[Analysis of DMD gene variants in a single center]

Objective: To investigate the DMD genetic variants of the Chinese population with Duchenne (DMD) and Becker muscular dystrophies (BMD). Methods: A cross-sectional study was conducted on 2 690 unrelated patients with DMD and BMD aged 0-18 who visited the Genetic and Prenatal Diagnosis Center of the First Affiliated Hospital of Zhengzhou University from January 2005 to February 2022. The clinical data, such as gender, age, clinical manifestations, and address, were collected. Multiplex ligation-dependent probe amplification, next generation sequencing panel, Sanger sequencing, and PCR amplification were used to detect the variants of the DMD gene in the patients, whose clinical information and gene detection results were descriptively analyzed. Results: The 2 690 patients included 2 648 males and 42 females, with an age of 6.0 (4.0, 9.0) years. The serum creatine kinase increased in all patients. Pathogenic DMD gene variants were detected in the 2 618 patients, including 1 875 cases (71.6%) large deletions, 231 cases (8.8%) duplications, and 512 cases (19.6%) small variants. Among the deletion variants, the deletion of 3 exons was the most common, accounting for 15.4% (288/1 875); and hotspot deletion involved exons 45 to 50, accounting for 6.3% (119/1 875). Exon 2 was the most common type duplication region, accounting for 13.0% (30/231). Small variants were distributed in all 79 exons of the DMD gene, with no hotspots. In addition, the 46 small variants were previously unreported. Conclusion: Exon deletion is the most common type of DMD gene variant, followed by small variants and exon duplication.

Development of a real-time impedance matching system for ion cyclotron resonance heating in experimental advanced superconducting tokamak

To achieve stable operation of an ion cyclotron resonance heating (ICRH) system in the Experimental Advanced Superconducting Tokamak (EAST), a real-time impedance matching system needs to be established to respond to antenna load variation during long pulse discharges. A new impedance matching method based on capacitors was proposed in this study. By considering the reflected voltage of the transmission line as the feedback parameter, the real-time impedance-matching system can quickly control the motors based on a programmable logic controller to determine the minimum reflection voltage. A real-time impedance matching system was successfully used on the test platform in the laboratory and on the ICRH system in EAST. A significant result is that we can match the variable impedance within 1 s by suitably adjusting the motor controller to ensure high-power and long-pulse operation of the ICRH system to satisfy the requirements of the EAST experiment.

Siglec-15 Promotes Evasion of Adaptive Immunity in B-cell Acute Lymphoblastic Leukemia

Siglec-15 (Sig15) has been implicated as an immune checkpoint expressed in solid tumor-infiltrating macrophages and is being targeted in clinical trials with mAbs to normalize the tumor immune microenvironment and stimulate antitumor immunity. However, the role of Sig15 in hematologic malignancies remains undefined. Sig15 mRNA and protein expression levels in hematologic malignancies were determined from publicly available databases, cell lines, and primary patient samples. Human B-cell acute lymphoblastic leukemia (B-ALL) cell lines were used to identify signaling pathways involved in the regulation of Sig15 expression. Secreted/soluble Sig15 and cytokine levels were measured from the plasma of children with leukemia and healthy controls. Knockdown and knockout of Siglec15 in a murine model of B-ALL was used to evaluate the effect of leukemia-derived Sig15 on the immune response to leukemia. We observed pathologic overexpression of Sig15 in a variety of hematologic malignancies, including primary B-ALL samples. This overexpression was driven by NFκB activation, which also increased the surface localization of Sig15. Secreted/soluble Sig15 was found to circulate at elevated levels in the plasma of children with B-ALL and correlated with an immune-suppressive cytokine milieu. Genetic inhibition of Sig15 in murine B-ALL promoted clearance of the leukemia by the immune system and a marked reversal of the immune-privileged leukemia bone marrow niche, including expanded early effector CD8⁺ T cells and reduction of immunosuppressive cytokines. Thus, Sig15 is a novel, potent immunosuppressive molecule active in leukemia that may be targeted therapeutically to activate T lymphocytes against leukemia cells.

Significance

We demonstrate that Sig15 is overexpressed in hematologic malignancies driven by NFκB, is required for immune evasion in a mouse model of leukemia, and, for the first time, that it circulates at high levels in the plasma of children with leukemia.

[Relationship between plasma levels of thrombin activatable fibrinolysis inhibitor, plasminogen activator inhibitor-1 and tissue-type plasminogen activator and deep venous thrombosis in patients with systemic lupus erythematosus]

Objective: To investigate the plasma levels of thrombin activatable fibrinolysis inhibitor (TAFI), plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) in patients with systemic lupus erythematosus (SLE), and their relationship with deep venous thrombosis of the lower limbs. Methods: A case-control study was conducted to retrospectively select 32 SLE patients with deep venous thrombosis of the lower extremities (thrombus group) admitted to Liaocheng People's Hospital in Shandong Province from June 2018 to June 2021, including 4 males and 28 females, with a mean age of (49.7±5.5) years. Meanwhile, 64 SLE patients without deep venous thrombosis of the lower extremities (control group) were also selected, including 11 males and 53 females, with a mean age of (50.8±5.5) years. The plasma levels of TAFI, PAI-1 and t-PA of the two groups were compared. A logistic regression model was used to analyze the correlation of TAFI, PAI-1 and t-PA with SLE in patients. Results: The plasma levels of TAFI, PAI-1 and t-PA were (32.77±5.17) mg/L, (29.43±5.51) μg/L and (6.58±1.40) μg/L in the thrombotic group, while the plasma levels of TAFI, PAI-1 and t-PA in the control group were (23.56±4.40) mg/L, (19.00±4.40) μg/L and (9.40±2.23) μg/L. The levels of TAFI and PAI-1 in the thrombotic group were higher than those in the control group, while the level of t-PA was lower than that in the control group (all P<0.05). The results of logistic regression model showed that higher TAFI levels (OR=1.75, 95%CI: 1.05-2.90, P=0.043), higher PAI-1 levels (OR=1.85, 95%CI: 1.04-3.29, P=0.046), and lower t-PA levels (OR=0.72, 95%CI: 0.52-0.99, P=0.048) were related factors for the occurrence of deep venous thrombosis of the lower limbs in SLE patients. Conclusion: The plasma levels of TAFI and PAI-1 in SLE patients with deep venous thrombosis of the lower extremities increase, while the t-PA level decreases, which are related factors for the occurrence of deep venous thrombosis of the lower extremities in SLE patients.

Quantitative assessment of Siglec-15 expression in lung, breast, head, and neck squamous cell carcinoma and bladder cancer

Immune checkpoint blockade with programmed cell death (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors has resulted in significant progress in the treatment of various cancer types. However, not all patients respond to PD-1/PD-L1 blockade, underscoring the importance of identifying new potential targets for immunotherapy. One promising target is the immune system modulator Siglec-15. In this study, we assess Siglec-15 expression in solid tumors, with a focus on lung, breast, head and neck squamous and bladder cancers. Using quantitative immunofluorescence (QIF) with a previously validated antibody, we found increased Siglec-15 expression in both tumor and immune cells in all the four cancer types. Siglec-15 was seen to be predominantly expressed by the stromal immune cells (83% in lung, 70.1% in breast, 95.2% in head and neck squamous cell and 89% in bladder cancers). Considerable intra-tumoral heterogeneity was noted across cancer types. As previously described for non-small cell lung cancer (NSCLC), Siglec-15 expression was seen to be mutually exclusive to PD-L1 in all the four cancer types, although this differential expression was maintained but somewhat diminished in head and neck squamous cell carcinoma (HNSCC). Siglec-15 was not prognostic either for overall survival (OS) or progression-free survival (PFS). In summary, we show broad expression of this potential immune modulatory target in a wide range of cancer types. These data suggest potential future clinical trials in these tumor types.

[Expression of miR-17-5p in the plasma of patients with multiple myeloma and its role in tumorigenesis and development]

Objective: To investigate the expression of miR-17-5p in the plasma of patients with multiple myeloma (MM) and its role in tumorigenesis and development. Methods: Patients diagnosed with unidentified monoclonal gammopathy of undetermined significance (MGUS) or MM in Cancer Hospital of Zhengzhou University from April 2013 to April 2018 were enrolled, as well as 20 healthy volunteers. Reverse transcription polymerase chain reaction (qRT-PCR) was used to detect the expression levels of miR-17-5p in plasma circulation and bone marrow mononuclear cells. There were 22 cases with newly diagnosed MM (NDMM), 11 cases with complete remission MM (CRMM) and 59 case with recurrent refractory MM (RRMM). The expression levels of miR-17-5p in each group were analyzed. The correlation analysis was used to evaluate the relationship between plasma miR-17-5p and the proportion of serum M protein and bone marrow plasma cells in patients with untreated multiple myeloma. Receiver operating characteristic (ROC) curve was used to evaluate the possibility of plasma miR-17-5p as a molecular marker related to MM diagnosis. After over expression or knockdown of miR-17-5p expression, CCK-8 method was used to detect the effect of miR-17-5p on the proliferation of MM cell line. The effect of miR-17-5p on the proliferation of MM cells was detected in nude mice subcutaneous tumorigenesis experiment. Results: The expression of miR-17-5p in bone marrow mononuclear cells in NDMM and RRMM group were higher than those in healthy volunteers [1.37 (0.47, 4.87), 2.68 (1.02, 5.02) vs 1.00 (1.00, 1.00), all P<0.05], and the expression levels of miR-17-5p in plasma were also higher than those in healthy control group [1.85 (0.92, 3.51), 2.79 (1.22, 5.04) vs 1.00 (1.00, 1.00), all P<0.05]. The expression of miR-17-5p in MM cell lines such as KMS-11, RPMI-8226, H929, MM-1R, U266B1 were higher than that in bone marrow mononuclear cells of healthy control group (3.96±0.68, 1.58±0.32, 3.51±0.55, 5.08±0.76, 3.22±0.75 vs 1.00±0, all P<0.05) ; Plasma miR-17-5p was positively correlated with the ratio of serum M protein and bone marrow plasma cells (r=0.50, P<0.05; r=0.60, P<0.01). ROC curve showed that the specificity was 0.591 and the sensitivity was 0.900 of plasma miR-17-5p as a molecular marker related to diagnosis (area under ROC curve=0.74, cut-off value: 0.491). CCK-8 results showed that over expression of miR-17-5p increased the proliferation of RPMI-8226 and NCI-H929 cell lines at 72 hours compared with the control group (1.37±0.11 vs 1.07±0.09, 2.14±0.09 vs 1.82±0.11, both P<0.05), and low expression of miR-17-5p reduced the proliferation of NCI-H929 and MM-1R cell lines at 72 hours compared with the control group (1.38±0.09 vs 1.83±0.11, 1.45±0.10 vs 1.73±0.09, both P<0.05). The subcutaneous tumorigenesis experiment in nude mice showed that the tumor volume of miR-17-5p over expression group was larger than that of the control group [(1 865±181) vs (1 389±227) mm3, P<0.05], and the tumor volume of miR-17-5p low expression group was smaller than that of the control group [ (1 006±171) vs (1 389±227) mm3, P<0.05]. Conclusion: miR-17-5p may play an oncogene role in MM cell lines as a plasma molecular marker related to the development of MM disease.

Development of an immunohistochemical assay for Siglec-15

Siglec-15, a member of sialic-acid binding immunoglobulin type lectins, is normally expressed by myeloid cells and upregulated in some human cancers and represents a promising new target for immunotherapy. While PD-L1 blockade is an important strategy for immunotherapy, its effectiveness is limited. The expression of Siglec-15 has been demonstrated to be predominantly mutually exclusive to PD-L1 in certain cancer histologies. Thus, there is significant opportunity for Siglec-15 as an immunotherapeutic target for patients that do not respond to PD-1/PD-L1 inhibition. The aim of this study was to prospectively develop an immunohistochemical (IHC) assay for Siglec-15 to be used as a companion diagnostic for future clinical trials. Here, we create and validate an IHC assay with a novel recombinant antibody to the cytoplasmic domain of Siglec-15. To find an enriched target, this antibody was first used in a quantitative fluorescence (QIF) assay to screen a broad range of tumor histologies to determine tumor types where Siglec-15 demonstrated high expression. Based on this and previous data, we focused on development of a chromogenic IHC assay for lung cancer. Then we developed a scoring system for this assay that has high concordance amongst pathologist readers. We then use this chromogenic IHC assay to test the expression of Siglec-15 in two cohorts of NSCLC. We found that this assay shows a higher level of staining in both tumor and immune cells compared to previous QIF assays utilizing a polyclonal antibody. However, similar to that study, only a small percentage of positive Siglec-15 cases showed high expression for PD-L1. This validated assay for Siglec-15 expression may support development of a companion diagnostic assay to enrich for patients expressing the Siglec-15 target for therapy.

Impedance matching system using triple liquid stub tuners for high-power ion cyclotron resonance heating in EAST tokamak

Ion cyclotron resonance heating (ICRH), one of the main auxiliary methods, for high-power and long-pulse plasma heating had been developed in Experimental Advanced Superconducting Tokamak (EAST). An impedance matching system, one important part of ICRH, had been developed for high-power injection and transmitter protection by reducing the reflected power from the antenna. The input impedance in the outlet of the stub tuner can be measured by voltage-current probes installed on the coaxial transmission line between the antenna and triple liquid stub tuners, and the optimum liquid levels in the stub tuners can be calculated based on the input impedance. The calculation and adjustment process of the optimum liquid levels are described comprehensively in this article. Finally, impedance matching had been achieved between two shots during EAST experiments. In the near future, a real-time impedance matching system will be developed to prevent large variations of the ICRH antenna impedance and achieve steady-state and long-pulse operation with the ICRH system.

[The expression of clock gene CLOCK and its clinical significance in nasopharyngeal carcinoma]

Objective: To explore the relationship between expression levels of CLOCK mRNA and protein and the clinical characteristics of patients with nasopharyngeal carcinoma. Methods: The frozen tissue specimens from 33 patients with nasopharyngeal carcinoma in the Affiliated Tumor Hospital of Guizhou Medical University from 2018 to 2019 were collected. Seventeen cases of tissue specimens from patients with nasopharyngeal chronic inflammation in the Affiliated Hospital of Guizhou Medical University in 2019 were collected. From 2008 to 2014, 68 cases of formalin-fixed paraffin-embedding (FFPE) nasopharyngeal carcinoma tissue and 37 cases of FFPE nasopharyngeal chronic inflammation tissue were collected from the Affiliated Tumor Hospital of Guizhou Medical University. Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot (WB) were used to detect the mRNA and protein expression levels of CLOCK. The nasopharyngeal carcinoma cells including CNE1, CNE2, 5-8F and the normal nasopharyngeal epithelial cell NP69 were cultured. qRT-PCR was used to detect the expression level of CLOCK mRNA in each cell line at the time points of ZT2, ZT6, ZT10, ZT14, ZT18 and ZT22. The cosine method was used to fit the rhythm of CLOCK gene in nasopharyngeal carcinoma. The protein expression of CLOCK protein was detected by using immunohistochemical method in 68 cases of nasopharyngeal carcinoma and 37 cases of nasopharyngeal chronic inflammation tissue. Survival was analyzed by Kaplan-Meier method and Log rank test, and the influencing factors was analyzed by Cox regression model. Results: The expression levels of CLOCK mRNA in CNE1, CNE2 and 5-8F cells (0.63±0.07, 0.91±0.02 and 0.33±0.04, respectively) were lower than that in NP69 cell (1.00±0.00, P<0.05). The expression levels of CLOCK protein in CNE1, CNE2 and 5-8F cells (0.79±0.06, 0.57±0.05 and 0.74±0.10, respectively) were lower than that of NP69 cells (1.00±0.00, P<0.05). The expressions of CLOCK mRNA in nasopharyngeal carcinoma cells including CEN1, CNE2, 5-8F and normal nasopharyngeal epithelial cell NP69 were different at different time points, with temporal fluctuations. The fluctuation periods of CLOCK mRNA in CNE1, CNE2, 5-8F, and NP69 cells were 16, 14, 22 and 24 hours, respectively. The peak and trough times were ZT10: 40 and ZT18: 40, ZT10 and ZT3, ZT14: 30 and ZT3: 30, ZT12: 39 and ZT0: 39, respectively. CLOCK mRNA and protein expression levels in nasopharyngeal carcinoma tissues (0.37±0.20 and 0.20±0.26, respectively) were lower than those in nasopharyngeal chronic inflammation tissues (1.00±0.00 and 0.51±0.41, respectively, P<0.05). The 1, 3, and 5-year survival rates of patients in the CLOCK protein high expression group (CLOCK protein expression level ≥ 0.178) were 96.2%, 92.1%, and 80.1%, respectively, which were higher than those in the low expression group (CLOCK protein expression level <0.178, 92.9% , 78.6% and 57.1%, respectively, P=0.009). The 1, 3, and 5-year progression-free survival (PFS) rates of patients in the CLOCK protein high expression group were 96.2%, 87.8%, and 87.7%, respectively, which were higher than those in the low expression group (92.7%, 82.2%, and 70.8%, respectively, P=0.105). Compared with the low-expression group (100.0%, 96.9%, and 90.0%, respectively), the 1, 3, and 5-year recurrence-free survival rates of patients in the CLOCK protein high expression group (100.0%, 95.7%, and 95.7%, respectively) were not statistically significant (P=0.514). Compared with the low-expression group (92.7%, 82.2%, and 79.3%), the 1, 3, and 5-year survival rates without metastasis in the CLOCK protein high expression group (96.2%, 92.0%, and 92.0%, respectively) were not statistically significant (P=0.136). CLOCK protein expression and T stage were independent prognostic factors of overall survival (P<0.05). Conclusions: The expression of CLCOK is downregulated in the nasopharyngeal carcinoma cell and nasopharyngeal carcinoma tissues. Clock gene CLOCK is rhythmically expressed in the nasopharyngeal carcinoma cells and normal nasopharyngeal epithelial cells. Compared with normal nasopharyngeal epithelial cells, the fluctuation period of CLOCK in nasopharyngeal carcinoma cells is shortened. The overall survival of patients in the CLOCK protein high expression group is better than that of low expression group. The expression of CLOCK protein is an independent influencing factor for overall survival. CLOCK gene may be a potential tumor suppressor gene in the nasopharyngeal carcinoma.

An antibody against Siglec-15 promotes bone formation and fracture healing by increasing TRAP+ mononuclear cells and PDGF-BB secretion

Osteoporosis (OP) is a common age-related disease characterized by a deterioration of bone mass and structure that predisposes patients to fragility fractures. Pharmaceutical therapies that promote anabolic bone formation in OP patients and OP-induced fracture are needed. We investigated whether a neutralizing antibody against Siglec-15 can simultaneously inhibit bone resorption and stimulate bone formation. We found that the multinucleation of osteoclasts was inhibited in SIGLEC-15 conditional knockout mice and mice undergoing Siglec-15 neutralizing antibody treatment. The secretion of platelet-derived growth factor-BB (PDGF-BB), the number of tartrate-resistant acid phosphatase-positive (TRAP⁺) mononuclear cells, and bone formation were significantly increased in the SIGLEC-15 conditional knockout mice and antibody-treated mice. The anabolic effect of the Siglec-15 neutralizing antibody on bone formation was blunted in mice with Pdgfb deleted in TRAP⁺ cells. These findings showed that the anabolic effect of the Siglec-15 neutralizing antibody was mediated by elevating PDGF-BB production of TRAP⁺ mononuclear cells. To test the therapeutic potential of the Siglec-15 neutralizing antibody, we injected the antibody in an ovariectomy-induced osteoporotic mouse model, which mimics postmenopausal osteoporosis in women, and in two fracture healing models because fracture is the most serious health consequence of osteoporosis. The Siglec-15 neutralizing antibody effectively reduced bone resorption and stimulated bone formation in estrogen deficiency-induced osteoporosis. Of note, the Siglec-15 neutralizing antibody promoted intramembranous and endochondral ossification at the damaged area of cortical bone in fracture healing mouse models. Thus, the Siglec-15 neutralizing antibody shows significant translational potential as a novel therapy for OP and bone fracture.

Abstract 3193: Development and functional characterization of NC762, a novel therapeutic antibody targeting B7-H4, for the treatment of malignancies

Human B7 homolog 4 (B7-H4) is a transmembrane protein in the B7 family of molecules that is expressed on tumor cells in the tumor microenvironment (TME). High protein expression on tumors and low expression on healthy tissue makes B7-H4 an attractive molecule for direct targeting with low off-target toxicity. NC762 is a humanized immunoglobulin gamma 1, kappa (IgG1κ) monoclonal antibody specific for human B7-H4 that is being developed for the treatment of cancer and demonstrates an excellent safety profile in IND-enabling studies. The IgG1κ region of NC762 contains three-point mutations (S239D/A330L/I332E a.k.a. DLE) which enhances binding to CD16a (FcγRIIIa) in order to increase antibody-dependent cellular cytotoxicity (ADCC) activity. NC762 binds to human B7-H4 on SKBR3 cells, a breast cancer cell line that endogenously expresses B7-H4 and induces in vitro ADCC activity. Despite the high homology, NC762 does not cross-react with rodent B7-H4, therefore, in vivo testing was performed in a humanized xenograft murine model in NSG mice, where NC762 restricted tumor growth in a dose-dependent manner. Depleting human natural killer (NK) cells prior to tumor inoculation reduced anti-B7-H4 parent antibody activity, supporting a role for NK-cell mediated ADCC in tumor growth retardation. However, in the absence of human PBMCs, NC762 also achieved significant anti-tumor activity. Furthermore, a mutant of NC762 with a low FcγR binding IgG1 domain showed similar activity as the DLE IgG1, demonstrating an ADCC-independent mechanism of tumor growth restriction mediated by B7-H4 mAb treatment. Together, these results indicate that even with the ADCC-enhanced IgG1κ region, NC762 is able to mediate ADCC-independent anti-tumor activity for the eradication of B7-H4 expressing tumors; and is expected to provide benefit in multiple oncology indications.

Citation Format: Kristina Archer, Justine Ceradoy, Tiffany Coupet, Jason Bosiacki, Chang Song, Ido Weiss, Sue Niu, Tete Obot, Jinglin Xu, Tom O'Neill, Alison Ferrell, Hasan Abukharma, Zac Cusumano, Dallas Flies, Sol Langermann, Linda N. Liu. Development and functional characterization of NC762, a novel therapeutic antibody targeting B7-H4, for the treatment of malignancies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3193.

A phase 1/2, open-label, dose-escalation, safety and tolerability study of NC410 in subjects with advanced or metastatic solid tumors

TPS2659

Background: Leukocyte-Associated Immunoglobulin-like Receptor (LAIR)-1 and LAIR-2 are members of the Leukocyte Receptor Complex (LRC) (An & Brodsky, 2016). LAIR-1 is a co-inhibitory receptor expressed on several subsets of immune cells, and functions to delimit immune responses (Meyaard et al., 1997). LAIR-2 is a secreted protein with homology to the transmembrane protein LAIR-1 (Lebbink et al., 2008). In cancer, it is hypothesized that LAIR-1 expression on several subsets of leukocytes prevents optimal immune responses by limiting both innate and adaptive immune functionality. LAIR-1 serves to suppress anti-tumor immunity through the inhibition of stimulatory signaling pathways. Specifically, LAIR-1 is a checkpoint and adhesion receptor on T cells that limits T cell activation and increases adhesion to collagens (Meyaard, 2008). LAIR-2 is capable of blocking LAIR-1 functional interactions with ligands, resulting in improved immune function on multiple immune cell subsets. Dysregulation of LAIR-1 ligands in the tumor microenvironment results in excessive production of collagens and complement C1q as well as altered forms of collagens, that leads to immune inhibition through binding to LAIR-1+ immune cells. NC410 is a dimeric form of the LAIR-2 protein fused to a human Fc domain of the immunoglobulin (Ig) subtype IgG1. The rationale for developing NC410 as a cancer therapeutic is based on nonclinical data demonstrating LAIR-1 signaling blockade can improve the immune response. Because LAIR-2 binds to ligands shared with LAIR-1 with increased affinity, NC410 acts as a decoy receptor for LAIR-1 ligands releasing suppression from myeloid cells and T cells and promoting anti-tumor immunity. NC410 may also mediate remodeling of the tumor extracellular matrix, further contributing to anti-tumor activity. Methods: This is a multi-center, first in human, phase 1/2, open-label, single-armed study to determine the safety and tolerability, define maximum tolerated dose (MTD) and/or pharmacologically active dose, assess preliminary efficacy, and explore predictive and pharmacodynamic biomarkers of NC410 in subjects with advanced or metastatic solid tumors. Key eligibility criteria include measurable disease based on RECIST v1.1 and being able to consent for collection of biopsies at screening and on treatment. Phase 1 is a classic 3+3 dose escalation design to determine the safety, tolerability, DLT, MTD and recommended phase 2 dose (RP2D) (NCT04408599). Ongoing exploratory analyses include the assessment of predictive biomarkers associated with treatment benefit, and pharmacodynamic markers associated with study drug activity. Phase 2 is going to enroll ovarian, colorectal, NSCLC, H&N, and gastric carcinomas and other tumors depending on biomarker data available from the Phase 1 part of the study. Clinical trial information: 04408599.

[The effect of extended depth of focus contact lenses on the accommodation of presbyopic eyes]

Objective: To evaluate the effect of extended depth of focus contact lenses on the accommodation of presbyopic eyes. Methods: It was a double-blind randomized controlled trial. Thirty eyes of 30 emmetropic volunteers (15 males, 15 females) who were staff or family members of Hainan Eye Hospital, aged (49.6±4.5) years, were selected. Non-dominant eyes were fitted with soft contact lenses with an extended depth of field. The subjects and examiners were double-blind. Visual acuities of the subjects were examined at 5 m, 40 cm and 60 cm distance before and after the contact lens wear. Meanwhile, the monocular accommodative amplitude, monocular accommodative facility (±1.00 D), accommodative response, binocular positive/negative relative accommodation and accommodation convergence/accommodation at 40 cm distance were measured. The data were analyzed by paired t test and Wilcoxon signed rank test before and after the contact lens wear, and a P value less than 0.05 was considered statistically significant. Results: Before and after the contact lens wear, the visual acuity at 40 cm was 4.59±0.14 and 4.69±0.10, and the difference was statistically significant (t=4.16, P<0.01). The visual acuity at 60 cm was 4.74±0.10 and 4.74±0.12, and the difference had no statistical significance (t=0.626, P>0.05). The distance visual acuity was 5.00±0.06 and 4.96±0.06, and the difference was statistically significant (t=3.89, P<0.01). The monocular accommodative amplitude was significantly improved from (3.26±0.26) D to (4.00±0.51) D (t=7.59, P<0.01). The monocular accommodative facility was also significantly improved from (2.67±1.60) cyc/min to (3.53±1.87) cyc/min (t=2.17, P<0.05). There was no statistically significant difference in the positive and negative relative accommodation (t=1.90, 0.66; P>0.05). The accommodation convergence/accommodation and adjustment lag had no statistical significance (Z=0.83, 0.11; P>0.05). Conclusion: Wearing contact lenses with an extended depth of field can improve the near vision and accommodation of presbyopes (Chin J Ophthalmol, 2021, 57:292-296).

[Analysis of the clinicopathologic features as well as diagnosis and treatment of 59 patients with Castleman disease]

Objective: To investigate the clinicopathologic features, treatment, and prognosis in patients with Castleman disease (CD) . Methods: We retrospectively analyzed the clinicopathologic data of 59 patients for whom a diagnosis of Castleman disease was confirmed using pathological examination from October 2011 to October 2019 at the Henan Cancer Hospital. The patients were divided into the following two groups as per the following clinical classifications: unicentric CD (UCD, n=47) and multicentric CD (MCD, n=12) . Data on clinical manifestations, laboratory findings, treatment, and prognosis were analyzed. Results: There was no significant difference in the median age and the ratio of male to female between the UCD and MCD. UCD was characterized by asymptomatic enlargement of the single lymph node. The main pathological type was hyaline vascular histopathology (83.0%) . Of these, 44 patients chose surgical resection, and their prognosis was good. Treatment. MCD was characterized by multiple enlarged superficial and/or deep lymph nodes with B symptoms, weakness, and hepatosplenomegaly. Anemia, hypoproteinemia, and globulin level were increased on laboratory examinations. Plasmacyte histopathology was the main pathological type and was present in about 50.0% of the subjects. Only chemotherapy was performed for these MCD patients, followed by chemotherapy or chemotherapy followed by radiotherapy, and the efficient was 58.3% (7/12) . Conclusions: UCD, characterized by asymptomatic enlargement of the single lymph node, shows good postoperative prognosis. MCD has relatively complex clinical manifestations and poor prognosis, and optimal treatment is yet to be established.

Ion cyclotron emission diagnostic system on the experimental advanced superconducting tokamak and first detection of energetic-particle-driven radiation

A passive and noninvasive diagnostic system based on high-frequency B-dot probes (HFBs) has been designed and developed for the measurement and identification of ion cyclotron emission (ICE) in the Experimental Advanced Superconducting Tokamak (EAST). Details of the hardware components of this system including HFBs, direct current blockers, radio frequency splitters, filters, and power detectors as well as data acquisition systems are presented. A spectrum analyzer is used in addition to the ordinary speed acquisition card for data registration and analysis. The reliability of a HFB based diagnostic system has been well validated during the 2018 spring experiments on the EAST. ICE signals corresponding to fundamental cyclotron frequency of hydrogen ions and harmonics of deuterium ions were observed in experiments where deuterium plasmas were heated with deuterium neutral beams. The field dependence of ICE has been verified by recent experiments with three different background magnetic fields. The observed ratio of the ICE frequency is consistent with the ratio of the magnetic field intensity within measurement errors of a few percent.

Siglec-15 as an immune suppressor and potential target for normalization cancer immunotherapy

Overexpression of the B7-H1 (PD-L1) molecule in the tumor microenvironment (TME) is a major immune evasion mechanism in some patients with cancer, and antibody blockade of the B7-H1/PD-1 interaction can normalize compromised immunity without excessive side-effects. Using a genome-scale T cell activity array, we identified Siglec-15 as a critical immune suppressor. While only expressed on some myeloid cells normally, Siglec-15 is broadly upregulated on human cancer cells and tumor-infiltrating myeloid cells, and its expression is mutually exclusive to B7-H1, partially due to its induction by macrophage colony-stimulating factor and downregulation by IFN-γ. We demonstrate that Siglec-15 suppresses antigen-specific T cell responses in vitro and in vivo. Genetic ablation or antibody blockade of Siglec-15 amplifies anti-tumor immunity in the TME and inhibits tumor growth in some mouse models. Taken together, our results support Siglec-15 as a potential target for normalization cancer immunotherapy.

[Effect of different medication time prior to corneal refractive surgery on tear film stability]

Objective: To investigate the effect of different medication time prior to corneal refractive surgery on tear film stability. Methods: Prospective cohort study. A total of 60 patients (60 eyes), including 38 males (63.3%) and 22 females (37.7%) with an average age of (24.2±5.1) years (form 18 to 37 years), who had planned for corneal refractive surgery with normal ocular surface disease index score were included in this study. The patients were divided into 1d group (medication of 1 day, 30 eyes) and 3d group (medication of 3 days, 30 eyes) randomly. The first tear break up time (FBUT), the average tear break up time (AVBUT) and the dry eye grade score were recorded on the examination day and the operation day with Keratograph 5M. The difference of FBUT and AVBUI between the two groups was compared with the independent sample t test. The difference of FBUT and AVBUT between the examination day and the operation day was compared with the paired t test. The difference of the dry eye classification between the two groups was compared using chi-square test. Results: The FBUT and AVBUT of 1d group and 3d group were (10.89±5.19)s and (10.88±6.82)s, (16.24±3.62)s and (16.21±4.74)s respectively in preoperative examination, and (10.65±6.03)s and (8.14±5.75)s, (15.14±5.30)s and (12.86±5.92)s respectively in operation day. There was no significant difference in FBUT and AVBUT between the two groups (t=0.01, 1,47, 0.02, 1.44; P>0.05). However, in the 3d group, the AVBUT of operation day decreased as compared with that of the examination day, and the difference was statistically significant (t=2.31, P<0.05). There was no significant difference in the distribution of dry eye classification between the two groups (χ(2)=0.07, 3.36; P>0.05). Conclusion: Both of medication of 1 day and medication of 3 days prior to corneal refractive surgery can provide a similar tear film stability, however more attention should be paid to the medication for patients with asymptomatic but abnormal BUT. (Chin J Ophthalmol, 2018, 54: 744-747).

B7-H4 Modulates Regulatory CD4+ T Cell Induction and Function via Ligation of a Semaphorin 3a/Plexin A4/Neuropilin-1 Complex

The potent immune regulatory function of an agonistic B7-H4-Ig fusion protein (B7-H4Ig) has been demonstrated in multiple experimental autoimmune models; however, the identity of a functional B7-H4 receptor remained unknown. The biological activity of B7-H4 is associated with decreased inflammatory CD4⁺ T cell responses as supported by a correlation between B7-H4-expressing tumor-associated macrophages and Foxp3⁺ T cells within the tumor microenvironment. Recent data indicate that members of the semaphorin (Sema)/plexin/neuropilin (Nrp) family of proteins both positively and negatively modulate immune cell function. In this study, we show that B7-H4 binds the soluble Sema family member Sema3a. Additionally, B7-H4Ig-induced inhibition of inflammatory CD4⁺ T cell responses is lost in both Sema3a functional mutant mice and mice lacking Nrp-1 expression in Foxp3⁺ T cells. These findings indicate that B7-H4Ig binds to Sema3a, which acts as a functional bridge to stimulate an Nrp-1/Plexin A4 heterodimer to form a functional immunoregulatory receptor complex resulting in increased levels of phosphorylated PTEN and enhanced regulatory CD4⁺ T cell number and function.

[Effects and its mechanism of Nimotuzumab on radiosensitivity of esophageal carcinoma ECA-109 and TE-13 cell lines]

Objective: To investigate the effects of nimotuzumab on radiosensitivity of ECA-109 and TE-13 esophageal carcinoma cell lines and explore its possible mechanism. Methods: The ECA-109 and TE-13 cells were divided into control group, irradiation group, medicine group, and combined group (irradiation + medicine). In the combined group, ECA-109 and TE-13 cells were treated with nimotuzumab for 24 h before irradiation, and the cells were collected 2 h after irradiation. The radiosensitizing effects of nimotuzumab on ECA-109 and TE-13 cells were evaluated by clone formation assay. Cell apoptosis was detected by flow cytometry. Western blotting was used to evaluate the expression of EGFR, p-EGFR, DNA-PKcs, p-DNA-PKcs and γH2AX. Results: The values of D_q (quasithreshold dose), D₀(mean lethal dose)and SF₂ (surviving fraction at 2 Gy) of ECA-109 and TE-13 cells in the combined group were significantly lower than those of the radiation group (for ECA-109 cells, 1.11 vs. 1.72, 1.40 vs. 2.14, 0.42 vs. 0.66, respectively; for TE-13 cells, 0.41 vs. 0.46, 0.43 vs. 0.65, 0.40 vs. 0.71, respectively (all P<0.05). The sensitivity enhancement ratio (SER) of ECA-109 and TE-13 cells were 1.35 and 1.43, respectively. Flow cytometry showed that the apoptosis rate of ECA-109 and TE-13 cells in the combined group were significantly higher than those of the radiation group [for ECA-109 cells, (41.31±1.52)% vs. (9.54±0.52)%; for TE-13 cells, (46.28±0.28)% vs. (11.32±0.31)%, both P<0.01]. Western blotting showed that the expression levels of EGFR and DNA-PKcs were not significantly different in all groups (all P>0.05). Compared with those of the control group, p-EGFR and p-DNA-PKcs of the radiation group were significantly higher in both cell lines (P<0.05), and the γH2AX levels in the radiation group and medicine group were significantly higher than that of the control group (P<0.05). Compared with those of the radiation group and medicine group, p-EGFR and p-DNA-PKcs protein expression in the combined group were decreased significantly (P<0.05), while γH2AX protein expression was significantly increased (P<0.05). Conclusions: Nimotuzumab can enhance the radiosensitivity of esophageal cancer ECA-109 and TE-13 cells. The potential mechanism may be related to the inhibition of EGFR phosphorylation and down-regulation of DNA damage repair proteins. The radiosensitizing effect of nimotuzumab is greater on poorly differentiated esophageal cancer cells.

[Evaluation and establishment of Mongolian gerbil model of long-term infection of Helicobacter pylori with highly-expressed thioredoxin-1 gene]

OBJECTIVE

To establish a Mongolian gerbils model by long-term infection of Helicobacter pylori (Hp) with highly-expressed thioredoxin-1 (Trx1) gene and to investigate the histopathological findings of gastric mucosa in Mongolian gerbils.

METHODS

In this study, 75 healthy male Mongolian gerbils were randomly divided into 3 groups: Hp with highly-expressed Trx1 gene group (n=30), Hp with lowly-expressed Trx1 gene group (n=30), and control group (n=15). The animals underwent gastric perfusion of Hp suspension once a week for 5 weeks. The animals were sacrificed at the end of 4, 20, 34, 48, 70, and 90 weeks after inoculation for detecting Hp colonization by rapid urease test and Warthin-Starry silver staining and histological examination, respectively.

RESULTS

(1) The Mongolian gerbil model of long-term infection of Hp with highly-expressed Trx1 gene and lowly-expressed Trx1 gene were successfully established. (2) The macroscopic mucosal lesions, including erythema, uneven, erosion, nodules, etc. could be observed in experimental groups. The severity of lesions and the time when lesions occurred in Hp with highly-expressed Trx1 gene group were heavier/earlier than that in Hp with lowly-expressed Trx1 gene group. (3) Histopathologically, the gastric mucosa of Hp with highly-expressed Trx1 gene group showed the mild dysplastic hyperplasia of epithelial cells 34 weeks after the Hp inoculation, and the time was in the 48th week in Hp with lowly-expressed Trx1 gene group. At the end of the 90th week after Hp inoculation, the gastric adenocarcinoma could be detected in the two experimental groups (71.4% vs. 42.8%). The difference between the two experimental groups did not reach statistical significance (P=0.592), which might be due to the small sample capacity and/or short observation time. In addition, there were 2 cases with severe epithelial dysplastic hyperplasia in Hp with highly-expressed Trx1 gene group, and only 3 cases with moderate epithelial dysplastic hyperplasia in Hp with lowly-expressed Trx1 gene group. The uninfected control animals showed no abnormal findings throughout the entire observation period.

CONCLUSION

Hp with highly-expressed/lowly-expressed Trx1 gene colonizes stably in the glandular gastric mucosa of Mongolian gerbils. The histological changes after infection are similar to those of the Hp infected human being, and Hp with highly-expressed Trx1 gene cause the injury of gastric mucosa and the occurrence of gastric adenocarcinoma. Trx1 maybe the virulence factor that participates in the pathogenesis of gastric cancer and Hp expressing high levels of Trx1 should be highly toxic for gastric diseases in China.

Metabolic response of maize plants to multi-factorial abiotic stresses

Clarification of the metabolic mechanisms underlying multi-stress responses in plants will allow further optimisation of crop breeding and cultivation to obtain high yields in an increasingly variable environment. Using NMR metabolomic techniques, we examined the metabolic responses of maize plants grown under different conditions: soil drought, soil salinity, heat and multiple concurrent stresses. A detailed time-course metabolic profile was also performed on maize plants sampled 1, 3 and 7 days after initiation of soil drought and heat stress. The metabolic profile of maize plants subjected to soil drought was more similar to plants exposed to salt stress than to heat-stressed plants. Drought-stressed maize plants subjected to salt or heat stress showed distinct integrated metabolic profiles compared with those exposed to either stressor individually. These differences show the considerable metabolic plasticity of maize in response to different growth conditions. Moreover, glucose, fructose, malate, citrate, proline, alanine, aspartate, asparagine, threonine and one unknown compound fluctuated obviously between maize plants grown in controlled growth cabinet and a natural regime. These changes were associated with the TCA cycle and core nitrogen metabolism, and could be related to their multiple functions during plant growth. The evident stress-induced trajectory of metabolic changes in maize indicated that the primary metabolic responses to soil drought, heat and combined drought and heat stresses occurred in a time-dependent manner. Plasticity at the metabolic level may allow maize plants to acclimatise their metabolic ranges in response to changing environmental conditions.

Control of PD-L1 Expression by Oncogenic Activation of the AKT-mTOR Pathway in Non-Small Cell Lung Cancer

Alterations in EGFR, KRAS, and ALK are oncogenic drivers in lung cancer, but how oncogenic signaling influences immunity in the tumor microenvironment is just beginning to be understood. Immunosuppression likely contributes to lung cancer, because drugs that inhibit immune checkpoints like PD-1 and PD-L1 have clinical benefit. Here, we show that activation of the AKT-mTOR pathway tightly regulates PD-L1 expression in vitro and in vivo. Both oncogenic and IFNγ-mediated induction of PD-L1 was dependent on mTOR. In human lung adenocarcinomas and squamous cell carcinomas, membranous expression of PD-L1 was significantly associated with mTOR activation. These data suggest that oncogenic activation of the AKT-mTOR pathway promotes immune escape by driving expression of PD-L1, which was confirmed in syngeneic and genetically engineered mouse models of lung cancer where an mTOR inhibitor combined with a PD-1 antibody decreased tumor growth, increased tumor-infiltrating T cells, and decreased regulatory T cells.

Analysis of Structures, Functions, and Epitopes of Aminopeptidase from Trichinella spiralis

We have previously reported that the recombinant T. spiralis aminopeptidase (rTsAP) could induce a partial protective immunity against T. spiralis infection in mice. The aim of this study was to predict the structures and functions of TsAP protein by using the full length cDNA sequence of TsAP gene. TsAP sequence was 1515 bp length with a 1515 bp biggest ORF encoding 504-amino acid protein. The molecular weight and isoelectric point of TsAP were 54.7 kDa and 6.69, respectively. TsAP structure domains contained a Peptidase_M17_N and a Peptidase_M17 domain, which has the function of catalysis of the hydrolysis of N-terminal amino acid residues. TsAP had no signal peptide site and transmembrane domain, and located in cytoplasm. The secondary structure of TsAP contained 16 α-helix, 14 β-strand and 29 coils. The TsAP had 11 and 21 potential antigenic epitopes of T cell and B cell, respectively. Based on the phylogenetic analyses of TsAP, T. spiralis have the closest relationship with Plasmodium falciparum. TsAP was a kind of proteolytic enzyme with a variety of biological functions and its antigenic epitopes could provide important insights on the diagnostic antigens and target molecular of anti-Trichinella drugs.

Ultrasound Findings of Intraductal Papillary Neoplasm in Bile Duct and the Added Value of Contrast-Enhanced Ultrasound

PURPOSE

To investigate the imaging features of intraductal papillary neoplasm in bile duct (IPNB) on baseline ultrasound and contrast-enhanced ultrasound (CEUS).

MATERIALS AND METHODS

The imaging features on baseline ultrasound and CEUS in 16 pathologically proven IPNB lesions in 15 patients were retrospectively analyzed. Real-time contrast specific modes and contrast agent of SonoVue were used for CEUS.

RESULTS

Bile duct dilation was present in all patients. The mean lengths for the intraductal papillary adenomas and adenocarcinomas were 2.5 ± 1.1 (range, 1.2 - 4.2 cm) and 5.6 ± 2.0 cm (range, 3.3 - 9.8 cm) (P = 0.004). Three imaging types of IPNB on ultrasound were depicted: bile duct dilation with intraductal mass (n = 8), bile duct dilation without intraductal mass (n = 3), and cystic-solid mixed type (n = 5). On CEUS, solid components of 13 lesions appeared hyper- (n = 12) or iso-enhancement (n = 1) in the arterial phase whereas all showed hypo-enhancement in the portal and late phases. For 3 lesions of bile duct dilation without intraductal mass, CEUS showed non-enhancement during all phases. Pre-surgical CEUS and conventional ultrasound made correct diagnoses in 12 (75.0 %) and 5(31.3 %) of 16 IPNBs respectively (P = 0.04). For CECT, correct diagnosis was also achieved in 12 (75.0 %) of 16 lesions (P = 1.00, in comparison with CEUS).

CONCLUSIONS

IPNB should be taken into consideration when intraductal mass or cystic-solid mass with bile duct dilation, or remarkable bile duct dilation without intraductal mass, are found on US. Intraductal mass length > 3.0 cm is more commonly found in malignant IPNB. CEUS might facilitate the diagnosis of IPNB by easily excluding the possibility of commonly found sludge, nonshadowing stones, or blood clots.

Analysis of structure, function and epitopes of Spirometra erinaceieuropaei casein kinase I

Spirometra erinaceieuropaei casein kinase I (SeCKI) was analyzed using bioinformatical methods to predict its structure and function based on the deduced amino acid sequence from full length cDNA sequence of SeCKI gene with online sites and software programs. The longest open reading frame contains 448 amino acids, 50 kDa and theoretical pI of 4.73, with a complete tubulin domain, a SMART tubulin_C domain and a low complexity region. SeCKI has no signal sequence and no transmembrane domain, but is predicted to be located extracellularly. The secondary structure of SeCKI contains 12 α-helixes, 11 β-strands and 22 coils. SeCKI had 19 potential antigenic epitopes and 25 HLA-I restricted epitopes. Based on phylogenetic analysis of SeCKI sequence, S. erinaceieuropaei has the closest evolutionary status with Hymenolepis microstoma. Information from this study could provide important insights into the identification of diagnostic antigens and molecular targets of anti-sparganum drugs.

[Correlation between epicardial adipose tissue and coronary flow reserve in coronary heart disease patients with no chest pain]

OBJECTIVE

To assess whether epicardial adipose tissue (EAT) thickness is associated with coronary flow reserve (CFR) and could be used to detect coronary microvascular dysfunction.

METHODS

We enrolled 62 nondiabetic patients who underwent computed tomography angiography or invasive coronary angiography and had no obstructive coronary artery disease. CFR and EAT thickness were measured by transthoracic Doppler echocardiography (TTDE).

RESULTS

In the study, a total of 62 patients were enrolled, echocardiographic coronary flow reserve were obtained in 61 of the patients with a mean age of (59±10) years. 34 patients (56%) had reduced CFR (CFR<3, 2.52±0.32) suggesting microvascular dysfunction and 27 patients (44%) had normal CFR (CFR≥3, 3.56±0.52). EAT thickness was significantly increased in the patients with microvascular dysfunction as compared with those without [(3.4±0.8) mm vs. (2.3±0.6) mm, P<0.001]. EAT thickness was strongly related to CFR (r=-0.668, P<0.001). By Logistic regression analysis, EAT thickness was the independent predictor of coronary microvascular dysfunction (OR=7.78, 95%CI: 2.44-24.79). EAT thickness>2.9 mm had 82.4% sensitivity and 92.3% specificity to detect CFR<3 (area under ROC curve 0.860, P<0.001).

CONCLUSION

EAT thickness was significantly increased in patients with coronary microvascular dysfunction. EAT thickness was independently associated with impaired CFR. EAT>2.9 mm had high sensitivity and specificity to detect coronary microvascular dysfunction.

Survey and genetic variation of Spirometra erinaceieuropaei sparganum in frogs and snakes from Guangxi of southern China

The prevalence of sparganum infection in wild frogs (Rana rugulosa and R. temporaria) and snakes (Enhydris chinensis) was investigated in Guangxi Zhuang Autonomous Region of Southern China from June 2013 to August 2013. The results showed that 30.37% (65/214) of the caught wild frogs and 50% (3/6) of examined snakes were found to be infected with plerocercoids (spargana) of the genus Spirometra. To investigate the genetic variation of the collected spargana, three mitochondrial DNA (mtDNA) regions, namely cytochrome c oxidase subunit 1 and 3 (cox1 and cox3), NADH dehydrogenase subunits 4 (nad4) were amplified, sequenced, and analyzed. The sequences of cox1, cox3 and pnad4 are 444, 387 and 585 bp in length, respectively. The base composition of cox1, cox3 and pnad4 were generally AT rich with a mean of 62.7%, 67.2% and 64.9%, respectively. Phylogenetic analyses using Bayesian inference (BI) and maximum parsimony (MP) indicated that all the Spirometra sparganum isolates in Guangxi represented S. erinaceieuropaei.

Structure and function of soil microbial community in artificially planted Sonneratia apetala and S. caseolaris forests at different stand ages in Shenzhen Bay, China

The present study examined the relationships between soil characteristics, microbial community structure and function in the forests artificially planted with exotic Sonneratia apetala at stand ages of 1-, 2-, 7-, 10- and 14-years and Sonneratia caseolaris of 1-, 4-, 7-, 10- and 14-years in Futian National Nature Reserve, Shenzhen Bay, China. The 7-years old forests of both Sonneratia species reached peak growth and had the highest content of nitrogen and phosphorus, enzymatic activities, including dehydrogenase, cellulase, phosphatase, urease and ß-glucosidase, except arylsulphatase which increased continuously with stand ages. The microbial community structure reflected by phospholipid fatty acid (PLFA) profiles also reached the maximum value in the 7-years old forests and soil bacterial PLFAs in both forests were significantly higher than fungal PLFAs. The canonical correlation analysis revealed that differences in microbial structural variables were significantly correlated to the differences in their functional variables, and the highest correlation was found between the soil enzymatic activities and the content of carbon and nitrogen.

Effect of cocaine on ion channels and glutamatergic EPSCs in noradrenergic locus coeruleus neurons

The locus coeruleus (LC) is an important brainstem area involved in cocaine addiction. However, evidence to elucidate how cocaine modulates the activity of LC neurons remains incomplete. Here, we performed whole recordings in brain slices to evaluate the effects of cocaine on the sodium (Na(+)), potassium (K(+)), calcium (Ca(2+)) channels, and glutamatergic synaptic transmission in the locus coeruleus neurons. Local application of cocaine significantly and reversibly reduced the spontaneous firing rate but did not affect action potential amplitude, rising time, decay time, or half width of noradrenergic locus coeruleus neurons. Moreover, cocaine attenuated the sodium current but did not affect potassium and calcium currents. The N-methyl-D-aspartate receptor mediated excitatory postsynaptic currents were reduced by neuropeptide galanin but not cocaine. All those data demonstrate that cocaine has inhibitory effect on the spontaneous activities and sodium current in locus coeruleus neurons. Therefore, neuromodulation of sodium channel in locus coeruleus neurons may play an important role in drug addiction.

Comparison of drug and cell-based delivery: engineered adult mesenchymal stem cells expressing soluble tumor necrosis factor receptor II prevent arthritis in mouse and rat animal models

Rheumatoid arthritis (RA) is a systemic autoimmune disease with unknown etiology where tumor necrosis factor-α (TNFα) plays a critical role. Etanercept, a recombinant fusion protein of human soluble tumor necrosis factor receptor II (hsTNFR) linked to the Fc portion of human IgG1, is used to treat RA based on the rationale that sTNFR binds TNFα and blocks TNFα-mediated inflammation. We compared hsTNFR protein delivery from genetically engineered human mesenchymal stem cells (hMSCs) with etanercept. Blocking TNFα-dependent intercellular adhesion molecule-1 expression on transduced hMSCs and inhibition of nitric oxide production from TNFα-treated bovine chondrocytes by conditioned culture media from transduced hMSCs demonstrated the functionality of the hsTNFR construction. Implanted hsTNFR-transduced mesenchymal stem cells (MSCs) reduced mouse serum circulating TNFα generated from either implanted TNFα-expressing cells or lipopolysaccharide induction more effectively than etanercept (TNFα, 100%; interleukin [IL]-1α, 90%; and IL-6, 60% within 6 hours), suggesting faster clearance of the soluble tumor necrosis factor receptor (sTNFR)-TNFα complex from the animals. In vivo efficacy of sTNFR-transduced MSCs was illustrated in two (immune-deficient and immune-competent) arthritic rodent models. In the antibody-induced arthritis BalbC/SCID mouse model, intramuscular injection of hsTNFR-transduced hMSCs reduced joint inflammation by 90% compared with untransduced hMSCs; in the collagen-induced arthritis Fischer rat model, both sTNFR-transduced rat MSCs and etanercept inhibited joint inflammation by 30%. In vitro chondrogenesis assays showed the ability of TNFα and IL1α, but not interferon γ, to inhibit hMSC differentiation to chondrocytes, illustrating an additional negative role for inflammatory cytokines in joint repair. The data support the utility of hMSCs as therapeutic gene delivery vehicles and their potential to be used in alleviating inflammation within the arthritic joint.

Clinical scale electroloading of mature dendritic cells with melanoma whole tumor cell lysate is superior to conventional lysate co-incubation in triggering robust in vitro expansion of functional antigen-specific CTL

Recent commercial approval of cancer vaccine, demonstrating statistically significant improvement in overall survival of prostate cancer patients has spurred renewed interest in active immunotherapies; specifically, strategies that lead to enhanced biological activity and robust efficacy for dendritic cell vaccines. A simple, widely used approach to generating multivalent cancer vaccines is to load tumor whole cell lysates into dendritic cells (DCs). Current DC vaccine manufacturing processes require co-incubation of tumor lysate antigens with immature DCs and their subsequent maturation. We compared electroloading of tumor cell lysates directly into mature DCs with the traditional method of lysate co-incubation with immature DCs. Electroloaded mature DCs were more potent in vitro, as judged by their ability to elicit significantly (p < 0.05) greater expansion of peptide antigen-specific CD8(+) T cells, than either lysate-electroloaded immature DCs or lysate-co-incubated immature DCs, both of which must be subsequently matured. Expanded CD8(+) T cells were functional as judged by their ability to produce IFN-γ upon antigen-specific re-stimulation. The electroloading technology used herein is an automated, scalable, functionally closed cGMP-compliant manufacturing technology supported by a Master File at CBER, FDA and represents an opportunity for translation of enhanced potency DC vaccines at clinical/commercial scale.

Expression of chimeric antigen receptors in natural killer cells with a regulatory-compliant non-viral method

Natural killer (NK) cells hold promise for cancer therapy. NK cytotoxicity can be enhanced by expression of chimeric antigen receptors that re-direct specificity toward target cells by engaging cell surface molecules expressed on target cells. We developed a regulatory-compliant, scalable non-viral approach to engineer NK cells to be target-specific based on transfection of mRNA encoding chimeric receptors. Transfection of eGFP mRNA into ex vivo expanded NK cells (N=5) or purified unstimulated NK cells from peripheral blood (N=4) resulted in good cell viability with eGFP expression in 85+/-6% and 86+/-4%, 24 h after transfection, respectively. An mRNA encoding a receptor directed against CD19 (anti-CD19-BB-z) was also transfected into NK cells efficiently. Ex vivo expanded and purified unstimulated NK cells expressing anti-CD19-BB-z exhibited enhanced cytotoxicity against CD19(+) target cells resulting in > or =80% lysis of acute lymphoblastic leukemia and B-lineage chronic lymphocytic leukemia cells at effector target ratios lower than 10:1. The target-specific cytotoxicity for anti-CD19-BB-z mRNA-transfected NK cells was observed as early as 3 h after transfection and persisted for up to 3 days. The method described here should facilitate the clinical development of NK-based antigen-targeted immunotherapy for cancer.

Rapid and efficient nonviral gene delivery of CD154 to primary chronic lymphocytic leukemia cells

Interactions between CD40 and CD40 ligand (CD154) are essential in the regulation of both humoral and cellular immune responses. Forced expression of human CD154 in B chronic lymphocytic leukemia (B-CLL) cells can upregulate costimulatory and adhesion molecules and restore antigen-presenting capacity. Unfortunately, B-CLL cells are resistant to direct gene manipulation with most currently available gene transfer systems. In this report, we describe the use of a nonviral, clinical-grade, electroporation-based gene delivery system and a standard plasmid carrying CD154 cDNA, which achieved efficient (64+/-15%) and rapid (within 3 h) transfection of primary B-CLL cells. Consistent results were obtained from multiple human donors. Transfection of CD154 was functional in that it led to upregulated expression of CD80, CD86, ICAM-I and MHC class II (HLA-DR) on the B-CLL cells and induction of allogeneic immune responses in MLR assays. Furthermore, sustained transgene expression was demonstrated in long-term cryopreserved transfected cells. This simple and rapid gene delivery technology has been validated under the current Good Manufacturing Practice conditions, and multiple doses of CD154-expressing cells were prepared for CLL patients from one DNA transfection. Vaccination strategies using autologous tumor cells manipulated ex vivo for patients with B-CLL and perhaps with other hematopoietic malignancies could be practically implemented using this rapid and efficient nonviral gene delivery system.

Efficient responses in a murine renal tumor model by electroloading dendritic cells with whole-tumor lysate

Electroporation of dendritic cells (DCs) with tumor lysate elicited greater antitumor responses in vitro and in vivo, using less lysate than standard coincubation. Electroloaded DCs had normal surface marker expression and matured into competent antigen-presenting cells. In a renal carcinoma (RENCA) model, mice were pretreated with lysate-loaded DCs before tumor challenge. Mice that received DCs electroloaded with RENCA lysate had significantly smaller tumors (9+/-6 mm2) than mice given DCs coincubated with the same lysate (23+/-5 mm2). To evaluate a metastatic therapeutic tumor model, mice were first injected with Lewis lung carcinoma (LLC) and then given 2 doses of cryopreserved LLC lysate-loaded DCs. Mice treated with electroloaded DCs had a 50% reduction in lung metastases compared with control mice that received no DCs or DCs loaded with liver lysate. In contrast, DCs coincubated with LLC lysate were indistinguishable from controls. Tumor lysate-electroloaded but not-coincubated DCs also primed syngeneic mouse splenocytes in vitro to produce interferon-gamma and, specifically, lyse tumor cells. The electroloaded DCs elicited specific T-cell responses with less lysate than the amount reported in standard coincubation procedures. This approach may be particularly useful when small amounts of tumor material are available.

Rapid, in vivo, evaluation of antiangiogenic and antineoplastic gene products by nonviral transfection of tumor cells

Using a nonviral, electroporation-based gene transfection approach, we demonstrate the efficient and consistent transfection of two poorly immunogenic tumor cell lines: B16F10 melanoma and renal carcinoma (RENCA). Three genes, IL-12, angiostatin (AS), and an endostatin:angiostatin fusion protein (ES:AS) were subcloned into a DNA plasmid containing EBNA1-OriP, which was then transfected into B16F10 and RENCA cells. Significant levels of protein were secreted into the culture supernatants of transfected cells in vitro. Transfected tumor cells were injected subcutaneously into mice. All the three transgenes were capable of significantly delaying and reducing the formation of primary B16F10 and RENCA tumors, as well as B16F10 lung metastases. By day 11 post-injection, all control mice that received either mock-transfected or empty vector DNA-transfected B16F10 tumor cells had developed large primary tumors. In contrast, mice that received IL-12-transfected B16F10 cells did not develop appreciable tumors until day 17, and these were significantly smaller than controls. Similar results were observed for the RENCA model, in which only one of the IL-12 mice had developed tumors out to day 31. Expression of AS or ES:AS also significantly delayed and reduced primary tumors. Overall, ES:AS was more effective than AS alone. Furthermore, 25% of the AS mice and 33% of the ES:AS mice remained tumor-free at day 17, by which point all control mice had significant tumors. Mouse survival rates also correlated with the extent of tumor burden. Importantly, no lung metastases were detected in the lungs of mice that had received either AS or ES:AS-transfected B16F10 tumor cells and significantly fewer metastases were found in the IL-12 group. The consistency of our transfection results highlight the feasibility of directly electroporating tumor cells as a means to screen, identify, and validate in vivo potentially novel antiangiogenic and/or antineoplastic genes.

A non-viral gene delivery system designed for clinical use

Gene delivery can be accomplished using non-viral systems, and these have received increased attention These include ex vivo transfection of cells using an electric field to induce transient cell-membrane permeability (electroporation). This approach has the distinct advantage of not requiring the inclusion of a secondary agent (e.g. a lipid, viral package or carrier protein) any of which can be immunogenic or toxic. Available electroporation systems utilize a low volume (<1 mL) processing chamber and are open systems. The MaxCyte system employs a continuous flow design and can very rapidly process volumes ranging from 0.02 mL to >1 L. Transgenes for markers (eGFP) and functional proteins (e.g., cytokines, angiogenic factors) have been loaded in plasmids up to 14 kB in size. With appropriate application of pre- and post-processing cell manipulations, very satisfactory loading efficiencies and cell viability have been obtained. Cells can be processed with multiple plasmids, resulting in expression of the corresponding number of gene products. This capability has been considered for therapeutic and bioprocessing applications. The MaxCyte system was designed specifically for ex vivo clinical applications. The electrodes are manufactured of special materials and under precise conditions, in order to eliminate potential risks from electrolytic effects. The processing chamber and associated containers can be provided as disposable, sterile, closed (or functionally closed) systems-quite similar to the disposable harnesses used with cell separators. This system is thus suitable for integration into a current good manufacturing practice environment.

Highly efficient, large volume flow electroporation

Electroporation is widely used to transfect and load cells with various molecules. Traditional electroporation using a static mode is typically restricted to volumes less than 1 mL, which limits its use in clinical and industrial bioprocessing applications. Here we report efficient, large volume transfection results by using a scalable-volume electroporation system. Suspended (Jurkat) and adherent cells (10T1/2 and Huh-7) were tested. A large macromolecule, FITC-conjugated dextran (MW=500 kD) was used to measure cell uptake, while a plasmid carrying the gene coding for enhanced green fluorescence protein (eGFP) was used to quantitate the flow electrotransfection efficiency as determined by flow cytometry. The flow electroloading efficiency of FITC-dextran was >90%, while the cell viability was highly maintained (>90%). High flow electrotransfection efficiency (up to 75%) and cell viability (up to 90%) were obtained with processing volumes ranging from 1.5 to 50 mL. No significant difference of electrotransfection efficiency was observed between flow and static electrotransfection. When 50 mL of cell volume was processed and samples collected at different time points during electroporation, the transgene expression and cell viability results were identical. We also demonstrated that DNA plasmid containing EBNA1-OriP elements from Epstein-Barr virus were more efficient in transgene expression than standard plasmid without the elements (at least 500 too 1000-fold increase in expression level). Finally, to examine the feasibility of utilizing flow electrotransfected cells as a gene delivery vehicle, 10T1/2 cells were transfected with a DNA plasmid containing the gene coding for mIL12. mIL12 transfected cells were injected subcutaneously into mice, and produced functional mIL12, as demonstrated by anti-angiogenic activity. This is the first demonstration of efficient, large volume, flow electroporation and the in vivo efficacy of flow electrotransfected cells. This technology may be useful for clinical gene therapy and large-scale bioprocesses.

p53/p21(CIP1) cooperate in enforcing rapamycin-induced G(1) arrest and determine the cellular response to rapamycin

The relationship between G(1) checkpoint function and rapamycininduced apoptosis was examined using two human rhabdomyosarcoma cell lines, Rh1 and Rh30, that express mutated p53 alleles. Serum-starved tumor cells became apoptotic when exposed to rapamycin, but were completely protected by expression of a rapamycin-resistant mutant mTOR. Exposure to rapamycin (100 ng/ml) for 24 h significantly increased the proportion of Rh1 and Rh30 cells in G(1) phase, although there were no significant changes in expression of cyclins D1, E, or A in drug-treated cells. To determine whether apoptosis was associated with continued slow progression through G(1) to S phase, cells were exposed to rapamycin for 24 h, then labeled with bromodeoxyuridine (BrdUrd). Histochemical analysis showed that >90% of cells with morphological signs of apoptosis had incorporated BRDURD: To determine whether restoration of G(1) arrest could protect cells from rapamycin-induced apoptosis, cells were infected with replication-defective adenovirus expressing either p53 or p21(CIP1). Infection of Rh30 cells with either Ad-p53 or Ad-p21, but not control virus (Ad-beta-gal), induced G(1) accumulation, up-regulation of p21(CIP1), and complete protection of cells from rapamycin-induced apoptosis. Within 24 h of infection of Rh1 cells with Ad-p21, expression of cyclin A was reduced by >90%. Similar results were obtained after Ad-p53 infection of Rh30 cells. Consistent with these data, incorporation of [(3)H]thymidine or BrdUrd into DNA was significantly inhibited, as was cyclin-dependent kinase 2 activity. These data indicate that rapamycin-induced apoptosis in tumor cells is a consequence of continued G(1) progression during mTOR inhibition and that arresting cells in G(1) phase, by overexpression of p53 or p21(CIP1), protects against apoptosis. The response to rapamycin was next examined in wild-type or murine embryo fibroblasts nullizygous for p53or p21(CIP1). Under serum-free conditions, rapamycin-treated wild-type MEFs showed no increase in apoptosis compared to controls. In contrast, rapamycin significantly induced apoptosis in cells deficient in p53 ( approximately 2.4-fold) or p21(CIP1) ( approximately 5.5-fold). Infection of p53(-/-) MEFs with Ad-p53 or Ad-p21 completely protected against rapamycin-induced apoptosis. Under serum-containing conditions, rapamycin inhibited incorporation of BrdUrd significantly more in wild-type murine embryo fibroblasts (MEFs) than in those lacking p53 or p21(CIP1). When BrdUrd was added 24 h after rapamycin, almost 90% and 70% of cells lacking p53 or p21(CIP1), respectively, incorporated nucleoside. In contrast, only 19% of wild-type cells incorporated BrdUrd in the presence of rapamycin. Western blot analysis of cyclin levels showed that rapamycin had little effect on levels of cyclins D1 or E in any MEF strain. However, cyclin A was reduced to very low levels by rapamycin in wild-type cells, but remained high in cells lacking p53 or p21(CIP1). Taken together, the data suggest that p53 cooperates in enforcing G(1) cell cycle arrest, leading to a cytostatic response to rapamycin. In contrast, in tumor cells, or MEFs, having deficient p53 function the response to this agent may be cell cycle progression and apoptosis.

Rapamycin causes poorly reversible inhibition of mTOR and induces p53-independent apoptosis in human rhabdomyosarcoma cells

The mammalian target of rapamycin (mTOR) has been shown to link growth factor signaling and posttranscriptional control of translation of proteins that are frequently involved in cell cycle progression. However, the role of this pathway in cell survival has not been demonstrated. Here, we report that rapamycin, a specific inhibitor of mTOR kinase, induces G1 cell cycle arrest and apoptosis in two rhabdomyosarcoma cell lines (Rh1 and Rh30) under conditions of autocrine cell growth. To examine the kinetics of rapamycin action, we next determined the rapamycin sensitivity of rhabdomyosarcoma cells exposed briefly (1 h) or continuously (6 days). Results demonstrate that Rh1 and Rh30 cells were equally sensitive to rapamycin-induced growth arrest and apoptosis under either condition. Apoptosis was detected between 24 and 144 h of exposure to rapamycin. Both cell lines have mutant p53; hence, rapamycin-induced apoptosis appears to be a p53-independent process. To determine whether induction of apoptosis by rapamycin was specifically due to inhibition of mTOR signaling, we engineered Rh1 and Rh30 clones to stably express a mutant form of mTOR that was resistant to rapamycin (Ser2035-->Ile; designated mTOR-rr). Rh1 and Rh30 mTOR-rr clones were highly resistant (>3000-fold) to both growth inhibition and apoptosis induced by rapamycin. These results are the first to indicate that rapamycin-induced apoptosis is mediated by inhibition of mTOR. Exogenous insulin-like growth factor (IGF)-I protected both Rh1 and Rh30 from apoptosis, without reactivating ribosomal p70 S6 kinase (p70S6K) downstream of mTOR. However, in rapamycin-treated cultures, the response to IGF-I differed between the cell lines: Rh1 cells proliferated normally, whereas Rh30 cells remained arrested in G1 phase but viable. Rapamycin is known to inhibit synthesis of specific proteins but did not inhibit synthesis or alter the levels of mTOR. To examine the rate at which the mTOR pathway recovered, the ability of IGF-I to stimulate p70S6K activity was followed in cells treated for 1 h with rapamycin and then allowed to recover in medium containing > or =100-fold excess of FK506 (to prevent rapamycin from rebinding to its cytosolic receptor FKBP-12). Our results indicate that, in Rh1 cells, rapamycin dissociates relatively slowly from FKBP-12, with a t1/2 of approximately 17.5 h. in the presence of FK506, whereas there was no recovery of p70S6K activity in the absence of this competitor. This was of interest because rapamycin was relatively unstable under conditions of cell culture having a biological t1/2 of approximately 9.9 h. These results help to explain why cells are sensitive following short exposures to rapamycin and may be useful in guiding the use of rapamycin analogues that are entering clinical trials as novel antitumor agents.

Studies on the mechanism of resistance to rapamycin in human cancer cells

Rapamycin is a potent cytostatic agent that arrests cells in the G1 phase of the cell cycle. The relationships between cellular sensitivity to rapamycin, drug accumulation, expression of mammalian target of rapamycin (mTOR), and inhibition of growth factor activation of ribosomal p70S6 kinase (p70(S6k)) and dephosphorylation of pH acid stable protein I (eukaryotic initiation factor 4E binding protein) were examined. We show that some cell lines derived from childhood tumors are highly sensitive to growth inhibition by rapamycin, whereas others have high intrinsic resistance (>1000-fold). Accumulation and retention of [14C]rapamycin were similar in sensitive and resistant cells, with all cells examined demonstrating a stable tight binding component. Western analysis showed levels of mTOR were similar in each cell line (<2-fold variation). The activity of p70(S6k), activated downstream of mTOR, was similar in four cell lines (range, 11.75-41. 8 pmol/2 x 10(6) cells/30 min), but activity was equally inhibited in cells that were highly resistant to rapamycin-induced growth arrest. Rapamycin equally inhibited serum-induced phosphorylation of pH acid stable protein I in Rh1 (intrinsically resistant) and sensitive Rh30 cells. In serum-fasted Rh30 and Rh1 cells, the addition of serum rapidly induced c-MYC (protein) levels. Rapamycin blocked induction in Rh30 cells but not in Rh1 cells. Serum-fasted Rh30/rapa10K cells, selected for high level acquired resistance to rapamycin, showed >/=10-fold increased c-MYC compared with Rh30. These results suggest that the ability of rapamycin to inhibit c-MYC induction correlates with intrinsic sensitivity, whereas failure of rapamycin to inhibit induction or overexpression of c-MYC correlates with intrinsic and acquired resistance, respectively.

Mutation of Thr115 in MyoD positively regulates function in murine fibroblasts and human rhabdomyosarcoma cells

Committed skeletal muscle myoblasts undergo terminal differentiation when shifted from a high-mitogen medium to a low-mitogen medium. However, expression of the myogenic regulatory factor MyoD seems to be similar in proliferating and differentiating cells, suggesting that its function is attenuated in proliferating myoblasts. To further understand the potential mechanisms that may attenuate MyoD function, we have examined the effect of posttranslational modification. By analogy with myogenin, we have examined the role of phosphorylation in regulating the function of MyoD. MyoD contains two putative protein kinase C (PKC) phosphorylation sites (Thr115 and Ser200). The former site is analogous to Thr85 within the highly conserved basic domain of myogenin that has been demonstrated to negatively regulate the myogenic differentiation functions of myogenin. To test whether hyperphosphorylation of the same PKC site in MyoD would attenuate its function, we generated a mutant MyoD with a single amino acid substitution (Thr115-Ala) that disrupts the PKC phosphorylation site (Thr115) within the conserved basic domain. Wild-type and mutant MyoD were introduced into cells using an E1, E3-deleted adenoviral vector. In mouse C3H10T1/2 fibroblasts, both wild-type and mutant MyoD induced terminal myogenic differentiation when growth factors were withdrawn from the cell culture. Consistent with these results, nuclear extracts from infected cells, but not those from uninfected cells, demonstrated complex formation with an oligonucleotide containing an E-box consensus sequence. Growth arrest was associated with the up-regulation of p21cip1, cell fusion to multinucleated myotubes, and the expression of a muscle differentiation marker (myosin heavy chain). On the other hand, when infected cells were maintained under high mitogenic conditions (in the presence of 10% fetal bovine serum), the expression of wild-type or mutant MyoD slowed cell growth and induced p21cip1. Only mutant MyoD caused cell fusion, myosin heavy chain expression, and altered mobility of the E-box oligonucleotide in gel shift assays. Furthermore, after infection, MyoD was phosphorylated, and phosphothreonine was detected in wild-type MyoD immunoprecipitated only from C3H10T1/2 cells grown under high mitogenic conditions. These results suggest that Thr115 may play an important role in the regulation of MyoD function under conditions of high mitogenesis. MyoD was also phosphorylated in malignant rhabdomyosarcoma (RMS) cells in which MyoD function was attenuated. Phosphothreonine was also detected in MyoD immunoprecipitates. Rh30 alveolar RMS cells were infected with an adenovirus expressing either wild-type or mutant MyoD. In contrast to the results in fibroblasts, when overexpressed in malignant Rh30 RMS cells, mutant MyoD arrested cell growth without inducing p21cip1 and caused cell fusion. However, no muscle differentiation markers were detected, indicating that an overexpression of mutant MyoD lacking Thr115 caused Rh30 cells to become quiescent and recapitulate at least some aspects of myogenesis (cell fusion).

Mutations in the endo domain of Sindbis virus glycoprotein E2 block phosphorylation, reorientation of the endo domain, and nucleocapsid binding

Exposure of the carboxyl terminus (endo domain) of Sindbis virus membrane glycoprotein E2 to the cell cytoplasm is critical for the interaction of the nucleocapsid with viral envelope proteins in modified cell membranes. We have shown that the endo domain of PE2/E2 is initially translocated into membranes of the endoplasmic reticulum and subsequently drawn back into the cell cytoplasm during virus assembly. We suggested that phosphorylation of PE2/E2 might be responsible for the reorganization of the PE2/E2 carboxyl terminus. To test this hypothesis, two potential phosphorylation sites in the endo domain of E2, Thr398 and Tyr400, were changed by site-directed mutagenesis. Virus structural proteins are produced at normal levels in BHK-21 cells transfected with RNA containing the double mutation, nucleocapsids are formed, and the envelope proteins are exported from the endoplasmic reticulum; however, no virus is produced. The double mutation prevents phosphorylation of PE2/E2, and electron microscopy of cells transfected with the double mutant RNA reveals no attachment of nucleocapsids to cell membranes. The double mutation blocks exposure of the carboxyl terminus of E2 to the cytoplasm. Revertants of the double mutant to virus production all restored tyrosine at position 400 and restored the ability of the E2 protein to be phosphorylated. Although the threonine at position 398 is conserved among the alphaviruses, no revertant restored threonine at this position.

[Preliminary study on intestinal microflora in patients with cirrhosis]

Intestinal microflora were studied in 62 patients with cirrhosis, 14 with hepatitis and 30 normal subjects. The fecal anaerobes, total viable organisms, E.coli, enterococcus, bifidobacterium, lactobacillus and clostridium were significantly greater in number in cirrhotic patients than in normal subjects and hepatitis. Significant increase in fecal enterococcus and clostridium was observed in the patients recently recovered from hepatic coma as compared with the patients without hepatic coma. Bifidobacterium was increased in cirrhotic patients between patients with or without LLT (+). These data suggest that there was a tendency of the intestinal microorganisms to be increased in cirrhotic patients and the existence of possible relationship between the severity of liver function impairment and quantity of intestinal flora.