working at liquid surfaces have immense potential for micromanipulation in tight and enclosed spaces, whereas constructing agile and functional microrobots with simple structures at liquid surfaces is a great challenge. Herein, a pair of magnetic circular microdisks working as partners at ethylene glycol (EG) surfaces are proposed in order to accomplish flexible locomotion and in situ micromanipulation tasks. The microdisks can be controlled to connect and separate by modulating the orientation of the applied magnetic field. After the two disks connect as an entity, they are transformed into micropartners under an oscillating magnetic field in 3D space. By changing the vertical component of the oscillating field, the micropartners can obtain controllable propulsion through paddling and wriggling modes, and the locomotion speed can reach approximately two body lengths per second. They can also climb a meniscus, and even crawl on a solid surface in a liquid. Finally, this pair of micropartners is demonstrated as a flexible microgripper to implement manipulations at the liquid surfaces, including cargo capture, delivery along prescribed paths, and release.

Novel Ensemble Feature Selection Approach and Application in Repertoire Sequencing Data

The T and B cell repertoire make up the adaptive immune system and is mainly generated through somatic V(D)J gene recombination. Thus, the VJ gene usage may be a potential prognostic or predictive biomarker. However, analysis of the adaptive immune system is challenging due to the heterogeneity of the clonotypes that make up the repertoire. To address the heterogeneity of the T and B cell repertoire, we proposed a novel ensemble feature selection approach and customized statistical learning algorithm focusing on the VJ gene usage. We applied the proposed approach to T cell receptor sequences from recovered COVID-19 patients and healthy donors, as well as a group of lung cancer patients who received immunotherapy. Our approach identified distinct VJ genes used in the COVID-19 recovered patients comparing to the healthy donors and the VJ genes associated with the clinical response in the lung cancer patients. Simulation studies show that the ensemble feature selection approach outperformed other state-of-the-art feature selection methods based on both efficiency and accuracy. It consistently yielded higher stability and sensitivity with lower false discovery rates. When integrated with different classification methods, the ensemble feature selection approach had the best prediction accuracy. In conclusion, the proposed novel approach and the integration procedure is an effective feature selection technique to aid in correctly classifying different subtypes to better understand the signatures in the adaptive immune response associated with disease or the treatment in order to improve treatment strategies.

676 Altered circulating myeloid states associated with anti-PD-1 resistance induce T cell paralysis in human biliary cancer

Background

Advanced biliary cancers (ABC) have a poor prognosis and low rates of response to immune checkpoint inhibition (CPI), with overall response rates ranging from 3–13%.1–3 Although suppressive myeloid cells have been proposed as a mechanism of resistance to immunotherapy in general, their relationship to response to CPI is unknown.

Methods

We used multiplexed simultaneous single cell RNA sequencing and cell surface proteomics (CITE-seq) to profile circulating immune cells in ABC patients receiving anti-PD-1 at longitudinal timepoints pre-immunotherapy and on treatment, as well as from healthy donors. We also performed single cell RNA sequencing on resected biliary tumors.

Results

We identified a novel population of circulating cancer-enriched myeloid cells (CEM) characterized by chemokines and extracellular matrix digestion-related gene expression, which were present pre-treatment. Anti-PD-1 treatment drove the CEMs into two diverging states that were associated with response or resistance to treatment. CEM induced in non-responders constituted over 40% of the circulating myeloid cells and expressed immunosuppressive programs, including the upregulation of suppressive cytokines and chemokines. The frequency of these myeloid cells were correlated with the abundance of SOCS3-expressing CD4+ T cells. These SOCS3+CD4+ T cells also colocalized with tumor-infiltrating myeloid cells that share CEM gene expression signatures in the biliary cancer microenvironment. Moreover, CEM can directly induce SOCS3-expressing T cells, which despite their naïve phenotype are functionally unresponsive. Finally, expression signatures of CEM and of SOCS3+CD4+ T cells are associated with worse survival in a larger cohort of ABC patients.

Conclusions

These results demonstrate the capacity of CEM to induce T cell paralysis as an alternate mode of tumor-mediated immunosuppression. A deeper understanding of immune cell biology in ABC provides insights for developing novel therapeutics that can overcome immunotherapy resistance in biliary cancer as well as other tumor types.

Trial Registration

NCT02703714

References

Ueno M, et al. Nivolumab alone or in combination with cisplatin plus gemcitabine in Japanese patients with unresectable or recurrent biliary tract cancer: a non-randomised, multicentre, open-label, phase 1 study. Lancet Gastroenterol Hepatol 2019;4:611–621.

Piha-Paul SA, et al. Efficacy and safety of pembrolizumab for the treatment of advanced biliary cancer: results from the KEYNOTE-158 and KEYNOTE-028 studies. Int J Cancer 2020.

Kim RD, et al. A Phase 2 Multi-institutional study of nivolumab for patients with advanced refractory biliary tract cancer. JAMA Oncol 2020;6:888–894.

Ethics Approval

Informed consent was obtained from all patients for participation in the listed trial and for use of blood and tumor samples in research studies.

[Autologous stem cell transplantation improves outcomes of patients with multiple myeloma receiving proteasome inhibitors and lenalidomide treatment]

OBJECTIVE

To evaluate the effect of autologous stem cell transplantation (ASCT) on treatment response and survival outcomes in patients with newly diagnosed multiple myeloma (MM) receiving treatments with proteasome inhibitors and lenalidomide.

METHODS

We retrospectively collected the clinical data of newly diagnosed MM patients, who were eligible for ASCT and received proteasome inhibitors or lenalidomide-based treatment in our hospital from January, 2015 to December, 2019. The patients were divided into transplantation group and non-transplantation group, and in transplantation group, the patients received 4 to 6 courses of induction therapy with proteasome inhibitors or lenalidomide before ASCT, while those in the non-transplantation group received more than 8 courses of induction and consolidation therapy with proteasome inhibitors or lenalidomide-based regimens. The therapeutic efficacy and survival outcomes of the patinets were compared between the two groups.

RESULTS

A total of 105 patients were enrolled in the study, including 48 (45.7%) in transplantation group and 57 (54.3%) in non-transplantation group. The two groups were matched for gender, age and treatment response after 4 courses of induction therapy (P > 0.05). The rate of optimal response before relapse differed significantly between the two groups (P=0.000), and the patients receiving ASCT had significantly higher rates of complete response (85.4% vs 54.4%, P= 0.001) and very good partial response or better (95.8% vs 73.7%, P=0.002) than those without ASCT. At the end of follow-up, the median progression-free survival in the transplantation group was not reached, as compared with 29 months in the nontransplantation group (P=0.013). The median overall survival (OS) in the two groups was not reached, but the OS was better in the transplant group than in the non-transplant group (P=0.022).

CONCLUSION

ASCT can further improve the depth of remission and survival outcomes in patients with newly diagnosed MM receiving treatments with proteasome inhibitors and lenalidomide.

The association of metabolic health obesity with incidence of carotid artery plaque in Chinese adults

BACKGROUND AND AIMS

We aimed to evaluate the association between different obese phenotypes with carotid artery plaque (CAP) event.

METHOD AND RESULTS

The current retrospective cohort study was performed in 32,778 Chinese adults (19,221 men and 13,557 women, aged 41.9 ± 11.0 years). Obese phenotypes were assessed based on baseline body mass index (<24.0 vs. ≥24.0 kg/m²) and metabolic characteristics (health vs. unhealth). All the participants were further classified into four groups: metabolic health and normal weight (MHNW), metabolic unhealth and normal weight (MUHNW), metabolic health and overweight (MHO), and metabolic unhealth and overweight (MUHO). Ultrasound B-mode imaging was annually performed to evaluate CAP throughout the study. We have identified 2142 CAP cases during 5-year follow-up. Comparing with the MHNW group, the hazard ratios for the risk of incident CAP was 2.44 (95% CI:1.92 and 3.09) for the MUHNW group, 1.52 (95% CI:1.06 and 2.18) for the MHO group, and 1.8 (95% CI:1.4 and 2.33) for the MUHO group. The association was more pronounced in young adults (<65 y) than that in aged adults (≥65 y). Sensitivity analysis generated similar results with the main analysis.

CONCLUSION

MUHNW, MHO, and MUHO were associated with the risk of CAP.

Copper stimulates neonicotinoid insecticide thiacloprid degradation by Ensifer adhaerens TMX-23

AIMS

Aims of this study are to elucidate the molecular mechanism of copper-improved thiacloprid (THI) degradation by Ensifer adhaerens TMX-23 and characterize copper resistance of this strain.

METHODS AND RESULTS

Resting cells of E. adhaerens TMX-23 were used to degrade THI, with formation of THI amide and 98·31% of 0·59 mmol l^-1 THI was degraded in 100 min. The addition of copper improved the degradation of THI and showed little inhibitory effects on the growth of E. adhaerens TMX-23. E. adhaerens TMX-23 degraded THI to THI amide by nitrile hydratases (NhcA and NhpA). QPCR analysis indicated that the expression of nhpA was up-regulated in the presence of copper. E. adhaerens TMX-23 nitrile hydratases were purified, and enzyme assay of NhpA exhibited the highest NHase activity toward THI. The addition of copper activated the activity of NhcA. Soil degradation experiment indicated that E. adhaerens TMX-23 could quickly eliminate THI residual in copper-added soil.

CONCLUSIONS

Copper improved THI degradation by E. adhaerens TMX-23 was attributed to the induced expression of nhpA and activated NhcA.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study broadens the investigation of regulatory mechanism of NHase expression and provided theoretical basis for using metal-resistant microbes to degrade pesticide in heavy metal co-contaminated environments.

Impact of the combined timing of PD-1/PD-L1 inhibitors and chemotherapy on the outcomes in patients with refractory lung cancer

Background

PD-1/PD-L1 inhibitors in combination with chemotherapy are widely used in clinical practice. However, the ideal combined timing of them has not been fully explored.

Methods

In this study, simulation experiments to explore the impacts of the combination of anti-PD-1 antibody (anti-PD-1 Ab) on the cytotoxic effects of chemotherapeutic drugs in peripheral blood mononuclear cells were performed. In addition, the effects of the combined timing of PD-1/PD-L1 inhibitors and chemotherapy on efficacy and safety were retrospectively analysed in patients with refractory lung cancer.

Results

Experiments in vitro showed that administering the anti-PD-1 Ab 3 days after chemotherapy (represented by dicycloplatin) resulted in significantly weaker cytotoxic effects on lymphocytes, compared with administering the anti-PD-1 Ab before or concurrent with chemotherapy. Moreover, data from 64 lung cancer patients treated with PD-1/PD-L1 inhibitors plus chemotherapy as a second- or higher-line therapy were retrospectively analysed. The results showed that administering PD-1/PD-L1 inhibitors 1-10 days (especially 3-5 days) after chemotherapy was associated with longer overall survival [17.3 months versus 12.7 months; hazard ratio (HR) = 0.58, 95% confidence interval (CI) 0.28-1.19, P = 0.137 in univariate analysis; HR = 0.36, 95% CI 0.16-0.80, P = 0.012 in multivariate analysis] and a trend of improved progression-free survival (5.1 months versus 4.2 months; HR = 0.81, 95% CI 0.42-1.54, P = 0.512) compared with administering PD-1/PD-L1 inhibitors before or concurrent with chemotherapy.

Conclusion

Our findings suggest that administering PD-1/PD-L1 inhibitors 1-10 days (especially 3-5 days) after chemotherapy is superior to administering PD-1/PD-L1 inhibitors before or concurrent with chemotherapy in patients with refractory lung cancer, but this result needs to be further explored by prospective studies.

•

The cytotoxic effects of chemotherapeutic drugs were positively correlated with the activation states of PBMCs.

•

Administering the anti-PD-1 Ab 3 days after chemotherapy resulted in weaker cytotoxic effects on lymphocytes in vitro.

•

Administering PD-1/PD-L1 inhibitors a few days after chemotherapy resulted in better survival in lung cancer patients.

Capillary Forces between Concave Gripper and Spherical Particle for Micro-Objects Gripping

The capillary action between two solid surfaces has drawn significant attention in micro-objects manipulation. The axisymmetric capillary bridges and capillary forces between a spherical concave gripper and a spherical particle are investigated in the present study. A numerical procedure based on a shooting method, which consists of double iterative loops, was employed to obtain the capillary bridge profile and bring the capillary force subject to a constant volume condition. Capillary bridge rupture was characterized using the parameters of the neck radius, pressure difference, half-filling angle, and capillary force. The effects of various parameters, such as the contact angle of the spherical concave gripper, the radius ratio, and the liquid bridge volume on the dimensionless capillary force, are discussed. The results show that the radius ratio has a significant influence on the dimensionless capillary force for the dimensionless liquid bridge volumes of 0.01, 0.05, and 0.1 when the radius ratio value is smaller than 10. The effectiveness of the theorical approach was verified using simulation model and experiments.

95 Invitro correction of F508del and G542X mutations in sheep fibroblasts of cystic fibrosis models

Cystic fibrosis (CF) is a human genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. Among the ∼2000 known CF mutations, the F508del mutation is found in 84% and G542X in 4.6% of the CF patients in the United States. The F508del mutation occurs in exon 11 and is characterised by deletion of the “CTT” nucleotides, resulting in deletion on the phenylalanine residue at the position 508 of CFTR. This causes misfolding of the CFTR protein, which is further degraded by proteases. The G542X mutation is a nonsense mutation found in exon 12 and associated with nonsense-mediated decay of the mutant transcript causing the absence of protein production. Previously, we generated CFTRF508del/F508del and CFTRG542X/G542X lambs (unpublished) using CRISPR/Cas9 and somatic cell nuclear transfer (SCNT) techniques. We hypothesised that gene editing may be an effective tool to correct these mutations and permanently cure this genetic disease. Thus, in this study, we evaluated the efficiency of CRISPR/Cas9-meditated gene knock-in to correct the F508del and G542X mutations in sheep fibroblasts invitro. We designed single guide (sg)RNAs using the Benchling software (https://benchling.com/academic) and approximately 100bp of single-stranded oligodeoxynucleotides (ssODNs) targeting the mutation sites at exon 11 and 12 to introduce either “CTT” or change the “T” to “G” nucleotide in genome of F508del or G542X CF sheep cells, respectively. Each of Cas9/sgRNA ribonucleoproteins was transfected into sheep fibroblast cells along with ssODNs using the Lonza-4D-NucleofectorTM (Lonza) system for homology-directed repair. The transfected cells were subsequently cultured in Dulbecco’s modified Eagle medium, supplemented with 15% fetal bovine serum and 1% penicillin, and incubated at 38.5°C. DNA was extracted 48h post-transfection to validate mutation efficiency. PCR products of the exons 11 and 12 were ligated into T-vector, and bacterial colonies were selected based on blue/white screening. In total, we isolated 32 single cell bacterial colonies for each mutant. Sequencing results indicate that “CTT” was introduced in 4/26 (15.3%) plasmid colonies, and “T to G” replaced in 13/31 (41.9%) colonies. Therefore, our results indicate that the F508del and G542X mutations can be effectively corrected in CF sheep fibroblasts invitro using a CRISPR/Cas9 approach.

92 Correction of the CFTR G542X mutation using CRISPR/Cas9 genome editing in ovine-bovine interspecies embryos

Cystic fibrosis (CF) is a human genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene. We have recently generated 3 CF sheep models: a CFTR−/− model (Fan et al. 2018 LCI Insight 3:e123529; https://doi.org/10.1172/jci.insight.123529) and 2 additional models where we introduced human G542X and F508del mutations into the sheep genome (unpublished). Correction of CFTR mutations in zygotes with gene-editing techniques could be a permanent solution to cure this disease. To assess the efficiency of mutation correction invitro by CRISPR/Cas9, we utilised embryos generated by ovine-bovine interspecies SCNT (iSCNT) due to limited access to sheep oocytes. First, we evaluated the developmental capacity of reconstructed iSCNT embryos, in which nucleus donors were derived from ovine fibroblasts and recipient cytoplasm from enucleated bovine oocytes. These iSCNT embryos were able to develop to 16- to 32-cell stage (3/30, 10.0%), which allowed the genotyping of each embryo using PCR-restriction fragment length polymorphism assays and Sanger sequencing. Then, specific single-guide RNAs (sgRNAs) and 101-bp single-stranded oligodeoxynucleotides (ssODNs) were designed and synthesised to correct the G542X mutation in the sheep CFTR gene. We optimized the concentrations of Cas9:sgRNA ribonucleoproteins (RNPs) for 1-cell stage embryonic injection. Mutation analysis of embryos was conducted at 3 days post injection. Genotyping results showed that we achieved high efficiencies (95.7–100%) of mutations (indels) at targeting loci after injection of different concentrations of Cas9:sgRNA RNPs (0.02 µg:0.6 pmol/µL to 1.4 µg:40 pmol/µL). Furthermore, when an RNP (1.4 µg:40 pmol/µL) was co-injected with a ssODN (80 pmol/µL), both targeting the G542X mutation, the mutation was successfully corrected in the genome of iSCNT embryos generated using G542X fibroblasts as nucleus donors at an efficiency of 5.7% (3/53) via homology-directed repair mechanism. During the invitro culture of iSCNT embryos, we did not observe significant difference (P&gt;0.05, unpaired t-test) in cleavage rates between embryos with or without injection (85.5% vs. 89.0%). Off-target analysis of those mutated and G542X-corrected embryos is in progress. Our strategy overcomes the limitation of oocyte source and provides an opportunity to mimic the editing of any other gene in embryos of different species.

Lrp6 Dynamic Expression in Tooth Development and Mutations in Oligodontia

Genes associated with the WNT pathway play an important role in the etiology of tooth agenesis. Low-density lipoprotein receptor-related protein 6 encoding gene (LRP6) is a recently defined gene that is associated with autosomal dominant inherited tooth agenesis. Here, we aimed to identify novel LRP6 mutations in patients with tooth agenesis and investigate the significance of Lrp6 during tooth development. Using whole-exome sequencing, we identified 4 novel LRP6 heterozygous mutations (c.2292G>A, c.195dup, c.1095dup, and c.1681C>T) in 4 of 77 oligodontia patients. Notably, a patient who carried a nonsense LRP6 mutation (c.2292G>A; p.W764*) presented a hypohidrotic ectodermal dysplasia phenotype. Preliminary functional studies, including bioinformatics analysis and TOP-/FOP-flash reporter assays, demonstrated that the activation of WNT/β-catenin signaling was compromised as a consequence of LRP6 mutations. RNAscope in situ hybridization revealed dynamic and special changes of Lrp6 expression during murine tooth development from E11.5 to E16.5. It was noteworthy that Lrp6 was specifically expressed in the epithelium at E11.5 to E13.5 but was expressed in both dental epithelium and dental papilla from E14.5 and persisted in both tissues at later stages. Our study broadens the mutation spectrum of human tooth agenesis and is the first to identify a LRP6 mutation in patients with hypohidrotic ectodermal dysplasia and reveal the dynamic expression pattern of Lrp6 during tooth development. Information from this study is conducive to understanding the functional significance of Lrp6 on the biological process of tooth development.

Mutations in Metabotropic Glutamate Receptor 1 Contribute to Natural Short Sleep Trait

Sufficient and efficient sleep is crucial for our health. Natural short sleepers can sleep significantly shorter than the average population without a desire for more sleep and without any obvious negative health consequences. In searching for genetic variants underlying the short sleep trait, we found two different mutations in the same gene (metabotropic glutamate receptor 1) from two independent natural short sleep families. In vitro, both of the mutations exhibited loss of function in receptor-mediated signaling. In vivo, the mice carrying the individual mutations both demonstrated short sleep behavior. In brain slices, both of the mutations changed the electrical properties and increased excitatory synaptic transmission. These results highlight the important role of metabotropic glutamate receptor 1 in modulating sleep duration.

Phase transitions in the classical exchange-anisotropic Kitaev-Heisenberg model

The Kitaev model on the honeycomb lattice has been receiving substantial attention due to the discovery of quantum spin liquid state associated with this model. Consequently, its classical partners such as the Kitaev-Heisenberg (KH) model and associated phase transitions become concerned. Specifically, an intermediate Kosterlitz-Thouless (KT) phase engaged in the transition from the high-temperature (T) disordered state to the low-T sixfold degenerate state is predicted in the isotropic KH model [Phys. Rev. Lett. 109, 187201 (2012)10.1103/PhysRevLett.109.187201], but so far no sufficient experimental proof has been reported. In this work, we consider an essential extension of this KH model on the honeycomb lattice by including the Kitaev exchange anisotropy that is non-negligible in realistic materials. The associated phase transitions are thus investigated using the Monte Carlo simulations. It is found that such an anisotropy will result in a degradation of the sixfold degeneracy of the ground state in the isotropic KH model down to the fourfold or twofold degenerate ground state, and the finite-T phase transitions will also be modified remarkably. Interestingly, the intermediate KT phase can be suppressed by this Kitaev exchange anisotropy. This work thus provides a more realistic description of the physics ingredient with the KH model and presents a possible explanation on absence of the intermediate phase in real materials where the Kitaev exchange anisotropy can be more or less available.

Second harmonic generation microscopy using pixel reassignment

Second harmonic generation (SHG) microscopy is expected to be a powerful tool for observing the cellular-level functionality and morphology information of thick tissue owe to its unique imaging properties. However, the maximum attainable resolution obtainable by SHG microscopy is limited by the use of long-wavelength, near-infrared excitation. In this paper, we report the use of pixel reassignment to improve the spatial resolution of SHG microscopy. The SHG signal is imaged onto a position-sensitive camera, instead of a point detector typically used in conventional SHG microscope. The data processing is performed through pixel reassignment and subsequent deblurring operation. We present the basic principle and a rigorous theoretical model for SHG microscopy using pixel reassignment (SHG-PR). And for the first time, the optimal reassignment factor for SHG-PR is derived based on the coherent characteristics and the dependence of wavelength in SHG microscopy. To evaluate the spatial resolution improvement, images of nano-beads separated by different distances and of a microtubule array have been simulated. We gain about a 1.5-fold spatial resolution enhancement compared to conventional SHG microscopy. When a further deblurring operation is implemented, this method allows for a total spatial resolution enhancement of about 1.87. Additionally, we demonstrate the validity of SHG-PR for raw data with noise. LAY DESCRIPTION: Second harmonic generation (SHG) microscopy has emerged as a powerful imaging technique in clinical diagnostics and biological research. SHG microscopy is label-free and provides intrinsic optical sectioning for three-dimensional (3D) imaging. However, a near-infrared excitation wavelength results a restriction in the maximum attainable spatial resolution of SHG microscopy. In this paper, we present a simple resolution-enhanced SHG imaging method, SHG microscopy using pixel reassignment (SHG-PR). We demonstrate a rigorous theoretical model for SHG-PR and derive the optimal reassignment factor. The simulation result shows the clear improvement of the image resolution and contrast in the SHG-PR after deblurring operation. The FWHM value of single microtubule shows that SHG-PR enables a spatial resolution enhancement by a factor of 1.5, compared to conventional SHG microscopy. After a proper deblurring operation, this method allows for a total spatial resolution enhancement of about 1.87. The improvements of spatial resolution and contrast are still valid for raw data with noise. It is expected that this method can contribute towards new insights in unstained tissue morphology, interaction of cells, and diseases diagnosis.

Mutant neuropeptide S receptor reduces sleep duration with preserved memory consolidation

Sleep is a crucial physiological process for our survival and cognitive performance, yet the factors controlling human sleep regulation remain poorly understood. Here, we identified a missense mutation in a G protein-coupled neuropeptide S receptor 1 (NPSR1) that is associated with a natural short sleep phenotype in humans. Mice carrying the homologous mutation exhibited less sleep time despite increased sleep pressure. These animals were also resistant to contextual memory deficits associated with sleep deprivation. In vivo, the mutant receptors showed increased sensitivity to neuropeptide S exogenous activation. These results suggest that the NPS/NPSR1 pathway might play a critical role in regulating human sleep duration and in the link between sleep homeostasis and memory consolidation.

Identifying a novel 5-gene signature predicting clinical outcomes in acute myeloid leukemia

BACKGROUND

Acute myeloid leukemia (AML) is the most common type of acute leukemia and biologically heterogeneous diseases with poor prognosis. Thus, we aimed to identify prognostic markers to effectively predict the prognosis of AML patients and eventually guide treatment.

METHODS

Prognosis-associated genes were determined by Kaplan-Meier and multivariate analyses using the expression and clinical data of 173 AML patients from The Cancer Genome Atlas database and validated in an independent Oregon Health and Science University dataset. A prognostic risk score was computed based on a linear combination of 5-gene expression levels using the regression coefficients derived from the multivariate logistic regression model. The classification of AML was established by unsupervised hierarchical clustering of CALCRL, DOCK1, PLA2G4A, FCHO2 and LRCH4 expression levels.

RESULTS

High FCHO2 and LRCH4 expression was related to decreased mortality. While high CALCRL, DOCK1, PLA2G4A expression was associated with increased mortality. The risk score was predictive of increased mortality rate in AML patients. Hierarchical clustering analysis of the five genes discovered three clusters of AML patients. The cluster1 AML patients were associated with lower cytogenetics risk than cluster2 or 3 patients, and better prognosis than cluster3 patients (P values < 0.05 for all cases, fisher exact test or log-rank test).

CONCLUSION

The gene panel comprising CALCRL, DOCK1, PLA2G4A, FCHO2 and LRCH4 as well as the risk score may offer novel prognostic biomarkers and classification of AML patients to significantly improve outcome prediction.

Comparison of efficacy of HCAG and CAG re-induction chemotherapy in elderly low- and intermediate-risk group patients diagnosed with acute myeloid leukemia

PURPOSE

The present study aimed to investigate the efficacy and severity of adverse effects of HCAG and CAG re-induction chemotherapy in elderly low- and intermediate-risk group patients diagnosed with acute myeloid leukemia (AML) following induction failure.

METHODS

A total of 94 AML patients were enrolled in the study, of whom 46 were treated with HCAG chemotherapy, while 48 were treated with CAG chemotherapy.

RESULT

The complete remission (CR) was 39.6% in the patients with HCAG, while the CR was 33.3% in the CAG group. The overall remission (ORR) was 63.0% and 43.5% in patients of the HCAG and CAG groups, respectively (P = 0.038). The median survival time of progression free survival (PFS) was 8.0 (95% CI 3.843-10.157) months in the HCAG group and 7.0 (95% CI 2.682-13.318) months in the CAG group (P = 0.032). A total of 31 patients in the HCAG group suffered from grade 4 hematological toxicity, whereas 29 patients were treated with CAG (P = 0.622). A total of 27 (58.7%) cases indicated apparent pulmonary infection in the HCAG group, while 25 (52.1%) were noted with this complication in the CAG group (P = 0.519). Oral cavity toxicity was evident for 13 (28.3%) and 11 (23.0%) cases in the HCAG and CAG groups, respectively (P = 0.216).

CONCLUSION

The HCAG regimen was more effective than the CAG regimen in elderly low- and intermediate-risk group patients diagnosed with acute myeloid leukemia although the HCAG regimen exhibited similar toxicity with that of the CAG group.

0718 Hypoxemia and Pulmonary Hypertension in Patients with Concomitant Restrictive Ventilatory Defect and Sleep Apnea: The Overlap Syndrome

Introduction

Patients with severe restrictive ventilatory defect (RVD) have hypoxemia and a high risk of pulmonary hypertension (PHTN). Sleep apnea (SA) aggravates the severity of nocturnal desaturation significantly. The aim of this study was to investigate the severity of hypoxemia and prevalence of PHTN in patient with the overlap syndrome (OS) of RVD and SA.

Methods

Patients referred for both sleep test and spirometry for suspected SA and RVD or obstructive ventilatory defect (OVD) were recruited prospectively from January-December, 2018. SA was determined by an apnea-hypopnea index ≥5/h; mean nocturnal oxygen saturation (meanSaO2), minimum oxygen saturation (minSaO2), saturation lower than 90% (T90) were calculated automatically. RVD was diagnosed in the presence of forced expiratory volume in the first second/forced vital capacity (FVC) &gt;0.7 and FVC&lt;80% predicted value. PHTN was defined by systolic pulmonary arterial pressure (SPAP) ≥ 50mmHg, documented by noninvasive transthoracic echocardiography. Patients with PHTN secondary to extrapulmonary factors were excluded.

Results

Of 65 patients who completed the investigation, 16 (24.6%) subjects were diagnosed with isolated SA (without RVD or OVD), and 28 (43.1%) subjects were verified to have RVD, in which 22 (78.6%) were diagnosed with OS and 6 (21.4%) presented as isolated RVD. Patients with OS vs. those with isolated RVD had lower minSaO2 (78.3% vs. 88.7%, p=0.003) and meanSaO2 (91.5% vs. 95.8%, p=0.007) but higher T90 (37.2% vs. 0.3%, p=0.009). Patients with OS vs. those with isolated RVD or with isolated SA had higher SPAP (62.6 mmHg vs. 45.3 mmHg or 35.9 mmHg, p=0.334 or p=0.016 respectively). Higher proportion of patients with OS were diagnosed with PHTN than those with isolated RVD or isolated SA (8 [36.4%] vs. 1 [16%] or 1 [6.25%], p=0.360 or p=0.031, respectively). T90 was the only polysomnographic data associated with the prevalence of PHTN after adjusting for age and sex (OR 4.90, 95% CI 1.23-25.56, p=0.023).

Conclusion

Patients with the OS of RVD and SA had high odds of PHTN, which is probably associated with severe hypoxemia. Further investigation is needed to discern whether therapeutic strategies toward OS might eliminate PHTN in this cohort.

Support

 

0061 Does Combining M1 M2 Reference Influence Amplitude of Slow Waves?

Introduction

Slow wave amplitudes are critical to determining Stage N3 sleep yet ECG artifact frequently interferes with accurate amplitude measurement. This artifact may be lessened by using a combined M1-M2 reference however theoretically this may decrease the amplitude due to shorter inter-electrode distance (predicted 27% loss). The AASM Scoring Manual recommends scoring slow wave activity using F4-M1 channel or alternatively F3-M2, but does not recognize a combined reference. This study measures the differences in slow wave amplitude using contralateral versus combine reference.

Methods

12 polysomnograms were randomly selected for analysis of amplitude of slow wave using contralateral and combined reference channels. Six separate EEG channels (F3-M1, F3-M2, F3-M1+M2, F4-M1, F4-M2, and F4-M1+M2) were used to analyze 25 different slow waves from each polysomnogram. Individual slow waves from Stage N3 sleep were analyzed using the Natus Sleepworks Amplitude Measurement Tool if their peak and trough were free EKG artifact. Averages and standard deviations of the waveforms were calculated for each patient and channel. Differences were normalized by dividing by the amplitude of the original wave using the contralateral reference.

Results

Subjects age ranged from 30–69 yrs, with 6 being females. Mean amplitudes were as follows: F3-M2 was 131.75µV, F3-M1+M2 125.84 µV, F4-M1 130.57 µV, and F4-M1+M2 128.22µV. The overall average difference of F4-M1 to F4-M1+M2 was 0.92% and the average difference of F3-M2 to F3-M1+M2 was 3.52% with the average standard deviation of 8.47%.

Conclusion

This study shows the average loss in amplitude of converting F4-M1 to F4-M1+M2 was less than 1% and 3.5% for F3-M2 to F3-M1+M2. Combining M1M2 reference may be a valuable alternative to reduce EKG artifact.

Support

None

[Specifications for diagnosis and treatment of non-neonatal tetanus]

Tetanus consists of neonatal tetanus and non-neonatal tetanus. Non-neonatal tetanus remains a serious public health problem, although neonatal tetanus has been eliminated in China since 2012. Non-neonatal tetanus is a potential fatal disease. In the absence of medical intervention, the mortality rate of severe cases is almost 100%. Even with vigorous treatment, the mortality rate is still 30%-50% globally. These specifications aim to regulate non-neonatal tetanus diagnosis and treatment in China, in order to improve medical quality and safety. These specifications introduce the etiology, epidemiology, pathogenesis, clinical manifestations and laboratory tests, diagnosis, differential diagnosis, grading and treatment of non-neonatal tetanus.

134 Generation of NANOS2 knockout goats using CRISPR/Cas9 and somatic cell nuclear transfer techniques

The NANOS2 gene, encoding an RNA binding protein, is known to play a critical role in the development of germline for all organisms studied to date. The male mice with biallelic NANOS2 knockouts (KOs) are sterile due to apoptosis of prospermatogonia shortly after birth but with morphologically intact seminiferous tubules. Thus, the choice of NANOS2 for targeting could be a viable strategy to develop germline ablated males that would serve as recipients for exogenous spermatogonial stem cell transplantation. The goat is a potential model of human physiology and an agriculturally important species. Here, we report successful generation of NANOS2 KO goats using CRISPR/Cas9 and somatic cell nuclear transfer (SCNT) techniques. We first designed 4 single-guide RNAs (sgRNAs) specific for the single exon of goat NANOS2 (GenBank: NC_030825.1). The targeting vectors were constructed by using the pX330 plasmid (Addgene: 42230) and transfected into sheep fetal fibroblasts. Mutation efficiency analysis showed that 3 of them (out of 4, 75.0%) were efficient in directing Cas9 to generate targeted cleavages, with mutation efficiencies of 10-30%. We established single cell-derived fetal fibroblast colonies by limiting dilution of the cells transfected with one of targeting vectors (sgRNA: GCTGGAGACCCAAGGGACTG). Colony screening with PCR/restriction fragment length polymorphism (RFLP) assays confirmed that we achieved biallelic mutations in the targeting site in 6 of 89 (6.7%) male and 6 of 172 (3.5%) female colonies. Sanger sequencing analysis of genomic DNA isolated from cell colonies with biallelic mutations showed that typical nucleotide deletions and insertions (indels), caused by repairing double-strand DNA breaks during the error-prone non-homologous end joining (NHEJ) process, were generated at the targeting site of NANOS2. Three male and two female colonies with NANOS2 null mutations were identified and used as cell donors for SCNT. In total, 202 cloned 1-cell stage embryos (130 male or 72 female) were generated and surgically transferred into 12 synchronized recipients. Six of them (6 of 12, 50.0%) were confirmed pregnant by ultrasonography on Day 40-45 of gestation. Four pregnancies developed to term, resulting in six offspring (five males and one female). Sequence analysis and PCR/RFLP assays showed that both male and female offspring carried the mutations in NANOS2, which were identical to the donor colonies from which they originated. Our results indicated that CRISPR/Cas9 combined with SCNT is an efficient system for generating NANOS2 KO goats. The phenotypic analysis to assess the effects of NANOS2 KO on the development of germline in male cloned goats is in progress.

132 Introduction of F508del human mutation into the CFTR gene of sheep fetal fibroblasts using CRISPR/Cas9 ribonucleoprotein

Cystic fibrosis (CF) is an autosomal recessive genetic disease that affects over 30 000 people in the United States and is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. The CFTR protein is a cAMP-regulated C− channel responsible for regulation of anion transport, primarily in the epithelial cells. We have previously generated a sheep model of CF by genetically inactivating the CFTR gene (Fan et al. 2018 JCI Insight 3, e123529). The newborn CFTR −/− sheep develops severe disease consistent with CF pathology in humans. The CF model is extremely valuable for understanding the developmental aspects of CF disease, as sheep have been used extensively in the study of human fetal growth and development. Sheep, like humans, typically give birth to only one or two offspring in each pregnancy, which make them more suitable than many other species for testing prenatal gene-editing treatments. Thus, in this new study, we are working on the generation of F508del sheep CF model. The F508del mutation was chosen because it is the most common mutation in the human CFTR gene (~70%). This mutation is characterised by the deletion of the CTT nucleotides, which ultimately deletes the phenylalanine residue at position 508. The F508del mutation causes misfolding of the CFTR protein, which is further degraded by proteases. Even though several CFTR modulators are available, they are not effective in all patients. Additionally, they cannot reverse deleterious prenatal CF manifestations. Hence, this model will be valuable for evaluating both prenatal drug and gene therapies. Here, we used a CRISPR/Cas9 gene-editing approach to introduce the F508del mutation into the sheep genome. We designed an sgRNA targeting exon 11 of the sheep CFTR gene using the Benchling software (https://benchling.com/academic). The sgRNA was synthesised by Synthego and Cas9 purchased from ThermoFisher. Using the Lonza-4D-Nucleofector system, Cas9/sgRNA ribonucleoprotein complex was transfected into sheep fetal fibroblasts (SFFs), along with 100bp single-stranded oligodeoxynucleotide, flanking the F508del mutation, for the homology-directed repair. The transfected cells were subsequently cultured in Dulbecco's modified Eagle's medium, supplemented with 15% fetal bovine serum and 1% penicillin, and incubated at 38.5°C. Two days post-transfection, SFFs were seeded individually into five 96-well plates by limited dilution. After seven days, the individual colonies were expanded into 24-well plates and cultured for three more days. A total of 56 single-cell-derived SFF colonies were isolated. The presence of F508del mutation was confirmed by amplifying the PCR products of the exon 11 flanking the mutation site and subjecting each amplicon to Sanger sequencing. The sequencing results indicated that the indels (insertion/deletion) were introduced in 49 out of 56 (87.5%) of the colonies, and four (7.14%) of them were confirmed to have biallelic F508del mutations based on sequencing peaks. Therefore, we successfully introduced the F508del mutation in SFFs that will be used for the production of F508del CF sheep by somatic cell nuclear transfer.

[Specifications for diagnosis and treatment of non-neonatal tetanus]

Tetanus consists of neonatal tetanus and non-neonatal tetanus. Although neonatal tetanus in China has been eliminated since 2012, non-neonatal tetanus remains a serious public health problem. Non-neonatal tetanus is a potential fatal disease, and the mortality rate of severe cases is almost 100% in the absence of medical intervention. Even with vigorous treatment, the mortality rate is still 30~50% globally. In order to standardize the diagnosis and treatment of non-neonatal tetanus in China, this specification is hereby formulated. This standard includes etiology, epidemiology, pathogenesis, clinical manifestations, laboratory tests, diagnosis, differential diagnosis, classification, grading and treatment of non-neonatal tetanus.