Thursday, January 19, 2012

peptide t| What is peptide t|Papers on peptide t|Research on peptide t| Publications on peptide t


1.
Proc Natl Acad Sci U S A. 2012 Jan 3;109(1):261-6. Epub 2011 Dec 14.

Immune recognition of tumor-associated mucin MUC1 is achieved by a fully synthetic aberrantly glycosylated MUC1 tripartite vaccine.

Source

Departments of Biochemistry and Molecular Biology and Hematology and Oncology, Mayo Clinic College of Medicine and Mayo Clinic Comprehensive Cancer Center, Scottsdale, AZ 85259.

Abstract

The mucin MUC1 is typically aberrantly glycosylated by epithelial cancer cells manifested by truncated O-linked saccharides. The resultant glycopeptide epitopes can bind cell surface major histocompatibility complex (MHC) molecules and are susceptible to recognition by cytotoxic T lymphocytes (CTLs), whereas aberrantly glycosylated MUC1 protein on the tumor cell surface can be bound by antibodies to mediate antibody-dependent cell-mediated cytotoxicity (ADCC). Efforts to elicit CTLs and IgG antibodies against cancer-expressed MUC1 have not been successful when nonglycosylated MUC1 sequences were used for vaccination, probably due to conformational dissimilarities. Immunizations with densely glycosylated MUC1 peptides have also been ineffective due to impaired susceptibility to antigen processing. Given the challenges to immuno-target tumor-associated MUC1, we have identified the minimum requirements to consistently induce CTLs and ADCC-mediating antibodies specific for the tumor form of MUC1 resulting in a therapeutic response in a mouse model of mammary cancer. The vaccine is composed of the immunoadjuvant Pam(3)CysSK(4), a peptide T(helper) epitope and an aberrantly glycosylated MUC1 peptide. Covalent linkage of the three components was essential for maximum efficacy. The vaccine produced CTLs, which recognized both glycosylated and nonglycosylated peptides, whereas a similar nonglycosylated vaccine gave CTLs which recognized only nonglycosylated peptide. Antibodies elicited by the glycosylated tripartite vaccine were significantly more lytic compared with the unglycosylated control. As a result, immunization with the glycosylated tripartite vaccine was superior in tumor prevention. Besides its own aptness as a clinical target, these studies of MUC1 are likely predictive of a covalent linking strategy applicable to many additional tumor-associated antigens.

PMID:
22171012
[PubMed - in process]
PMCID: PMC3252914
[Available on 2012/7/3]
Click here to read
2.
PLoS One. 2011;6(10):e25685. Epub 2011 Oct 21.

Induction of a protective response in mice by the dengue virus NS3 protein using DNA vaccines.

Source

Laboratório de Biotecnologia e Fisiologia de Infecções Virais, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil.

Abstract

The dengue non-structural 3 (NS3) is a multifunctional protein, containing a serino-protease domain, located at the N-terminal portion, and helicase, NTPase and RTPase domains present in the C-terminal region. This protein is considered the main target for CD4+ and CD8+ T cell responses during dengue infection, which may be involved in protection. However, few studies have been undertaken evaluating the use of this protein as a protective antigen against dengue, as well as other flavivirus. In the present work, we investigate the protective efficacy of DNA vaccines based on the NS3 protein from DENV2. Different recombinant plasmids were constructed, encoding either the full-length NS3 protein or only its functional domains (protease and helicase), fused or not to a signal peptide (t-PA). The recombinant proteins were successfully expressed in transfected BHK-21 cells, and only plasmids encoding the t-PA signal sequence mediated protein secretion. Balb/c mice were immunized with the different DNA vaccines and challenged with a lethal dose of DENV2. Most animals immunized with plasmids encoding the full-length NS3 or the helicase domain survived challenge, regardless of the presence of the t-PA. However, some mice presented clinical signs of infection with high morbidity (hind leg paralysis and hunched posture), mainly in animal groups immunized with the DNA vaccines based on the helicase domain. On the other hand, inoculation with plasmids encoding the protease domain did not induce any protection, since mortality and morbidity rates in these mouse groups were similar to those detected in the control animals. The cellular immune response was analyzed by ELISPOT with a specific-CD8+ T cell NS3 peptide. Results revealed that the DNA vaccines based on the full-length protein induced the production of INF-γ, thus suggesting the involvement of this branch of the immune system in the protection.

PMID:
22031819
[PubMed - in process]
PMCID: PMC3198735
Free PMC Article
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3.
PLoS One. 2011;6(7):e20528. Epub 2011 Jul 11.

DNA vaccines against dengue virus type 2 based on truncate envelope protein or its domain III.

Source

Laboratório de Biotecnologia e Fisiologia de Infecções Virais, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil.

Abstract

Two DNA vaccines were constructed encoding the ectodomain (domains I, II and III) of the DENV2 envelope protein (pE1D2) or only its domain III (pE2D2), fused to the human tissue plasminogen activator signal peptide (t-PA). The expression and secretion of recombinant proteins was confirmed in vitro in BHK cells transfected with the two plasmids, detected by immunofluorescence or immunoprecipitation of metabolically labeled gene products, using polyclonal and monoclonal antibodies against DENV2. Besides, results reveal that the ectodomain of the E protein can be efficiently expressed in vivo, in a mammalian system, without the prM protein that is hypothesized to act as a chaperonin during dengue infection. Balb/c mice were immunized with the DNA vaccines and challenged with a lethal dose of DENV2. All pE1D2-vaccinated mice survived challenge, while 45% of animals immunized with the pE2D2 died after infection. Furthermore, only 10% of pE1D2-immunized mice presented some clinical signs of infection after challenge, whereas most of animals inoculated with the pE2D2 showed effects of the disease with high morbidity degrees. Levels of neutralizing antibodies were significantly higher in pE1D2-vaccinated mice than in pE2D2-immunized animals, also suggesting that the pE1D2 vaccine was more protective than the pE2D2.

PMID:
21779317
[PubMed - indexed for MEDLINE]
PMCID: PMC3136928
Free PMC Article
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4.
Methods Mol Biol. 2011;751:343-55.

On-resin convergent synthesis of a glycopeptide from HIV gp120 containing a high mannose type N-linked oligosaccharide.

Abstract

This chapter describes a rapid and efficient approach for the solid-phase synthesis of N-linked glycopeptides that utilizes on-resin glycosylamine coupling to produce N-linked glycosylation sites. In this method, the full-length nonglycosylated peptide is first synthesized on a solid-phase support using standard Fmoc chemistry. The glycosylation site is then introduced through an orthogonally protected 2-phenylisopropyl (PhiPr) aspartic acid (Asp) residue. After selective deprotection of the Asp residue, a high mannose type oligosaccharide glycosylamine is coupled on-resin to the free Asp side chain to form a N-glycosidic bond. Subsequent protecting group removal and peptide cleavage from the resin ultimately yields the desired glycopeptide. This strategy provides an effective route for conducting glycosylation reactions on a solid-phase support, simplifies the process of glycopeptide purification relative to solution-phase glycopeptide synthesis strategies, and enables the recovery of potentially valuable, un-reacted oligosaccharides. This approach has been applied to the solid-phase synthesis of the N-linked high mannose glycosylated form of peptide T (ASTTTNYT), a fragment of the HIV-1 envelope glycoprotein gp120.

PMID:
21674342
[PubMed - indexed for MEDLINE]
PMCID: PMC3141317
Free PMC Article
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5.
Open Virol J. 2011;5:44-51. Epub 2011 May 12.

Inhibition of HIV-1 Env-Mediated Cell-Cell Fusion by Lectins, Peptide T-20, and Neutralizing Antibodies.

Source

Department of Biomedical Sciences, University of the Pacific Arthur A. Dugoni School of Dentistry, San Francisco, CA 94115, USA.

Abstract

BACKGROUND:

Broadly cross-reactive, neutralizing human monoclonal antibodies, including 2F5, 2G12, 4E10 and IgG1 b12, can inhibit HIV-1 infection in vitro at very low concentrations. We examined the ability of these antibodies to inhibit cell-cell fusion between Clone69TRevEnv cells induced to express the viral envelope proteins, gp120/gp41 (Env), and highly CD4-positive SupT1 cells. The cells were loaded with green and red-orange cytoplasmic fluorophores, and fusion was monitored by fluorescence microscopy.

RESULTS:

Cell-cell fusion was inhibited completely by the carbohydrate binding proteins (CBPs), Hippeastrum hybrid (Amaryllis) agglutinin (HHA), and Galanthus nivalis (Snowdrop) agglutinin (GNA), and by the peptide, T-20, at relatively low concentrations. Anti-gp120 and anti-gp41 antibodies, at concentrations much higher than those required for neutralization, were not particularly effective in inhibiting fusion. Monoclonal antibodies b12, m14 IgG and 2G12 had moderate inhibitory activity; the IC(50) of 2G12 was about 80 µg/ml. Antibodies 4E10 and 2F5 had no inhibitory activity at the concentrations tested.

CONCLUSIONS:

These observations raise concerns about the ability of neutralizing antibodies to inhibit the spread of viral genetic material from infected cells to uninfected cells via cell-cell fusion. The interaction of gp120/gp41 with cell membrane CD4 may be different in cell-cell and virus-cell membrane fusion reactions, and may explain the differential effects of antibodies in these two systems. The fluorescence assay described here may be useful in high throughput screening of potential HIV fusion inhibitors.

PMID:
21660189
[PubMed]
PMCID: PMC3109660
Free PMC Article
Click here to read
6.
Drug Test Anal. 2011 Jan;3(1):68-73. doi: 10.1002/dta.212. Epub 2010 Dec 29.

Screen and confirmation of PEG-epoetin β in equine plasma.

Source

Anti-Doping Research Inc., Los Angeles, CA 90066, USA.

Abstract

Methods have been developed to screen for and confirm darbepoetin alfa, recombinant human EPO, and methoxy polyethylene glycol-epoetin β (PEG-epoetin β) in horse plasma. All three methods screen samples with an enzyme-linked immunosorbent assay (ELISA) and confirm by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This report focuses on PEG-epoetin β. The ELISA assay was able to detect PEG-epoetin β at 0.02 ng/mL in 50 µL of horse plasma. Many samples had high background levels of immunoreactivity; however, introducing polyethylene glycol 6000 (PEG 6000) into the samples before the ELISA assay removed the high background and increased the apparent concentrations of PEG-epoetin β. In samples collected following the administration of 100 µg of PEG-epoetin β by the intravenous (IV), intramuscular (IM) and subcutaneous (SC) routes, PEG-epoetin β was detectable up to 72, 144, and 120 h, respectively. The samples were prepared for LC-MS/MS analysis by extraction with anti-rHuEPO-antibodies-coated Dynabeads followed by digestion with trypsin. The LC-MS/MS confirmation method used the multiple reaction monitoring (MRM) scan mode to monitor four precursor-product ion transitions of the EPO-derived peptide T₆. All four transitions of T₆ were detectable with S/N > 3. The limit of confirmation for PEG-epoetin β was 1.0 ng/mL in 2 mL of horse plasma. The method successfully confirmed the presence of PEG-epoetin β in a sample collected from a Mircera®-treated horse. Compared to PEG-epoetin β, better sensitivity was achieved for darbepoetin alfa and recombinant human EPO. Darbepoetin alfa was detected in horse plasma four days after IM administration of 100 µg.

Copyright © 2010 John Wiley & Sons, Ltd.

PMID:
21254454
[PubMed - indexed for MEDLINE]
Click here to read
7.
PLoS One. 2010 Dec 28;5(12):e14433.

Pharmacological treatment of painful HIV-associated sensory neuropathy: a systematic review and meta-analysis of randomised controlled trials.

Source

Department of Anaesthetics, Pain Medicine and Intensive Care, Imperial College London, Chelsea and Westminster Hospital Campus, London, United Kingdom.

Abstract

BACKGROUND:

Significant pain from HIV-associated sensory neuropathy (HIV-SN) affects ∼40% of HIV infected individuals treated with antiretroviral therapy (ART). The prevalence of HIV-SN has increased despite the more widespread use of ART. With the global HIV prevalence estimated at 33 million, and with infected individuals gaining increased access to ART, painful HIV-SN represents a large and expanding world health problem. There is an urgent need to develop effective pain management strategies for this condition.

METHOD AND FINDINGS:

OBJECTIVE:

To evaluate the clinical effectiveness of analgesics in treating painful HIV-SN.

DESIGN:

Systematic review and meta-analysis.

DATA SOURCES:

Medline, Cochrane central register of controlled trials, www.clinicaltrials.gov, www.controlled-trials.com and the reference lists of retrieved articles.

SELECTION CRITERIA:

Prospective, double-blinded, randomised controlled trials (RCTs) investigating the pharmacological treatment of painful HIV-SN with sufficient quality assessed using a modified Jadad scoring method.

REVIEW METHODS:

Four authors assessed the eligibility of articles for inclusion. Agreement of inclusion was reached by consensus and arbitration. Two authors conducted data extraction and analysis. Dichotomous outcome measures (≥ 30% and ≥ 50% pain reduction) were sought from RCTs reporting interventions with statistically significant efficacies greater than placebo. These data were used to calculate RR and NNT values.

RESULTS:

Of 44 studies identified, 19 were RCTs. Of these, 14 fulfilled the inclusion criteria. Interventions demonstrating greater efficacy than placebo were smoked cannabis NNT 3.38 95%CI(1.38 to 4.10), topical capsaicin 8%, and recombinant human nerve growth factor (rhNGF). No superiority over placebo was reported in RCTs that examined amitriptyline (100mg/day), gabapentin (2.4 g/day), pregabalin (1200 mg/day), prosaptide (16 mg/day), peptide-T (6 mg/day), acetyl-L-carnitine (1g/day), mexilitine (600 mg/day), lamotrigine (600 mg/day) and topical capsaicin (0.075% q.d.s.).

CONCLUSIONS:

Evidence of efficacy exists only for capsaicin 8%, smoked cannabis and rhNGF. However,rhNGF is clinically unavailable and smoked cannabis cannot be recommended as routine therapy. Evaluation of novel management strategies for painful HIV-SN is urgently needed.

PMID:
21203440
[PubMed - indexed for MEDLINE]
PMCID: PMC3010990
Free PMC Article
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8.
Drug Test Anal. 2010 Dec 29. [Epub ahead of print]

Screen and confirmation of PEG-epoetin β in equine plasma.

Source

Anti-Doping Research Inc., 3873 Grand View Boulevard, Los Angeles, CA 90066, USA.

Abstract

Methods have been developed to screen for and confirm darbepoetin alfa, recombinant human EPO, and methoxy polyethylene glycol-epoetin ${\bf{\beta}}$ (PEG-epoetin ${\bf{\beta}}$) in horse plasma. All three methods screen samples with an enzyme-linked immunosorbent assay (ELISA) and confirm by liquid chromatography-tandem mass spectrometry (LC-MS/MS). This report focuses on PEG-epoetin ${\bf{\beta}}$. The ELISA assay was able to detect PEG-epoetin ${\bf{\beta}}$ at 0.02 ng/mL in 50 µL of horse plasma. Many samples had high background levels of immunoreactivity; however, introducing polyethylene glycol 6000 (PEG 6000) into the samples before the ELISA assay removed the high background and increased the apparent concentrations of PEG-epoetin ${\bf{\beta}}$. In samples collected following the administration of 100 µg of PEG-epoetin ${\bf{\beta}}$ by the intravenous (IV), intramuscular (IM) and subcutaneous (SC) routes, PEG-epoetin ${\bf{\beta}}$ was detectable up to 72, 144, and 120 h, respectively. The samples were prepared for LC-MS/MS analysis by extraction with anti-rHuEPO-antibodies-coated Dynabeads followed by digestion with trypsin. The LC-MS/MS confirmation method used the multiple reaction monitoring (MRM) scan mode to monitor four precursor-product ion transitions of the EPO-derived peptide T(6). All four transitions of T(6) were detectable with S/N > 3. The limit of confirmation for PEG-epoetin ${\bf{\beta}}$ was 1.0 ng/mL in 2 mL of horse plasma. The method successfully confirmed the presence of PEG-epoetin ${\bf{\beta}}$ in a sample collected from a Mircera®-treated horse. Compared to PEG-epoetin ${\bf{\beta}}$, better sensitivity was achieved for darbepoetin alfa and recombinant human EPO. Darbepoetin alfa was detected in horse plasma four days after IM administration of 100 µg. Copyright © 2010 John Wiley & Sons, Ltd.

PMID:
21191970
[PubMed - as supplied by publisher]
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9.
Exp Mol Pathol. 2011 Apr;90(2):157-66. Epub 2010 Nov 24.

Quantitative and phenotypic analyses of lymphocyte-monocyte heterokaryons induced by the HIV envelope proteins: Significant loss of lymphoid markers.

Source

Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado postal 70228, Ciudad Universitaria, Distrito Federal, CP 04510, México.

Abstract

Cells infected with the human immunodeficiency virus (HIV) can fuse with CD4(+) cells leading to the formation of multinucleated cells. The presence of multinucleated cells infected with HIV in tissues of patients has been documented, although their cellular composition and role in AIDS pathogenesis is still under study. Here, we present evidence of in vitro heterotypic lymphocyte-monocyte fusion in cocultures of lymphocytic Jurkat T cells expressing the HIV-1 gp120/gp41 glycoproteins (Env) and CD4(+) monocytic THP-1 cells. Using a previously characterized method that involves differential labeling of fusion partners with fluorescent probes and flow cytometry analysis after coculture, up to 20% of double fluorescent cells were detected in 48h. This double fluorescent cell population was produced by heterotypic lymphocyte-monocyte fusion as it was not observed when Jurkat T cells expressing a mutant non-fusogenic Env protein were used. Heterokaryon formation was inhibited by an anti-CD4 monoclonal antibody and the HIV-fusion inhibitor peptide T-20. About 68% of heterokaryons remained alive and non-apoptotic after 2days of coculture. In heterokaryons, CD4 was barely detectable and the expression of the CD3 and CD28 lymphoid markers was greatly reduced, whereas the expression of CD32 and the intracellular antigen CD68, both markers of monocytic cells, remained unchanged. In contrast with unfused T cells, heterokaryons only expressed very low levels of the lymphoid activation marker CD25 following treatment with PMA plus ionomycin. These studies point to the possible generation of lymphocyte-monocyte heterokaryons with a myeloid phenotype during HIV infection, with unknown consequences for AIDS pathogenesis.

Copyright © 2010 Elsevier Inc. All rights reserved.

PMID:
21110955
[PubMed - indexed for MEDLINE]
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10.
Adv Gerontol. 2010;23(1):68-70.

[Peptidergic regulation of the expression of signal factors of fibroblast differentiation in the human prostate gland in cell aging].

[Article in Russian]

Abstract

The effect of short peptides T-32, T-38 and cardiogen on the expression of signaling factors of the differentiation of human prostate's fibroblasts (PFM), which are the main cells of its microenvironment--protein CXCL12, WEDC1 and ghrelin in aging cultures has been studied. Confocal laser microscopy has demonstrated that all the investigated peptides possess the ability to actively enhance the expression of the above markers, whose synthesis significantly reduced in senescent cultures. It has been shown that the rate of expression of the studied factors in older cultures (after 7 passages) under the action of the peptides have a tendency to even higher than those of controls (young culture, after 1 passage). Thus, peptide T-38 is the most active among the investigated ones. These studies show promise for detailed development of methods of peptides' regulation of aging and age-correction of violations of functioning of the prostate gland.

PMID:
20586252
[PubMed - indexed for MEDLINE]
11.
J Immunol. 2010 May 1;184(9):4620-4. Epub 2010 Apr 5.

Cutting edge: human latency-associated peptide+ T cells: a novel regulatory T cell subset.

Source

Center for Neurologic Diseases, Brigham and Women's Hospital, Boston, MA 02115, USA.

Abstract

Regulatory T cells (Tregs) play an important role in the maintenance of peripheral tolerance. Several molecules including TGF-beta have been linked to the function and differentiation of Tregs. In this study, we describe a unique population of T cells expressing a membrane bound form of TGF-beta, the latency-associated peptide (LAP), and having regulatory properties in human peripheral blood. These CD4(+)LAP(+) T cells lack Foxp3 but express TGF-betaR type II and the activation marker CD69. CD4(+)LAP(+) T cells are hypoproliferative compared with CD4(+)LAP(-) T cells, secrete IL-8, IL-9, IL-10, IFN-gamma, and TGF-beta upon activation, and exhibit TGF-beta- and IL-10-dependent suppressive activity in vitro. The in vitro activation of CD4(+)LAP(-) T cells results in the generation of LAP(+) Tregs, which is further amplified by IL-8. In conclusion, we have characterized a novel population of human LAP(+) Tregs that is different from classic CD4(+)Foxp3(+)CD25(high) natural Tregs.

PMID:
20368276
[PubMed - indexed for MEDLINE]
PMCID: PMC2904991
Free PMC Article
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12.
Curr Pharm Des. 2010;16(9):1143-58.

Peptide-based inhibitors of the HIV envelope protein and other class I viral fusion proteins.

Source

Institute of Virology, OE 5230, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany. Poehlmann.Stefan@MH-Hannover.DE

Abstract

Viruses need to deliver their genomic information into the host cell lumen to establish productive infection. Enveloped viruses accomplish this task by fusing their membrane with a host cell membrane. Membrane fusion is facilitated by specialized viral membrane proteins, which mediate binding and entry into host cells. The architecture of the fusion machinery of envelope proteins can differ between viruses, and class I, II and III fusion systems have been described. However, the conformational rearrangements associated with membrane fusion are comparable and constitute attractive targets for intervention. The fusion apparatus of the human immunodeficiency virus (HIV) envelope protein (Env), a class I fusion protein, is located in the transmembrane unit gP41 of Env. The fusion machinery is activated by Env binding to CD4 and a chemokine coreceptor, and the structural rearrangements in gp41 associated with membrane fusion comprise the insertion of a fusion peptide into the target cell membrane and the formation of a stable six-helix bundle structure. These processes can be efficiently inhibited by peptides mimicking conserved functional elements in gp41. A prominent example for such peptides, termed fusion inhibitors, is the peptide T-20 (enfuvirtide, Fuzeon) which is used as salvage therapy of HIV/AIDS. Here, we will discuss how HIV mediates fusion with host cell membranes and how this process can be blocked by peptides targeting gp41. In addition, we will discuss peptide inhibitors of other class I viral fusion proteins.

PMID:
20030613
[PubMed - indexed for MEDLINE]
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13.
J Pept Sci. 2009 Dec;15(12):818-23.

Peptide T exhibits a well-defined structure in fluorinated solvent at low temperature.

Source

Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL, Canada.

Abstract

The structure of Peptide T was determined by solution NMR spectroscopy, under strong structure-inducing conditions: 40% hexafluoro-2-propanol aqueous solution at 5 degrees C. Under these conditions it was possible to detect medium-range NOEs for the first time for this peptide. This allowed a much better-defined structure to be determined for Peptide T in comparison with earlier NMR and computational studies. Peptide structures consistent with the experimental restraints were generated using a restrained MD simulation with a full empirical force field. Residues 4-8 of Peptide Ttake on a well-defined structure with a heavy atom RMSD of 0.78 A. The structure is stabilized by hydrogen bonding to side-chain oxygen atoms of Thr 4 and Thr 8, as well as backbone hydrogen bonding between residues 5 and 7 that forms this region into a classic gamma-turn.

(c) 2009 European Peptide Society and John Wiley & Sons, Ltd.

PMID:
19862845
[PubMed - indexed for MEDLINE]
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14.
Circ Heart Fail. 2009 Jul;2(4):311-9. Epub 2009 May 14.

Serum levels of the interleukin-1 receptor family member ST2, cardiac structure and function, and long-term mortality in patients with acute dyspnea.

Source

Department of Medicine, Cardiology Division, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.

Abstract

BACKGROUND:

ST2, a biomarker of cardiomyocyte stretch, powerfully predicts poor outcomes in patients with acute dyspnea, but nothing is known about associations between soluble ST2 (sST2) and cardiac structure and function, or whether sST2 retains prognostic meaning in the context of such measures.

METHODS AND RESULTS:

One hundred thirty-four dyspneic patients with and without decompensated heart failure had echocardiography during index admission and vital status was ascertained at 4 years. Echocardiographic and clinical correlates of sST2 as well as independent predictors of death at 4 years were identified. sST2 correlated with left ventricular end-systolic dimensions/volumes and left ventricular ejection fraction. sST2 was inversely associated with right ventricular fractional area change (rho=-0.18; P=0.046), higher right ventricular systolic pressure (rho=0.26; P=0.005), and right ventricular hypokinesis (P<0.001) and was correlated with tissue Doppler Ea wave peak velocity, but not to other indices of diastolic function. In multivariate regression, independent predictors of sST2 included right ventricular systolic pressure (t=2.29; P=0.002), left ventricular ejection fraction (t=-2.15; P=0.05) and dimensions (end systolic, t=2.57; end diastolic, t=2.98; both P<0.05), amino-terminal pro-B-type natriuretic peptide (t=3.31; P=0.009), heart rate (t=2.59; P=0.01), and presence of jugular venous distension (t=2.00; P=0.05). In a Cox proportional hazards model that included echocardiographic results and other biomarkers, sST2 independently predicted death at 4 years (hazard ratio=2.70; P=0.003).

CONCLUSIONS:

Among dyspneic patients with and without acute heart failure, sST2 concentrations are associated with prevalent cardiac abnormalities on echocardiography, a more decompensated hemodynamic profile and are associated with long-term mortality, independent of echocardiographic, clinical, or other biochemical markers of risk.

PMID:
19808354
[PubMed - indexed for MEDLINE]
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15.
Glycoconj J. 2010 Jan;27(1):125-32. Epub 2009 Jun 27.

Syntheses of mucin-type O-glycopeptides and oligosaccharides using transglycosylation and reverse-hydrolysis activities of Bifidobacterium endo-alpha-N-acetylgalactosaminidase.

Source

Graduate School of Biostudies, Kyoto University, Kyoto, 606-8502, Japan. ashida@lif.kyoto-u.ac.jp

Abstract

Endo-alpha-N-acetylgalactosaminidase catalyzes the release of Galbeta1-3GalNAc from the core 1-type O-glycan (Galbeta1-3GalNAcalpha1-Ser/Thr) of mucin glycoproteins and synthetic p-nitrophenyl (pNP) alpha-linked substrates. Here, we report the enzymatic syntheses of core 1 disaccharide-containing glycopeptides using the transglycosylation activity of endo-alpha-N-acetylgalactosaminidase (EngBF) from Bifidobacterium longum. The enzyme directly transferred Galbeta1-3GalNAc to serine or threonine residues of bioactive peptides such as PAMP-12, bradykinin, peptide-T and MUC1a when Galbeta1-3GalNAcalpha1-pNP was used as a donor substrate. The enzyme was also found to catalyze the reverse-hydrolysis reaction. EngBF synthesized the core 1 disaccharide-containing oligosaccharides when the enzyme was incubated with either glucose or lactose and Galbeta1-3GalNAc prepared from porcine gastric mucin using bifidobacterial cells expressing endo-alpha-N-acetylgalactosaminidase. Synthesized oligosaccharides are promising prebiotics for bifidobacteria.

PMID:
19562481
[PubMed - indexed for MEDLINE]
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16.
AIDS Res Hum Retroviruses. 2009 Feb;25(2):193-8.

Enfuvirtide (T-20) resistance-related mutations in HIV type 1 subtypes B, C, and F isolates from Brazilian patients failing HAART.

Source

Laboratory of Molecular Virology, Department of Genetics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.

Abstract

The synthetic peptide T-20 (enfuvirtide, EFV) represents the first compound approved by the FDA known as entry inhibitors (EIs). The resistance mutations associated with this new class of antiretroviral drug are located in the first heptad repeat (HR1) region of gp41. Amino acid changes in codons G36D/S, I37V, V38A/M/E, Q39H/R, Q40H, N42T, and N43D can confer resistance to EFV. In this work we investigated the presence of resistance mutations that occur in patients never treated with EFV and failing HAART with protease inhibitors (PIs), nucleoside reverse transcriptase (RT) inhibitors (NRTIs), and nonnucleoside RT inhibitors (NNRTIs). This knowledge can reveal whether this salvage therapy can be effective in patients failing HAART. For this, we amplified 65 samples from plasma isolates and than sequenced a fragment of 416 nt encompassing the HR1 and HR2 regions (amino acids 33-170 of gp41). The subtype distribution among the 65 isolates was 45 (69.23%) subtype B, 9 (13.85%) subtype C, 7 (10.77%) subtype F1, and 4 (6.15%) mosaics B/F1, B/C, F1/C, and C/F1/B. We found a high prevalence (7.6%) of EFV-associated mutation G36D in this cohort of patients failing HAART therapy, five isolates from subtype B (11.11% within this group). In contrast, when 1079 sequences from drug-naive patients were analyzed, only one showed the G36D substitution. This finding indicates a strong association between the selected position G36D and HAART therapy (p < 0.0001). The isolates that possess these mutations can develop resistance to EFV more rapidly. Nevertheless, more information about the impact of these mutations in salvage therapy with EFV in patients failing HAART must still be obtained.

PMID:
19239358
[PubMed - indexed for MEDLINE]
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17.
Chembiochem. 2009 Feb 13;10(3):455-63.

Increasing the antigenicity of synthetic tumor-associated carbohydrate antigens by targeting Toll-like receptors.

Source

Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602, USA.

Abstract

SYNTHETIC CANCER VACCINES: A number of fully synthetic vaccine candidates have been designed, chemically synthesized, and immunologically evaluated to establish a strategy to overcome the poor immunogenicity of tumor-associated carbohydrates and glycopeptides and to determine the importance of Toll-like receptor (TLR) engagement for antigenic responses against these compounds.Epithelial cancer cells often overexpress mucins that are aberrantly glycosylated. Although it has been realized that these compounds offer exciting opportunities for the development of immunotherapy for cancer, their use is hampered by the low antigenicity of classical immunogens composed of a glycopeptide derived from a mucin conjugated to a foreign carrier protein. We have designed, chemically synthesized, and immunologically evaluated a number of fully synthetic vaccine candidates to establish a strategy to overcome the poor immunogenicity of tumor-associated carbohydrates and glycopeptides. The compounds were also designed to allow study of the importance of Toll-like receptor (TLR) engagement for these antigenic responses in detail. We have found that covalent attachment of a TLR2 agonist, a promiscuous peptide T-helper epitope, and a tumor-associated glycopeptide gives a compound (1) that elicits in mice exceptionally high titers of IgG antibodies that recognize MCF7 cancer cells expressing the tumor-associated carbohydrate. Immunizations with glycolipopeptide 2, which contains lipidated amino acids instead of a TLR2 ligand, gave significantly lower titers of IgG antibodies; this demonstrates that TLR engagement is critical for optimum antigenic responses. Although mixtures of compound 2 with Pam(3)CysSK(4) (3) or monophosphoryl lipid A (4) elicited titers of IgG antibodies similar to those seen with 1, the resulting antisera had impaired ability to recognize cancer cells. It was also found that covalent linkage of the helper T-epitope to the B-epitope is essential, probably because internalization of the helper T-epitope by B-cells requires assistance of the B-epitope. The results presented here show that synthetic vaccine development is amenable to structure-activity relationship studies for successful optimization of carbohydrate-based cancer vaccines.

PMID:
19145607
[PubMed - indexed for MEDLINE]
PMCID: PMC2806797
Free PMC Article
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18.
Bull Exp Biol Med. 2008 Jun;145(6):748-50.

Protective effect of tripeptide in the presence of cyclophosphamide on the growth of cultured lymphoid tissue from rats of different age.

Source

St. Petersburg Institute of Bioregulation and Gerontology, Northwestern Division of the Russian Academy of Medical Sciences, Russia. ni_chalisova@mail.ru

Abstract

We studied the effect of tripeptide T-38 (Lys-Glu-Asp) in the presence of cyclophosphamide on cell proliferation and apoptosis in explants of splenic lymphoid tissue from young and old rats. Peptide T-38 in a concentration of 0.05 ng/ml produced a stimulatory effect on the growth zone of the explants. Addition of 1 mg/ml cyclophosphamide to the culture medium suppressed cell proliferation, which was associated with enhanced expression of proapoptotic p53 protein. Under conditions of combined treatment with cyclophosphamide and T-38 no inhibiting effect of the cytostatics was observed. Thus, tripeptide T-38 in the presence of cytostatics produces a protective effect on cell proliferation in lymphoid tissue explants.

PMID:
19110568
[PubMed - indexed for MEDLINE]
19.
Proteins. 2009 Jun;75(4):931-53.

Mechanism of formation of the C-terminal beta-hairpin of the B3 domain of the immunoglobulin binding protein G from Streptococcus. I. Importance of hydrophobic interactions in stabilization of beta-hairpin structure.

Source

Laboratory of Biopolymer Structure, Intercollegiate Faculty of Biotechology, University of Gdańsk, Medical University of Gdańsk, Kładki 24, 80-822 Gdańsk, Poland.

Abstract

We previously studied a 16-amino acid-residue fragment of the C-terminal beta-hairpin of the B3 domain (residues 46-61), [IG(46-61)] of the immunoglobulin binding protein G from Streptoccocus, and found that hydrophobic interactions and the turn region play an important role in stabilizing the structure. Based on these results, we carried out systematic structural studies of peptides derived from the sequence of IG (46-61) by systematically shortening the peptide by one residue at a time from both the C- and the N-terminus. To determine the structure and stability of two resulting 12- and 14-amino acid-residue peptides, IG(48-59) and IG(47-60), respectively, we carried out circular dichroism, NMR, and calorimetric studies of these peptides in pure water. Our results show that IG(48-59) possesses organized three-dimensional structure stabilized by hydrophobic interactions (Tyr50-Phe57 and Trp48-Val59) at T = 283 and 305 K. At T = 313 K, the structure breaks down because of increased chain entropy, but the turn region is preserved in the same position observed for the structure of the whole protein. The breakdown of structure occurs near the melting temperature of this peptide (T(m) = 310 K) measured by differential scanning calorimetry (DSC). The melting temperature of IG(47-60) determined by DSC is T(m) = 330 K and its structure is similar to that of the native beta-hairpin at all (lower) temperatures examined (283-313 K). Both of these truncated sequences are conserved in all known amino acid sequences of the B domains of the immunoglobulin binding protein G from bacteria. Thus, this study contributes to an understanding of the mechanism of folding of this whole family of proteins, and provides information about the mechanism of formation and stabilization of a beta-hairpin structural element.

Copyright 2008 Wiley-Liss, Inc.

PMID:
19089955
[PubMed - indexed for MEDLINE]
PMCID: PMC2791351
Free PMC Article
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20.
J Neuroimmune Pharmacol. 2009 Mar;4(1):150-60. Epub 2008 Nov 26.

M- and T-tropic HIVs promote apoptosis in rat neurons.

Source

Department of Neuroscience, Georgetown University Medical Center, Research Building, Room EP04, Box 571464, Washington, DC 20057, USA.

Abstract

Neuronal loss, reactive astrocytes, and other abnormalities are seen in the brain of individuals with acquired immune deficiency syndrome-associated Dementia Complex (ADC). Human immunodeficiency virus-1 (HIV-1) is believed to be the main agent causing ADC. However, little is known about the molecular and cellular mechanisms of HIV-1 neurotoxicity considering that HIV-1 does not infect post-mitotic neurons and that viral load does not necessarily correlate with ADC. Various viral proteins, such as the envelope protein gp120 and the transcription activator Tat, have been shown to induce neuronal apoptosis through direct and indirect mechanisms both in vitro and in vivo. Progeny HIV-1 virions can also cause neuronal death. However, it has not been fully established yet whether HIV-1 promotes neuronal apoptosis by a direct mechanism. To explore the neurotoxic effect of HIV-1, we exposed rat cerebellar granule cells and cortical neurons in culture to two different strains of HIV-1, IIIB and BaL, T- and M-tropic strains that utilize CXCR4 and CCR5 coreceptors, respectively, to infect cells. We observed that both viruses elicit a time-dependent apoptotic cell death in these cultures without inducing a productive infection as determined by the absence of the core protein of HIV-1, p24, in cell lysates. Instead, neurons were gp120 positive, suggesting that the envelope protein is shed by the virus and then subsequently internalized by neurons. The CXCR4 receptor antagonist AMD3100 or the CCR5 receptor inhibitor D-Ala-peptide T-amide blocked HIV IIIB and HIV Bal neurotoxicity, respectively. In contrast, the N-methyl-D-aspartate receptor blocker MK801 failed to protect neurons from HIV-mediated apoptosis, suggesting that HIV-1 neurotoxicity can be initiated by the viral protein gp120 binding to neuronal chemokine receptors.

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