Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.7 (DNA polymerase)
 17,007 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The human herpesvirus 6 (HHV-6) is known to interact intimately with cells of the immune system. Here we report that HHV-6 is a potent inducer of interleukin-1 beta (IL-1 beta) and tumor necrosis factor alpha (TNF-alpha) in cultures of peripheral blood mononuclear cells. In contradistinction, HHV-6 has no effect on IL-6 synthesis. Maximal IL-1 beta and TNF-alpha gene transcription, as detected by polymerase chain reaction amplification analysis, is observed at 12 and 6 h postinfection, respectively. Release of IL-1 beta and TNF-alpha into the culture supernatants peaked at 24 h and gradually decreased with time. Heat-inactivated virus was unable to stimulate IL-1 beta and TNF-alpha syntheses, whereas UV-irradiated virus retained the full monokine-inducing potential of the native particle. Preincubation of viral preparation with neutralizing anti-HHV-6 antibody resulted in the abrogation of this cytokine-inducing effect, whereas treatment of cells with phosphonoacetic acid (an inhibitor of viral DNA polymerase activity) had no effect on the ability of the virus to stimulate monokine release. These results indicate that HHV-6 can exert a strong immunomodulatory effect by stimulating the cells of myeloid lineage to produce these cytokines.
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PMID:Human herpesvirus 6 induces interleukin-1 beta and tumor necrosis factor alpha, but not interleukin-6, in peripheral blood mononuclear cell cultures. 165 26

In order to facilitate cytokine mRNA detection in blood cells, we have developed a highly reproducible and easily performed RNA isolation method for use with whole blood. Previously frozen human whole blood samples were lysed in guanidine thiocyanate solution to isolate total RNA. After reverse transcription a PCR method was applied to detect beta-actin and cytokine mRNA expression (interleukin-(IL)2, IL4, IL10, tumor necrosis factor alpha (TNF alpha) and interferon gamma (IFN gamma)). The presence of cDNA was confirmed by agarose gel electrophoresis and quantitated on-line using sequence-specific fluorochrome labeled internal oligonucleotide probes. This quantitative method is based on the cleavage of fluorescent dye labeled probes by the 5' --> 3' endonuclease activity of the Taq DNA polymerase during PCR and measurement of fluorescence intensity by a Sequence Detector System. The signal generated was directly proportional to the starting copy number of target molecules in the sample over 6 log concentrations and quantitative analysis of cDNA concentrations was performed in comparison to beta-actin or cytokine cDNA standards. mRNAs coding for beta-actin and TNF alpha were readily detectable in cDNAs prepared from the whole blood of eight healthy donors, while the other cytokines were expressed in lower amounts (IFN gamma, IL10) or were undetectable (IL2, IL4). The assay described is highly reproducible, requires no post PCR manipulation of the amplicons and permits the analysis of several hundred PCR reactions per day. Using this method it is possible to detect and quantify cytokine mRNA expression reliably in small amounts of previously frozen blood even after storage of samples for at least several months.
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PMID:Quantification of cytokine mRNA expression by RT PCR in samples of previously frozen blood. 952 Mar 2

The products of the tumor suppressor genes are considered to function as specific inhibitors of tumor cell growth. In this communication, we present evidence to show that these proteins inhibit tumor cell proliferation by participating in the activation of tumor cell differentiation. The ML-1 human myeloblastic leukemia cells used in this study proliferate when treated with insulin-like growth factor I and transferrin but differentiate to monocytes when exposed to tumor necrosis factor alpha or transforming growth factor beta1, or to macrophage-like cells when treated with both these cytokines. Initiation of proliferation but not of differentiation was followed by a 20- to 25-fold increase in the nuclear level of the DNA polymerase-associated processivity factor PCNA and of the proliferation-specific transcription factor E2F1. In contrast, induction of differentiation but not of proliferation was followed by a 25- to 30-fold increase in the nuclear level of the tumor suppressor proteins p53 (wild type), pRb, and p130/Rb2 and of the p53-dependent cyclin kinase inhibitor p21/Cip1. p53 and p21/Cip1, respectively, inhibit the expression and activation of PCNA, whereas p130 and pRb, respectively, inhibit the expression and activation of E2F1. As a result, G1-S-associated DNA and mRNA synthesis is inhibited, growth uncoupled from differentiation, and maturation enabled to proceed. Where this function of the tumor suppressor proteins is impaired, the capacity for differentiation is lost, which leads to the sustained proliferation that is characteristic of the cancer cell.
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PMID:Tumor suppressor proteins as regulators of cell differentiation. 976 53

Development of a novel group of antiviral agents, acyclic nucleoside phosphonates, has provided a new perspective for treating human immunodeficiency virus (HIV) infection. One of the compounds, 9-(R)-[2-(phosphonomethoxy)propyl]adenine (PMPA) (tenofovir), has been shown to confer complete protection against AIDS in a simian model of the infection. The aim of our study was to investigate whether the antiviral efficacy of PMPA, which depends mainly on inhibition of virus-induced DNA polymerase or of reverse transcriptase, could be contributed by immunomodulatory potential of this drug. We screened for its ability to activate production of cytokines and chemokines that are known to interfere with the replication and/or the entry of HIV in cells. Using the in vitro test system of mouse macrophages and lymphocytes, it has been found that PMPA stimulates macrophage secretion of interleukin-1beta (IL-1beta), IL-10, and tumor necrosis factor alpha. Production of the chemokines RANTES and macrophage inflammatory protein 1alpha was activated in both macrophages and lymphocytes, and also in human cell line U937. Other cytokines--i.e., IL-2, IL-12, IL-13, and gamma interferon-remained uninfluenced by PMPA. The cytokines were stimulated in a dose-dependent fashion, with rapid onset, and peak concentrations were achieved within 5 to 24 h. The findings contribute to a more complex understanding of mechanisms of antiviral effectiveness of PMPA and support the view that this drug could become a promising candidate for therapeutic exploitation in anti-HIV preventive medicine.
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PMID:Activation by 9-(R)-[2-(phosphonomethoxy)propyl]adenine of chemokine (RANTES, macrophage inflammatory protein 1alpha) and cytokine (tumor necrosis factor alpha, interleukin-10 [IL-10], IL-1beta) production. 1170 12

Erythema multiforme (EM) is a clinical conundrum the name of which reflects the broad morphological spectrum of the lesions. Molecular and immunologic evidence that herpes simplex virus (HSV) causes a subset of EM lesions [herpes-associated EM (HAEM)] is reviewed, and new data are presented which suggest that autoreactive T-cells triggered by virus infection play an important role in HAEM pathogenesis. Disease development begins with viral DNA fragmentation and the transport of the DNA fragments to distant skin sites by peripheral blood mononuclear cells (PBMCs). HSV genes within DNA fragments deposited on the skin [notably DNA polymerase (Pol)] are expressed, leading to recruitment of HSV-specific CD4+ Th1 cells that respond to viral antigens with production of interferon-gamma (IFN-gamma). This step initiates an inflammatory cascade that includes expression of IFN-gamma induced genes, increased sequestration of circulating leukocytes, monocytes and natural killer (NK) cells, and the recruitment of autoreactive T-cells generated by molecular mimicry or the release of cellular antigens from lysed cells. The PBMCs that pick up the HSV DNA [viz. macrophages or CD34+ Langerhans cells (LC) precursors], their ability to process it, the viral proteins expressed in the skin and the presence of epitopes shared with cellular proteins may determine whether a specific HSV episode is followed by HAEM development. Drug-associated EM (DIEM) is a mechanistically distinct EM subset that involves expression of tumor necrosis factor alpha (TNF-alpha) in lesional skin. It is our thesis that the polymerase chain reaction (PCR) assay for HSV DNA detection in lesional skin and staining with antibodies to IFN-gamma and TNF-alpha, are important criteria for the diagnosis of skin eruptions and improved patient management.
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PMID:Herpes simplex virus (HSV)-associated erythema multiforme (HAEM): a viral disease with an autoimmune component. 1263 59

KCTD10 is a TNF-alpha inducible protein that can interact with the small subunit of DNA polymerase a and PCNA. In order to study the function of KCTD10, we prepared the rabbit anti-mouse KCTD10 polyclonal antibody by using the His-tagged recombinant mouse KCTD10 protein to immune New Zealand white rabbit. Mouse KCTD10 shares significant similarity with PDIP1 (polymerase delta-interacting protein 1) and TNFAIP1 (tumor necrosis factor alpha-induced protein 1) protein,and then KCTD10 polyclonal antiserum possesses cross-reactivity with PDIP1 protein and TNFAIP1 protein. The partially digested fragments of homogeneous proteins PDIP1 and TNFAIP1 were mixed and incubated with anti-KCTD10 antiserum at 4 degrees C for 3 h to deplete unspecific antibodies. Through this method, we removed successfully the cross-reactivity of anti-KCTD10 antibody with PDIP1 and TNFAIP1 and obtained specific anti-KCTD10 antibody. Then, the anti-KCTD10 antibody was used in immunohistochemistry experiments of mouse. The results of immunohistochemistry on whole-mount embryo and paraffin section demonstrated that KCTD10 is highly expressed in neuroepithelium of neural tube and dorsal root ganglion of 12.5 d embryos. These results suggest that KCTD10 may play roles in the development of neuroepithelium of neural tube and dorsal root ganglion.
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PMID:[Preparation of mouse KCTD10 antibody and expression analysis of KCTD10 in neuroepithelium of neural tube and dorsal root ganglion]. 1825 28