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)

The human immunodeficiency virus type 1 (HIV-1) Vif protein has an important role in the regulation of virus infectivity. This function of Vif is cell type specific, and virions produced in the absence of Vif in restrictive cells have greatly reduced infectivity. We show here that the intracellular localization of Vif is dependent on the presence of the intermediate filament vimentin. Fractionation of acutely infected T cells or transiently transfected HeLa cells demonstrates the existence of a soluble and a cytoskeletal form and to a lesser extent the presence of a detergent-extractable form of Vif. Confocal microscopy suggests that in HeLa cells, Vif is predominantly present in the cytoplasm and closely colocalizes with the intermediate filament vimentin. Treatment of cells with drugs affecting the structure of vimentin filaments affect the localization of Vif accordingly, indicating a close association of Vif with this cytoskeletal component. The association of Vif with vimentin can cause the collapse of the intermediate filament network into a perinuclear aggregate. In contrast, analysis of Vif in vimentin-negative cells reveals significant staining of the nucleus and the nuclear membrane in addition to diffuse cytoplasmic staining. In addition to the association of Vif with intermediate filaments, analyses of virion preparations demonstrate that Vif is incorporated into virus particles. In sucrose density gradients, Vif cosediments with capsid proteins even after detergent treatment of virus preparations, suggesting that Vif is associated with the inner core of HIV particles. We propose a model in which Vif has a crucial function as a virion component either by regulating virus maturation or following virus entry into a host cell possibly involving an interaction with the cellular cytoskeletal network.
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PMID:Cytoskeleton association and virion incorporation of the human immunodeficiency virus type 1 Vif protein. 852 63

Although the CD4 molecule is the major cellular receptor for human immunodeficiency virus (HIV), several lines of evidence suggest participation of additional molecules that are engaged after the binding of HIV to the CD4 receptor and that may facilitate viral entry into the target cell. Some of the post-CD4 binding, perfusion events involve the third hypervariable region (V3 loop) of the viral envelope protein gp120. To identify cellular proteins that interact with the V3 loop, we chose as a probe an antiidiotypic monoclonal antibody (MAb), anti-id2, which was prepared against the neutralizing MAb 110.4 that binds the V3 domain in the envelope glycoprotein gp120 of the LAI isolate of HIV-1. Anti-id2 reacted specifically with a 55- to 60-kDa protein in human T cell and monocytoid cell lines, and in a mouse melanoma cell line. This protein was identified immunologically and by protein sequence analysis as vimentin, an intermediate filament protein of lymphoid and other cells of mesodermal origin. Antiserum raised against vimentin inhibited nuclear translocation of HIV-1 DNA following infection of monocytes and CD4+ T cells with live virus, and reduced the amount of HIV-1 gag-specific RNA in the nuclei of monocytes following inoculation with HIV-1 pseudovirions. These data suggest that vimentin may participate in the early steps of HIV-1 replication, perhaps during the uptake of HIV-1 preintegration complexes into the nuclear compartment.
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PMID:Anti-idiotypic antibody to the V3 domain of gp120 binds to vimentin: a possible role of intermediate filaments in the early steps of HIV-1 infection cycle. 882 24

Polyomaviruses have proven oncogenicity in nonhost experimental animals; however, studies concerning the association between human brain tumors and simian and human polyomaviruses have yielded inconclusive results. We examined the relationship of SV40 to a malignant astrocytoma found in the right frontal lobe of a pigtail macaque (Macaca nemestrina) infected with simian immunodeficiency virus (SIV). Consistent with the histologic diagnosis, the tumor was immunoreactive with antibodies to S-100 protein, vimentin, and glial fibrillary acidic protein, but negative for neurofilament protein, synaptophysin, neuron-specific enolase, and chromogranin A. At the time of SIV inoculation, the animal was seropositive for SV40. Polymerase chain reaction assay of tumor DNA, but not normal brain DNA, yielded a 300 base-pair fragment corresponding to the carboxy-terminal coding region (C-terminus) of the large T antigen gene of SV40, suggesting an association with the tumor.
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PMID:A malignant astrocytoma containing simian virus 40 DNA in a macaque infected with simian immunodeficiency virus. 937 84

Cells with fibroblast-like features were isolated from the villous tissue of normal term human placentas. Immunocytochemical characterization of the cells showed that they were vimentin-positive but negative for factor-VIII, CD14 and CD4. Thus, the cells are mesenchymal and are not endothelial cells, macrophages or trophoblast. These cells were exposed to nine different cell-free virus isolates, including seven isolates of human immunodeficiency virus type 1 (HIV-1), one HIV-2 isolate and one simian immunodeficiency virus isolate (SIVmac251). The susceptibility of the cells to infection was evaluated by immunocytochemical and virological techniques. No evidence of infection could be found using immunofluorescence microscopy or by p24 antigen capture and reverse transcriptase assays. However, virus rescue experiments using 11 different target cell types provided evidence that the placental fibroblasts were susceptible to infection with HIV-1Lai, HIV-1IIIB, HIV-2CBL-20, and SIVmac251, yet were resistant to infection by all other isolates. The infected fibroblasts exhibited neither cytopathic effects nor released virus into the culture medium. For each infected fibroblast population, some, but not all, indicator target cell lines or human peripheral blood mononuclear cells were able to rescue the respective virus. Based on these observations, we conclude that placental fibroblasts can be infected with HIV during transplacental transmission and could act as virus reservoirs, capable of infecting other fetal cells.
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PMID:Infection of primary human placental fibroblasts with HIV-1, HIV-2, and SIV. 967 89

After interaction of human immunodeficiency virus type 1 (HIV-1) virions with cell surface receptors, a series of poorly characterized events results in establishment of a viral reverse transcription complex in the host cell cytoplasm. This process is coordinated in such a way that reverse transcription is initiated shortly after formation of the viral reverse transcription complex. However, the mechanism through which virus entry and initiation of reverse transcription are coordinated and how these events are compartmentalized in the infected cell are not known. In this study, we demonstrate that viral reverse transcription complexes associate rapidly with the host cell cytoskeleton during HIV-1 infection and that reverse transcription occurs almost entirely in the cytoskeletal compartment. Interruption of actin polymerization before virus infection reduced association of viral reverse transcription complexes with the cytoskeleton. In addition, efficient reverse transcription was dependent on intact actin microfilaments. The localization of reverse transcription to actin microfilaments was mediated by the interaction of a reverse transcription complex component (gag MA) with actin but not vimentin (intermediate filaments) or tubulin (microtubules). In addition, fusion, but not endocytosis-mediated HIV-1 infectivity, was impaired when actin depolymerizing agents were added to target cells before infection but not when added after infection. These results point to a previously unsuspected role for the host cell cytoskeleton in HIV-1 entry and suggest that components of the cytoskeleton promote establishment of the reverse transcription complex in the host cell and also the process of reverse transcription within this complex.
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PMID:Establishment of a functional human immunodeficiency virus type 1 (HIV-1) reverse transcription complex involves the cytoskeleton. 984 25

Proteases (PRs) of retroviruses cleave viral polyproteins into their mature structural proteins and replication enzymes. Besides this essential role in the replication cycle of retroviruses, PRs also cleave a variety of host cell proteins. We have analyzed the in vitro cleavage of mouse vimentin by proteases of human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2), bovine leukemia virus (BLV), Mason-Pfizer monkey virus (M-PMV), myeloblastosis-associated virus (MAV), and two active-site mutants of MAV PR. Retroviral proteases display significant differences in specificity requirements. Here, we show a comparison of substrate specificities of several retroviral proteases on vimentin as a substrate. Vimentin was cleaved by all the proteases at different sites and with different rates. The results show that the physiologically important cellular protein vimentin can be degraded by different retroviral proteases.
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PMID:Cleavage of vimentin by different retroviral proteases. 1084

We report an 18-month-old Japanese girl with purely epithelioid leiomyosarcoma presenting as a huge intraabdominal mass. The patient had been well from birth and had shown no signs of immunodeficiency. She was negative for human immunodeficiency virus. Blood examination revealed elevated serum neuron specific enolase (NSE). Histologically, the tumor was comprised of solid growths of round or polygonal cells with vesicular nuclei and often vacuolated cytoplasm rich in glycogen. The tumor cells were positive for vimentin, NSE, and MIC2, and were negative for desmin and neurofilament. The age, clinical presentation, and histologic findings mostly favored Ewing's sarcoma/primitive neuroectodermal tumor. Silver stain, however, demonstrated well-developed reticulin fibers often outlining individual tumor cells. An expanded panel of immunostains showed that the tumor cells were intensely positive for smooth muscle actin, and ultrastructural study revealed abundant fine cytoplasmic filaments with focal subsarcolemmal densities, various amounts of glycogen, and irregularly arranged, thick basal lamina. The diagnosis of epithelioid leiomyosarcoma was made. Following reduction in tumor size by chemotherapy, the serum NSE level was normalized. From the surgical finding, the primary site was presumed to be the urachus or the urinary bladder dome. Although extremely rare, epithelioid leiomyosarcoma should be added in the list of differential diagnoses of pediatric "round cell tumors."
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PMID:Epithelioid leiomyosarcoma in a non-immunocompromised infant: additional differential diagnosis of pediatric "round cell tumors". 1104 12

A variant human immunodeficiency virus type 1 (HIV-1) vif gene, vifA45-2, which encodes a protein lacking 19 amino acids at the C terminus but which is fully functional in supporting HIV replication in non-permissive cells has been described previously. By employing newly generated anti-VifA45 serum, further properties of VifA45 and its full-length counterpart, VifA45open, in comparison to Vif from HIV strain BH10 are reported in permissive HeLa and COS-7 cells. The results obtained using confocal microscopic localization studies and in vitro binding assays do not support a requirement for the direct interaction of HIV Gag with Vif. Furthermore and in contrast to previous conclusions, detergent solubility analyses do not demonstrate a role for the C terminus of Vif in mediating localization to the fraction containing cellular membrane proteins. Localization of Vif from HIV strain BH10 to perinuclear aggregates in a small fraction (about 10%) of transfected HeLa cells has been previously reported. The intermediate filament protein vimentin colocalizes to these structures. In contrast, VifA45 and VifA45open form perinuclear aggregates in nearly all transfected HeLa cells; vimentin as well as the cytoskeletal-bridging protein plectin, but not the microtubular protein tubulin, become relocalized to these structures. Interestingly, in COS-7 cells, all of the functional Vif proteins tested (Vif from strain BH10, VifA45 and VifA45open) predominantly localize in the cytoplasm but still induce dramatic aggregation of vimentin and plectin, i.e. in these cells the respective Vif proteins are influencing intermediate filament structure in the absence of colocalization.
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PMID:Fully functional, naturally occurring and C-terminally truncated variant human immunodeficiency virus (HIV) Vif does not bind to HIV Gag but influences intermediate filament structure. 1117 97

A 31-year-old Japanese male was admitted to our hospital for investigation of an asymptomatic nodular lesion of the liver detected by abdominal ultrasonography (US) during a routine medical examination. Computed tomography (CT) revealed a single, hypovascular mass 35 mm in diameter, within the left lobe of the liver. The tumor demonstrated hypointensity on T1-weighted, and hyperintensity on T2-weighted magnetic resonance (MR) imaging. Hematological and biochemical investigations were normal. There were no abnormalities of the gastrointestinal or urinary tracts. A left lateral segmentectomy of the liver was performed. Pathological examination of the nodule revealed a primary leiomyoma of the liver, with positive immunohistochemical staining for vimentin and desmin antigens. Primary leiomyoma of the liver is rare, with the majority of cases associated with immunodeficiency disorders. This patient had no evidence of any underlying disease. Primary leiomyoma of the liver should be considered when a nodular lesion is found in a patient without evidence of viral hepatitis.
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PMID:A case of primary leiomyoma of the liver in a patient without evidence of immunosuppression. 1224 95

We describe the clinical, radiologic, surgical, and pathologic findings of a 29-year-old Peruvian human immunodeficiency virus-infected man with a primary parasellar meningeal leiomyosarcoma involving the left lesser esphenoidal wing and the cavernous sinus. Over a period of 13 months, he developed headache, vomiting, insomnia, and diplopia. Magnetic resonance imaging revealed a left parasellar extra-axial mass that was isointense in T1, hypointense in T2, and gadolinium-enhanced. The patient underwent subtotal resection of the tumor. The neoplasm was composed of spindle cells with smooth-muscle features. It showed moderate atypia, inconspicuous nucleoli, and scanty mitosis. No tumor necrosis was detected. The immunohistochemistry revealed strong positivity for vimentin, desmin, and smooth-muscle alpha-actin. A low-grade leiomyosarcoma was diagnosed. The in situ hybridization showed positive nuclear reactivity for Epstein-Barr virus-encoded RNA. The immunohistochemistry was negative for Epstein-Barr virus latent membrane protein 1. The main differential diagnosis of primary meningeal smooth-muscle tumors includes meningioma and peripheral nerve sheath tumors. Epstein-Barr virus has been demonstrated in most smooth-muscle tumors associated with acquired immune deficiency syndrome (AIDS). Primary meningeal smooth-muscle tumors, exceedingly rare neoplasms, remarkably affect young adults with AIDS. Comparatively, most AIDS-related visceral (nonmeningeal) smooth-muscle tumors have been reported in children. The permissiveness and tumorigenesis associated with Epstein-Barr virus may depend on the age of human immunodeficiency virus infection.
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PMID:Primary meningeal Epstein-Barr virus-related leiomyosarcoma in a man infected with human immunodeficiency virus: review of literature, emphasizing the differential diagnosis and pathogenesis. 1553 43


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