OBJECTIVETo observe the inhibitory effect of 1,2,6-Tri-O-galloyl-beta-D-glucopyranose (TGGP) from Balanophora japonica Makino on human immunodeficiency virus (HIV) entry into the host cells and explore the mechanisms.

METHODSTGGP was purified from Balanophora japonica Makino by n-hexane and ethyl acetate extraction and column chromatography. The inhibitory activity of TGGP on HIV gp41 six-helix bundle formation was measured with ELISA, N-PAGE and SE-HPLC, and the inhibitory effect of TGGP on HIV envelope grlycoprotein-induced cell-cell fusion was detected using a non-infectious cell-based assay.

RESULTSTGGP inhibited HIV gp41 six-helix bundle formation, with an IC50 of 1.37-/+0.19 microg/ml as determined by ELISA, and this activity was further confirmed by N-PAGE and SE-HPLC. TGGP at 25 microg/ml significantly inhibited syncytium formation between the effector (CHO-WT) and the target (MT-2) cells.

CONCLUSIONThe HIV transmembrane subunit gp41 mediates the entry of HIV into the target cells. TGGP can inhibit HIV fusion and entry into the target cells by inhibiting the formation of gp41 six-helix bundles, suggesting the potential of TGGP as a microbicide to prevent sexual transmission of HIV.

Anti-HIV Agents ; pharmacology ; Cell Membrane ; drug effects ; metabolism ; HIV Envelope Protein gp41 ; metabolism ; HIV Fusion Inhibitors ; pharmacology ; HIV-1 ; drug effects ; growth & development ; metabolism ; Humans ; Hydrolyzable Tannins ; pharmacology ; Membrane Fusion ; drug effects

OBJECTIVETo probe into the feasibility of screening anti-HIV compounds by using HIV-1 p24 detection kit made by Hebei Medical University.

METHODSThe sensitivity, reproducibility and efficacy of the Hebei p24 kit were evaluated compared with the commercially available Vironostika HIV-1 Antigen Microelisa System (Biomerieux).

RESULTSHebei p24 kit had high sensitivity and good reproducibility. In vitro screening demonstrated that there was no statistically significant difference (P greater than 0.05) between these two kits in assessing anti-HIV compounds.

CONCLUSIONHebei p24 kit could be used as an easily affordable alternative method for detection of HIV-1 in screening anti-HIV compounds.

Anti-HIV Agents ; isolation & purification ; pharmacology ; Cell Line ; Drug Evaluation, Preclinical ; instrumentation ; methods ; Feasibility Studies ; HIV Core Protein p24 ; analysis ; HIV-1 ; drug effects ; growth & development ; immunology ; Humans ; Reagent Kits, Diagnostic ; standards ; Reproducibility of Results

BACKGROUNDInterferon (IFN) can inhibit human immunodeficiency virus type 1 (HIV-1) replication in vitro and in clinic. However, IFN therapy for HIV infection was limited by its moderate antiviral efficacy and its frequent adverse effects. In the present study we evaluated the anti-HIV efficacy of a novel synthesized superior interferon α (sIFNα).

METHODSWe performed in vitro experiments with HIV-1 IIIB infected MT4 cells, and evaluated in vivo anti-HIV efficacy of sIFNα in severe combined immunodeficient (SCID) mice reconstituted with human peripheral blood leukocytes (hu-PBL-SCID mice).

RESULTSWe found that the 50% effective concentrations (EC(50)) of sIFNα against the replication of HIV-1 in MT4 cells was 0.06 ng/ml, representing stronger antiviral activity than interferon-α in vitro. In the hu-PBL-SCID mice, a dose-dependent protection pattern was observed: with 0.45 µg and 1.35 µg sIFNα daily treatments, parts of SCID mice were protected from HIV infection, whereas 2.25 µg sIFNα daily treatments resulted in a terminally complete protection.

CONCLUSIONSsIFNα shows good anti-HIV activity both in vitro and in SCID mice, may be a promising anti-HIV agent deserving clinical investigation, especially considering the potential of IFN-α to inhibit HIV replication in patients infected with drug-resistant variants or co-infected with hepatitis C virus (HCV).

Animals ; Cell Line ; Cells, Cultured ; Enzyme-Linked Immunosorbent Assay ; Female ; HIV-1 ; drug effects ; growth & development ; Humans ; Interferon-alpha ; pharmacology ; Leukocytes, Mononuclear ; virology ; Mice ; Mice, SCID ; Virus Replication ; drug effects

BACKGROUNDVirus with nucleoside reverse transcriptase inhibitors (NRTIs) or nonnucleoside reverse transcriptase inhibitors (NNRTIs) resistant mutations show different evolution tendencies when the anti-viral therapies are interrupted. Understanding the replication fitness of drug-resistant virus is important for the study of the prevalence of drug-resistance. For this purpose, we characterized the replication capacity of HIV-1 virus carrying lamivudine (3TC) or nevirapine (NVP) resistant mutations.

METHODS3TC and NVP resistant variants were induced in vitro by selecting wild type virus in the presence of drugs. For the competitive replication assay, drug-resistant variants were cocultured with wild-type virus in the presence or absence of drugs. The ratios of the viral species were determined over time by using a real-time RT-PCR-based assay.

RESULTS3TC-resistant (M184I mutation) and NVP-resistant (Y181I mutation) virus should be selected in vitro in two different ways. The competitive replication assay showed that the ratio of virus carrying a M184I mutation increased from 98.8%, while the wild type virus decreased to 1.2% after 4 passages in the presence of 3TC; the percentage of virus carrying the Y181I mutation increased to 90.5%, while wild type virus decreased to 9.5% in the presence of NVP. In the absence of drugs, the ratio of virus carrying the M184I mutation decreased to 5.3%, while wild type virus increased to 94.7%; the ratio of virus carrying Y181I increased to 75%, while wild type virus decreased to 25% after 4 passages.

CONCLUSIONSThe NVP-resistant virus is fitter than wild type virus even in the absence of NVP that may be the reason that NNRTIs-resistant virus is spreading quickly.

Cell Line ; Drug Resistance, Viral ; genetics ; HIV-1 ; drug effects ; genetics ; growth & development ; physiology ; Humans ; Lamivudine ; pharmacology ; Mutation ; Nevirapine ; pharmacology ; Reverse Transcriptase Inhibitors ; pharmacology ; Reverse Transcriptase Polymerase Chain Reaction ; Virus Replication ; genetics ; physiology

The constrained alpha-helical structure of a C-peptide is useful for enhancing anti-HIV-1 activity. The i and i+3 positions in an alpha-helical structure are located close together, therefore D-Cys (dC) and L-Cys (C) were introduced at the positions, respectively, to make a dC-C disulfide bond in 28mer C-peptides. Accordingly, this study tested whether a dC-C disulfide bond would increase the alpha-helicity and anti-HIV-1 activity of peptides. A C-peptide can be divided into three domains, the N-terminal hydrophobic domain (HPD), middle interface domain (IFD), and C-terminal hydrogen domain (HGD), based on the binding property with an N-peptide. In general, the dC-C modifications in HPD enhanced the anti-HIV-1 activity, while those in IFD and HGD resulted in no or much less activity. The modified peptides with no activity clearly showed much less alpha-helicity than the native peptides, while those with higher activity showed an almost similar or slightly increased alpha-helicity. Therefore, the present results suggest that the introduction of a dC-C bridge in the N-terminal hydrophobic domain of a C-peptide may be useful for enhancing the anti-HIV-1 activity.
Amino Acid Sequence ; Anti-HIV Agents/chemical synthesis/*chemistry/isolation & purification/*pharmacology ; Cell Line ; Circular Dichroism ; Cysteine/chemistry ; Disulfides/chemistry ; HIV Envelope Protein gp41/*chemistry ; HIV-1/*drug effects/growth & development ; Humans ; Inhibitory Concentration 50 ; Models, Molecular ; Molecular Sequence Data ; Peptides/chemical synthesis/*chemistry/isolation & purification/*pharmacology ; Protein Structure, Secondary ; Protein Structure, Tertiary ; Research Support, Non-U.S. Gov't ; Structure-Activity Relationship

Hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) is a key component of the endosomal sorting complexes required for transport and has been demonstrated to play a regulatory role in endocytosis/exocytosis and the accumulation of internal vesicles in multivesicular bodies. Citron kinase is a Ser/The kinase that we previously reported to enhance human immunodeficiency virus type 1 (HIV-1) virion production. However, the relationship between Hrs and citron kinase in HIV-1 production remains elusive. Here, we report that Hrs interacts with citron kinase via its FYVE domain. Overexpression of Hrs or the FYVE domain resulted in a significant decrease in HIV-1 virion production. Depletion of Hrs by RNA interference in HEK293T cells increased HIV-1 virion production and enhanced the activity of citron kinase. These data suggest that Hrs inhibits HIV-1 production by inhibiting citron kinase-mediated exocytosis.
Down-Regulation ; Endosomal Sorting Complexes Required for Transport ; genetics ; metabolism ; Endosomes ; metabolism ; Exocytosis ; Gene Expression ; Gene Silencing ; drug effects ; HEK293 Cells ; HIV Infections ; genetics ; metabolism ; virology ; HIV-1 ; drug effects ; genetics ; growth & development ; Humans ; Immunoprecipitation ; Intracellular Signaling Peptides and Proteins ; genetics ; metabolism ; Microscopy, Fluorescence ; Phosphoproteins ; genetics ; metabolism ; Plasmids ; Protein Binding ; drug effects ; genetics ; Protein Interaction Domains and Motifs ; Protein Structure, Tertiary ; Protein Transport ; Protein-Serine-Threonine Kinases ; genetics ; metabolism ; RNA, Small Interfering ; pharmacology ; Transfection ; Virion ; drug effects ; genetics ; growth & development ; Virus Release ; drug effects ; Virus Replication ; drug effects