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H Koprowski

Publications and source records attributed to H Koprowski.

At least 55 records · Page 3Linked to original sources
PubMed1997

Human- and mouse-inducible nitric oxide synthase promoters require activation of phosphatidylcholine-specific phospholipase C and NF-kappa B.

BACKGROUND: The production of nitric oxide by type II inducible nitric oxide synthase (type II NOS) gene is controlled at least in part by transcriptional activation. Although the murine and human type II NOS genes share significant sequence homology, they differ in the induction stimuli required for activation. MATERIALS AND METHODS: The A549 human and murine RAW 264.7 cell lines were cultured in the presence of inducers of the type II NOS gene and exposed to specific inhibitors of phosphatidyl choline-specific phospholipase C, NF-kappa B, and endocytosis, as well as to reagents that deplete stores of ATP or prevent the acidification of endosomes. The effect of these reagents on the induction of the type II NOS gene transcription, translation, and NO expression was studied using electromobility shift assays, Western blotting, and the detection of NO as nitrates, as appropriate. Additionally, the ability of the native human type II NOS NF-kappa B recognition sequence to bind NF-kappa B was compared with a concensus sequence and with a mutated oligomer. RESULTS: Type II NOS production by both human and mouse cells could be prevented by the addition of the specific inhibitor of phosphatidylcholine-specific phospholipase C, D609, and of agents that interfere with the activation of NF-kappa B. Both mouse and human cells also required acidic endosome formation and the production of 1,2-diacylglycerol for type II NOS expression. Additionally, the native human type II NOS NF-kappa B recognition sequence bound NF-kappa B with significantly less affinity than did the recognition sequence derived from the human immunoglobulin light-chain gene promoter. CONCLUSIONS: These experiments show that whereas mouse cells can be activated by lipopolysaccharide to produce nitric oxide, and human cells require activation by a mixture of cytokines to produce nitric oxide, the intracellular activation pathway following receptor binding of these heterologous stimuli is shared. Additionally, NF-kappa B activation is necessary but not sufficient for inducible nitric oxide synthase production in human cells, in contrast to murine cells in which it serves as a complete inducer.

Animals↗
PubMed1996

Intrinsic responses to Borna disease virus infection of the central nervous system.

Immune cells invading the central nervous system (CNS) in response to Borna disease virus (BDV) antigens are central to the pathogenesis of Borna disease (BD). We speculate that the response of the resident cells of the brain to infection may be involved in the sensitization and recruitment of these inflammatory cells. To separate the responses of resident cells from those of cells infiltrating from the periphery, we used dexamethasone to inhibit inflammatory reactions in BD. Treatment with dexamethasone prevented the development of clinical signs of BD, and the brains of treated animals showed no neuropathological lesions and a virtual absence of markers of inflammation, cell infiltration, or activation normally seen in the CNS of BDV-infected rats. In contrast, treatment with dexamethasone exacerbated the expression of BDV RNA, which was paralleled by a similarly elevated expression of mRNAs for egr-1, c-fos, and c-jun. Furthermore, dexamethasone failed to inhibit the increase in expression of mRNAs for tumor necrosis factor alpha, macrophage inflammatory protein 1 beta, interleukin 6, and mob-1, which occurs in the CNS of animals infected with BDV. Our findings suggest that these genes, encoding transcription factors, chemokines, and proinflammatory cytokines, might be directly activated in CNS resident cells by BDV. This result supports the hypothesis that the initial phase of the inflammatory response to BDV infection in the brain may be dependent upon virus-induced activation of CNS resident cells.

Animals↗
PubMed1996

Characterization of a unique variant of bat rabies virus responsible for newly emerging human cases in North America.

The silver-haired bat variant of rabies virus (SHBRV) has been identified as the etiological agent of a number of recent human rabies cases in the United States that are unusual in not having been associated with any known history of conventional exposure. Comparison of the different biological and biochemical properties of isolates of this virus with those of a coyote street rabies virus (COSRV) revealed that there are unique features associated with SHBRV. In vitro studies showed that, while the susceptibility of neuroblastoma cells to infection by both viruses was similar, the infectivity of SHBRV was much higher than that of COSRV in fibroblasts (BHK-21) and epithelial cells (MA-104), particularly when these cells were kept at 34 degrees C. At this temperature, low pH-dependent fusion and cell-to-cell spread of virus is seen in BHK-21 cells infected with SHBRV but not with COSRV. It appears that SHBRV may possess an unique cellular tropism and the ability to replicate at lower temperature, allowing a more effective local replication in the dermis. This hypothesis is supported by in vivo results which showed that while SHBRV is less neurovirulent than COSRV when administered via the intramuscular or intranasal routes, both viruses are equally neuroinvasive if injected intracranially or intradermally. Consistent with the above findings, the amino acid sequences of the glycoproteins of SHBRV and COSRV were found to have substantial differences, particularly in the region that contains the putative toxic loop, which are reflected in marked differences in their antigenic composition. Nevertheless, an experimental rabies vaccine based on the Pittman Moore vaccine strain protected mice equally well from lethal doses of SHBRV and COSRV, suggesting that currently used vaccines should be effective in the postexposure prophylaxis of rabies due to SHBRV.

Animals↗
PubMed1996

HLA-B-restricted, CD8+ cytolytic human T cell clones derived from a melanoma-invaded lymph node.

We have reported that medium containing recombinant human IL-1 (rIL-1), rIL-2, rIL-4, and rIL-6 (MB-1,2,4,6 medium) efficiently expanded autologous tumor specific CTLs in vitro. For further examination of the CTLs cultured in MB-1,2,4,6, the therapeutic activity on tumor growth inhibition in vivo and established CTL clones were studied. In vivo therapy with the CTLs in combination with rIL-2 was highly effective. To investigate CTL clones, 19 CD8+ T cell clones were obtained by limiting dilution method, each clone retained autologous-melanoma-specific, HLA-class I-restricted cytolytic activity. Four T cell clones were analyzed in detail. These T cell clones displayed a CD3+, CD4-, CD8+, CD11b-, CD16-, CD56-, CD45RA-, TcR alpha/beta + phenotype and monoclonal antibodies to HLA class I, CD3, and CD8 antigens inhibited their cytolytic activity. Moreover, these CTL clones recognize one of common melanoma antigens associated with HLA-B (B49). Analysis of the effect of different cytokines on the proliferation and cytotoxicity of cloned CTL revealed the highest growth rate in MB-1,2,4,6 but no dependence on particular cytokine combinations for autologous tumor-specific cytolytic activity. These results suggest (1) the usefulness of MB-1,2,4,6 medium in expanding autologous tumor-specific CTLs, which can be used in adoptive immunotherapy, (2) HLA-B molecules can present one of common melanoma antigens, and (3) the independence of CTLs from any cytokine combination once they become target-specific.

Antibodies, Monoclonal↗
PubMed1996

Inhibition of rabies virus infection by an oligodeoxynucleotide complementary to rabies virus genomic RNA.

To develop antirabies virus-specific agents, eight oligodeoxynucleotides (ODN) complementary to either rabies virus genomic RNA (negative polarity) or rabies virus transcripts (mRNA) were synthesized and tested for their activity to inhibit rabies virus infection in cell cultures. It was found that the ODN RH+1 complementary to rabies virus genomic RNA blocked almost completely rabies virus infection at concentrations as low as 2 microM, whereas ODN complementary to viral transcripts did poorly even at concentrations as high as 20 microM. The antigenomic ODN also has the ability to inhibit cell-to-cell spread of rabies virus, which is an indicator for protection of rabies virus infection in vivo. These results indicate that ODN complementary to rabies virus genomic RNA have strong ability to inhibit rabies virus infection in cell culture and may have the potential to be used for therapy in clinical rabies.

Animals↗
PubMed1996

Characterization and functional analysis of the human inducible nitric oxide synthase gene promoter.

BACKGROUND: Nitric oxide has a wide variety of homeostatic and pathological effects. Control of the production of nitric oxide by the inducible form of the enzyme resides in the 5' promoter region of the gene. Although control of the murine isoform has been investigated, little is known about the functional aspects of the human analog. MATERIALS AND METHODS: A 3.9-kb 5' nontranslated region of the human gene was cloned, sequenced, and several reporter constructs prepared. The promoter-reporter constructs were transfected into human or murine monocytoid cells and reporter expression quantified following cytokine activation of the cells. The production of nitric oxide was also monitored. RESULTS: Although a murine promoter-reporter functioned efficiently in both human and mouse cells, the human constructs functioned only in human cells. The activity of the mouse construct increased progressively with the addition of activating cytokines, but the human promoter-reporter did not. Although interleukin 1 beta drove expression of the human inducible nitric oxide synthase reporter, actual expression of nitric oxide required both interleukin 1 beta and interferon-gamma. CONCLUSIONS: The data indicate that despite the significant homology between the human and mouse inducible nitric oxide synthase promoter sequence, control of the two genes is quite different. In addition to being more efficient in promoter activity, the murine promoter responds increasingly to cytokines that are not effective for the human analog. It is also apparent that human inducible nitric oxide synthase is controlled at both the level of transcription and post-translationally.

Animals↗
PubMed1996

Theatrum vacunae.

Explore the source record for details and available documents.

History, 20th Century↗
PubMed1995

Activation of the inducible form of nitric oxide synthase in the brains of patients with multiple sclerosis.

Nitric oxide (NO) has been implicated as a pathogenic mediator in a variety of central nervous system (CNS) disease states, including the animal model of multiple sclerosis (MS) and experimental allergic encephalomyelitis. We have examined post-mortem brain tissues collected from patients previously diagnosed with MS, as well as tissues collected from the brains of patients dying without neuropathies. Both Northern blot analysis and reverse transcriptase (RT)-driven in situ PCR (RT-in situ PCR) studies demonstrated that inducible NO synthase (iNOS) mRNA was present in the brain tissues from MS patients but was absent in equivalent tissues from normal controls. We have also performed experiments identifying the cell type responsible for iNOS expression by RT-in situ PCR in combination with immunohistochemistry. Concomitantly, we analyzed the tissues for the presence of the NO reaction product nitrotyrosine to demonstrate the presence of a protein nitrosylation adduct. We report here that iNOS mRNA was detectable in the brains of 100% of the CNS tissues from seven MS patients examined but in none of the three normal brains. RT-in situ PCR experiments also demonstrated the presence of iNOS mRNA in the cytoplasm of cells that also expressed the ligand recognized by the Ricinus communis agglutinin 1 (RCA-1), a monocyte/macrophage lineage marker. Additionally, specific labeling of cells was observed when brain tissues from MS patients were exposed to antisera reactive with nitrotyrosine residues but was significantly less plentiful in brain tissue from patients without CNS disease. These results demonstrate that iNOS, one of the enzymes responsible for the production of NO, is expressed at significant levels in the brains of patients with MS and may contribute to the pathology associated with the disease.

Autopsy↗
PubMed1995

Local nitric oxide production in viral and autoimmune diseases of the central nervous system.

Because of the short half-life of NO, previous studies implicating NO in central nervous system pathology during infection had to rely on the demonstration of elevated levels of NO synthase mRNA or enzyme expression or NO metabolites such as nitrate and nitrite in the infected brain. To more definitively investigate the potential causative role of NO in lesions of the central nervous system in animals infected with neurotropic viruses or suffering from experimental allergic encephalitis, we have determined directly the levels of NO present in the central nervous system of such animals. Using spin trapping of NO and electron paramagnetic resonance spectroscopy, we confirm here that copious amounts of NO (up to 30-fold more than control) are elaborated in the brains of rats infected with rabies virus or borna disease virus, as well as in the spinal cords of rats that had received myelin basic protein-specific T cells.

Amino Acid Oxidoreductases↗
PubMed1995

Expression of C1q, a subcomponent of the rat complement system, is dramatically enhanced in brains of rats with either Borna disease or experimental allergic encephalomyelitis.

In situ hybridization, RT-PCR and Northern blot analysis as well immunohistochemistry were used to examine the expression of C1q, a subcomponent of the rat complement system, in brains of rats infected with Borna disease virus (BDV) and rats afflicted with experimental allergic encephalomyelitis (EAE) induced by the adoptive transfer of myelin basic protein specific T cells. C1q mRNA, which was not detected in normal brain, became clearly detectable using RT-PCR analysis by d14 post infection (p.i.) with BDV. Maximal levels of C1q mRNA were reached 21 days p.i. when inflammatory reactions in the brain were also at a peak. Similarly, C1q mRNA was elevated when the clinical symptoms of EAE became evident 5 days following cell transfer. C1q positive cells, as identified by immunohistology, were preferentially localized in grey and white matter of the hippocampus and basolateral cortex. The C1q positive cells resembled microglial cells in morphology. The correlation of C1q expression with the development of neurological disease as well as the dramatic increase of C1q within brain regions with inflammatory lesions suggest that local biosynthesis of C1q may play a role in the pathogenesis of Borna virus induced and autoimmune encephalomyelitis.

Animals↗
PubMed1995

Expression of the rabies virus glycoprotein in transgenic tomatoes.

We have engineered tomato plants (Lycopersicon esculentum Mill var. UC82b) to express a gene for the glycoprotein (G-protein), which coats the outer surface of the rabies virus. The recombinant constructs contained the G-protein gene from the ERA strain of rabies virus, including the signal peptide, under the control of the 35S promoter of cauliflower mosaic virus. Plants were transformed by Agrobacterium tumefaciens-mediated transformation of cotyledons and tissue culture on selective media. PCR confirmed the presence of the G-protein gene in plants surviving selection. Northern blot analysis indicated that RNA of the appropriate molecular weight was produced in both leaves and fruit of the transgenic plants. The recombinant G-protein was immunoprecipitated and detected by Western blot from leaves and fruit using different antisera. The G-protein expressed in tomato appeared as two distinct bands with apparent molecular mass of 62 and 60 kDa as compared to the 66 kDa observed for G-protein from virus grown in BHK cells. Electron microscopy of leaf tissue using immunogold-labeling and antisera specific for rabies G-protein showed localization of the G-protein to the Golgi bodies, vesicles, plasmalemma and cell walls of vascular parenchyma cells. In light of our previous demonstration that orally administered rabies G-protein from the same ERA strain elicits protective immunity in animals, these transgenic plants should provide a valuable tool for the development of edible oral vaccines.

Agrobacterium tumefaciens↗
PubMed1995

Effect of neurotropic virus infection on neuronal and inducible nitric oxide synthase activity in rat brain.

To elucidate the potential role of inducible nitric oxide synthase (iNOS) and neuronal constitutive nitric oxide synthase (cNOS) in the pathogenesis of virus-induced encephalopathy, the activities of both NOS isoforms were determined in the brains of rats infected with Borna disease virus (BDV) or rabies virus. iNOS activity strongly increased, whereas neuronal cNOS activity significantly decreased in a time-dependent manner after either BDV or rabies virus infection. Choline acetyltransferase activity in the brain remained unchanged during both virus infections, suggesting that the decrease in cNOS activity does not reflect a generalized neuronal loss. Immunohistochemistry and Northern blot analyses indicate that the decrease in neuronal cNOS activity is due to a decrease in cNOS protein and mRNA synthesis. These results suggest that both an excessive generation of NO by activated macrophages or microglia, as well as a decrease of NO production in neurons may contribute to the neuropathogenesis of neurotropic virus infections.

Animals↗
PubMed1994

Rabies ribonucleocapsid as an oral immunogen and immunological enhancer.

The administration of rabies ribonucleocapsid (RNP) by oral as well as parenteral routes was found to prime specific T cells and elicit N-protein-specific antibodies. per os and intramuscular immunization led to the production of antibodies of the IgA and IgG isotypes, respectively. Mice primed orally with RNP produced significantly enhanced amounts of virus-neutralizing antibody, compared with non-immune controls, upon subsequent parenteral booster immunization with inactivated rabies virus. Thus oral immunization with rabies RNP primed cells capable of mediating a secondary systemic response to rabies virus. The results of experiments in which peptide and protein antigens were administered either physically coupled to or mixed with RNP indicate that RNP has an inherent capacity to enhance immune responses.

Adjuvants, Immunologic↗
PubMed1994

Both the N- and the C-terminal domains of the nominal phosphoprotein of rabies virus are involved in binding to the nucleoprotein.

The interaction of the nominal phosphoprotein (NS) and the nucleoprotein (N) of rabies virus (Evelyn Rokitnicki Abelseth strain) was investigated by expressing these proteins in insect cells and in an in vitro coupled transcription-translation system. The N and NS proteins individually expressed in insect cells interacted with each other in vitro and formed complexes at a N:NS ratio similar to those found in rabies virions. In the in vitro transcription-translation system, both the N and NS proteins when synthesized simultaneously formed N-NS complexes which could be immunoprecipitated with either anti-N or anti-NS antibodies. NS mutant proteins with C-terminal deletion of up to 166 amino acids were still able to form complexes with N protein when synthesized simultaneously. However, when the NS mutant proteins and the N protein were synthesized individually and then mixed together, only the intact NS protein and NS mutant protein with 24 amino acids deleted from the C-terminus bound to the N protein, whereas deletion of 47 or more amino acids from the C-terminus of the NS protein resulted in total loss of binding to the N protein. NS mutants with N-terminal deletions of up to 68 amino acids bound to the N protein when synthesized either simultaneously or individually. These results indicate that both the N- and C-terminal domains of the NS protein of rabies virus are involved in the binding to rabies virus N protein but not in a mutually dependent manner. The interaction of the N-terminal domain of the NS protein with N protein occurs only during simultaneous synthesis of both proteins, whereas the C-terminal region of the NS protein can bind to the N protein when these two proteins are synthesized either simultaneously or separately. The two binding sites of the NS protein to N protein might have important functions in regulating virus transcription and replication as well as in virus assembly.

Base Sequence↗
PubMed1994

In vitro expansion of tumor-specific, HLA-restricted human CD8+ cytolytic T lymphocytes.

The effect of cytokines with human recombinant interleukin-2 (rIL-2) on cytolytic T cell (CTL) generation was studied. Lymphocytes were isolated from involved lymph nodes of melanoma patients and expanded in medium containing rIL-2 alone or in combination with other human cytokines (rIL-1, rIL-4, rIL-6, and recombinant human tumor necrosis factor-alpha (rTNF alpha)). Lymphocytes incubated with rIL-2 alone did not grow, whereas addition of the other cytokines augmented IL-2-mediated lymphocyte proliferation. In all cultures, the majority of expanded lymphocytes were CD3+, CD56- T cells. Lymphocytes cultured with rIL-1, rIL-2, rIL-4, and rIL-6 exhibited cytolytic activity specific for autologous melanoma, which increased during the culture period (24.08 and 58.18% at 16 and 30 days in culture, respectively) without detectable changes in cell surface phenotype and remained high even after 100 days in culture. Moreover, the cytolytic activity was inhibited by monoclonal antibodies (mAbs) against HLA-class I, CD3, and CD8 molecules but not by mAbs against HLA-class II or CD4 molecules. Lymphokine-activated killer (LAK) activity was detected in lymphocytes cultured with rIL-1, rIL-2, and rIL-6 in the presence or absence of rTNF alpha. These data indicate that lymphocytes derived from melanoma-invaded lymph nodes and cultured in the presence of rIL-1, rIL-2, rIL-4, and rIL-6 offers an efficient system to expand CD8+ CTLs with HLA-restricted cytolytic specificity against autologous tumor cells.

Antigens, CD↗
PubMed1994

Proliferation, phenotype, and cytotoxicity of human lymphocytes isolated from lymph nodes invaded by melanoma cells.

The effects of human recombinant interleukin-4 (rIL-4) on metastatic melanoma (lymph node)-derived T lymphocytes cultured with human recombinant interleukin-2 (rIL-2) were studied. Lymphocytes isolated from melanoma-invaded lymph nodes were cultured in media with rIL-2 in the presence (MB-2,4) or absence (MB-2) or rIL-4 for up to 48 days. A majority of lymphocytes grown in both cultures were CD3+ T lymphocytes. Addition of rIL-4 to the rIL-2 culture abrogated the growth of the CD3-, CD56+ cell population [natural killer (NK) cell], which were present in culture with rIL-2 alone. Lymph-node-derived T lymphocytes that had expanded under MB-2,4 conditions lysed only autologous melanoma cells and they maintained the autologous-specific cytolytic activity during the entire culture period. They did not lyse K562, Daudi, or allogeneic target cells. Monoclonal antibodies (MAbs) against CD3 molecules and MHC class I molecules but not MHC class II molecules inhibited the specific lytic functions of T lymphocytes under MB-2,4 culture conditions. Collectively, these data indicate that in lymphocyte culture derived from melanoma-invaded lymph nodes, rIL-4 inhibits the rIL-2-dependent proliferation of NK cells and antigen nonspecific killer T lymphocytes and also effectively abrogates the rIL-2-induced NK and lymphokine-activated killer (LAK) activities.

Cytotoxicity Tests, Immunologic↗