• Title/Summary/Keyword: T protein

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Functional Implication of the tRNA Genes Encoded in the Chlorella Virus PBCV-l Genome

  • Lee, Da-Young;Graves, Michael V.;Van Etten, James L.;Choi, Tae-Jin
    • The Plant Pathology Journal
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    • v.21 no.4
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    • pp.334-342
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    • 2005
  • The prototype Chlorella virus PBCV-l encodes 11 tRNA genes and over 350 protein-encoding genes in its 330 kbp genome. Initial attempts to overexpress the recombinant A189/192R protein, a putative virus attachment protein, in E. coli strain BL21(DE3) SI were unsuccessful, and multiple protein bands were detected on Western blots. However, the full-length A189/192R recombinant protein or fragments derived from it were detected when they were expressed in E. coli BL21 CodonPlus (DE3) RIL, which contains extra tRNAs. Codon usage analysis of the a189/192r gene showed highly biased usage of the AGA and AVA codons compared to genes encoded by E. coli and Chlorella. In addition, there were biases of XXA/U($56\%$) and XXG/ C($44\%$) in the codons recognized by the viral tRNAs, which correspond to the codon usage bias in the PBCV-1 genome of XXA/U ($63\%$) over those ending in XXC/G ($37\%$). Analysis of the codon usage in the major capsid protein and DNA polymerase showed preferential usage of codons that can be recognized by the viral tRNAs. The Asn (AAC) and Lys (AAG) codons whose corresponding tRNA genes are duplicated in the tRNA gene cluster were the most abundant (i.e., preferred) codons in these two proteins. The tRNA genes encoded in the PBCV-l genome seem to play a very important role during the synthesis of viral proteins through supplementing the tRNAs that are frequently used in viral proteins, but are rare in the host cells. In addition, these tRNAs would help the virus to adapt to a wide range of hosts by providing tRNAs that are rare in the host cells.

A role of carboxy-terminal region of Toxoplasma gondii-heat shock protein 70 in enhancement of T. gondii infection in mice

  • Mun, Hye-Seong;Norose, Kazumi;Aosai, Fumie;Chen, Mei;Yano, Akihiko
    • Parasites, Hosts and Diseases
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    • v.38 no.2
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    • pp.107-110
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    • 2000
  • We investigated the role of recombinant Toxoplasma gondii heat shock protein (rT.g.HSP) 70-full length, rT.g. HSP70-NH2-terminal region, or rT.g. HSP70-carboxy-terminal region in prophylactic immunity in C57BL/6 mice perorally infected with Fukaya cysts of T. gondii. At 3, 4, 5, and 6 weeks after infection, the number of T gondii in the brain tissue of each mouse was measured by quantitative competitive-polymerase chain reaction (QC-PCR) targeting the surface antigen (SAG) 1 gene. Immunization with rT.g.HSP70-full length or rT.g.HSP70-carboxy-terminal region increased the number of T. gondii in the brain tissue after T. gondii infection, whereas immunization with rT.g.HSP70-NHa-terminal region did not. These results suggest that T.g. HSP70-carboxy-terminal region as well as T.g.HSP70-full length may induce deleterious effects on the protective immunity of mice infected with a cyst-forming T. gondii strain, Fukaya.

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Interaction of the Bacteriophage P2 Tin Protein and Bacteriophage T4 gp32 Protein Inhibites Growth of Bacteriophage T4

  • Jin, Hee-Kyung;Kim, Min-Jung;Park, Chan-Hee;Park, Jung-Chan;Myung, Hee-Joon
    • Journal of Microbiology and Biotechnology
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    • v.11 no.4
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    • pp.724-726
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    • 2001
  • The growth of baceriophage T4 is inhibited by the presence of the tin gene product o bacteriophage P2. The interaction between purified Tin and gp32 proteins was observed using coimmunoprecipitation experiments. The in vivo interaction was confirmed by yeast two-hybrid experiments. A deletion analysis showed that the Asp 163 region of gp32 to DNA substrates was not affected by the presence of Tin, Thus, it would appear that the inhibition of 4 growth by Tin was due to a protein-protein interaction rather than affecting the DNA-binding ability of gp32.

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T-cell epitope specificity for Porphyromonas gingivalis heat shock protein in periodontitis (치주염환자의 Porphyromonas gingivalis 열충격단백에 대한 T-세포 항원 결정부위 특이성 연구)

  • Lee, Ji-Young;Lee, Ju-Yeon;Choi, Jeom-Il
    • Journal of Periodontal and Implant Science
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    • v.33 no.4
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    • pp.543-553
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    • 2003
  • Due to considerably high degree of sequence homology between bacterial and human heat shock proteins(hsp), it has been widely thought that this protein might be involved in autoimmune disease mechanisms in humans. To elucidate how stress proteins contribute in the immunopathogenesis of periodontitis, the present study was performed to evaluate the T cell immune responses specific to Porphyromonas gingivalis (P. gingivalis) heat shock protein (hsp)60 and T-cell epitope specificities for P. gingivalis hsp60 in periodontitis. Anti-P. gingivalis IgG antibody titers were elevated in all patients. We could establish P. gingivalis hsp-specific T cell ines from the peripheral blood of peridontitis, a mixture of $CD4^+$ and $CD8^+$ cells. Of 108 overlapping synthetic peptides spanning whole P. gingivalis hsp60 moleculc, ten peptides with cpitopes specifities for T-cell were showed. Interestingly, ten epitopes were also identified as T-cell epitopes in the present study as well as B-cell epitopes in peridontitis. Therefore, all the ten representative epitopes were designated as common T-and B-cell epitopes for peridontitis. It is critical in developing a peptide vaccine strategy for potential prevention of periodontitis. It was concluded that P. gingivalis hsp60 might be involved in the immunoregulatory process of periodontitis with heat shock protein specificities.

Effects of Dyglomera® on leptin expression, pro-inflammatory cytokines, and adipocyte browning in 3T3-L1 cells

  • Da-Eun Min;Sung-Kwon Lee;Hae Jin Lee;Bong-Keun Choi;Dong-Ryung Lee
    • Journal of Applied Biological Chemistry
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    • v.66
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    • pp.186-196
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    • 2023
  • Dyglomera® is an aqueous ethanol extract derived from the fruit and pods of Dichrostachys glomerata. A previous study has revealed that Dyglomera regulates adipogenesis and lipolysis by modulating AMP-activated protein kinase (AMPK) phosphorylation and increased expression levels of lipolysis-related proteins in white adipose tissue of high fat diet-induced mice and 3T3-L1 adipocyte cells. To further investigate mechanisms of Dyglomera, additional studies were performed using 3T3-L1 cells. Results revealed that Dyglomera downregulated adipogenesis by inhibiting the protein kinase B/mammalian target of rapamycin signaling pathway and reconfirmed that it downregulated gene expression levels of proliferator-activated receptor (PPAR)-γ, CCAAT enhancer binding protein α, sterol-regulation element-binding protein-1c. Dyglomera also reduced adipokines such as tumor necrosis factor alpha, interleukin-1β, and interleukin 6 by regulating leptin expression. Moreover, Dyglomera promoted beige-and-brown adipocyte-related phenotypes and regulated metabolism by increasing mitochondrial number and expression levels of genes such as T-box protein 1, transmembrane protein 26, PR domain 16, and cluster of differentiation 40 as well as thermogenic factors such as uncoupling protein 1, proliferator-activated receptor-gamma co-activator-1α, Sirtuin 1, and PPARα through AMPK activation. Thus, Dyglomera not only can inhibit adipogenesis, but also can promote lipolysis and thermogenesis and regulate metabolism by affecting adipokine secretion from 3T3-L1 adipocytes.

Immunotherapeutic Effects of CTLA4Ig Fusion Protein on Murine EAE and GVHD (마우스 EAE, GVHD 질환에서 CTLA4Ig 융합단백의 면역치료 효과)

  • Jang, Seong-Ok;Hong, Soo-Jong;Cho, Hoon-Sik;Chung, Yong-Hoon
    • IMMUNE NETWORK
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    • v.3 no.4
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    • pp.302-309
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    • 2003
  • Background: CTLA4 (CD152), which is expressed on the surface of T cells following activation, has a much higher affinity for B7 molecules comparing to CD28, and is a negative regulator of T cell activation. In contrast to stimulating and agonistic capabilities of monoclonal antibodies specific to CTLA-4, CTLA4Ig fusion protein appears to act as CD28 antagonist and inhibits in vitro and in vivo T cell priming in variety of immunological conditions. We've set out to confirm whether inhibition of the CD28-B7 costimulatory response using a soluble form of human CTLA4Ig fusion protein would lead to persistent inhibition of alloreactive T cell activation. Methods: We have used CHO-$dhfr^-$ cell-line to produce CTLA4Ig fusion protein. After serum free culture of transfected cell line we purified this recombinant molecule by using protein A column. To confirm characterization of fusion protein, we carried out a series of Western blot, SDS-PAGE and silver staining analyses. We have also investigated the efficacy of CTLA4Ig in vitro such as mixed lymphocyte reaction (MLR) & cytotoxic T lymphocyte (CTL) response and in vivo such as experimental autoimmune encephalomyelitis (EAE), graft versus host disease (GVHD) and skin-graft whether this fusion protein could inhibit alloreactive T cell activation and lead to immunosuppression of activated T cell. Results: In vitro assay, CTLA4Ig fusion protein inhibited immune response in T cell-specific manner: 1) Human CTLA4Ig inhibited allogeneic stimulation in murine MLR; 2) CTLA4Ig prevented the specific killing activity of CTL. In vivo assay, human CTLA4Ig revealed the capacities to induce alloantigen-specific hyporesponsiveness in mouse model: 1) GVHD was efficiently blocked by dose-dependent manner; 2) Clinical score of EAE was significantly decreased compared to nomal control; 3) The time of skin-graft rejection was not different between CTLA4Ig treated and control group. Conclusion: Human CTLA4Ig suppress the T cell-mediated immune response and efficiently inhibit the EAE, GVHD in mouse model. The mechanism of T cell suppression by human CTLA4Ig fusion protein may be originated from the suppression of activity of cytotoxic T cell. Human CTLA4Ig could not suppress the rejection in mouse skin-graft, this finding suggests that other mechanism except the suppression of cytotoxic T cell may exist on the suppression of graft rejection.

Tenderization of Bovine Longissimus Dorsi Muscle using Aqueous Extract from Sarcodon aspratus

  • Kim, Ho-Kyoung;Lee, Sang-Hoon;Ryu, Youn-Chul
    • Food Science of Animal Resources
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    • v.35 no.4
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    • pp.533-540
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    • 2015
  • The aim of this study was to investigate the effects of aqueous extract from Sarcodon aspratus on tenderization of the bovine longissimus dorsi muscles in comparison with commercial proteolytic enzymes. Furthermore, meat quality and muscle protein degradation were examined. We marinated meat with 2% Sarcodon aspratus extract, 2% kiwi extract, and 0.2% papain. Beef chunks (3×3×3 cm3) were marinated with distilled water (control), Sarcodon aspratus extract (T1), kiwi extract (T2) or papain (T3) for 48 h at 4℃. There were no significant differences in muscle pH and lightness between control and treated samples. T1 had the lowest redness (p<0.01), and higher cooking loss and water holding capacity than control and T2 (p<0.05). T1 and T3 exhibited lower shear force values than control (p<0.05). Total protein solubility did not differ significantly between T1 and control, but T1 had less myofibrillar protein solubility than control and T2 (p<0.001). The degradation of myosin heavy chain in T1 and T3 was observed. This degradation of myofibrillar protein suggests that Sarcodon aspratus extract could influence tenderization. These results show that aqueous extract of Sarcodon aspratus extract actively affect the tenderness of the bovine longissimus dorsi muscle.

Electrophoretic Studies on Haemolymph Protein, Digestive Fluid Protein and Digestive Amylase Activity in the Wild silkworm, Theophila mandarina. (상잠의 형액과 소화액에 있어서 단백질과 Amylase 활성에 관한 전기영동적 연구)

  • 문재유;박광의
    • Journal of Sericultural and Entomological Science
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    • v.27 no.1
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    • pp.37-41
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    • 1985
  • The haemolymph protein, digestive fluid proteins and digestive fluid amylase activity of wild silkworm, Theophila mandarina those of the were studied by polyacrylamide gel electrophoresis. In addition, they was also compared with silkworm. 1. 6 main protein bands in female and 7 main protein bands in male were detected in the larval haemolymph of T. mandarina where as 8 and 7 main protein bands in female and male of B. mori were observed. Some differences in the haemolymph protein ands of T. mandarina and B. mori were observed. 2. 15 protein bands and 12 protein bands were found in the larval digestive fluid of T. mandarina and B. mori respectively. Some differences in the mobility of digestive fluid proteins of T. mandarina and B. mori were noticed. 3. Larval digestive fluid amylases were anionic and moved near the tracking dye in both T. mandarina and B. mori. Mobility of the digestive fluid amylases relative to bromophenol blue were 0.019 and 0.020 in T. mandarina and B. mori respectively.

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The Binding Properties of Glycosylated and Non- Glycosylated Tim-3 Molecules on $CD4^+CD25^+$T Cells

  • Lee, Mi-Jin;Heo, Yoo-Mi;Hong, Seung-Ho;Kim, Kyong-Min;Park, Sun
    • IMMUNE NETWORK
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    • v.9 no.2
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    • pp.58-63
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    • 2009
  • Background: T cell immunoglobulin and mucin domain containing 3 protein (Tim-3) expressed on terminally differentiated Th1 cells plays a suppressive role in Th1-mediated immune responses. Recently, it has been shown that N-glycosylation affects the binding activity of the Tim-3-Ig fusion protein to its ligand, galectin-9, but the binding properties of non-glycosylated Tim-3 on $CD4^+CD25^+$T cells has not been fully examined. In this study, we produced recombinant Tim-3-Ig fusion proteins in different cellular sources and its N-glycosylation mutant forms to evaluate their binding activities to $CD4^+CD25^+$T cells. Methods: We isolated and cloned Tim-3 cDNA from BALB/C mouse splenocytes. Then, we constructed a mammalian expression vector and a prokaryotic expression vector for the Tim-3-Ig fusion protein. Using a site directed mutagenesis method, plasmid vectors for Tim-3-Ig N-glycosylation mutant expression were produced. The recombinant protein was purified by protein A sepharose column chromatography. The binding activity of Tim-3-Ig fusion protein to $CD4^+CD25^+$T cells was analyzed using flow cytometry. Results: We found that the nonglycosylated Tim-3-Ig fusion proteins expressed in bacteria bound to $CD4^+CD25^+$T cells similarly to the glycosylated Tim-3-Ig protein produced in CHO cells. Further, three N-glycosylation mutant forms (N53Q, N100Q, N53/100Q) of Tim-3-Ig showed similar binding activities to those of wild type glycosylated Tim-3-Ig. Conclusion: Our results suggest that N-glycosylation of Tim-3 may not affect its binding activity to ligands expressed on $CD4^+CD25^+$T cells.

Resistance to Toxoplasma gondii Infection in Mice Treated with Silk Protein by Enhanced Immune Responses

  • Moon, Joung-Ho;Pyo, Kyoung-Ho;Jung, Bong-Kwang;Chun, Hyang-Sook;Chai, Jong-Yil;Shin, Eun-Hee
    • Parasites, Hosts and Diseases
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    • v.49 no.3
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    • pp.303-308
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    • 2011
  • This study investigated whether elevated host immune capacity can inhibit T. gondii infection. For this purpose, we used silk protein extracted from Bombyx mori cocoons as a natural supplement to augment immune capacity. After silk protein administration to BALB/c mice for 6 weeks, ratios of T lymphocytes ($CD4^+$ and $CD8^+$ T-cells) and splenocyte proliferative capacities in response to Con A or T. gondii lysate antigen (TLA) were increased. Of various cytokines, which regulate immune systems, Th1 cytokines, such as IFN-${\gamma}$, IL-2, and IL-12, were obviously increased in splenocyte primary cell cultures. Furthermore, the survival of T. gondii (RH strain)-infected mice increased from 2 days to 5 or more days. In a state of immunosuppression induced by methylprednisolone acetate, silk protein-administered mice were resistant to reduction in T-lymphocyte ($CD4^+$ and $CD8^+$ T-cells) numbers and the splenocyte proliferative capacity induced by Con A or TLA with a statistical significance. Taken together, our results suggest that silk protein augments immune capacity in mice and the increased cellular immunity by silk protein administration increases host protection against acute T. gondii infection.