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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,225 records · Page 68
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Over-expression of Stat5b confers protection against diabetes in the non-obese diabetic (NOD) mice via up-regulation of CD4{sup +}CD25{sup +} regulatory T cells

Highlights: Black-Right-Pointing-Pointer This is the first study to provide direct evidence of the role of Stat5b in NOD mice. Black-Right-Pointing-Pointer Over-expression of wild type Stat5b transgene protects NOD mice against diabetes. Black-Right-Pointing-Pointer This protection may be mediated by the up-regulation of CD4{sup +}CD25{sup +} Tregs. -- Abstract: The signal transducers and activators of transcription (STAT) family of proteins play a critical role in cytokine signaling required for fine tuning of immune regulation. Previous reports showed that a mutation (L327M) in the Stat5b protein leads to aberrant cytokine signaling in the NOD mice. To further elaborate the role of Stat5b in diabetes, we established a NOD transgenic mouse that over-expresses the wild type Stat5b gene. The incidences of spontaneous diabetes as well as cyclophosphamide-induced diabetes were significantly reduced and delayed in the Stat5b transgenic NOD mice compared to their littermate controls. The total cell numbers of CD4{sup +} T cells and especially CD8{sup +} T cells in the spleen and pancreatic lymph node were increased in the Stat5b transgenic NOD mice. Consistent with these findings, CD4{sup +} and CD8{sup +} T cells from the Stat5b transgenic NOD mice showed a higher proliferation capacity and up-regulation of multiple cytokines including IL-2, IFN-{gamma}, TNF-{alpha} and IL-10 as well as anti-apoptotic gene Bcl-xl. Furthermore, the number and proportion of CD4{sup +}CD25{sup +} regulatory T cells were significantly increased in transgenic mice although in vitro suppression ability of the regulatory T-cells was not affected by the transgene. Our results suggest that Stat5b confers protection against diabetes in the NOD mice by regulating the numbers and function of multiple immune cell types, especially by up-regulating CD4{sup +}CD25{sup +} regulatory T cells.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

miR-9 modulates the expression of interferon-regulated genes and MHC class I molecules in human nasopharyngeal carcinoma cells

Highlights: ► miR-9 can negatively or positively modulate interferon-induced gene expression. ► miR-9 can up-regulate major histocompatibility complex class I molecule expression. ► miR-9 can down-regulate the expression of interleukin-related genes. -- Abstract: The functions of miR-9 in some cancers are recently implicated in regulating proliferation, epithelial–mesenchymal transition (EMT), invasion and metastasis, apoptosis, and tumor angiogenesis, etc. miR-9 is commonly down-regulated in nasopharyngeal carcinoma (NPC), but the exact roles of miR-9 dysregulation in the pathogenesis of NPC remains unclear. Therefore, we firstly used miR-9-expressing CNE2 cells to determine the effects of miR-9 overexpression on global gene expression profile by microarray analysis. Microarray-based gene expression data unexpectedly demonstrated a significant number of up- or down-regulated immune- and inflammation-related genes, including many well-known interferon (IFN)-induced genes (e.g., IFI44L, PSMB8, IRF5, PSMB10, IFI27, PSB9{sub H}UMAN, IFIT2, TRAIL, IFIT1, PSB8{sub H}UMAN, IRF1, B2M and GBP1), major histocompatibility complex (MHC) class I molecules (e.g., HLA-B, HLA-C, HLA-F and HLA-H) and interleukin (IL)-related genes (e.g., IL20RB, GALT, IL7, IL1B, IL11, IL1F8, IL1A, IL6 and IL7R), which was confirmed by qRT-PCR. Moreover, the overexpression of miR-9 with the miRNA mimics significantly up- or down-regulated the expression of above-mentioned IFN-inducible genes, MHC class I molecules and IL-related genes; on the contrary, miR-9 inhibition by anti-miR-9 inhibitor in CNE2 and 5–8F cells correspondingly decreased or increased the aforementioned immune- and inflammation-related genes. Taken together, these findings demonstrate, for the first time, that miR-9 can modulate the expression of IFN-induced genes and MHC class I molecules in human cancer cells, suggesting a novel role of miR-9 in linking inflammation and cancer, which remains to be fully characterized.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

The human leukocyte antigen G promotes trophoblast fusion and β-hCG production through the Erk1/2 pathway in human choriocarcinoma cell lines

Highlights: •HLA-G expression promotes BeWo cells fusion and fusogenic gene expression. •HLA-G is capable of inducing β-hCG production in human choriocarcinoma cell lines. •Up-regulation of β-hCG production by HLA-G is mediated via the Erk1/2 pathway. -- Abstract: The human leukocyte antigen G (HLA-G) is expressed on the fetal–maternal interface and plays a role in protecting fetal-derived trophoblasts from the maternal immune response, allowing trophoblasts to invade the uterus. However, HLA-G also possesses immune suppressing-independent functions. We found that HLA-G expressing BeWo choriocarcinoma cells increased cell–cell fusion compared to control BeWo cells under forskolin treatment. Regardless of forskolin treatment, the expression of fusogenic gene mRNAs, including syncytin-1, the transcription factor glial cell missing 1 (Gcm1), and beta human chorionic gonadotropin (β-hCG) were elevated. HLA-G up-regulates β-hCG production in human choriocarcinoma cells because HLA-G knockdown in JEG-3 cells induces a dramatic decrease in β-hCG compared with control cells. The defect in β-hCG production in HLA-G knocked-down cells could not be completely overcome by stimulating hCG production through increasing intracellular cAMP levels. HLA-G expressing cells have increased phosphorylation levels for extracellular signal-regulated kinase1/2 (Erk1/2) in BeWo cells. The Erk1/2 pathway is inactivated after the inhibition of HLA-G expression in JEG-3 cells. Finally, Erk1/2 inhibition was able to suppress the increased hCG production induced by HLA-G expression. Together, these data suggest novel roles for HLA-G in regulating β-hCG production via the modulation of the Erk1/2 pathway and by inducing trophoblast cell fusion.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Procyanidin dimer B2-mediated IRAK-M induction negatively regulates TLR4 signaling in macrophages

Highlights: •Pro B2 elevated the expression of IRAK-M, a negative regulator of TLR signaling. •LPS-induced expression of cell surface molecules was inhibited by Pro B2. •LPS-induced production of pro-inflammatory cytokines was inhibited by Pro B2. •Pro B2 inhibited LPS-induced activation of MAPKs and NF-κB through IRAK-M. •Pro B2 inactivated naïve T cells by inhibiting LPS-induced cytokines via IRAK-M. -- Abstract: Polyphenolic compounds have been found to possess a wide range of physiological activities that may contribute to their beneficial effects against inflammation-related diseases; however, the molecular mechanisms underlying this anti-inflammatory activity are not completely characterized, and many features remain to be elucidated. In this study, we investigated the molecular basis for the down-regulation of toll-like receptor 4 (TLR4) signal transduction by procyanidin dimer B2 (Pro B2) in macrophages. Pro B2 markedly elevated the expression of the interleukin (IL)-1 receptor-associated kinase (IRAK)-M protein, a negative regulator of TLR signaling. Lipopolysaccharide (LPS)-induced expression of cell surface molecules (CD80, CD86, and MHC class I/II) and production of pro-inflammatory cytokines (tumor necrosis factor-α, IL-1β, IL-6, and IL-12p70) were inhibited by Pro B2, and this action was prevented by IRAK-M silencing. In addition, Pro B2-treated macrophages inhibited LPS-induced activation of mitogen-activated protein kinases such as extracellular signal-regulated kinase 1/2, p38, and c-Jun N-terminal kinase and the translocation of nuclear factor κB and p65 through IRAK-M. We also found that Pro B2-treated macrophages inactivated naïve T cells by inhibiting LPS-induced interferon-γ and IL-2 secretion through IRAK-M. These novel findings provide new insights into the understanding of negative regulatory mechanisms of the TLR4 signaling pathway and the immune-pharmacological role of Pro B2 in the immune response against the development and progression of many chronic diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Th1-skewed tissue responses to a mycolyl glycolipid in mycobacteria-infected rhesus macaques

Highlights: •Glucose monomycolate (GMM) is a marker glycolipid for active tuberculosis. •Tissue responses to GMM involved up-regulation of Th1-attracting chemokines. •Th1-skewed local responses were mounted at the GMM-injected tissue. -- Abstract: Trehalose 6,6′-dimycolate (TDM) is a major glycolipid of the cell wall of mycobacteria with remarkable adjuvant functions. To avoid detection by the host innate immune system, invading mycobacteria down-regulate the expression of TDM by utilizing host-derived glucose as a competitive substrate for their mycolyltransferases; however, this enzymatic reaction results in the concomitant biosynthesis of glucose monomycolate (GMM) which is recognized by the acquired immune system. GMM-specific, CD1-restricted T cell responses have been detected in the peripheral blood of infected human subjects and monkeys as well as in secondary lymphoid organs of small animals, such as guinea pigs and human CD1-transgenic mice. Nevertheless, it remains to be determined how tissues respond at the site where GMM is produced. Here we found that rhesus macaques vaccinated with Mycobacterium bovis bacillus Calmette–Guerin mounted a chemokine response in GMM-challenged skin that was favorable for recruiting T helper (Th)1 T cells. Indeed, the expression of interferon-γ, but not Th2 or Th17 cytokines, was prominent in the GMM-injected tissue. The GMM-elicited tissue response was also associated with the expression of monocyte/macrophage-attracting CC chemokines, such as CCL2, CCL4 and CCL8. Furthermore, the skin response to GMM involved the up-regulated expression of granulysin and perforin. Given that GMM is produced primarily by pathogenic mycobacteria proliferating within the host, the Th1-skewed tissue response to GMM may function efficiently at the site of infection.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2013

Network signatures of cellular immortalization in human lymphoblastoid cell lines

Highlights: •We identified network signatures of LCL immortalization from transcriptomic profiles. •More than 41% of DEGs are possibly regulated by miRNAs in LCLs. •MicroRNA target genes in LCLs are involved in apoptosis and immune-related functions. •This approach is useful to find functional miRNA targets in specific cell conditions. -- Abstract: Human lymphoblastoid cell line (LCL) has been used as an in vitro cell model in genetic and pharmacogenomic studies, as well as a good model for studying gene expression regulatory machinery using integrated genomic analyses. In this study, we aimed to identify biological networks of LCL immortalization from transcriptomic profiles of microRNAs and their target genes in LCLs. We first selected differentially expressed genes (DEGs) and microRNAs (DEmiRs) between early passage LCLs (eLCLs) and terminally differentiated late passage LCLs (tLCLs). The in silico and correlation analysis of these DEGs and DEmiRs revealed that 1098 DEG–DEmiR pairs were found to be positively (n = 591 pairs) or negatively (n = 507 pairs) correlated with each other. More than 41% of DEGs are possibly regulated by miRNAs in LCL immortalizations. The target DEGs of DEmiRs were enriched for cellular functions associated with apoptosis, immune response, cell death, JAK–STAT cascade and lymphocyte activation while non-miRNA target DEGs were over-represented for basic cell metabolisms. The target DEGs correlated negatively with miR-548a-3p and miR-219-5p were significantly associated with protein kinase cascade, and the lymphocyte proliferation and apoptosis, respectively. In addition, the miR-106a and miR-424 clusters located in the X chromosome were enriched in DEmiR–mRNA pairs for LCL immortalization. In this study, the integrated transcriptomic analysis of LCLs could identify functional networks of biologically active microRNAs and their target genes involved in LCL immortalization.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

A high-throughput assay of NK cell activity in whole blood and its clinical application

Graphical abstract: - Highlights: • We demonstrated a simple assay of NK cell activity from whole blood. • The measurement of secreted IFN-γ from NK cell enables high-throughput screening. • The NKA assay was validated by clinical results of colorectal cancer patients. - Abstract: Natural killer (NK) cells are lymphocytes of the innate immune system and have the ability to kill tumor cells and virus-infected cells without prior sensitization. Malignant tumors and viruses have developed, however, strategies to suppress NK cells to escape from their responses. Thus, the evaluation of NK cell activity (NKA) could be invaluable to estimate the status and the outcome of cancers, viral infections, and immune-mediated diseases. Established methods that measure NKA, such as {sup 51}Cr release assay and CD107a degranulation assay, may be used to determine NK cell function, but they are complicated and time-consuming because they require isolation of peripheral blood mononuclear cells (PBMC) or NK cells. In some cases these assays require hazardous material such as radioactive isotopes. To overcome these difficulties, we developed a simple assay that uses whole blood instead of PBMC or isolated NK cells. This novel assay is suitable for high-throughput screening and the monitoring of diseases, because it employs serum of ex vivo stimulated whole blood to detect interferon (IFN)-γ secreted from NK cells as an indicator of NKA. After the stimulation of NK cells, the determination of IFNγ concentration in serum samples by enzyme-linked immunosorbent assay (ELISA) provided a swift, uncomplicated, and high-throughput assay of NKA ex vivo. The NKA results microsatellite stable (MSS) colorectal cancer patients was showed significantly lower NKA, 263.6 ± 54.5 pg/mL compared with healthy subjects, 867.5 ± 50.2 pg/mL (p value <0.0001). Therefore, the NKA could be utilized as a supportive diagnostic marker for microsatellite stable (MSS) colorectal cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

A nanobody directed to a functional epitope on VEGF, as a novel strategy for cancer treatment

Highlights: • A novel nanobody directed to antigenic regions on VEGF was identified. • Our nanobody was successfully purified. • Our nanobody significantly inhibited VEGF-induced proliferation of HUVECs in a dose dependent manner. - Abstract: Compelling evidence suggests that vascular endothelial growth factor (VEGF), due to its essential role in angiogenesis, is a critical target for cancer treatment. Neutralizing monoclonal antibodies against VEGF are important class of drugs used in cancer therapy. However, the cost of production, large size, and immunogenicity are main drawbacks of conventional monoclonal therapy. Nanobodies are the smallest antigen-binding antibody fragments, which occur naturally in camelidae. Because of their remarkable features, we decided to use an immune library of nanobody to direct phage display to recognition of novel functional epitopes on VEGF. Four rounds of selection were performed and six phage-displayed nanobodies were obtained from an immune phage library. The most reactive clone in whole-cell ELISA experiments, was purified and assessed in proliferation inhibition assay. Purified ZFR-5 not only blocked interaction of VEGF with its receptor in cell ELISA experiments, but also was able to significantly inhibit proliferation response of human umbilical vein endothelial cells to VEGF in a dose-dependent manner. Taken together, our study demonstrates that by using whole-cell ELISA experiments, nanobodies against antigenic regions included in interaction of VEGF with its receptors can be directed. Because of unique and intrinsic properties of a nanobody and the ability of selected nanobody for blocking the epitope that is important for biological function of VEGF, it represents novel potential drug candidate.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Nascent histamine induces α-synuclein and caspase-3 on human cells

Highlights: • Nascent histamine alters cyclin expression pattern. • Nascent histamine increases expression of α-synuclein. • Nascent histamine activates caspase-3. - Abstract: Histamine (Hia) is the most multifunctional biogenic amine. It is synthetized by histidine decarboxylase (HDC) in a reduced set of mammalian cell types. Mast cells and histaminergic neurons store Hia in specialized organelles until the amine is extruded by exocytosis; however, other immune and cancer cells are able to produce but not store Hia. The intracellular effects of Hia are still not well characterized, in spite of its physiopathological relevance. Multiple functional relationships exist among Hia metabolism/signaling elements and those of other biogenic amines, including growth-related polyamines. Previously, we obtained the first insights for an inhibitory effect of newly synthetized Hia on both growth-related polyamine biosynthesis and cell cycle progression of non-fully differentiated mammalian cells. In this work, we describe progress in this line. HEK293 cells were transfected to express active and inactive versions of GFP-human HDC fusion proteins and, after cell sorting by flow cytometry, the relative expression of a large number of proteins associated with cell signaling were measured using an antibody microarray. Experimental results were analyzed in terms of protein–protein and functional interaction networks. Expression of active HDC induced a cell cycle arrest through the alteration of the levels of several proteins such as cyclin D1, cdk6, cdk7 and cyclin A. Regulation of α-synuclein and caspase-3 was also observed. The analyses provide new clues on the molecular mechanisms underlying the regulatory effects of intracellular newly synthetized Hia on cell proliferation/survival, cell trafficking and protein turnover. This information is especially interesting for emergent and orphan immune and neuroinflammatory diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Lactic acid delays the inflammatory response of human monocytes

Lactic acid (LA) accumulates under inflammatory conditions, e.g. in wounds or tumors, and influences local immune cell functions. We previously noted inhibitory effects of LA on glycolysis and TNF secretion of human LPS-stimulated monocytes. Here, we globally analyze the influence of LA on gene expression during monocyte activation. To separate LA-specific from lactate- or pH-effects, monocytes were treated for one or four hours with LPS in the presence of physiological concentrations of LA, sodium lactate (NaL) or acidic pH. Analyses of global gene expression profiles revealed striking effects of LA during the early stimulation phase. Up-regulation of most LPS-induced genes was significantly delayed in the presence of LA, while this inhibitory effect was attenuated in acidified samples and not detected after incubation with NaL. LA targets included genes encoding for important monocyte effector proteins like cytokines (e.g. TNF and IL-23) or chemokines (e.g. CCL2 and CCL7). LA effects were validated for several targets by quantitative RT-PCR and/or ELISA. Further analysis of LPS-signaling pathways revealed that LA delayed the phosphorylation of protein kinase B (AKT) as well as the degradation of IκBα. Consistently, the LPS-induced nuclear accumulation of NFκB was also diminished in response to LA. These results indicate that the broad effect of LA on gene expression and function of human monocytes is at least partially caused by its interference with immediate signal transduction events after activation. This mechanism might contribute to monocyte suppression in the tumor environment. - Highlights: • Lactic acid broadly delays LPS-induced gene expression in human monocytes. • Expression of important monocyte effector molecules is affected by lactic acid. • Interference of lactic acid with TLR signaling causes the delayed gene expression. • The profound effect of lactic acid might contribute to immune suppression in tumors.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Pam2 lipopeptides systemically increase myeloid-derived suppressor cells through TLR2 signaling

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells that exhibit potent immunosuppressive activity. They are increased in tumor-bearing hosts and contribute to tumor development. Toll-like receptors (TLRs) on MDSCs may modulate the tumor-supporting properties of MDSCs through pattern-recognition. Pam2 lipopeptides represented by Pam2CSK4 serve as a TLR2 agonist to exert anti-tumor function by dendritic cell (DC)-priming that leads to NK cell activation and cytotoxic T cell proliferation. On the other hand, TLR2 enhances tumor cell progression/invasion by activating tumor-infiltrating macrophages. How MDSCs respond to TLR2 agonists has not yet been determined. In this study, we found intravenous administration of Pam2CSK4 systemically up-regulated the frequency of MDSCs in EG7 tumor-bearing mice. The frequency of tumor-infiltrating MDSCs was accordingly increased in response to Pam2CSK4. MDSCs were not increased by Pam2CSK4 stimuli in TLR2 knockout (KO) mice. Adoptive transfer experiments using CFSE-labeled MDSCs revealed that the TLR2-positive MDSCs survived long in tumor-bearing mice in response to Pam2CSK4 treatment. Since the increased MDSC population sustained immune-suppressive properties, our study suggests that Pam2CSK4-triggered TLR2 activation enhances the MDSC potential and suppress antitumor immune response in tumor microenvironment. - Highlights: • Pam2CSK4 administration induces systemic accumulation of CD11b{sup +}Gr1{sup +} MDSCs. • TLR2 is essential for Pam2CSK4-induced accumulation of CD11b{sup +}Gr1{sup +} MDSCs. • Pam2CSK4 supports survival of CD11b{sup +}Gr1{sup +} MDSCs in vivo.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Ectopic expression of anti-HIV-1 shRNAs protects CD8{sup +} T cells modified with CD4ζ CAR from HIV-1 infection and alleviates impairment of cell proliferation

Chimeric antigen receptors (CARs) are artificially engineered receptors that confer a desired specificity to immune effector T cells. As an HIV-1-specific CAR, CD4ζ CAR has been extensively tested in vitro as well as in clinical trials. T cells modified with this CAR mediated highly potent anti-HIV-1 activities in vitro and were well-tolerated in vivo, but exerted limited effects on viral load and reservoir size due to poor survival and/or functionality of the transduced cells in patients. We hypothesize that ectopic expression of CD4ζ on CD8{sup +} T cells renders them susceptible to HIV-1 infection, resulting in poor survival of those cells. To test this possibility, highly purified CD8{sup +} T cells were genetically modified with a CD4ζ-encoding lentiviral vector and infected with HIV-1. CD8{sup +} T cells were vulnerable to HIV-1 infection upon expression of CD4ζ as evidenced by elevated levels of p24{sup Gag} in cells and culture supernatants. Concurrently, the number of CD4ζ-modified CD8{sup +} T cells was reduced relative to control cells upon HIV-1 infection. To protect these cells from HIV-1 infection, we co-expressed two anti-HIV-1 shRNAs previously developed by our group together with CD4ζ. This combination vector was able to suppress HIV-1 infection without impairing HIV-1-dependent effector activities of CD4ζ. In addition, the number of CD4ζ-modified CD8{sup +} T cells maintained similar levels to that of the control even under HIV-1 infection. These results suggest that protecting CD4ζ-modified CD8{sup +} T cells from HIV-1 infection is required for prolonged HIV-1-specific immune surveillance. - Highlights: • Ectopic expression of CD4ζ CAR in CD8{sup +} T cells renders them susceptible to HIV-1 infection. • Co-expression of two anti-HIV-1 shRNAs protects CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection. • Protecting CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection suppresses its cytopathic effect.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Hypermethylation of MST1 in IgG4-related autoimmune pancreatitis and rheumatoid arthritis

The serine/threonine kinase Mst1 plays important roles in the control of immune cell trafficking, proliferation, and differentiation. Previously, we reported that Mst1 was required for thymocyte selection and regulatory T-cell functions, thereby the prevention of autoimmunity in mice. In humans, MST1 null mutations cause T-cell immunodeficiency and hypergammaglobulinemia with autoantibody production. RASSF5C(RAPL) is an activator of MST1 and it is frequently methylated in some tumors. Herein, we investigated methylation of the promoter regions of MST1 and RASSF5C(RAPL) in leukocytes from patients with IgG4-related autoimmune pancreatitis (AIP) and rheumatoid arthritis (RA). Increased number of CpG methylation in the 5′ region of MST1 was detected in AIP patients with extrapancreatic lesions, whereas AIP patients without extrapancreatic lesions were similar to controls. In RA patients, we detected a slight increased CpG methylation in MST1, although the overall number of methylation sites was lower than that of AIP patients with extrapancreatic lesions. There were no significant changes of the methylation levels of the CpG islands in the 5′ region of RASSF5C(RAPL) in leukocytes from AIP and RA patients. Consistently, we found a significantly down-regulated expression of MST1 in regulatory T cells of AIP patients. Our results suggest that the decreased expression of MST1 in regulatory T cells due to hypermethylation of the promoter contributes to the pathogenesis of IgG4-related AIP. - Highlights: • Mst1 controls immune cells trafficking, cell proliferation and differentiation. • Autoimmune pancreatitis (AIP) is an idiopathic pancreatitis affecting multiple organs. • Decreased MST1 expression and increased CpG methylation of promoter of MST1 in AIP. • Slight increased CpG methylation of MST1 in rheumatoid arthritis patients. • MST1 contributes pathogenesis of IgG4-related AIP.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Activation of human natural killer cells by the soluble form of cellular prion protein

Cellular prion protein (PrP{sup C}) is widely expressed in various cell types, including cells of the immune system. However, the specific roles of PrP{sup C} in the immune system have not been clearly elucidated. In the present study, we investigated the effects of a soluble form of recombinant PrP{sup C} protein on human natural killer (NK) cells. Recombinant soluble PrP{sup C} protein was generated by fusion of human PrP{sup C} with the Fc portion of human IgG{sub 1} (PrP{sup C}-Fc). PrP{sup C}-Fc binds to the surface of human NK cells, particularly to CD56{sup dim} NK cells. PrP{sup C}-Fc induced the production of cytokines and chemokines and the degranulation of granzyme B from NK cells. In addition, PrP{sup C}-Fc facilitated the IL-15-induced proliferation of NK cells. PrP{sup C}-Fc induced phosphorylation of ERK-1/2 and JNK in NK cells, and inhibitors of the ERK or the JNK pathways abrogated PrP{sup C}-Fc-induced cytokine production in NK cells. In conclusion, the soluble form of recombinant PrP{sup C}-Fc protein activates human NK cells via the ERK and JNK signaling pathways. - Highlights: • Recombinant soluble PrP{sup C} (PrP{sup C}-Fc) was generated by fusion of human PrP{sup C} with IgG1 Fc portion. • PrP{sup C}-Fc protein induces the production of cytokines and degranulation from human NK cells. • PrP{sup C}-Fc protein enhances the IL-15-induced proliferation of human NK cells. • PrP{sup C}-Fc protein activates human NK cells via the ERK and JNK signaling pathways.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

MAR binding protein SMAR1 favors IL-10 mediated regulatory T cell function in acute colitis

T{sub reg} cells are not only crucial for controlling immune responses to autoantigens but also prevent those directed towards commensal pathogens. Control of effector immune responses by T{sub reg} cells depend on their capacity to accumulate at inflammatory site and accordingly accommodate to inflammatory environment. Till date, the factors associated with maintaining these aspects of T{sub reg} phenotype is not understood properly. Here we have shown that a known nuclear matrix binding protein SMAR1 is selectively expressed more in colonic T{sub reg} cells and is required for their ability to accumulate at inflammatory site and to sustain high levels of Foxp3 and IL-10 expression during acute colitis. Elimination of anti-inflammatory subsets revealed a protective role for IL-10 producing T{sub reg} cells in SMAR1{sup −/−} mice. Moreover, a combined action of Foxp3 and SMAR1 restricts effector cytokine production and enhance the production of IL-10 by colonic T{sub reg} cells that controls acute colitis. This data highlights a critical role of SMAR1 in maintaining T{sub reg} physiology during inflammatory disorders. - Highlights: • SMAR1 is essential to sustain high level of Foxp3 and IL-10 in T{sub reg} cells. • SMAR1{sup −/−} T{sub reg} cells produce pro-inflammatory cytokine IL-17 leads to inflammation. • IL-10 administration can control the inflammation in SMAR1{sup −/−} mice. • Both Foxp3 and SMAR1 maintain T{sub reg} phenotype that controls colitis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Tumor-promoting effect of IL-23 in mammary cancer mediated by infiltration of M2 macrophages and neutrophils in tumor microenvironment

Interleukin 23 (IL-23) is an inflammatory cytokine which plays a vital role in autoimmune diseases as well as in tumorigenesis. However, the role of IL-23 in tumor procession is still controversial and the underlying mechanism remains unclear. Here we established a stable cell line overexpressing IL-23 to prove that IL-23 promoted tumor growth and pulmonary metastasis through induction of tumor-related inflammation and absence of immune surveillance. IL-23 promotes tumor-associate inflammatory response such as infiltration of M2 macrophages, neutrophils and their elevated secretions of immunosuppressive cytokines transforming growth factor-β (TGF-β), IL-10 and vascular endothelial growth factor (VEGF) into tumor tissues, meanwhile the increase of the matrix metalloprotease MMP9. In addition, IL-23 increases the expression of the endothelial marker CD31 and proliferative marker Ki67 in tumors. Moreover, IL23 induces immunosuppression though reducing the infiltration of CD4{sup +}and CD8{sup +}T cells into tumor tissues. In conclusion, IL-23 is a considerable molecular in tumor progression, which simultaneously facilitates processes of pro-tumor inflammation, such as angiogenesis, immunosuppressive cytokines as well as infiltrations of M2 macrophages and neutrophils, and suppresses antitumor immune responses through reduction of CD4{sup +} T cells and CD8{sup +} T cells. - Highlights: • IL-23 promoted mammary tumor growth and pulmonary metastasis. • IL-23 enhanced the infiltration of M2 macrophages and neutrophils into IL-23-dominated tumor microenvironment (TME). • Immunosuppressing cytokines IL-10, TGF-β and VEGF were detected to rise in IL-23-transduced tumor tissues. • IL-23 down regulated the ability of CD8{sup +}T and CD4{sup +}T cells to infiltrate tumors.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Structural study of the effects of mutations in proteins to identify the molecular basis of the loss of local structural fluidity leading to the onset of autoimmune diseases

Protein-Protein Interactions (PPIs) are crucial in most of the biological processes and PPI dysfunctions are known to be associated with the onsets of various diseases. One of such diseases is the auto-immune disease. Auto-immune diseases are one among the less studied group of diseases with very high mortality rates. Thus, we tried to correlate the appearances of mutations with their probable biochemical basis of the molecular mechanisms leading to the onset of the disease phenotypes. We compared the effects of the Single Amino Acid Variants (SAVs) in the wild type and mutated proteins to identify any structural deformities that might lead to altered PPIs leading ultimately to disease onset. For this we used Relative Solvent Accessibility (RSA) as a spatial parameter to compare the structural perturbation in mutated and wild type proteins. We observed that the mutations were capable to increase intra-chain PPIs whereas inter-chain PPIs would remain mostly unaltered. This might lead to more intra-molecular friction causing a deleterious alteration of protein's normal function. A Lyapunov exponent analysis, using the altered RSA values due to polymorphic and disease causing mutations, revealed polymorphic mutations have a positive mean value for the Lyapunov exponent while disease causing mutations have a negative mean value. Thus, local spatial stochasticity has been lost due to disease causing mutations, indicating a loss of structural fluidity. The amino acid conversion plot also showed a clear tendency of altered surface patch residue conversion propensity than polymorphic conversions. So far, this is the first report that compares the effects of different kinds of mutations (disease and non-disease causing polymorphic mutations) in the onset of autoimmune diseases. - Highlights: • Protein-Protein Interaction. • Changes in Relative Solvent Accessibility (RSA). • Amino acid conversion matrix. • Polymorphic mutations. • Disease causing mutations.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Selenoprotein K modulate intracellular free Ca{sup 2+} by regulating expression of calcium homoeostasis endoplasmic reticulum protein

Selenoprotein K (SelK) is an 11-kDa selenoprotein, which may be involved in the regulation of oxidative stress, endoplasmic reticulum (ER) stress and immune response. To explore the function of SelK in the process of immune response, several short-hairpin RNAs (shRNA) were designed for the construction of recombinant plasmids to down-regulate the expression of SelK gene in vitro. These shRNAs specifically and efficiently interfered with the expression of SelK at both mRNA and protein levels. The expression of calcium homoeostasis endoplasmic reticulum protein (CHERP) and the intracellular free Ca{sup 2+} concentration were significantly down-regulated in anti-CD3 stimulated SelK-knockdown cells. The expression of Interleukin 2 receptor alpha chain (IL-2Rα) and the secretion of Interleukin 4 (IL-4), which play a significant role in the process of T cell activation and proliferation, were also reduced in SelK-knockdown cells. Selenomethionine (Se-Met) at an optimum concentration of 5 μM could up-regulate SelK expression and reverse the change of the expression of CHERP and the intracellular free calcium caused by SelK-knockdown. These results hereby imply SelK may regulate the release of Ca{sup 2+} by CHERP and play an important role in the proliferation and differentiation of T cell by TCR stimulation.

60 APPLIED LIFE SCIENCES↗