Automatic generation of assembly dimension chain based on tolerance cell

In the process of generating assembly dimension chain automatically, there are many problems such as complex assembly relationship, variety of constraints of components and complex dimension and tolerance relations of components. These problems lead to many difficulties in search process and need lots of man-machine interaction. Because of these difficulties, this paper presents a method of automatic generation of assembly dimension chain based on tolerance cell. This method is realized through obtaining assembly tolerance cell and part tolerance cell first. These two types of tolerance cell are extracted and expressed in the form of linked list structure in computer further. Then assembly dimension chain is searched automatically based on obtained tolerance cell, and the correct assembly dimension chain is extracted finally. A system of generating assembly dimension chain automatically has been developed based on DELMIA and successfully deployed in aircraft assembly simulation in the engineerine practice.

Role of OX40 in mechanisms of memory T cells in islet transplant tolerance

Objective To investigate the role of OX40 in the mechanisms of memory T cells in islet transplant tolerance. Methods The expression of OX40 on native, like memory and memory CD8 + T cells was detected by RT - PCR. Splenic T ceels from B6 mice were injected into Rag - / - mice via the tail vein,and the Rag mice were divided into three groups ( n = 8 each) :

Clinical efficacy and tolerance of sunitinib in the treatment of advanced renal cell carcinoma

Objective To evaluate the clinical efficacy and side effects of sunitinib in treatment of advanced renal cell carcinoma. Methods Forty-five patients with advanced renal cell carcinorna and an average age of 48. 6 yrs were treated with sunitinib. of the study group。

BCR-mediated apoptosis associated with negative selection of immature B cells is selectively dependent on Pten

The molecular basis of B cell receptor （BCR）-induced apoptosis during the negative selection of immature B cells is largely unknown. We use transitional immature B cells that are highly susceptible to BCR-induced apoptosis to show that Pten is selectively required for BCR-mediated initiation of the mitochondrial death pathway. Specifically, deleting Pten, but not other pro-apoptotic molecules, abrogates BCR-elicited apoptosis and improves viability in wild-type immature B cells. We further identify a physiologically and significantly higher intracellular Pten level in immature B cells, as compared to mature B cells, which is responsible for low AKT activity and the propensity to- wards death in immature B cells. Restoration of AKT activity using a constitutive form of AKT or reduction of Pten to a level comparable with that seen in mature B cells rescues immature B cells from BCR-induced apoptosis. Thus, we provide evidence that Pten is an essential mediator of BCR-induced cell death, and that differential regulation of intracellular Pten levels determines whether BCR ligation promotes cell death or survival. Our findings provide a valuable insight into the mechanisms underlying negative selection and clonal deletion of immature B cells.

Autoantigen administration confers diabetes-preventive properties to NOD mice derived dendritic cells

Administration of autoantigen can be of value for prevention of autoimmune diabetes and it has been speculated that the control point of dendritic cells(DC)for the induction of peripheral toler- ance may be highly relevant.We examined the properties of DC associated with immune suppression in NOD mice by insulin injection subcutaneously and their ability to suppress diabetes transfer by diabeto- genic effector cells in secondary NOD-SCID recipients.Our data showed that the surface expressions of MHCⅡand CD86 on NOD-derived DC were increased after insulin treatment compared with those on PBS controlled mice.The dendritic cells with a mature phenotype and increased MLR stimulation adop- tively transferred immune tolerogenic effects on secondary NOD-SCID mice,which were associated with significantly greater IL-10,TGF-beta production and CD4^+ CD25^+ T differentiation from splenocytes compared with NOD-SCID control recipients.Moreover,treatment with DC remarkably decreased the incidence of diabetes in secondary recipients.These results suggest that a subtype of DC generated by insulin subcutaneous treated NOD mice confers potential protection against diabetes through polarizing the immune response towards a Th2 regulatory pathway.

Intracellular detection of cytokine expression with four-color flow cytometry in pregnant NOD/SCID mice

The aim of this study was to evaluate the relationship between the embryo resorption rate （RR） and the status of local immunity at the feto-maternal interface in pregnant NOD/SCID mice. RR was calculated in NOD/SCID x NOD/SCID mice and compared with non-immunodeficiency BALB/c × BALB/c mice on day 13.5 of gestation. Intraeellular detection of cytokine expression was performed with four-color flow cytometry to identify the functional subsets of lymphocytes in NOD/SCID mice before being bred or during pregnancy. No statistically supported difference in RRs was observed between NOD/SCID × NOD/SCID and control BALB/c × BALB/c mice. Accordingly, although multiple immunodeficits were confirmed in NOD/SCID mice, the percentages of several functional cell subsets were spontaneously altered during pregnancy, and this may be correlated with the roughly normal pregnancy outcomes observed in these mice. The spontaneous alteration of cell percentages at the feto-maternal interfaee in NOD/SCID mice may be of benefit to the pregnancy outcomes.

Expression of Acyl-lipid 12-desaturase Gene in Prokaryotic and Eukaryotic Cells and Its Effect on Cold Stress Tolerance of Potato

We report the expression profile of acyl-lipid △12-desaturase （desA） gene from Synechocystis sp. PCC6803 and its effect on cell membrane lipid composition and cold tolerance in prokaryotic （Escherichia coil） and eukaryotic （Solanum tuberosum） cells. For this purpose, a hybrid of desA and reporter gene encoding thermostable lichenase （licBM3） was constructed and used to transform these cells. The expression of this hybrid gene was measured using qualitative （Petri dish test, electrophoregram and zymogram） and quantitative methods （spectrometry and gas liquid chromatography assays）. The maximum level of linoleic acid in the bacterial cells containing hybrid gene was 1.9% of total fatty acids. Cold stress tolerance assays using plant damage index and growth parameters showed that cold tolerance was enhanced in primary transgenic lines because of increased unsaturated fatty acid concentration in their lipids. The greatest content of 18：2 and 18：3 fatty acids in primary transgenic plants was observed for lines 2 （73%） and 3 （41%）. Finally, our results showed that desaturase could enhance tolerance to cold stress in potato, and desaturase and lichenase retain their functionality in the structure of the hybrid protein where the enzymatic activity of target gene product was higher than in the case of reporter lichenase gene absence in the construction.

Single-cell approaches to investigate B cells and antibodies in autoimmune neurological disorders

Autoimmune neurological disorders,including neuromyelitis optica spectrum disorder,anti-N-methyl-D-aspartate receptor encephalitis,anti-MOG antibody-associated disorders,and myasthenia gravis,are clearly defined by the presence of autoantibodies against neurological antigens.Although these autoantibodies have been heavily studied for their biological activities,given the heterogeneity of polyclonal patient samples,the characteristics of a single antibody cannot be definitively assigned.This review details the findings of polyclonal serum and CSF studies and then explores the advances made by single-cell technologies to the field of antibody-mediated neurological disorders.High-resolution single-cell methods have revealed abnormalities in the tolerance mechanisms of several disorders and provided further insight into the B cells responsible for autoantibody production.Ultimately,several factors,including epitope specificity and binding affinity,finely regulate the pathogenic potential of an autoantibody,and a deeper appreciation of these factors may progress the development of targeted immunotherapies for patients.Access options.

Deubiquitinases as pivotal regulators of T cell functions

T cells efficiently respond to foreign antigens to mediate immune responses against infections but are tolerant to self-tissues. Defect in T cell activation is associated with severe immune deficiencies, whereas aberrant T cell activation contributes to the pathogenesis of diverse autoimmune and inflammatory diseases. An emerging mechanism that regulates T cell activation and tolerance is ubiquitination, a reversible process of protein modification that is counter-regulated by ubiquitinating enzymes and deubiquitinases （DUBs）. DUBs are isopeptidases that cleave polyubiquitin chains and remove ubiquitin from target proteins, thereby controlling the magnitude and duration of ubiquitin signaling. It is now well recognized that DUBs are crucial regulators of T cell responses and serve as potential therapeutic targets for manipulating immune responses in the treatment of immunological disorders and cancer. This review will discuss the recent progresses regarding the functions of DUBs in T cells.

Production of (2S)-sakuranetin from (2S)-naringenin in Escherichia coli by strengthening methylation process and cell resistance

(2S)-Sakuranetin is a 7-O-methylflavonoid that has anticancer,antiviral,and antimicrobial activities.Methylation process is involved in biosynthesizing(2S)-sakuranetin from(2S)-naringenin,in which S-adenosylmethionine(SAM)serves as the methyl donor.In this study,after methyl donor and substrate inhibition were identified as limiting factors for(2S)-sakuranetin biosynthesis,an efficient(2S)-sakuranetin-producing strain was constructed by enhancing methyl donor supply and cell tolerance to(2S)-naringenin.Firstly,PfOMT3 from Perilla frutescens was selected as the optimal flavonoid 7-O-methyltransferase(F7-OMT)for the conversion of(2S)-naringenin to(2S)-sakuranetin.Then,the methylation process was upregulated by regulating pyridoxal 5′-phosphate(PLP)content,key enzymes in methionine synthesis pathway,and the availability of ATP.Furthermore,genes that can enhance cell resistance to(2S)-naringenin were identified from molecular chaperones and sRNAs.Finally,by optimizing the fermentation process,681.44 mg/L of(2S)-sakuranetin was obtained in 250-mL shake flasks.The titer of(2S)-sakuranetin reached 2642.38 mg/L in a 5-L bioreactor,which is the highest titer ever reported.This work demonstrates the importance of cofactor PLP in methylation process,and provides insights to biosynthesize other O-methylated flavonoids efficiently in E.coli.