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Query: UMLS:C0021051 (
immunodeficiency
)
71,517
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Common variable immunodeficiency represents the most frequently occurring primary
immunodeficiency
disorder and is usually detected sporadically in patients with no family history of
immunodeficiency
. We present the case stories of two monozygote twins, who following a period of decreasing serum immunoglobulins developed primary central nervous system lymphomas. One twin had clinical and paraclinical features mimicking multiple sclerosis. Immunohistochemical investigations on biopsy tissue showed expression of the bcl-2 and
p53
gene products, and Epstein-Barr virus (EBV) encoded small RNA's (EBER) indicating latent infection were detected in lymphoma cells using in situ hybridisation techniques. The pathogenetic role of EBV in oncogenesis is discussed.
...
PMID:EBV-positive primary central nervous system lymphomas in monozygote twins with common variable immunodeficiency and suspected multiple sclerosis. 949 19
Previous reports have indicated that benzothiophenes exhibit broad anti-inflammatory properties and inhibit human
immunodeficiency
virus-type 1 (HIV-1) replication. We show that the immunosuppressant cyclosporin A (CsA) and benzothiophene-2-carboxamide, 5-methoxy-3-(1-methyl ethoxy)-1-oxide (PD 144795) block the induction of
p53
and NF-kappaB binding to the HIV-1 long terminal repeat (LTR) by the T cell receptor activator phytohemagglutinin. CsA and PD 144795 also inhibit the induction by phytohemagglutinin of the transcription mediated by an HIV-1 LTR fragment containing the
p53
and NF-kappaB sites. These effects of PD 144795 on HIV-1 transcription correlate with its ability to inhibit the phosphatase activity of calcineurin and are similar to those previously described for CsA. Moreover, a constitutive active form of calcineurin is able to induce expression from the HIV-1 LTR in a
p53
- and NF-kappaB-dependent manner and PD 144795 is able to block this induction. These results demonstrate that the DNA binding of
p53
to the HIV-1 LTR can be modulated by calcineurin and provide a framework to understand the anti-HIV properties of benzothiophene derivatives.
...
PMID:p53 transactivation of the HIV-1 long terminal repeat is blocked by PD 144795, a calcineurin-inhibitor with anti-HIV properties. 950 19
Infections of the genital and oral epithelia by human papillomaviruses cause condylomata, papillomas, and squamous intraepithelial neoplasms, some of which can progress to invasive cancers. We describe an induction of p21cip1/WAF1/sdi1 protein in a fraction of the spinous cells in benign lesions and in cervical intraepithelial neoplasia grades I and II. The induction appears to be post-transcriptional and independent of
p53
. p21cip1 antigen-positive cells were sporadic in cervical intraepithelial neoplasia III and rare and focal in carcinomas. In contrast, p21cip1 protein was below or at the threshold of detection in the differentiated cells of normal squamous epithelia from different body sites despite an up-regulation of p21cip1 RNA. In cervical intraepithelial neoplasias from patients who were also positive for the human
immunodeficiency
virus, there was an additional increase in p21cip1 RNA in the upper spinous cells without concomitant p21cip1 protein induction. A consistent inverse relationship was observed between the p21cip1 protein induction and abundant human papillomavirus DNA and RNAs. We propose that p21cip1 protein induction is a novel host response that inhibits viral DNA replication and thus prevents elevated viral transcription. This hypothesis can partly account for the heterogeneity and the differentiation-dependent viral activities commonly observed in benign human papillomavirus lesions.
...
PMID:Post-transcriptional induction of p21cip1 protein in condylomata and dysplasias is inversely related to human papillomavirus activities. 954 62
Epstein-Barr virus (EBV) has been detected in the large majority of HIV-related primary central nervous system lymphomas (PCNSL) suggesting a pathogenetic role of the virus. Unlike HIV-related PCNSL, conflicting data exist with regard to the presence of EBV in non
immunodeficiency
-related (sporadic) PCNSL. For this reason, a population based material of 41 sporadic PCNSL was analysed for the presence of EBV genome (EBER, BHLF) using RNA in situ hybridisation (RISH). Furthermore, the expression of the gene products of the bcl-2 oncogene and the
p53 tumor suppressor
gene and the tumor growth fraction reactive with the monoclonal antibody Ki-67 have been evaluated. All cases but two were EBV genome negative. In the two positive cases less than 5% of tumor cells showed EBER positivity. In contrast, more than 75% of cells morphologically belonging to the tumor-cell population stained positively for EBER in two cases of HIV related PCNSL. Immunostaining for the bcl-2 oncoprotein was positive in 28 (72%) of 39 cases examined. In most cases more than 75% of tumor cells showed cytoplasmic expression. Of 37 cases investigated for
p53
expression, 21 (57%) stained positively. However, in the large majority of positive cases less than 10% of the neoplastic cells stained. The percentage of Ki-67 positive cells ranged between 10% and 80% with a mean of 50%. The expression of the
p53
and bcl-2 oncoproteins and the growth fraction did not have any prognostic impact. We conclude that the EBV genome is rarely detected in sporadic PCNSL, indicating that a pathogenetic role of EBV is unlikely. Like extracerebral B-cell lymphomas a large fraction of PCNSL expresses the
p53
and bcl-2 oncoproteins, a feature, however, which does not seem to have prognostic implications.
...
PMID:Primary central nervous system lymphomas in immunocompetent individuals: histology, Epstein-Barr virus genome, Ki-67 proliferation index, p53 and bcl-2 gene expression. 966 83
Transcription of the human
immunodeficiency
virus type-1 (HIV-1) genome is controlled by cooperative interaction of viral encoded proteins and host regulatory proteins. In this study, we have examined the capacity of the viral auxiliary protein, Vpr, to modulate transcriptional activity of the HIV-1 promoter sequence located within the long terminal repeat (LTR). We demonstrate that ectopic expression of Vpr in human astrocytic cells, U-87MG, enhances the basal activity of the viral promoter in transfected cells and that the GC-rich sequences, spanning nucleotides -80 to -43, are important for this activity. Since this region serves as the target for
p53
-induced suppression of LTR activity and interacts with the ubiquitous transcription factor, Sp1, we examined the cooperative activity of Vpr,
p53
, and Sp1 upon LTR transcription. Results from co-transfection studies indicated that overexpression of wild type
p53
, but not mutant p53, decreases the level of activation of the LTR by Vpr. Transcriptional activation of the LTR by Vpr required the presence of Sp1 since overexpression of Vpr in cells with no endogenous Sp1 failed to augment LTR activity. Results from protein-protein interaction studies indicated that Vpr is associated with both
p53
and Sp1 in cells with ectopic expression of these proteins. Moreover, it was evident that
p53
and Sp1 interact with each other in these cells. These functional and structural studies provided a working model on the cooperative interaction of Vpr with cellular proteins Sp1 and
p53
and control of viral gene transcription at immediate early stage of infection prior to the participation of other viral regulatory proteins.
...
PMID:Cooperative actions of HIV-1 Vpr and p53 modulate viral gene transcription. 968 44
The tumour suppressor
p53
becomes activated as a transcription factor in response to DNA damage, but the mechanism for this activation is unclear. A good candidate for an upstream activator of
p53
is the DNA-dependent protein kinase (DNA-PK) that depends on the presence of DNA breaks for its activity. Here we investigate the link between DNA damage and the activation of DNA-PK and of
p53
. To determine whether DNA-PK is an upstream mediator of the
p53
DNA-damage response, we analysed a severe combined-
immunodeficiency
(SCID) mouse cell line, SCGR11, and the human glioma cell line M059J . Both cell lines lack any detectable DNA-PK activity. We find that
p53
is incapable of binding to DNA in the absence of DNA-PK, that DNA-PK is necessary but not sufficient for activation of
p53
sequence-specific DNA binding, and that this activation occurs in response to DNA damage. Our results establish DNA-PK as a link between DNA damage and
p53
activation, and reveal the existence of a mammalian DNA-damage-response pathway.
...
PMID:DNA-dependent protein kinase acts upstream of p53 in response to DNA damage. 971 37
Malignant lymphomas frequently develop in the pleural cavity of patients with long-standing pyothorax. Thus, the term pyothorax-associated lymphoma (PAL) has been proposed for this type of tumor. Most PAL are of the type diffuse lymphoma of B cell and contain Epstein-Barr virus (EBV) DNA. This article reviews the mechanism for the development of PAL. The possible contribution of EBV infection, inflammatory cytokines and other genetic lesions, including the
p53
gene, towards the growth advantage of neoplastic cells is described. Although the presence of EBV is focused in PAL cells, the contribution of EBV-mediated growth promotion in PAL is limited. Another important characteristic of PAL is that the virus antigen-positive lymphoma develops in patients with pyothorax, in whom the systemic
immunodeficiency
is unlikely to be present. Therefore, in the course of the development of PAL, the mechanism for the evading host immune surveillance must be obvious. In this context, the production of an immunosuppressive cytokine from PAL cells, human histocompatibility leukocyte antigen class I alleles of patients with PAL, and the mutations of cytotoxic T lymphocyte epitopes in an EBV-latent antigen are described. These mechanisms could be involved in the development of PAL, an EBV-positive lymphoma developing in an immunocompetent host, and also shed light on the tumorigenesis of other EBV-positive neoplasms and on the lymphomagenesis of other inflammatory lesions.
...
PMID:Mechanism for the development of pyothorax-associated lymphoma. 977 4
The human genetic disorder ataxia-telangiectasia (AT) is characterized by
immunodeficiency
, progressive cerebellar ataxia, radiosensitivity, cell cycle checkpoint defects and cancer predisposition. The gene mutated in this syndrome, ATM (for AT mutated), encodes a protein containing a phosphatidyl-inositol 3-kinase (PI-3 kinase)-like domain. ATM also contains a proline-rich region and a leucine zipper, both of which implicate this protein in signal transduction. The proline-rich region has been shown to bind to the SH3 domain of c-Abl, which facilitates its phosphorylation and activation by ATM. Previous results have demonstrated that AT cells are defective in the G1/S checkpoint activated after radiation damage and that this defect is attributable to a defective
p53
signal transduction pathway. We report here direct interaction between ATM and
p53
involving two regions in ATM, one at the amino terminus and the other at the carboxy terminus, corresponding to the PI-3 kinase domain. Recombinant ATM protein phosphorylates
p53
on serine 15 near the N terminus. Furthermore, ectopic expression of ATM in AT cells restores normal ionizing radiation (IR)-induced phosphorylation of
p53
, whereas expression of ATM antisense RNA in control cells abrogates the rapid IR-induced phosphorylation of
p53
on serine 15. These results demonstrate that ATM can bind
p53
directly and is responsible for its serine 15 phosphorylation, thereby contributing to the activation and stabilization of
p53
during the IR-induced DNA damage response.
...
PMID:ATM associates with and phosphorylates p53: mapping the region of interaction. 984 17
Molecular epidemiological studies of populations at high risk for liver cancer have shown that hepatitis B virus (HBV) and aflatoxin B1 exposures are two major risk factors for this disease. Oltipraz is currently being considered for clinical trial to protect against aflatoxin B1-induced hepatocarcinogenesis based on its proven protective effect in many different animal models. In addition, oltipraz inhibits human
immunodeficiency
virus (HIV) replication. The inactivation of reverse transcriptase of HIV appears to be the antiviral mechanism. It has been demonstrated that a number of compounds that inhibit HIV replication also inhibit HBV replication in vitro. Therefore, we tested the possibility of oltipraz blocking HBV replication in 2.2.15 cells (clonal cells derived from HepG2 cells that were transfected with a plasmid containing HBV DNA) in vitro. Results of the experiments indicate that oltipraz has a dose-dependent inhibitory effect on HBV replication and specifically blocks HBV transcription in 2.2.15 cells. In addition, oltipraz induces endogenous wild-type
p53 protein
in a dose- and time-course-dependent manner. Taken together, we speculate that the effects of oltipraz against replication of HBV and specific blocking of HBV transcription may be through the induction of
p53
-mediated pathway in 2.2.15 cells. In addition to its known chemopreventive action on aflatoxin B1 hepatocarcinogenesis, oltipraz was shown here to inhibit HBV replication. These dual effects put oltipraz as the excellent candidate for the chemopreventive agent of human hepatocellular carcinoma.
...
PMID:Oltipraz, a novel inhibitor of hepatitis B virus transcription through elevation of p53 protein. 988 68
Lymphomas in 10 cynomolgus monkeys infected with a simian
immunodeficiency
virus (SIVsm) were studied with regard to proliferative activity and apoptosis-related gene expression. All were diffuse large-cell lymphomas, showed mono or oligoclonality and a 9/10 diploid cellular DNA content. Expression of a simian homologue to Epstein-Barr virus (HVMF-1) was shown in nine cases. The lymphomas showed moderate to high proliferative activity by Ki67 immunostaining and DNA flow cytometry, and a low number of apoptotic cells detected by TdT-mediated dUTP nick-end labeling (TUNEL). Immunohistochemistry showed abundant tumor infiltrating TIA-1(+) cytotoxic lymphocytes (CTL) and macrophages. Bcl-2, Mcl-1, and also Bax and Bak, but not
p53
were demonstrable in the tumor cells by immunostaining. Our findings suggest a causal relationship between HVMF-1 infection and a low apoptotic index of the lymphomas due to the expression of Bcl-2. The apparent inefficient function of tumor-infiltrating CTL could be due to inactivation of CTL and/or resistance of the lymphoma cells to CTL effects. The tumors showed immunoreactivity for CD18, CD29, and CD49d, but not for CD11a, mimicking the phenotype of human Epstein-Barr virus (EBV)-related lymphomas. In summary, our observations indicate a high similarity between this simian model of acquired immunodeficiency syndrome (AIDS)-related lymphomas (ARL) and human ARL and other immunosuppression-related lymphomas.
...
PMID:Proliferation and apoptosis-related gene expression in experimental acquired immunodeficiency syndrome-related simian lymphoma. 994 80
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