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Biomedical subjects

D D Anthony

Publications and source records attributed to D D Anthony.

At least 19 recordsLinked to original sources
PubMed2002

Characterization of the immune response against hepatitis C infection in recovered, and chronically infected chimpanzees.

The immune response to hepatitis C virus (HCV) is believed to be critical in determining the outcome of the disease. In this study we have analysed epitope recognition, cytokine profile, and anti-HCV antibody responses in chronically HCV-infected and recovered chimpanzees. Quantitative measurement of anti-HCV antibody in HCV-infected chimpanzees revealed that the response in HCV- recovered chimpanzees peaked within 4-20 weeks. In contrast, the anti-HCV antibody responses in chronically HCV infected chimpanzees did not peak until 100-200 weeks after infection, and decreased gradually thereafter. T cell proliferation assays measuring responses to pooled HCV proteins revealed significant increases in the 3H-uptake during the early stages of infection in recovered chimpanzees in comparison to the chronically infected ones. Class I-restricted epitopes of the core, and NS3 proteins of HCV were analysed using 9-10 mer overlapping peptides covering the core and NS3 proteins, and IFN-gamma ELISPOT technique. Our data indicated early and broad class-I restricted core, and NS3 protein epitope recognitions in HCV-recovered chimpanzees but not in chimpanzees that had been chronically infected. Additionally, dominant epitopes recognized early in infection (8 weeks) were no longer recognized later in infection (followed up to 64 weeks). Cytokines profiling revealed a 50-fold increase in TNF-alpha secretion in the supernatant of core-specific CD8 memory cells of the chronically infected chimpanzees in comparison to the recovered ones. In summary, multiple parameters correlate with HCV recovery in chimpanzees.

Animals↗
PubMed2001

ELISPOT analysis of hepatitis C virus protein-specific IFN-gamma-producing peripheral blood lymphocytes in infected humans with and without cirrhosis.

An improved ability to monitor hepatitis C virus (HCV)-specific T cell immunity in infected patients may provide novel information regarding the pathogenesis and prognosis of this infection. We used an ELISPOT assay to analyze a cross-section of HCV-infected humans. HCV-infected patients without cirrhosis, those with cirrhosis, and controls with other liver diseases were tested for recall responses to HCV Core and NS3 proteins. Peripheral blood lymphocytes (PBLs) from HCV-infected patients without cirrhosis responded to NS3 and Core proteins, producing predominantly IFN-gamma, with little IL-4 or IL-5. In contrast, PBLs from HCV-infected patients with cirrhosis responded to NS3, but not to the Core protein, suggesting a selectively altered immune state during cirrhosis. Our data provide support for the notion that HCV-specific IFN-gamma-producing immunity is important in the pathogenesis of progressing HCV-related disease.

Enzyme-Linked Immunosorbent Assay↗
PubMed2001

Human glioma cells transformed by IGF-I triple helix technology show immune and apoptotic characteristics determining cell selection for gene therapy of glioblastoma.

AIMS: Insulin-like growth factor type I (IGF-I) antisense cellular gene therapy of tumours is based on the following data: rat glioma or hepatoma cells transfected with the vector encoding IGF-I antisense cDNA lose their tumorigenicity and induce a tumour specific immune response involving CD8(+) T cells. Recently, using the IGF-I triple helix approach in studies of tumorigenicity, major histocompatibility complex class I (MHC-I) antigens were demonstrated in rat glioma transfected cells. This study used comparative IGF-I antisense and triple helix technologies in human primary glioma cells to determine the triple helix strategy that would be most appropriate for the treatment of glioblastoma. METHODS: The cells were transfected using the IGF-I triple helix expression vector, pMT-AG, derived from the pMT-EP vector. pMT-AG contains a cassette comprising a 23 bp DNA fragment transcribing a third RNA strand, which forms a triple helix structure within a target region of the human IGF-I gene. Using pMT-EP, vectors encoding MHC-I or B7 antisense cDNA were also constructed. RESULTS: IGF-I triple helix transfected glioma cells are characterised by immune and apoptotic phenomena that appear to be related. The expression of MHC-I and B7 in transfected cells (analysed by flow cytometry) was accompanied by programmed cell death (detected by dUTP fluorescein terminal transferase labelling of nicked DNA and electron microscopic techniques). Cotransfection of these cells with MHC-I and B7 antisense vectors suppressed the expression of MHC-I and B7, and was associated with a pronounced decrease in apoptosis. CONCLUSION: When designing an IGF-I triple helix strategy for the treatment of human glioblastoma, the transfected tumour cells should have the following characteristics: the absence of IGF-I, the presence of both MHC-I and B7 molecules, and signs of apoptosis.

Apoptosis↗
PubMed2001

The analysis of peri-tumor necrosis following the subcutaneous implantation of autologous tumor cells transfected with an episome transcribing an antisense insulin-like growth factor 1 RNA in a glioblastoma multiforme subject.

A subject inflicted with glioblastoma multiforme who received partial tumor resection and radiotherapy was recruited for an ex vivo gene therapy protocol using irradiated autologous tumor cells that had been engineered to suppress the expression of insulin-like growth factor I as the tumor vaccine. After subcutaneous injection for 8 weeks, the subject developed peri-tumor necrosis with mass effect. The authors wondered whether this event could have resulted from the tumor vaccine. The tissue section bordering the necrotic tumor tissue to the viable normal tissue was examined for nature of any infiltrated cells and their activities. Lymphocytes, macrophages, and a small number of neutrophils diffused into the necrotic tumor tissue were found. The infiltrated lymphocytes consisted of both CD4+ and CD8+ T cells. The functional activity of these lymphocytes was demonstrated by the active production of interferon y and tumor necrosis factor alpha based on the respective immunofluorescent staining localized to these cells. This finding is compatible with the proposed mechanism underlying the tumor vaccination. However, the contribution of radiation treatment to this event cannot be clearly ruled out.

Brain Neoplasms↗
PubMed2000

Enhancement of immunogenicity of tumor cells by cotransfection with genes encoding antisense insulin-like growth factor-1 and B7.1 molecules.

Insulin-like growth factor-1 (IGF-1) is expressed in many tumor cell lines and has a role in both normal cell proliferation and in the growth of cancers. Tumor cells transfected with a vector encoding an IGF-1 antisense cDNA transcriptional cassette driven by the mouse metallothionein-1 promoter become immunogenic and lose their tumorigenicity in syngeneic animals. The enhanced immunogenicity is associated with an up-regulation in the expression of major histocompatibility complex class I molecule on cell surfaces. Blockade of the expression of IGF-1 in tumor cells by the IGF-1 antisense RNA approach is not uniformly effective in the induction of antitumoral protective immunity in low and nonimmunogenic tumor model systems. Here, we report that the immunogenicity of hepa 1-6 hepatoma and SMCC-1 colon carcinoma cells, which are poorly immunogenic and unresponsive to antisense IGF-1 gene transfer, can be induced by cotransfection with genes encoding antisense IGF-1 and mouse B7.1 molecules. The tumor cells modified in this manner become strongly immunogenic and can be used as a cellular vaccine to induce a protective immune response in vivo. Immunization with the transfected tumor cells also results in regression of the established hepa 1-6 hepatoma and SMCC-1 colon cancer. The immunity is tumor-specific and is mediated by CD3+ CD8+ T cells. Cytotoxic T lymphocytes generated in vitro by priming naive spleen cells and in vivo by immunizing mice with the double-transfected tumor cells specifically lysed autologous tumors cells and were effective in adoptive immunotherapy. The data suggest that modification of tumor cells in vitro by cotransfection with genes encoding antisense IGF-1 and B7.1 molecules may open a new avenue for cancer immunogene therapy.

Adjuvants, Immunologic↗
PubMed1999

Prevention of collagen-induced arthritis in mice by a polyphenolic fraction from green tea.

Identification of common dietary substances capable of affording protection or modulating the onset and severity of arthritis may have important human health implications. An antioxidant-rich polyphenolic fraction isolated from green tea (green tea polyphenols, GTPs) has been shown to possess anti-inflammatory and anticarcinogenic properties in experimental animals. In this study we determined the effect of oral consumption of GTP on collagen-induced arthritis in mice. In three independent experiments mice given GTP in water exhibited significantly reduced incidence of arthritis (33% to 50%) as compared with mice not given GTP in water (84% to 100%). The arthritis index also was significantly lower in GTP-fed animals. Western blot analysis showed a marked reduction in the expression of inflammatory mediators such as cyclooxygenase 2, IFN-gamma, and tumor necrosis factor alpha in arthritic joints of GTP-fed mice. Histologic and immunohistochemical analysis of the arthritic joints in GTP-fed mice demonstrated only marginal joint infiltration by IFN-gamma and tumor necrosis factor alpha-producing cells as opposed to massive cellular infiltration and fully developed pannus in arthritic joints of non-GTP-fed mice. The neutral endopeptidase activity was approximately 7-fold higher in arthritic joints of non-GTP-fed mice in comparison to nonarthritic joints of unimmunized mice whereas it was only 2-fold higher in the arthritic joints of GTP-fed mice. Additionally, total IgG and type II collagen-specific IgG levels were lower in serum and arthritic joints of GTP-fed mice. Taken together our studies suggest that a polyphenolic fraction from green tea that is rich in antioxidants may be useful in the prevention of onset and severity of arthritis.

Animals↗
PubMed1997

Effective tumor vaccines generated by in vitro modification of tumor cells with cytokines and bispecific monoclonal antibodies.

Antitumor immune responses are mediated primarily by T cells. Downregulation of the major histocompatibility complex (MHC) and the molecules that costimulate the immune response is associated with defective signaling by tumor cells for T-cell activation. In vitro treatment with a combination of cytokines significantly increased the expression of MHC class I and adhesion molecules on tumor cell surfaces. When tumor cells were first incubated with a bispecific monoclonal antibody that binds antigen on tumor cells to CD28 on T cells, the modified tumor cells become immunogenic and are able to stimulate naive T cells, generating tumor-specific cytotoxic T cells in vitro. Immunization with the modified tumor cells elicits an immune response mediated by CD8+ T cells. This response protected against a challenge with parental tumor cells and cured established tumors. The approach was effective in both low immunogenic and nonimmunogenic tumor model systems. Modification of tumor cells with this two-step procedure may provide a strategy for development of tumor vaccines that is effective for cancer immunotherapy.

Animals↗
PubMed1994

Gene therapy of murine teratocarcinoma: separate functions for insulin-like growth factors I and II in immunogenicity and differentiation.

Teratocarcinoma is a germ-line carcinoma giving rise to an embryoid tumor with structures derived from the three embryonic layers: mesoderm, endoderm, and ectoderm. Teratocarcinoma is widely used as an in vitro model system to study regulation of cell determination and differentiation during mammalian embryogenesis. Murine embryonic carcinoma (EC) PCC3 cells express insulin-like growth factor I(IGF-I) and its receptor, while all derivative tumor structures express IGF-I and IGF-II and their receptors. Therefore the system lends itself to dissect the role of these two growth factors during EC differentiation. With an episomal antisense strategy, we define a role for IGF-I in tumorigenicity and evasion of immune surveillance. Antisense IGF-I EC transfectants are shown to elicit a curative anti-tumor immune response with tumor regression at distal sites. In contrast, IGF-II is shown to drive determination and differentiation in EC cells. Since IGF-I and IGF-II bind to type I receptor and antisense sequence used for IGF-II cannot form duplex with endogenous IGF-I transcripts, it follows that this receptor is not involved in determination and differentiation.

Animals↗
PubMed1992

Analysis of 40 S and 80 S complexes with mRNA as measured by sucrose density gradients and primer extension inhibition.

The technique of primer extension inhibition has been adapted to analyze the eukaryotic ribosome-mRNA interaction. Formation of the ribosome-mRNA complex was performed in a nuclease-treated rabbit reticulocyte lysate. Before primer extension analysis, however, the complex is isolated by sucrose gradient centrifugation. Both 80 S- and 40 S-mRNA complexes can be individually analyzed because of this isolation step. 80 S ribosomes and 40 S ribosomal subunits could be localized at the initiation codon by a number of independent means where all complexes were formed in a manner consistent with the current understanding of the initiation pathway for translation in eukaryotes. Complexes were also isolated with the aid of the antibiotic edeine, where the 40 S ribosomal subunit was not located at the initiation codon, but 5' to the initiation codon. This extension inhibition assay was used to complement studies regarding the ATP dependence of the 40 S-mRNA interacting initiation steps that involve the mammalian RNA-interacting initiation factors eIF-4A, -4B, and -4F. A strong requirement for ATP was observed for 40 S-mRNA complex formation. A factor-mediated stimulation of complex formation by a combination of eIF-4A, -4B, and -4F was observed, and was one which required the presence of ATP. This factor-mediated ATP-dependent stimulation of complex formation was significantly inhibited by preincubating eIF-4A with the ATP analog 5'-p-fluorosulfonylbenzoyl adenosine. Finally, all complexes accumulated to a significant degree were analyzed by the primer extension assay. It was found that the 40 S ribosomal subunit was positioned at the initiation codon for all variations tested.

Adenosine↗
PubMed1991

Eukaryotic initiation factor (eIF)-4F. Implications for a role in internal initiation of translation.

In order to study the eukaryotic translation initiation mechanisms of "internal initiation," "re-initiation," and/or "coupled internal initiation," a series of model mRNAs have been constructed which contain two non-overlapping open reading frames (ORFs) that encode different lengths of rabbit alpha globin. These mRNAs, along with the bicistronic constructs TK/CAT and TK/P2CAT developed by Pelletier and Sonenberg (Pelletier, J., and Sonenberg, N. (1988) Nature 334, 320-325, 1988), were used to program an in vitro rabbit reticulocyte lysate translation system. Cap-dependent and cap-independent translation were distinguished by monitoring translation in the presence or absence of exogenously added cap analog (m7GTP). Messenger RNAs which translate both ORF1 and ORF2 by a cap-dependent mechanism, as well as mRNAs that translate ORF2 by a cap-independent mechanism while still translating ORF1 in a cap-dependent fashion have been obtained. These same alpha globin mRNAs differ by no more than 45 nucleotides in intercistronic length. Initiation factor addition studies were performed in this same in vitro translation system. Both eukaryotic initiation factor (eIF)-4F and, to a lesser extent, eIF-4B can stimulate translation of an internally located ORF independent of upstream ORF translation and in a manner not dependent on mRNA cap recognition. This indicates that the cap-recognition initiation factor, eIF-4F, and eIF-4B facilitate cap-independent and internal initiation of an open reading frame.

Animals↗
PubMed1990

Affinity labeling of eukaryotic initiation factor 2 and elongation factor 1 alpha beta gamma with GTP analogs.

As part of an attempt to understand the specific function and role of each subunit in multisubunit protein synthesis factors, we have attempted to identify the nucleotide binding peptides of eukaryotic initiation factor 2 (eIF-2). To ensure that the interactions were of a specific nature, two general controls were used: first, other protein factors with characterized GTP binding activity were tested; second, all affinity labeling was checked for nucleotide specificity by protection with the authentic nucleotide at a 10-fold molar excess over the affinity reagent. Results with a number of GTP modifying reagents ([alpha-32P]GTP, [alpha-32P]GDP, oxidized [alpha-32P]GTP, 3'-p-azidobenzoyl-[alpha-32P]GTP, 3'-p-azidobenzoyl-[alpha-32P]GDP, and 5'-p-[8-3H]fluorosulfonylbenzoyl guanosine) indicate that appropriate conditions for both nucleotide and subunit specific labeling have been achieved. Under these conditions all reagents modified the beta subunit of eIF-2. Complementary studies with subunit-deficient forms of eIF-2 also suggest that the beta subunit of eIF-2 is involved with GTP binding. Coupled with other data suggesting that the gamma subunit of eIF-2 might be involved in GTP binding and amino acid sequence data of eIF-2 gamma from which a part of a GTP binding consensus sequence can be localized, support is provided for the concept of alternate GTP binding domains or a GTP binding domain shared between different subunits of eIF-2.

Affinity Labels↗
PubMed1990

Induction of cervical neoplasia in the mouse by an extract of cells infected by varicella-zoster virus.

Since several human herpesviruses, including varicella-zoster virus (VZV), have been demonstrated to transform mammalian cells in vitro, VZV was tested in a mouse model of virus-induced cervical neoplasia to determine whether it is oncogenic in vivo. Herpes simplex viruses types 1 and 2 and cytomegalovirus have been previously shown to induce cervical neoplasia in this mouse model. VZV was propagated in WI-38 cell cultures and inactivated by ultraviolet irradiation. Control material was prepared in an identical manner from uninfected cell cultures. Cotton tampons, saturated with inactivated virus or control material, were inserted into the vaginas of C57BL mice three times a week for 60 weeks. Cervical dysplasia was detected in 40% and invasive carcinoma in 34% of virus-exposed mice by histological examination. No lesions were detected in control animals. These observations indicate that VZV, or some product of virus-infected cells, is oncogenic in vivo for the mouse cervix.

Animals↗
PubMed1989

Induction of cervical neoplasia in the mouse by herpes simplex virus type 2 DNA.

Induction of cervical neoplasia in the mouse cervix by herpes simplex virus types 1 (HSV-1) and 2 (HSV-2) has been reported. The present study was done to determine if transfection with DNA of HSV-2 can induce carcinogenesis in this animal model. Genomic HSV-2 DNA was isolated from infected HEp-2 cells and separated from host cell DNA by cesium chloride density gradient centrifugation. The DNA was applied to mouse cervix for periods of 80-100 weeks. Experimental controls were treated with uninfected genomic HEp-2 cell DNA or with calf thymus DNA. Vaginal cytological preparations from all animals were examined monthly to detect epithelial abnormalities. Animals were sacrificed and histopathology studies were done when cellular changes indicative of premalignant or malignant lesions were seen on vaginal smears. Cytologic and histologic materials were coded and evaluated without knowledge of whether they were from animals treated with virus or control DNA. Premalignant and malignant cervical lesions similar to those that occur in women were detected in 61% of the histologic specimens obtained from animals exposed to HSV-2 DNA. The yield of invasive cancers was 21% in animals treated with HSV-2 DNA. No cancers were detected in mice treated with either HEp-2 or calf thymus DNA. Dysplasia was detected in only one of these control animals.

Animals↗
PubMed1986

Roles of cytomegalovirus and Chlamydia trachomatis in the induction of cervical neoplasia in the mouse.

Cytomegalovirus and Chlamydia trachomatis are prevalent sexually transmissible pathogens. They produce persistent infections of the cervix and have been associated with cervical neoplasia. Cytomegalovirus has also been shown to induce transformation of cells in culture. Because of the high prevalence of genital infections with these pathogens and evidence that they may have oncogenic effects on the cervix, cytomegalovirus (strain AD-169) and C. trachomatis (serovar LGV-2) were tested for oncogenicity in a mouse model in which induction of cervical neoplasia by repeated exposure to inactivated herpes simplex viruses has been demonstrated previously. Cotton tampons, saturated with UV-inactivated cytomegalovirus, C. trachomatis, or corresponding control fluids, were inserted into the vaginas of virgin C57 mice 3 times a week. Smears of vaginal aspirates for cytological examination were obtained every 5 weeks. After 75-90 weeks of exposure, the mice were sacrificed and serial sections of their reproductive tracts were examined. Cervical dysplasia was detected by histological examination in 51% and cervical carcinoma in 10% of mice exposed to cytomegalovirus. In control mice, in contrast, dysplasia developed in 3% and carcinoma in none. The progression from normal cervical epithelium to dysplasia to carcinoma observed with cytomegalovirus exposure was similar to that observed previously in this model after exposure of mice to herpes simplex virus types 1 and 2. The frequencies of cervical abnormalities in mice exposed to C. trachomatis or corresponding control fluid were low, and differences between the two groups were not statistically significant. These data indicate that strain AD-169 of cytomegalovirus is oncogenic for the mouse cervix and suggest that the LGV-2 serovar of C. trachomatis is not.

Animals↗
PubMed1985

Reductive alkylation with oxidized nucleotides. Use in affinity labeling or affinity chromatography.

A study has been made of the products of a reaction of oxidized ribonucleotides with a primary amine. As a model reaction, periodate-oxidized adenosine was combined with glycine in the presence of NaCNBH3. The purified major product of this reaction, adenine 9,2'-(4'-carboxymethyl-6'-hydroxymethylmorpholine), was characterized by 13C and 1H NMR spectroscopy, ultraviolet spectroscopy, and thin layer chromatography. When used to generate affinity columns, oxidized adenosine or oxidized ATP formed stable products with immobilized diaminohexane when treated with NaCNBH3. Failure to treat with NaCNBH3 yielded an unstable affinity matrix. These results are used in the interpretation of differing results when oxidized nucleotides have been used as affinity labels for different proteins.

Adenosine↗
PubMed1983

Effect of prior immunization on induction of cervial cancer in mice by herpes simplex virus type 2.

Previous studies at this laboratory showed that repeated application of inactivated herpes simplex virus type 2 to the mouse cevix produced premalignant and malignant lesions. In the present study mice were inoculated with inactivated herpes simplex virus type 2 or control solution and Freund's adjuvant by intraperitoneal and subcuaneous routes before exposure of the cervix to inactivated virus. It appears that immunization with inactivated virus conferred a protection against the induction of cervical carcinoma.

Animals↗