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)

Persons with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfection are at increased risk for progression to cirrhosis compared with persons with HCV alone, but the reasons for this are unclear. In chronic HCV, the mechanism of liver injury is presumed to be due to HCV-specific T cell destruction of hepatocytes, so it is paradoxical that immunosuppressed hosts have higher rates of fibrosis progression. We examined intrahepatic cellular immune responses to HCV antigens to determine whether there were qualitative or quantitative differences in subjects with and without HIV. Expanded, CD4-enriched, liver-infiltrating lymphocytes from 18 subjects with chronic HCV and 12 subjects with HIV/HCV were cultured in the presence of HCV core protein, nonstructural proteins NS3 and NS5, and recall antigens tetanus toxoid and Candida. Secretion of interferon gamma (IFN-gamma), tumor necrosis factor alpha (TNF-alpha), and interleukin (IL) 10 was determined using enzyme-linked immunosorbent spot assay. There were no significant differences in liver biopsy grade or stage for HIV/HCV versus HCV groups. There were no significant differences between groups in the secretion of IFN-gamma or TNF-alpha in response to HCV or recall antigens. However, there was a significant increase in IL-10 secretion in response to NS3 and NS5 in subjects with HCV compared with HIV and HCV coinfection. In conclusion, subjects with coinfection have an alteration of intrahepatic HCV-specific IL-10 cytokine response that may have implications for HCV-related disease progression.
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PMID:Comparison of HCV-specific intrahepatic CD4+ T cells in HIV/HCV versus HCV. 1523 95

Chronic infection with hepatitis C virus (HCV) is associated with liver cirrhosis that often leads to hepatic failure and hepatocellular carcinoma (HCC). HCV infection has become a global health threat and the main cause of adult liver transplants in developed nations. Current approved anti-HCV therapies (interferon and pegylated interferon alone or in combination with ribavirin) are not effective in eliminating the viral infection in a significant population of patients (e.g., those infected with HCV genotype 1). Furthermore, these therapies are plagued with many undesirable side effects. Therefore, the HCV epidemic represents a huge unmet medical need that has triggered intensive research efforts towards the development of more effective drugs. Given its essential role in the process of HCV replication, the viral NS3/4A serine protease is arguably the most thoroughly characterized HCV enzyme and the most intensively pursued anti-HCV target for drug development. This is further fueled by the successful use of small-molecule inhibitors of the human immunodeficiency virus (HIV) viral protease, which have had an impressive effect on HIV-related morbidity and mortality, offering hope that analogous drugs might also have a similar impact against HCV. Here, we review the recent progress and development of small-molecule inhibitors of the HCV NS3/4A protease. In particular, we focus on the discovery of VX-950, the latest HCV NS3-4A protease inhibitor to be advanced to clinical studies. While the challenges of designing potent inhibitors of the viral protease have been solved, as highlighted by BILN 2061 and VX-950, it is still too early to determine whether these efforts will eventually yield promising drug candidates. For the emerging small-molecule HCV inhibitors, viral resistance will likely be a big problem. Thus, combination therapy of different drugs with different targets/mechanisms will be necessary to effectively inhibit HCV replication. It is also hoped that a detail characterization of how the resistance mutations that affect NS3 inhibitor binding may provide useful information for the design of inhibitors with the potential to treat resistant viruses that may arise during chronic HCV infection.
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PMID:Discovery of small-molecule inhibitors of HCV NS3-4A protease as potential therapeutic agents against HCV infection. 1618 Nov 35

The release of Bluetongue virus (BTV) and other members of the Orbivirus genus from infected host cells occurs predominantly by cell lysis, and in some cases, by budding from the plasma membrane. Two nonstructural proteins, NS3 and NS3A, have been implicated in this process. Here we show that both proteins bind to human Tsg101 and its ortholog from Drosophila melanogaster with similar strengths in vitro. This interaction is mediated by a conserved PSAP motif in NS3 and appears to play a role in virus release. The depletion of Tsg101 with small interfering RNA inhibits the release of BTV and African horse sickness virus, a related orbivirus, from HeLa cells up to fivefold and threefold, respectively. Like most other viral proteins which recruit Tsg101, NS3 also harbors a PPXY late-domain motif that allows NS3 to bind NEDD4-like ubiquitin ligases in vitro. However, the late-domain motifs in NS3 do not function as effectively in facilitating the release of mini Gag virus-like particles from 293T cells as the late domains from human immunodeficiency virus type 1, human T-cell leukemia virus, and Ebola virus. A mutagenesis study showed that the arginine residue in the PPRY motif is responsible for the low activity of the NS3 late-domain motifs. Our data suggest that the BTV late-domain motifs either recruit an antagonist that interferes with budding or fail to recruit an agonist which is different from NEDD4.
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PMID:Nonstructural protein 3 of bluetongue virus assists virus release by recruiting ESCRT-I protein Tsg101. 1635 70

The role of viral factors in the pathogenesis of chronic hepatitis C is unknown. The objective of the present study was to characterize markers of hepatitis C virus (HCV) infection and replication in liver biopsy specimens obtained from 65 genotype 1-infected subjects, including 31 who were coinfected with human immunodeficiency virus (HIV), and to analyze associations between intrahepatic viral markers and hepatitis C disease severity. The percentages of liver cells harboring HCV genomes (%G) and replicative-intermediate RNAs (%RI) were evaluated using strand-specific in situ hybridization, while HCV core and NS3 antigens were assessed by immunocytochemistry. HIV-positive and HIV-negative subjects had similar mean grades and stages of liver disease and had similar indices of HCV infection and replication in liver, even though coinfected subjects had significantly shorter mean disease duration (P = 0.0003). Multivariate analysis showed that %G was not associated with grade or stage of liver disease (P = 0.5 and 0.4, respectively), while %RI was strongly associated with liver inflammation (P < 0.001), liver fibrosis (P < 0.001), and serum alanine aminotransferase levels (P = 0.01). NS3 antigen (but not core) was more frequently detected in HCV RI-positive versus RI-negative specimens (P = 0.028). These findings demonstrate a link between HCV proliferation and hepatitis C disease severity and suggest similar pathogenic mechanisms in HIV-positive and HIV-negative individuals.
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PMID:Intrahepatic hepatitis C virus replication correlates with chronic hepatitis C disease severity in vivo. 1647 35

The hepatitis C virus (HCV) genotype 4 is spreading among southern European intravenous drug users, who are frequently co-infected with human immunodeficiency virus type 1 (HIV-1). Response to interferon (IFN) alpha-based therapies in HIV-1 positive patients co-infected with HCV genotype 4 is poor, similar to that obtained for HCV genotype 1 and much lower than for HCV genotypes 2 and 3. The lack of sequence data related to HCV of genotype 4 prompted us to sequence the complete genome of two genotype 4 variants isolated from two HIV-1 co-infected patients (24 and 25). Our aim was to investigate the evolutionary relationships of the former variants with other genotypes and/or genotype 4 subtypes. Sequence alignments and phylogenetic analysis from genomic regions 5'NC, core-E1 and NS5B revealed that the variants isolated from patients 24 and 25 (both subtyped 4c/4d by INNO-LIPA II HCV) belong to subtypes 4d and 4a, respectively. When looking at the complete genome sequence one of the variants showed a new genotype 4 subtype. Interestingly, sequence length differences in the interferon sensitivity determining region coding regions were observed when compared with sequences from other genotypes. Similarly, when the catalytic efficiency of the NS3/4 protease from patients 24 and 25 samples were determined, they displayed 70.6+/-7.7 and 23.5+/-3.4%, respectively, of the activity shown by genotype 1 NS3/4 proteases. Overall, pairwise comparison and phylogenetic analysis of nucleotide sequences of the complete genome or the different protein-encoding regions showed that genotype 4 sequences were more closely related to genotype 1 sequences. The description of new HCV genome variants may help our understanding of the HCV biology as well as the role of different genotypes in HCV treatment and therapy response.
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PMID:Complete nucleotide sequence of genotype 4 hepatitis C viruses isolated from patients co-infected with human immunodeficiency virus type 1. 1702 84

Tumor progression and metastasis are complex processes involving intricate interplay among multiple gene products. Astrocyte elevated gene (AEG)-1 was cloned as an human immunodeficiency virus (HIV)-1-inducible and tumor necrosis factor-alpha (TNF-alpha)-inducible transcript in primary human fetal astrocytes (PHFA) by a rapid subtraction hybridization approach. AEG-1 down-regulates the expression of the glutamate transporter EAAT2; thus, it is implicated in glutamate-induced excitotoxic damage to neurons as evident in HIV-associated neurodegeneration. Interestingly, AEG-1 expression is elevated in subsets of breast cancer, glioblastoma multiforme and melanoma cells, and AEG-1 cooperates with Ha-ras to augment the transformed phenotype of normal immortal cells. Moreover, AEG-1 is overexpressed in >95% of human malignant glioma samples when compared with normal human brain. Overexpression of AEG-1 increases and siRNA inhibition of AEG-1 decreases migration and invasion of human glioma cells, respectively. AEG-1 contains a lung-homing domain facilitating breast tumor metastasis to lungs. These findings indicate that AEG-1 might play a pivotal role in the pathogenesis, progression and metastasis of diverse cancers. Our recent observations indicate that AEG-1 exerts its effects by activating the nuclear factor kappa B (NF-kappaB) pathway and AEG-1 is a downstream target of Ha-ras and plays an important role in Ha-ras-mediated tumorigenesis. These provocative findings are intensifying interest in AEG-1 as a crucial regulator of tumor progression and metastasis and as a potential mediator of neurodegeneration. In this review, we discuss the cloning, structure and function(s) of AEG-1 and provide recent insights into the diverse actions and intriguing properties of this molecule.
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PMID:Astrocyte elevated gene-1: recent insights into a novel gene involved in tumor progression, metastasis and neurodegeneration. 1739 30

A short peptide, corresponding to the nuclear localization signal of the human immunodeficiency virus-1 Tat protein, Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg, was modified by adding a cysteine residue at the COOH terminus. The peptide was mixed with a reporter plasmid, and then with cationic lipids, to form a tripartite complex, DNA/peptide/lipid (DPL). Various cell lines were treated with the DPL complex and compared for transfection efficiency with those of the conventional DNA/lipid (DL) complex. With the simple inclusion of the peptide, the DPL complex showed much enhanced transfection. Meanwhile, the plasmid DNA mixed only with the peptide exhibited some improvement but with much lower transfection than the DPL complex. When the DPL complex was formed with various cationic lipids, the DOSPA/DOPE exhibited superior transfection efficiency than the other cationic lipids tested at the optimal ratio of 1:3:5 (w:w:w) in many cell types. At the optimal ratio of the DPL components, transfection efficiency was routinely shown to be approximately 10-fold higher for reporter gene expression than that of the conventional DL complex. Furthermore, when subcutaneous tumors of a colon cancer cell line (SW480) were treated intratumorally with antisense oligos, k-ras-RiAS, delivered as a DPL complex, tumor growth was markedly suppressed. This study shows that the DPL complex, which is easy to formulate by ordered mixing, can be employed for a much enhanced cellular uptake of a transgene both in vitro and in vivo.
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PMID:Marked transfection enhancement by the DPL (DNA/peptide/lipid) complex. 1778 72

Approximately 30-40% of patients infected with the human immunodeficiency virus (HIV) in the U.S. are also infected with the hepatitis C virus (HCV). Studies have shown that HIV can worsen hepatitis C, while the impact of hepatitis C on HIV disease is less clear. In this study, we described that HCV NS3/4A protein can activate HIV-1 transcription from its long terminal repeat (LTR) region, while the serine protease-inactive mutant of NS3/4A fails to do so. The activation effect of NS3/4A to HIV-1 transcription can be explained by its ability to enhance DNA binding activities of the transcription factor AP-1. These results have provided insights into the mechanism involved in the co-infection of HCV and HIV.
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PMID:HCV NS3/4A protein activates HIV-1 transcription from its long terminal repeat. 1843 8

To take into account polarization effects, the linear interaction energy model with continuum electrostatic solvation (LIECE) is supplemented by the linear-scaling semiempirical quantum mechanical calculation of the intermolecular electrostatic energy (QMLIECE). QMLIECE and LIECE are compared on three enzymes belonging to different classes: the West Nile virus NS3 serine protease (WNV PR), the aspartic protease of the human immunodeficiency virus (HIV-1 PR), and the human cyclin-dependent kinase 2 (CDK2). QMLIECE is superior for 44 peptidic inhibitors of WNV PR because of the different amount of polarization due to the broad range of formal charges of the inhibitors (from 0 to 3). On the other hand, QMLIECE and LIECE show similar accuracy for 24 peptidic inhibitors of HIV-1 PR (20 neutral and 4 with one formal charge) and for 73 CDK2 inhibitors (all neutral). These results indicate that quantum mechanics is essential when the inhibitor/protein complexes have highly variable charge-charge interactions.
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PMID:Is quantum mechanics necessary for predicting binding free energy? 1857 69

New treatments are urgently needed to combat the increasing number of dengue fever cases in endemic countries as well as amongst a large number of travellers from non-endemic countries. Of the 10 virus encoded proteins, NS3 (non-structural 3) and NS5 carry out all the enzymatic activities needed for polyprotein processing and genome replication, and are considered to be amenable to antiviral inhibition by analogy with successes for similar targets in human immunodeficiency virus and hepatitis C virus. The multifunctional NS3 protein of flavivirus forms a non-covalent complex with the NS2B cofactor and contains the serine-protease activity domain at its N-terminus that is responsible for proteolytic processing of the viral polyprotein and a ATPase/helicase and RNA triphosphatase at its C-terminal end that are essential for RNA replication. In addition, NS3 seems to be also involved in virus assembly. This review covers the recent biochemical and structural advances on the NS2B-NS3 protease-helicase and presents an outlook for the development of small molecules as antiviral drugs targeting this fascinating multifunctional protein.
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PMID:Towards the design of antiviral inhibitors against flaviviruses: the case for the multifunctional NS3 protein from Dengue virus as a target. 1867 67


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