Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sera from hemophiliacs were analyzed for antibodies to human immunodeficiency virus type 1 (HIV-1) by using radioimmunoprecipitation (RIP), western blotting (WB) with nonreducing buffer (NR), and WB with reducing buffer (R). We analyzed envelope gp160, gp120, and gp41; pol gene proteins p64, p53, and p34; and gag gene protein p24. Of 215 samples positive for reactivity to gp160 and gp120(RIP), antibodies to p24 were undetectable in 2 (0.9%), to gp41 in 9 (4.2%), to the pol antigens in 5 (2.3%), to gp120(NR) in 3 (1.4%), and to gp120(R) in 55 (25.6%). By sequential analysis of samples, antibodies to gp120(NR), gp120(R), p24, gp41, p64/53, and p34 were observed later in the course of infection than were antibodies to gp120(RIP) or gp160. This result suggests caution against reliance on WB as the "gold standard." A significantly higher rate of progression to AIDS-related complex was found for individuals lacking antibodies to gp120(R). It is possible that antigenic domains represented by gp120(R) may play a role in the pathogenesis of HIV-1 infection.
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PMID:Antibody responses in early human immunodeficiency virus type 1 infection in hemophiliacs. 334 72

The antibody response to human immunodeficiency virus (HIV) after primary infection was monitored in eight homosexual men with the acute mononucleosis-like illness associated with seroconversion. Multiple sera from each subject, taken at frequent intervals after onset of acute illness, were tested for antibody to HIV by IgM and IgG immunofluorescent assays (IFAs), four commercial enzyme-linked immunosorbent assays (ELISAs), and Western immunoblot (WB). Antibody to HIV was detected first by IgM IFA (mean +/- SD, 5 +/- 3 days), followed by IgG IFA (11 +/- 3 days); the IgM antibody titer peaked at 24 +/- 17 days and disappeared by 81 +/- 27 days, whereas the IgG antibody titer peaked at 133 +/- 63 days and has not disappeared in any subject. Antibody to HIV was first detected by ELISA from 31 +/- 14 to 58 +/- 32 days, depending on the assay kit used. Antibody to p24 and gp41 was first detected by WB at 24 +/- 10 days, followed by antibody to p55 (40 +/- 20 days), p68 (57 +/- 19 days), and p34 (71 +/- 22 days).
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PMID:Antibody response to human immunodeficiency virus after primary infection. 355 44

Lentiviral Gag polyproteins have a proline-rich protein, p6, at their C terminus. There are conflicting reports about the function of p6 in virus release. In the present work, mutants that affect p6 of human immunodeficiency virus type 1 (HIV-1) Gag polyprotein were constructed and analysed. None of the mutants prevented virus release completely; however, detachment of budding particles was less efficient as evidenced by electron microscopy. Virions of the p6 truncation mutant B2TAA had a significantly reduced number of Pol proteins (p66, p51 and p34) and an increased amount of incompletely processed Gag proteins compared with the parental virus. A mutation that altered the cleavage site between p6 and p1 did not significantly affect virus assembly, virus release or protein processing with the exception of cleavage between p6 and p1. However, virions of this mutant (B2P6C) exhibited irregular-shaped core structures that were distinct from the cone-shaped core structure seen in the parental virion. B2P6C mutant virus was non-infectious in CD4+ T cells. These results suggest that mutations in p6 affect efficient detachment of budding particles from the cell surface. Proper cleavage between p6 and p1 may be critical for the formation of the distinctive cone-shaped core structure of HIV-1 virions.
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PMID:Role of the C terminus Gag protein in human immunodeficiency virus type 1 virion assembly and maturation. 884 26

Hepatitis B virus core protein (HBc) in particulate form is a potent immunogen for the design of vaccines with a broad T-cell reactivity. Hybrid HBc proteins with N-terminal insertions of human immunodeficiency virus (HIV-1) B- and T-cell epitopes from gp41 and p34 pol, respectively, were constructed HBc hybrids formed particles with HIV-1 epitopes exposed on the surface. The proliferative response of peripheral blood mononuclear cells (PBMC) from HIV-1 infected donors to the hybrids was studied in vitro and compared to that of synthetic peptides representing the same HIV-1 sequences. The epitope from p34 pol induced PBMC proliferation both when inserted into HBc and as a peptide. The epitope from gp41, when inserted into HBc, and to a lesser extent the relevant peptide caused a decreased reactivity. The inhibitory effect of the HBc hybrid carrying the gp41-epitope was pronounced even in the HIV-1 infected donors with proliferative responses to HBc. The similarity between the mode of action of the peptides and hybrid HBcs implies either correct processing of the latter or T-cell recognition of HIV-1 epitopes in the intact hybrid HBc particles.
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PMID:HIV-1 epitopes exposed by hybrid hepatitis B core particles affect proliferation of peripheral blood mononuclear cells from HIV-1 positive donors. 887 17

The Vpr gene of human immunodeficiency virus type 1 and type 2 (HIV-1, HIV-2) and simian immunodeficiency virus (SIV) encodes a small nuclear protein which is virion-associated and assists nuclear transport of the preintegration complex. Expression of HIV-1 Vpr has been shown to induce differentiation and prevent proliferation of human cells. HIV-1 Vpr has also been shown to arrest cell growth and cause morphological defects in yeast. In contrast, the Vpx gene of HIV-2 and SIV, which shares sequence homology with Vpr, does not seem to inhibit proliferation of human cells. It has been suggested that the cell cycle arrest effect of Vpr and Vpx is species and cell-type dependent. In this study, we have taken advantage of a conditional expression system to characterize the growth inhibitory effects of Vpr and Vpx of HIV-1, HIV-2, and SIV in the fission yeast Schizosaccharomyces pombe. Our results show that both Vpr and/or Vpx of HIV-1, HIV-2, and SIV arrest cell growth in S. pombe, and HIV-1 Vpr is more cytotoxic than HIV-2 or SIV Vpr or Vpx. Flow cytometry analysis indicated that yeast cells cease proliferating with DNA contents indicative of arrest in G1 and G2, with some cells showing signs of overreplication of DNA. While the observed cell cycle arrest phenotype was not identical to that observed in mammalian cells, there were similarities of growth arrest phenotype caused by Vpr and Vpx in yeast and mammalian cells. Specifically, the observation that yeast and mammalians cell both arrest in G2 with reduced p34/cdc2 kinase activity indicates that Vpr and Vpx interact with conserved target(s) in yeast and mammalian cells. The ability to use genetic analysis to elucidate the mechanisms involved makes S. pombe an excellent model system in which to study the effects of Vpr and Vpx on cellular function.
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PMID:Cell cycle inhibitory effects of HIV and SIV Vpr and Vpx in the yeast Schizosaccharomyces pombe. 912 66

The Vpr protein of primate lentiviruses arrests cell cycling at the G(2)/M phase through an inactivation of cyclin B-p34(cdc2) and its upstream regulator cdc25. We provide here biochemical and functional evidence demonstrating that human immunodeficiency virus type 1 (HIV-1) Vpr mediates G(2) arrest by forming a complex with protein phosphatase 2A (PP2A), an upstream regulator of cdc25. Vpr associates with PP2A through a specific interaction with the B55 regulatory subunit. This interaction is necessary but not sufficient for G(2) arrest. Interestingly, we found that Vpr association with B55-containing PP2A targets the enzymatic complex to the nucleus and, importantly, enhances the recruitment and dephosphorylation of the cdc25 substrate. Our data suggest that Vpr mediates G(2) arrest by enhancing the nuclear import of PP2A and by positively modulating its catalytic activity towards active phosphorylated nuclear cdc25.
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PMID:Human immunodeficiency virus type 1 Vpr-mediated G(2) cell cycle arrest: Vpr interferes with cell cycle signaling cascades by interacting with the B subunit of serine/threonine protein phosphatase 2A. 1211 Jun 3

Human immunodeficiency virus (HIV)-infection is characterized by loss of CD4+ T cells associated with high levels of immune activation, T-cell proliferation, and lymphocyte apoptosis. To investigate the role of intrinsic perturbations of cell-cycle control in the immunopathogenesis of acquired immunodeficiency syndrome (AIDS), we studied the expression of cell-cycle-dependent proteins in lymphocytes from HIV-infected patients. Cyclin B1 expression, Nucleolar Organizer Regions (NORs) number, and NORs area of distribution were all consistently increased in HIV-infected patients, but returned to normal after effective antiretroviral therapy, suggesting that viral replication is directly implicated in the genesis of the observed changes. Analysis of cyclin B1 intracellular turnover showed that the increased cyclin B1 expression is (1) caused by defective degradation in the presence of normal rates of synthesis, and (2) is temporally associated with decreased levels of ubiquitination. After in vitro activation of lymphocytes from healthy individuals, cyclin B1 and cdc25 expression and ubiquitination, p34 cdc2 activity, NORs morphology, and C23/nucleolin localization showed a 72- to 96-hour cyclic pattern that led to a biologic state similar to baseline. On the contrary, complex but consistent changes of the same indices followed activation of T lymphocytes from HIV-infected patients, resulting in a 5-fold increase in apoptosis. Overall, our data indicate that a profound dysregulation of cell-cycle control is present in lymphocytes from HIV-infected patients. This finding may provide a novel biologic link between immune activation, accelerated lymphocyte turnover, and increased apoptosis during HIV infection.
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PMID:Abnormal intracellular kinetics of cell-cycle-dependent proteins in lymphocytes from patients infected with human immunodeficiency virus: a novel biologic link between immune activation, accelerated T-cell turnover, and high levels of apoptosis. 1123 18

Lymphocytes isolated from human immunodeficiency virus (HIV)-infected patients have dysregulated cell-cycle control, consisting of increased activation of the cyclin B1/p34 cdc2 complex and abnormal nucleolar structure. To better characterize the molecular features of the HIV-associated cell-cycle perturbations, we performed a detailed analysis of the posttranslational regulation of nucleolin, a key structural protein in the nucleolus. We found that, in concanavalin A-stimulated lymphocytes from HIV-infected patients, the inappropriate activation of the cyclin B1/p34 cdc2 kinase complex is temporally associated with increased threonine phosphorylation, augmented fragmentation, and prominent extranuclear and cell-surface localization of nucleolin. Importantly, increased lymphocyte apoptosis is observed at the time of cell-surface localization of nucleolin. These results may delineate a direct molecular link between abnormal activation of cyclin B1/p34 cdc2 and the changes in the nucleolar structure, thus providing a better molecular definition of HIV-associated cell-cycle dysregulation.
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PMID:Specific changes in the posttranslational regulation of nucleolin in lymphocytes from patients infected with human immunodeficiency virus. 1462 73

A 23-year-old man presented with disturbance of consciousness and convulsion. Two weeks prior to his admission, he had general arthralgia, retro-orbital pain, and body temperature increase to 40 degrees C. These symptoms persisted for two weeks. He was admitted to the hospital because of general convulsion, followed by disturbance of consciousness. On admission, he was deeply lethargic. Cerebrospinal fluid obtained on admission showed pleocytosis (247/mm3) and an increased level of protein. Electroencephalogram obtained on admission disclosed diffuse slow waves. Enhanced cranial MR image did not show any abnormal lesions in the cerebral parenchyma. The patient was diagnosed as having meningoencephalitis and the treatment consisting of aciclovir, CTRX, and methylprednisolone was undertaken. A test for human immunodeficiency virus (HIV) antibody was found to be positive on the second day of hospitalization. A Western blot was positive with bands at gp160 and P24 confirming HIV infection. Antibody titers of paired acute and convalescent sera including HSV, EBV, CMV, mumps, measles, and Japanese encephalitis did not show any significant increase. The patient became alert on the 3rd day of hospitalization. Electroencephalogram obtained on the 10th day of hospitalization was normal. Western blot, which was obtained 4 months later, was positive with bands at gp120, p68, p55, p52, gp41, p40, p34, p18, including gp160 and P24. He was diagnosed as having primary HIV infection. Meningoencephalitis was attributed to acute primary HIV infection. Acute HIV infection should be considered as an etiology of meningoencephalitis.
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PMID:[A case of primary HIV infection presenting as meningoencephalitis]. 1631 72

In contrast to human immunodeficiency virus (HIV) infection of humans and experimental simian immunodeficiency virus (SIV) infection of rhesus macaques (RMs), SIV infection of sooty mangabeys (SMs), a natural host African monkey species, is typically nonpathogenic and associated with preservation of CD4+ T-cell counts despite chronic high levels of viral replication. In previous studies, we have shown that the lack of SIV disease progression in SMs is related to lower levels of immune activation and bystander T-cell apoptosis compared to those of pathogenic HIV/SIV infection (G. Silvestri, D. Sodora, R. Koup, M. Paiardini, S. O'Neil, H. M. McClure, S. I. Staprans, and M. B. Feinberg, Immunity 18:441-452, 2003; G. Silvestri, A. Fedanov, S. Germon, N. Kozyr, W. J. Kaiser, D. A. Garber, H. M. McClure, M. B. Feinberg, and S. I. Staprans, J. Virol. 79:4043-4054, 2005). In HIV-infected patients, increased T-cell susceptibility to apoptosis is associated with a complex cell cycle dysregulation (CCD) that involves increased activation of the cyclin B/p34-cdc2 complex and abnormal nucleolar structure with dysregulation of nucleolin turnover. Here we report that CCD is also present during pathogenic SIV infection of RMs, and its extent correlates with the level of immune activation and T-cell apoptosis. In marked contrast, naturally SIV-infected SMs show normal regulation of cell cycle control (i.e., normal intracellular levels of cyclin B and preserved nucleolin turnover) and a low propensity to apoptosis in both peripheral blood- and lymph node-derived T cells. The absence of significant CCD in the AIDS-free, non-immune-activated SMs despite high levels of viral replication indicates that CCD is a marker of disease progression during lentiviral infection and supports the hypothesis that the preservation of cell cycle control may help to confer the disease-resistant phenotype of SIV-infected SMs.
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PMID:Perturbations of cell cycle control in T cells contribute to the different outcomes of simian immunodeficiency virus infection in rhesus macaques and sooty mangabeys. 1637 66


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