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Y Lu

Publications and source records attributed to Y Lu.

At least 325 records · Page 18Linked to original sources
PubMed2000

8 Br-cAMP enhances both humoral and cell-mediated immune responses induced by an HIV-1 DNA vaccine.

From a series of preclinical studies and animal experiments, we have been able to demonstrate that DNA vaccines are a promising tool in strategies for protecting hosts from a variety of infectious diseases. Since the promoter activity of the human cytomegalovirus immediate-early promoter/ enhancer (CMV promoter) is known to be responsive to an elevation in the level of intracellular cAMP, we hypothesized that use of cAMP analogue (8-Bromo adenosine 3'5'-cyclic monophosphate, 8 Br-cAMP) would increase the level of transgene expression supported by the CMV, and enhance the ability of DNA vaccines to evoke an immune response against the transgene product in vivo. To evaluate this hypothesis, immune responses against HIV-1 envelope protein, gp160, an immunogenic HIV-1 component expressed under the control of the CMV promoter, were evaluated in BALB/c mice with or without stimulation by 8 Br-cAMP. DNA vaccine with 8 Br-cAMP was intramuscularly (i.m.) or intranasally (i.n.) administered to BALB/c mice twice on days 0 and 14. Regardless of which route was used, the combination increased the serum IgG antibody (Ab) titer, HIV-1-specific cytotoxic T lymphocyte (CTL) activity and the delayed-type hypersensitivity (DTH) response, compared with the effect of using the vaccine alone. When administered via the i.n. route, the combination also remarkably increased the titer of secretory IgA (sIgA). Moreover, it induced increased production of interferon-gamma with reduction in IL-4 synthesis, and decreased the ratio of serum IgG1/IgG2a. However, these enhancements were not observed when 8 Br-cAMP was coadministered with peptide vaccine or protein antigen. These data suggest that 8 Br-cAMP is able to enhance both humoral and cellular immune responses induced by the DNA vaccine. The induction of T helper type 1 (Th1) immunity against HIV-1 was also enhanced by coadministration of 8 Br-cAMP. A CAT assay study demonstrated that the adjuvant effect of 8 Br-cAMP may be due to the activation of the CMV promoter in the DNA vaccine. The virus challenge experiment in a mouse influenza model also proved our hypothesis.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed2000

Multiepitope vaccines intensively increased levels of antibodies recognizing three neutralizing epitopes on human immunodeficiency virus-1 envelope protein.

A few neutralizing antibodies against human immunodeficiency virus-1 (HIV-1) envelope proteins have been shown to be highly effective at neutralizing different strains in vitro, and exist at very low levels in the sera of HIV-1-infected individuals. Based on our hypothesis that epitope vaccination may be a novel strategy for inducing high levels of antibodies against HIV-1, we prepared multiepitope vaccines using three neutralizing epitopes (GPGRAFY, ELDKWA and RILAVERYLKD) on HIV-1 envelope proteins. The PI [C-G-(ELDKWA-GPGRAFY)2-K] and PII (CG-GPGRAFY-G-ELDKWA-G-RILAVERYLKD) peptides were synthesized and conjugated to a carrier protein, bovine serum albumin (BSA). After vaccination, both the PI-BSA and PII-BSA multiepitope vaccines induced high levels of epitope-specific antibodies to the three neutralizing epitopes (antibody titre: 1 : 12,800-102,400). The recombinant glycoprotein 160 (rgp160) subunit vaccine induced strong antibody responses to rgp160, but only very weak epitope-specific antibody responses to the three epitopes. The epitope-specific antibodies were isolated from rabbit sera by single epitope-peptide-conjugated sepharose columns. A yield of 51 microg of epitope-specific antibodies/ml of serum (mean value) was obtained and identified to recognize these epitopes, while 0.35 microg of protein was isolated from 1 ml of pooled preserum by C-(ELDKWAG)4- or C-(RILAVERYLKD-G)2-K- and C-(GPGRAFY)4-sepharose columns. The levels of these epitope-specific antibodies induced in rabbits were much greater than 1 microg/ml, a level that is considered to confer long-term protection against some viruses. Moreover, these antibodies recognized the neutralizing epitopes on peptides and rgp41. Based on the fact that a very low level of ELDKWA epitope-specific antibodies exist in HIV-1-infected individuals, these results suggesting that synthetic epitope vaccines could induce high levels of multiepitope-specific neutralizing antibodies indicate a new strategy for developing an effective neutralizing antibody-based epitope/peptide vaccine against HIV-1.

AIDS Vaccines↗
PubMed2000

Induction of apoptosis and activation of the caspase cascade by anti-EGF receptor monoclonal antibodies in DiFi human colon cancer cells do not involve the c-jun N-terminal kinase activity.

We previously reported that exposure of DiFi human colon cancer cells to the anti-epidermal growth factor (EGF) receptor monoclonal antibody (mAb) 225 resulted in apoptosis, but the mechanisms remain to be elucidated. In the present study, we investigated the effects of a panel of four anti-EGF receptor mAbs, each of which binds to different epitopes of the EGF receptor in DiFi cells, on the induction of apoptosis. We found that each of these mAbs induced apoptosis in DiFi cells. Exposure of DiFi cells to mAb 225 activated the initiation caspase-8, which was detectable between 8 and 16 h after exposure of the cells to the antibody. There was also an activation of the initiation caspase-9, which lagged a few hours behind the activation of caspase-8. Exposure of DiFi cells to mAb 225 also activated the execution caspase-3, which was accompanied temporally by evidence of cleavage of a well-characterized caspase-3 substrate, poly(ADP)ribosepolymerase (PARP). Pre-exposure of the cells to the caspase-3-specific inhibitor DEVD-CHO partially reduced the mAb 225-induced PARP cleavage and apoptosis, whereas pre-exposure of the cells to the caspase pan-inhibitor z-VAD-fmk completely inhibited mAb 225-induced apoptosis. Caspases-3, -8 and -9 were not activated in the cell lines in which mAb 225 only induced G1 phase arrest of the cell cycle. In contrast to the apoptosis of DiFi cells induced by ultraviolet irradiation, which strongly activated the c-jun N-terminal kinase-1 (JNK1) and the caspase cascade, mAb 225-induced apoptosis and activation of the caspase cascade in DiFi cells were not associated with activation of JNK1.

Adenocarcinoma↗
PubMed2000

A locus for brachydactyly type A-1 maps to chromosome 2q35-q36.

Brachydactyly type A-1 (BDA1) was, in 1903, the first recorded example of a human anomaly with Mendelian autosomal dominant inheritance. Two large families, the affected members of which were radiographed, were recruited in the study we describe here. Two-point linkage analysis for pedigree 1 (maximum LOD score [Zmax] 6.59 at recombination fraction [theta] 0.00) and for pedigree 2 (Zmax=5.53 at straight theta=0.00) mapped the locus for BDA1 in the two families to chromosome 2q. Haplotype analysis of pedigree 1 confined the locus for family 1 within an interval of <8.1 cM flanked by markers D2S2248 and D2S360, which was mapped to chromosome 2q35-q36 on the cytogenetic map. Haplotype analysis of pedigree 2 confined the locus for family 2 within an interval of <28. 8 cM flanked by markers GATA30E06 and D2S427, which was localized to chromosome 2q35-q37. The two families had no identical haplotype within the defined region, which suggests that the two families were not related.

Adolescent↗
PubMed2000

Reorientation of aquaporin-1 topology during maturation in the endoplasmic reticulum.

The topology of most eukaryotic polytopic membrane proteins is established cotranslationally in the endoplasmic reticulum (ER) through a series of coordinated translocation and membrane integration events. For the human aquaporin water channel AQP1, however, the initial four-segment-spanning topology at the ER membrane differs from the mature six-segment-spanning topology at the plasma membrane. Here we use epitope-tagged AQP1 constructs to follow the transmembrane (TM) orientation of key internal peptide loops in Xenopus oocyte and cell-free systems. This analysis revealed that AQP1 maturation in the ER involves a novel topological reorientation of three internal TM segments and two peptide loops. After the synthesis of TMs 4-6, TM3 underwent a 180-degree rotation in which TM3 C-terminal flanking residues were translocated from their initial cytosolic location into the ER lumen and N-terminal flanking residues underwent retrograde translocation from the ER lumen to the cytosol. These events convert TM3 from a type I to a type II topology and reposition TM2 and TM4 into transmembrane conformations consistent with the predicted six-segment-spanning AQP1 topology. AQP1 topological reorientation was also associated with maturation from a protease-sensitive conformation to a protease-resistant structure with water channel function. These studies demonstrate that initial protein topology established via cotranslational translocation events in the ER is dynamic and may be modified by subsequent steps of folding and/or maturation.

Amino Acid Sequence↗
PubMed2000

Mutations affecting the development of the peripheral nervous system in Drosophila: a molecular screen for novel proteins.

In our quest for novel genes required for the development of the embryonic peripheral nervous system (PNS), we have performed three genetic screens using MAb 22C10 as a marker of terminally differentiated neurons. A total of 66 essential genes required for normal PNS development were identified, including 49 novel genes. To obtain information about the molecular nature of these genes, we decided to complement our genetic screens with a molecular screen. From transposon-tagged mutations identified on the basis of their phenotype in the PNS we selected 31 P-element strains representing 26 complementation groups on the second and third chromosomes to clone and sequence the corresponding genes. We used plasmid rescue to isolate and sequence 51 genomic fragments flanking the sites of these P-element insertions. Database searches using sequences derived from the ends of plasmid rescues allowed us to assign genes to one of four classes: (1) previously characterized genes (11), (2) first mutations in cloned genes (1), (3) P-element insertions in genes that were identified, but not characterized molecularly (1), and (4) novel genes (13). Here, we report the cloning, sequence, Northern analysis, and the embryonic expression pattern of candidate cDNAs for 10 genes: astray, chrowded, dalmatian, gluon, hoi-polloi, melted, pebble, skittles, sticky ch1, and vegetable. This study allows us to draw conclusions about the identity of proteins required for the development of the nervous system in Drosophila and provides an example of a molecular approach to characterize en masse transposon-tagged mutations identified in genetic screens.

Animals↗
PubMed2000

A mathematical model of hepatitis B virus transmission and its application for vaccination strategy in china.

BACKGROUND: Before universal infant immunization against hepatitis B virus (HBV) in 1986 China was a region endemic for HBV infection. The prevalence of HBV infection in the population was about 60% and the proportion of chronic HBV carriers around 10%. These HBV carriers could progress to chronic hepatitis B, cirrhosis, and primary hepatocellular carcinoma. Since 1976, large-scale sero-surveys of HBV infection have been carried out and a lot of data have been collected. METHOD: This paper describes a mathematical model developed to predict the dynamics of HBV transmission and to evaluate the long-term effectiveness of the vaccination programme. We used a compartment model expressed by a set of partial differential equations based on the characteristics of HBV infection. RESULTS: All parameters, expressed in the model as a non-linear function of age and time since vaccination, were estimated using sero-survey data. The model fits well with both pre-vaccination and post-vaccination sero-surveys. The observed and estimated age-specific prevalence rates of HBV infection and HBV carriage agree with each other. According to our model, if all newborns are vaccinated according to schedule, the rate of HBV carriage will decline sharply over time to 0.2% in 70 years. By then, the ratio of acute hepatitis B will be less than 0.5% and the ratio of chronic hepatitis B will be around 5%. CONCLUSIONS: The results suggest that HBV infection in China can be controlled in just one generation, and eventually eliminated. Our model shows that vaccination coverage is the most important indicator for the elimination of HBV transmission. The higher the vaccination coverage, the better the long-term effectiveness of immunization. Thus, the key to controlling and eliminating HBV transmission in China is to find ways to immunize all infants throughout the country, especially in poor, rural areas.

Adolescent↗
PubMed2000

Protective immune responses induced by a non-pathogenic simian/human immunodeficiency virus (SHIV) against a challenge of a pathogenic SHIV in monkeys.

A simian/human immunodeficiency virus (SHIV)-NM3n containing the human nef, but not the monkey nef, and vpr genes of SIV was inoculated into two cynomolgus monkeys, resulting in systemic infection with a minimum level of transient virus load. In order to study the nature of immune responses associated with the prevention of a pathogenic SHIV, the SHIV-NM3n-inoculated monkeys and three naive monkeys were intravenously challenged with a pathogenic SHIV containing the envelope gene of HIV-1 89.6. After the heterologous virus challenge, all of the SHIV-NM3n-inoculated animals completely avoided the loss of CD4+ T lymphocytes in PBMC as well as lymphoid tissues compared to pathogenic SHIV-injected control animals. The inhibition of CD4+ cell depletion was associated with maintaining the proliferative response of helper T-cells against SIV p27 in the previously nonpathogenic virus-inoculated animals following the pathogenic virus challenge. Furthermore, the decline of CD28+ cells, the increase in CD95+ cells, and the enhancement of in vitro apoptosis in PBMC were inhibited in the non-pathogenic virus-inoculated animals. These results suggest that nonpathogenic SHIV-NM3n infection induces the protection of monkeys from heterologous pathogenic viruses that may be associated with blocking the change in immune responses and the cell loss induced by a pathogenic virus.

AIDS Vaccines↗
PubMed2000

Candidate multi-epitope vaccines in aluminium adjuvant induce high levels of antibodies with predefined multi-epitope specificity against HIV-1.

Some neutralizing epitopes on HIV-1 envelope proteins were identified to induce antibodies which could effectively inhibit the infection of different strains in vitro. But only very low levels of these antibodies were determined in the HIV-1 infected individuals. To increase the levels of protective antibodies in vivo, we suggested multi-epitope vaccine as a new strategy to induce high level of neutralization antibodies with predefined multi-epitope specificity. A synthesized epitope peptide MP (CG-GPGRAFY-G-ELDKWA-G-RILAVERYLKD) containing three neutralizing epitopes (GPGRAFY, ELDKWA, RILAVERYLKD) was conjugated to carrier protein KLH, and then used for immunization in mouse together with aluminium adjuvant or Freund's adjuvant (FA). The candidate MP-KLH multi-epitope vaccine in aluminium adjuvant could induce antibody response very strongly to the epitope peptide C-(RILAVERYLKD-G)2 and the immunosuppressive peptide (P1) (LQARILAVERYLKDQQL) (antibody titer: 1:51200), strongly to the epitope peptide C-(ELDKWA-G)4 and the C-domain peptide (P2) (1:12800), and moderately to the epitope peptide C-(GPGRAFY)4 and the V3 loop peptide (1:1600). The immunoblotting analysis demonstrated that the antibodies in sera could recognize P1, P2, V3 loop peptides and rsgp41 (aa 539-684). These results are similar with that in the case of PI-BSA in FA, and suggest that the multi-epitope vaccine in aluminium could induce high levels of antibodies of predefined multi-epitope specificity, which provides experimental evidence for the new strategy to develop an effective neutralizing antibody-based multi-epitope vaccine against HIV-1.

AIDS Vaccines↗
PubMed2000

Cytochrome P-450 2C9 sensitizes human prostate tumor cells to cyclophosphamide via a bystander effect.

The goal of the present study was to examine the ability of cytochrome P450-2C9 (CYP2C9) to activate cyclophosphamide (CPA) and elicit tumor cell death. A CYP2C9-deficient human lymphoblastoid cell line (AHH-1 cells) and a derivative cell line (H2C9 cells) stably transfected with a cDNA encoding CYP2C9 were used. The catalytic activity present in cell lines was examined by measuring the conversion of diclofenac, a CYP2C9-specific substrate, to its 4'-hydroxy metabolite by high-pressure liquid chromatography. Initial rate plots were constructed and the maximal rate of formation (V(max)) and the Michaelis-Menten constant (K(m)) for diclofenac metabolism were determined. Cytotoxicity was studied by exposing the cells to 0.01 to 4 mM CPA in the presence or absence of sulfaphenazole, a CYP2C9-specific inhibitor. Cell survival was quantitated by determination of the level of tritiated thymidine incorporation. H2C9 cells quickly metabolized diclofenac, indicating the presence of high levels of CYP2C9. Kinetic experiments demonstrated a V(max) and K(m) of 0.62+/-0.012 pmol/min/10(6) cells and 6.16+/-0.62 microM, respectively, for diclofenac metabolism. Diclofenac 4'-hydroxylase activity was undetectable in AHH-1 cells. H2C9 cells were more sensitive to the cytotoxic effects of CPA (50% inhibitory concentration [IC(50)], 0.80+/-0.03 mM) than AHH-1 cells (IC(50), 4.07+/-0.35 mM). The cytotoxicity (IC(50), 1.99+/-0.14 mM) of CPA to H2C9 cells was blocked by sulfaphenazole, demonstrating that the chemosensitivity of these cells is a consequence of intracellular prodrug activation. H2C9 cells mediated a bystander killing effect for CYP2C9-negative PPC-1 cells, reducing the IC(50) of CPA from about 14 to 3.62+/-0.73 mM in PPC-1 cells when they were cocultured with H2C9 cells. These results suggest that the enzyme-prodrug system of CYP2C9 and CPA may be an effective combination for gene-directed enzyme prodrug therapy. Ongoing studies are examining the utility of this system for use in prostate cancer cells.

Antineoplastic Agents, Alkylating↗
PubMed2000

Tol1, a fission yeast phosphomonoesterase, is an in vivo target of lithium, and its deletion leads to sulfite auxotrophy.

Lithium is the drug of choice for the treatment of bipolar affective disorder. The identification of an in vivo target of lithium in fission yeast as a model organism may help in the understanding of lithium therapy. For this purpose, we have isolated genes whose overexpression improved cell growth under high LiCl concentrations. Overexpression of tol1(+), one of the isolated genes, increased the tolerance of wild-type yeast cells for LiCl but not for NaCl. tol1(+) encodes a member of the lithium-sensitive phosphomonoesterase protein family, and it exerts dual enzymatic activities, 3'(2'),5'-bisphosphate nucleotidase and inositol polyphosphate 1-phosphatase. tol1(+) gene-disrupted cells required high concentrations of sulfite in the medium for growth. Consistently, sulfite repressed the sulfate assimilation pathway in fission yeast. However, tol1(+) gene-disrupted cells could not fully recover from their growth defect and abnormal morphology even when the medium was supplemented with sulfite, suggesting the possible implication of inositol polyphosphate 1-phosphatase activity for cell growth and morphology. Given the remarkable functional conservation of the lithium-sensitive dual-specificity phosphomonoesterase between fission yeast and higher-eukaryotic cells during evolution, it may represent a likely in vivo target of lithium action across many species.

Amino Acid Sequence↗
PubMed2000

Normal and hypoplastic fetal lungs: volumetric assessment with prenatal single-shot rapid acquisition with relaxation enhancement MR imaging.

PURPOSE: To determine which parameters are most closely correlated with normal fetal total lung volume and to investigate the use of these parameters in the evaluation of fetal pulmonary hypoplasia. MATERIALS AND METHODS: Single-shot rapid acquisition with relaxation enhancement (RARE) magnetic resonance (MR) imaging was used to perform planimetric measurement of total lung volume in 46 fetuses at 18-32 weeks gestation. Total lung volume was correlated with gestational age, and biometric parameters in fetuses were correlated with normal chest findings at ultrasonography (US) (n = 24). This analysis was used to evaluate relative lung volume in fetuses suspected of having pulmonary hypoplasia (n = 22). RESULTS: Normal fetal total lung volume was strongly correlated with liver volume measured at MR imaging (r = 0.94), fetal weight estimated at US (r = 0.93), head circumference measured at US (r = 0.90), and gestational age (r = 0.87). In fetuses suspected of having pulmonary hypoplasia, the relative lung volume varied from 4.6% to 81.6% when the observed total lung volume was expressed as a percentage of the predicted total lung volume. CONCLUSION: Normal fetal total lung volume is strongly correlated with biometric measurements. Relative fetal lung volume can be calculated by expressing the observed volume as a percentage of the predicted volume calculated from biometric measurements; knowledge of the relative fetal lung volume assists in the confirmation and quantification of fetal pulmonary hypoplasia.

Adolescent↗
PubMed2000

Prediction of deep myometrial invasion in patients with endometrial cancer: clinical utility of contrast-enhanced MR imaging-a meta-analysis and Bayesian analysis.

PURPOSE: To determine if, in a patient with an endometrial cancer, in addition to the knowledge of tumor grade, preoperative magnetic resonance (MR) imaging findings contribute to treatment stratification and specialist referral. MATERIALS AND METHODS: By using a MEDLINE literature search and institutional pathology reports, pretest probabilities for myometrial invasion were correlated with tumor grade. Likelihood ratios (LRs) were obtained through summary receiver operating characteristics. RESULTS: The mean pretest probabilities of deep myometrial invasion were derived from seven articles (1,875 patients) and from 125 institutional pathology reports. LRs for the prediction of myometrial invasion with contrast-enhanced MR imaging were derived from nine studies (742 patients); positive and negative LRs were 10.11 and 0.1, respectively. The mean weighted pretest probabilities of deep myometrial invasion in patients with tumor grades 1, 2, or 3 were 13%, 35%, or 54%, respectively. Posttest probabilities of deep myometrial invasion for grades 1, 2, or 3 increased to 60%, 84%, or 92%, respectively, for positive and decreased to 1%, 5%, or 10%, respectively, for negative MR imaging findings. CONCLUSION: Use of contrast-enhanced MR imaging significantly affects the posttest probability of deep myometrial invasion in patients with all grades of endometrial cancer and could be used to select patients for specialist referral.

Bayes Theorem↗
PubMed2000

Changes in calcaneal trabecular bone structure after heart transplantation: an MR imaging study.

PURPOSE: To use high-spatial-resolution magnetic resonance (MR) imaging to analyze the trabecular bone structure of the calcaneus in patients before and after heart transplantation and to compare this technique with bone mineral density (BMD) measurement in predicting therapy-induced bone loss and vertebral fracture status. MATERIALS AND METHODS: High-spatial-resolution 1.5-T MR imaging of the calcaneus was performed in 40 men 11-120 months after heart transplantation, in 11 men before heart transplantation, and in 10 age-matched male volunteers. Sagittal and transverse T1-weighted spin-echo images with a voxel size of 0.195 x 0.195 x 1.000 mm were obtained, and structure measurements analogous to bone histomorphometric values were calculated. In addition, the BMD of the lumbar spine was determined in the transplant recipients pre- and postoperatively by using quantitative computed tomography, and vertebral fracture status was assessed. RESULTS: Significant differences in structure and BMD measurements were found between patients before and after heart transplantation (P <. 05). In 17 (42%) of 40 transplant recipients, vertebral fractures were found. Although structure measurements were significantly different between patients with and those without fractures (P <.05), BMDs were not. Correlations between time after transplantation and some structure measurements were moderately significant (P <. 05), but such correlations with BMD measurements were not. CONCLUSION: MR imaging-derived structure measurements in the calcaneus are useful for monitoring bone changes after heart transplantation and assessing vertebral fracture status.

Adult↗
PubMed2000

US characterization of ovarian masses: a meta-analysis.

PURPOSE: To compare the effectiveness of current ultrasonographic (US) techniques for characterizing ovarian masses. MATERIALS AND METHODS: Through a MEDLINE literature search, articles with imaging-histopathologic correlation and data that allowed calculation of contingency tables were identified. Results of morphologic assessment, Doppler US, color Doppler flow imaging, and combined techniques were compared. RESULTS: Among 89 data sets from 46 included studies (5,159 subjects), 35 sets used morphologic information, 36 measured Doppler US indexes, 10 assessed tumor vascularity with color Doppler flow imaging, and eight used combined techniques. Summary receiver operating characteristic curves revealed significantly higher performance for combined techniques than for morphologic information (P: =.003), Doppler US indexes (P: =.003), or color Doppler flow imaging alone (P: =.001). The Q* point (and 95% CI) for combined techniques was 0.92 (0.87, 0.96) versus 0. 85 (0.83, 0.88) for morphology, 0.82 (0.78, 0.86) for Doppler US, and 0.73 (0.58, 0.87) for color Doppler flow imaging. Morphologic assessment showed a trend toward better performance than color Doppler flow imaging (P: =.09) or Doppler US indexes (P: =.07). Doppler US index results were better in earlier studies (P: =.005). CONCLUSION: Combined US techniques and a diagnostic algorithm perform significantly better than morphologic assessment, color Doppler flow imaging, or Doppler US indexes alone in characterizing ovarian masses.

Analysis of Variance↗
PubMed2000

Impairment of NF-kappaB activation and modulation of gene expression by calpastatin.

To address the involvement of the calpain system in both basal and silica-induced nuclear factor (NF)-kappaB activation, several human bronchial epithelial cell lines were established in which an intracellular inhibitor of calpain, calpastatin, was stably expressed. Reduced basal and silica-induced inhibitor (IkappaBalpha) degradation and NF-kappaB activation were observed in cells stably overexpressing calpastatin. In addition, the cells in which calpain was constitutively inhibited by the overexpression of calpastatin exhibited a notable morphological change. Whereas empty vector-transfected cells displayed a morphology indistinguishable from that of parental cells, cells overexpressing calpastatin exhibited a mosaic morphological change with reduced formation of lamella 30 min after the cells were seeded. Genefilter microarray experiments, in which 3,965 human genes can be evaluated for their expression at the same time, showed that calpastatin downregulated genes encoding several membrane-associated proteins or nuclear proteins and upregulated genes of collagen alpha2, DAZ, and mitochondrial capsule selenoprotein. These results suggest that, in addition to their proteolytic activities on cytoskeletal proteins and other cellular regulatory proteins, calpain-calpastatin systems can also affect the expression levels of genes encoding structural or regulatory proteins.

Adrenergic beta-Agonists↗
PubMed2000

Immunogenicity of neutralizing epitopes on multiple-epitope vaccines against HIV-1.

Based on our hypothesis that epitope vaccine may be a new strategy to induce high levels of neutralization antibodies against HIV-1, we prepared multiple-epitope vaccines using three neutralizing epitopes (GPGRAFY, RILAVERYLKD and ELDKWA) of HIV-1 gp160, and characterized their immunogenicity. Peptide 1 [C-G-(ELDKWA-GPGRAFY)(2)-K] and peptide 2 (CG-GPGRAFY-ELDKWA-G-RILAVERYLKD) were synthesized and conjugated with carrier protein bovine serum albumin (BSA). After vaccination antibody responses to these immunogens were induced and evaluated by ELISA. The C-G-(ELDKWA-GPGRAFY)(2)-K-BSA (BSA: carrier protein) multiple-epitope vaccine induced a strong antibody response to the C-G-(ELDKWA-GPGRAFY)(2)-K peptide (antibody titer: 1:25,600) and C-(ELDKWAG)(4) peptide (antibody titer: 1:12,800), but a weak antibody response to the C-(GPCGRAFY)(4) peptide. The CG-GPGRAFY-ELDKWA-G-RILAVERYLKD-K-BSA (BSA: carrier protein) multiple-epitope vaccine also induced strong antibody response to the CG-GPGRAFY-ELDKWA-G-RILAVERYLKD-K peptide (antibody titer: 1:25, 600) and C-(ELLDKWAG)(4) peptide (antibody titer: 1:6,400), a very strong response to C-(RIVALVERYLKD-G)(2)-K peptide (dilution: 1:102, 400), and a very weak response to the C-(GPGRAFY)(4) peptide (dilution: 1:400) in mice. Both antisera induced by both multiple-epitope vaccines interacted with the recombinant soluble gp41 (rgp41), but did not bind two control peptides. In comparison with both epitope vaccines, the rgp160 subunit vaccine could induce weak epitope-specific antibody response to these three epitopes on the three epitope peptides and V3, N-domain and C-domain peptides (dilution: 1:400-1:1,600). These results indicate that both multiple-epitope vaccines could induce high levels of antibodies to both neutralizing epitopes RILAVERYLKD and ELDKWA, while the GPGRAFY epitope on both vaccines appeared to have weak immunogenicity. Both multiple-epitope vaccines showed significant potency on inducing high levels of epitope-specific neutralization antibodies in comparison with rgp160 subunit vaccine.

AIDS Vaccines↗