[Establishment of leukemia cell model with inducible AML1-ETO expression and its effect on fatty acid metabolism in leukemia cells]

Objective: To investigate the effect of the AML1-ETO (AE) fusion gene on the biological function of U937 leukemia cells by establishing a leukemia cell model that induces AE fusion gene expression. Methods: The doxycycline (Dox) -dependent expression of the AE fusion gene in the U937 cell line (U937-AE) were established using a lentivirus vector system. The Cell Counting Kit 8 methods, including the PI and sidanilide induction, were used to detect cell proliferation, cell cycle-induced differentiation assays, respectively. The effect of the AE fusion gene on the biological function of U937-AE cells was preliminarily explored using transcriptome sequencing and metabonomic sequencing. Results: ①The Dox-dependent Tet-on regulatory system was successfully constructed to regulate the stable AE fusion gene expression in U937-AE cells. ②Cell proliferation slowed down and the cell proliferation rate with AE expression (3.47±0.07) was lower than AE non-expression (3.86 ± 0.05) after inducing the AE fusion gene expression for 24 h (P<0.05). The proportion of cells in the G(0)/G(1) phase in the cell cycle increased, with AE expression [ (63.45±3.10) %) ] was higher than AE non-expression [ (41.36± 9.56) %] (P<0.05). The proportion of cells expressing CD13 and CD14 decreased with the expression of AE. The AE negative group is significantly higher than the AE positive group (P<0.05). ③The enrichment analysis of the transcriptome sequencing gene set revealed significantly enriched quiescence, nuclear factor kappa-light-chain-enhancer of activated B cells, interferon-α/γ, and other inflammatory response and immune regulation signals after AE expression. ④Disorder of fatty acid metabolism of U937-AE cells occurred under the influence of AE. The concentration of the medium and short-chain fatty acid acylcarnitine metabolites decreased in cells with AE expressing, propionyl L-carnitine, wherein those with AE expression (0.46±0.13) were lower than those with AE non-expression (1.00±0.27) (P<0.05). The metabolite concentration of some long-chain fatty acid acylcarnitine increased in cells with AE expressing tetradecanoyl carnitine, wherein those with AE expression (1.26±0.01) were higher than those with AE non-expression (1.00±0.05) (P<0.05) . Conclusion: This study successfully established a leukemia cell model that can induce AE expression. The AE expression blocked the cell cycle and inhibited cell differentiation. The gene sets related to the inflammatory reactions was significantly enriched in U937-AE cells that express AE, and fatty acid metabolism was disordered.

Constraints on Sub-GeV Dark Matter-Electron Scattering from the CDEX-10 Experiment

We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4  kg·day dataset from the CDEX-10 experiment. Using a novel calculation technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80  MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90  MeV/c^{2} with heavy mediators and m_{χ} larger than 100  MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.

Exotic Dark Matter Search with the CDEX-10 Experiment at China's Jinping Underground Laboratory

A search for exotic dark matter (DM) in the sub-GeV mass range has been conducted using 205 kg day data taken from a p-type point contact germanium detector of the CDEX-10 experiment at China's Jinping underground laboratory. New low-mass dark matter searching channels, neutral current fermionic DM absorption (χ+A→ν+A) and DM-nucleus 3→2 scattering (χ+χ+A→ϕ+A), have been analyzed with an energy threshold of 160 eVee. No significant signal was found; thus new limits on the DM-nucleon interaction cross section are set for both models at the sub-GeV DM mass region. A cross section limit for the fermionic DM absorption is set to be 2.5×10^{-46}  cm^{2} (90% C.L.) at DM mass of 10  MeV/c^{2}. For the DM-nucleus 3→2 scattering scenario, limits are extended to DM mass of 5 and 14  MeV/c^{2} for the massless dark photon and bound DM final state, respectively.

[A real-world study of sofosbuvir-based drug treatment for hepatitis C virus genotype 6 infection in Hainan region of China]

Objective: To explore the real-world effectiveness and safety of sofosbuvir-based regimen for patients with chronic hepatitis C virus (HCV) genotype 6 infection in Hainan Island. Methods: Fifty-three cases with chronic hepatitis C virus (HCV) genotype 6 infection who were initially treated with a sofosbuvir (SOF)-based regimen [sofosbuvir/velpatasvir (SOF/VEL) for 12 weeks or sofosbuvir combined with ribavirin (SOF+RBV) for 24 weeks], followed by 24 weeks of follow-up after discontinuation of the drug from January 2018 to March 2020 were selected. The primary outcome measures were incidence of sustained virological response at 12 weeks (SVR12) after the drug withdrawal. The secondary outcome measures were adverse drug events with sustained virological response at the end of treatment and 24 weeks after the end of treatment. The occurrence of adverse events was observed during the treatment. An intragroup comparison was performed by t-test. Intention-to-treat and modified intention-to-treat analysis was used for sustained virological respons. Results: The subtype distribution of chronic hepatitis C virus (HCV) genotype 6 in 53 cases of chronic hepatitis C infection were as follows: 22 cases of type 6a, 5 cases of type 6w, 5 cases of type 6xa, 3 cases of type 6v, 2 cases of type 6e, 2 cases of type 6r, 1 case of type 6xh, and 13 cases of special virus strains with undetermined genotype. The overall sustained virological response rate at 12 weeks after the drug withdrawal was 100%. Furthermore, HCV RNA was undetectable during the treatment period (4 weeks), at the end of treatment and after the treatment (24 weeks). There were seven cases of adverse events, mainly including fatigue, anorexia, and mild anemia; however, no serious adverse events were reported. Conclusion: Sofosbuvir-based regimen combined with ribavirin or velpatasvir cannot only achieve high response rate to HCV subtype 6a, but also obtain a good sustained virological response to the rare prevalent sub-genotypes and special virus strains of HCV genotype 6, with mild adverse reactions and acceptable safety profile.

[Preparation of a novel tri-specific T cell engager targeting CD19 antigen and its anti-leukemia effect exploration]

Objective: To prepare a novel tri-specific T cell engager (19TriTE) targeting CD19 antigen, and to investigate its immunotherapeutic effect on CD19-positive hematological malignancies. Methods: 19TriTE was constructed by molecular cloning technology and successfully expressed through the eukaryotic expressing system. The effects of 19TriTE on the proliferation and activation of T cells, as well as the specific cytotoxicity against CD19 positive tumor cell lines were verified. Results: ①19TriTE expressing plasmid was constructed and successfully expressed through the eukaryotic expressing system. ②19TriTE can specifically bind to T cells and Nalm6 cells, with equilibrium dissociation constants of 19.21 nmol/L and 11.67 nmol/L, respectively. ③The expression rates of CD69 positive T cells and CD25 positive T cells were 35.4% and 49.8% respectively, when 2 nmol/L 19TriTE were added in the co-culture system, which were significantly higher than those in the control group. ④19TriTE can significantly promote the proliferation of T cells. The absolute count of T cells expanded from the initial one million to 74 million with an 74 fold increase at the concentration of 1 nmol/L on day 12. ⑤19TriTE can significantly mediate T cells killing of CD19 positive target cells in a dose-dependent manner. At the concentration of 10 nmol/L, the target cells lysis reached 50%. ⑥Degranulation experiment verified that 19TriTE can activate T cells in the presence of CD19 positive target cells, and the activation of T cells positively correlated with the dose of 19TriTE. ⑦When 19TriTE fusion protein co-cultured with T cells and target cells overexpression RFP and luciferase genes respectively, 19TriTE can notably mediate T cells killing of CD19 positive target cells through fluorescent microscope or bioluminescence imaging technology. Conclusion: In this study, we successfully constructed and expressed 19TriTE fusion protein and verified that it can effectively activate T cells and promote their proliferation in vitro. At the same time, it can bind to CD19 positive target cells and T cells, as well as enhance T cells anti-leukemia effect in vitro, providing the foundation for further clinical research.

[CD19 antigen loss after treatment of Bispecific T-cell Engager and effective response to salvage bispecific CAR-T therapy in B cell acute lymphoblastic leukemia: a case report and literature review]

Objective: To analyze the influence of CD19 isoforms to the efficacy of CD19/CD3 Bispecific T-cell Engager (BiTE) antibody, and explore the resistance mechanism of BiTE immunotherapy. Methods: Semi-quantitative RT-PCR (qRT-PCR) was used to detect the expression of CD19 mRNA isoforms before and after BiTE treatment in a patient with CD19(+) B cell acute lymphoblastic leukemia (ALL) . CD19 isoforms were analyzed by Sanger sequencing. Flow cytometry and transcriptome sequencing were performed to analyze the expression of cell lineage specific molecules before and after BiTE treatment. Results: The expression of CD19 isoform with exon 2 deletion was identified at diagnosis. After relapsed and treatment of BiTE antibody, the patient did not achieve remission and CD19 antigen on leukemic cells turned negative detected by flow cytometry after BiTE treatment. However the expression ratio of CD19 isoform with exon 2 deletion was not increased. Flow cytometry phenotype and transcriptome sequencing confirmed that no linage switching developed, which suggested the expression of CD19 isoform caused by exon alternative splicing and lineage switching was not related to CD19 epitope loss in this patient. This patient achieved complete remission by sequential administration of self-developed CD22 CAR-T and CD19 CAR-T after disease progression. Conclusion: Targeting or combining an alternative antigen specific CAR-T may be a promising treatment option after losing CD19 expression in relapsed ALL.

[Construction of a new anti-CD123 chimeric antigen receptor T cells and effect of anti-acute myeloid leukemia]

目的

构建一种新的靶向CD123的嵌合抗原受体T细胞(CAR-T细胞)，为CD123阳性白血病的免疫治疗提供实验参考。

方法

通过单克隆筛选技术获得能稳定分泌CD123抗体的杂交瘤细胞株6E11，将杂交瘤细胞扩增后腹腔注射至Balb/c小鼠腹腔内，收集腹水并处理、纯化得到单克隆抗体，测定抗体效价并对其特异性进行验证；RT-PCR法获得轻链和重链可变区序列，并以此为基础利用分子克隆技术构建一种新的靶向CD123嵌合抗原受体，包装病毒后感染T细胞制备CD123CAR-T细胞，通过功能实验初步探讨6E11CAR-T细胞体外抗白血病的能力。

结果

①获得1株稳定分泌抗人CD123抗体的杂交瘤细胞株6E11并获得其可变区序列。②6E11单克隆抗体对CD123蛋白亲和性高，解离常数(K_d值)为2.10nmol/L，特异性识别CD123阳性细胞且与CD123阴性细胞无交叉反应。 ③成功构建了CD123CAR慢病毒载体，感染T细胞后获得了靶向CD123的CAR-T细胞(6E11CAR-T)，感染效率大于60％。 ④6E11CAR-T能明显杀伤CD123阳性靶细胞MV4-11，效靶比1∶1时6E11CAR-T细胞对MV4-11细胞的杀伤比例明显高于 Vecor-T细胞[(98.60±1.20)％对(20.28±6.74)％，P<0.001]，但对CD123阴性靶细胞K562没有明显杀伤作用。 ⑤MV4-11细胞可以显著激活6E11CAR-T，但对Vecor-T细胞无明显激活作用[(26.33±3.30)％对(1.17±0.06)％，P<0.001]。⑥6E11CAR-T与MV4-11细胞共培养上清中细胞因子水平均显著高于Vecor-T组[IL-2：(92.90±1.51)pg/ml对(6.05±3.41)pg/ml，P<0.001；TNF-α：(1 407.20±91.95)pg/ml对(7.86±0.85)pg/ml，P<0.001；IFN-γ：(5 614.60±170.17)pg/ml对(8.42±2.70)pg/ml，P<0.001]但与 K562细胞共培养后，两组各细胞因子水平差异无统计学意义。 ⑦6E11CAR-T在与CD123阳性髓系白血病(AML)原代细胞共培养过程中被显著激活，且能有效杀伤原代 AML细胞。

结论

杂交瘤细胞株6E11能稳定分泌高效特异的抗人CD123单克隆抗体，可用于检测表达人CD123的细胞，也能应用在靶向人CD123蛋白的肿瘤免疫治疗中，以 6E11Ig可变区序列为抗原识别区的CD123CAR-T细胞，具有明确的体外抗白血病活性，为进一步的临床研究奠定了基础。

Direct Detection Constraints on Dark Photons with the CDEX-10 Experiment at the China Jinping Underground Laboratory

We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m_{V}) from 10 to 300  eV/c^{2} in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m_{V} from 0.1 to 4.0  keV/c^{2} are set from 449.6 kg-day data, with a minimum of κ=1.3×10^{-15} at m_{V}=200  eV/c^{2}.

Search for Light Weakly-Interacting-Massive-Particle Dark Matter by Annual Modulation Analysis with a Point-Contact Germanium Detector at the China Jinping Underground Laboratory

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6  GeV/c^{2} among WIMP AM measurements to date.

Constraints on Spin-Independent Nucleus Scattering with sub-GeV Weakly Interacting Massive Particle Dark Matter from the CDEX-1B Experiment at the China Jinping Underground Laboratory

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35}  cm^{2} for TI analysis at m_{χ}∼50-180  MeV/c^{2}, and 3×10^{-32}∼9×10^{-38}  cm^{2} for AM analysis at m_{χ}∼75  MeV/c^{2}-3.0  GeV/c^{2}.

Limits on Light Weakly Interacting Massive Particles from the First 102.8 kg×day Data of the CDEX-10 Experiment

We report the first results of a light weakly interacting massive particles (WIMPs) search from the CDEX-10 experiment with a 10 kg germanium detector array immersed in liquid nitrogen at the China Jinping Underground Laboratory with a physics data size of 102.8 kg day. At an analysis threshold of 160 eVee, improved limits of 8×10^{-42} and 3×10^{-36}  cm^{2} at a 90% confidence level on spin-independent and spin-dependent WIMP-nucleon cross sections, respectively, at a WIMP mass (m_{χ}) of 5  GeV/c^{2} are achieved. The lower reach of m_{χ} is extended to 2  GeV/c^{2}.

[The bacteriologic features of recurrent acute rhinosinusitis]

Objective:To investigate the bacteriologic characteristics of recurrent acute rhinosinusitis(RAR).Method:Twenty-nine patients (29 with RAR) from outpatient clinic in our hospital between June 2010 and May 2016 were enrolled in the study. Specimens of the middle meatus or olfactory cleft area using the sinus endoscopy through were transported to the laboratory for bacterial culture.Result:Twenty-five specimens out of 29 were bacterial culture positive (culture positive rate was 86.2%).A total of 32 isolates (25 aerobic or facultative and 7 anaerobic) were recovered from the 29 cases of RAR. The predominant aerobic or facultative bacteria were Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus. The predominant anaerobic bacteria were Bacteroides fragilis and Propionibacterium. Antibiotic susceptibility tests showed that the resistance rate of these aerobic or facultative bacteria to Macrolides (Erythromycin and Azithromycin) and quinolones (Levofloxacin) was 88% and 92%, respectively. Similarly, the resistance rate of bacteria to β-lactamase antibiotics (penicillin, ampicillin, and cefazolin) was also greater than 90% (100%, 92%, and 92%, respectively). But the drug resistance of these bacteria to the thirdgeneration cephalosporin combined with beta lactamase inhibitors (Cefoperazone/sulbactam) was 20%. Among the 7 strains of anaerobic bacteria, 6 strains were sensitive to ornidazole.Conclusion:The major pathogens of RAR are the aerobic and facultative bacteria Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Staphylococcus aureus, most of which are resistant to commonly used antibiotics.

Genome-wide comparison of AP2/ERF superfamily genes between Gossypium arboreum and G. raimondii

The APETALA2/ethylene response factor (AP2/ERF) transcription factor superfamily is known to regulate diverse processes of plant development and stress responses. We conducted a genome-wide analysis of the AP2/ERF gene in Gossypium arboreum and G. raimondii. Using RPSBLAST and HMMsearch, a total of 271 and 269 AP2/ERF genes were identified in the G. arboreum and G. raimondii genomes, respectively. A phylogenetic analysis classified diploid Gossypium spp AP2/ERF genes into 4 families and 16 subfamilies. Orthologous genes predominated the terminal branch of the phylogenetic tree. Physical mapping showed at least 30% of AP2/ERF genes clustered together. A high level of intra- and inter-species collinearity involving AP2/ERF genes was observed, indicating common (before species divergence) or parallel (after species divergence) segmental duplications, along with tandem duplications, resulting in the species-specific expansion of AP2/ERF genes in diploid Gossypium species. Motif analyses of the AP2/ERF proteins revealed that motif arrangements were highly diverse among subfamilies, but shared by orthologous gene pairs. An examination of nucleotide divergence of AP2/ERF coding regions identified small and non-significant sequence differences among orthologs. Expression profiling of AP2/ERF orthologous gene pairs showed similar abundance levels of orthologous copies between G. arboreum and G. raimondii. Thus, cotton species possess abundant and diverse AP2/ERF genes, resulting from tandem and segmental duplications. Protein and nucleotide sequence and mRNA expression analyses revealed symmetrical evolution, indicating that most AP2/ ERF genes may not have undergone significant biochemical and morphological divergence between sister species. Our study provides detailed insights into the evolutionary characteristics and functional importance of AP2/ERF genes, and could aid in the genetic improvement of agriculturally significant crops in this genus.

Identification and analysis of the TIFY gene family in Gossypium raimondii

The highly conserved TIFY domain is included in the TIFY protein family of transcription factors, which is important in plant development. Here, 28 TIFY family genes were identified in the Gossypium raimondii genome and classified into JAZ (15 genes), ZML (8), PPD (3), and TIFY (2). The normal (TIF[F/Y]XG) motif was dominant in the TIFY family, excluding the ZML subfamily, in which TLSFXG was prevalent. TIFY family genes were unevenly distributed in the G. raimondii genome, with TIFY clusters present on chromosome 9. Phylogenetic analysis indicated abundant variations in the G. raimondii TIFY family, which were most closely related to those in Theobroma cacao among 5 species. Exon-intron organization and intron phases were homologous within each subfamily, correlating with their phylogeny. Intra-species synteny analyses indicated that genomic duplication contributed to the expansion of the TIFY family. Inter-species synteny analyses indicated that synteny regions involved in G. raimondii TIFY family genes were also present in the comparison of G. raimondii vs Arabidopsis thaliana or T. cacao, signifying that these genes had common ancestors and play the same or similar roles in biological processes. Greater synteny was present in the comparison of G. raimondii vs T. cacao than of G. raimondii vs A. thaliana. The expression patterns of TIFY family genes were characterized and most TIFY family genes were indicated to be involved in fiber development. Our study provides new data related to the evolution of TIFYs and their role as important regulators of transcription; these data can be useful for fiber development.

Fabrication and Evaluation of Curcumin-loaded Nanoparticles Based on Solid Lipid as a New Type of Colloidal Drug Delivery System

Curcumin has very broad spectrum of biological activities; however, photodegradation, short half-life and low bioavailability have limited its clinical application. Curcumin-loaded solid lipid nanoparticles were studied to overcome these problems. The aim of this study was to optimize the best formulation on curcumin-loaded solid lipid nanoparticles. Emulsion-evaporation and low temperature-solidification technique was applied with monostearin as lipid carriers. The single factor analysis and orthogonal design were used to optimize formulation and various parameters were investigate. By the optimisation of a single factor analysis and orthogonal test, the particles size, polydispersity index, zeta potential, encapsulation efficiency and drug loading capacity of the optimised formulation were 99.99 nm, 0.158, -19.9 mV, 97.86%, and 4.35%, respectively. The differential scanning calorimetry and X-ray diffraction analysis results demonstrated new structure was formed in nanoparticles. The release kinetics in vitro demonstrated curcumin-loaded solid lipid nanoparticles can control drug release. These studies confirmed that curcumin-loaded solid lipid nanoparticles could be prepared successfully with high drug entrapment efficiency and loading capacity. Curcumin-loaded solid lipid nanoparticles may be a promising drug delivery system to control drug release and improve bioavailability.

Enhanced disease resistance conferred by expression of an antimicrobial magainin analog in transgenic tobacco

Magainins are a group of short peptides originally isolated from frog skin and thought to function as a natural defense mechanism against infection due to their antimicrobial properties. The engineered magainin analog peptide Myp30 was found to inhibit spore germination of the oomycete, Peronospora tabacina (Adam) in vitro, and the growth of a bacterial pathogen Erwinia carotovora subsp. carotovora (Jones). Transgenic tobacco (Nicotiana tabacum L.) plants expressing Myp30 were evaluated for resistance to these pathogens. The expression of the peptide only to an extracellular location resulted in significant reduction in sporulation and lesion size due to P. tabacina infection. A significant increase in resistance to the bacterial pathogen was also observed regardless of the targeting location of the peptide.

Endotoxin-induced defenestration of the hepatic sinusoidal endothelium: a factor in the pathogenesis of cirrhosis?

Defenestration and capillarisation of the hepatic sinusoidal endothelium occurs early in the pathogenesis of cirrhosis, both in patients suffering from alcohol abuse and in animal models. It is possible also that alcohol abuse promotes the absorption of bacterial endotoxins from the gastrointestinal tract. In this study we have investigated the effects of a single intravenous injection of endotoxin on the hepatic sinusoidal endothelium of rats. Seven days after the dose of endotoxin, the porosity of the sinusoidal endothelium was reduced to 40% of that of controls, due to a decrease in both diameter and number of fenestrae. The livers examined 14 days after dosing exhibited normal porosity. We postulate that bacterial endotoxins play a role in the pathogenesis of cirrhosis by modulating the fenestrated sinusoidal endothelium (liver sieve).