OBJECTIVETo study the effects of HIV Tat protein on CCR5 expression of monocytes and HIV infection in monocytes.

METHODSMembrane expression of CCR5 on monocytes was analyzed by flow cytometry. Stimulated with HIV Tat protein, monocytes were infected with monocyte-tropic HIV(Ba-L) and HIV gag p24 level in the supernatant was measured by ELISA methods.

RESULTSHIV Tat protein increased CCR5 expression in human monocytes,which was inhibited by rabbit anti-Tat polyclonal antibody. Tat protein also increased p24 level after monocyte-tropic HIV-1(Ba-L) infected monocytes.

CONCLUSIONTat increases CCR5 expression and HIV-1 infection in monocytes, which indicates that HIV Tat might be a key protein in HIV-1 infection.

Flow Cytometry ; Gene Products, tat ; pharmacology ; HIV ; HIV Infections ; metabolism ; Humans ; Monocytes ; metabolism ; Receptors, CCR5 ; biosynthesis ; genetics ; tat Gene Products, Human Immunodeficiency Virus

Anti-HIV Agents ; pharmacology ; Ciprofloxacin ; analogs & derivatives ; pharmacology ; Gene Products, tat ; chemistry ; genetics ; Genes, tat ; HIV-1 ; drug effects ; genetics ; Humans ; Oligopeptides ; pharmacology ; Organophosphates ; pharmacology ; Transcription, Genetic ; Transcriptional Activation ; Uridine ; analogs & derivatives ; pharmacology ; tat Gene Products, Human Immunodeficiency Virus

OBJECTIVETo develop a novel gene delivery vector TAT-PEI-beta-CyD.

METHODSbeta-cyclodextrin (beta-CyD) was linked by low molecular weight (PEI 600) via 1, 1-carbonyldiimidazole (CDI), and TAT peptide (RRRQRRKKRC) was coupled to PEI 600 by [N-succinimidy-3-(2-pyridyldithio) propionate, SPDP]. The copolymer was characterized by (1)H-NMR and FT-IR. Physiochemical characteristics of TAT-PEI-beta-CyD/DNA complexes were tested by agarose gel electrophoresis and particle size measurements. Cell viability and transfection efficiency were evaluated in A293 and B16 cells using PEI 25 kDa as a control.

RESULTTAT peptide was successfully coupled to PEI-beta-CyD. The result of gel electrophoresis showed that the TAT-PEI-beta-CyD was able to condense DNA efficiently at N/P ratio of 4. The particle size of TAT-PEI-beta-CyD/DNA complexes was around 100 nm. The cytotoxicity of TAT-PEI-beta-CyD was lower than that of PEI 25 kDa. The transfection efficiency of TAT-PEI-beta-CyD was higher than that of PEI 25 kDa in A293 and B16 cells at N/P ratio of 30.

CONCLUSIONThe novel vector TAT-PEI-beta-CyD has been developed successfully with low cytotoxicity and high transfection efficiency.

Cell Line ; Gene Transfer Techniques ; Genetic Therapy ; methods ; Humans ; Peptide Fragments ; chemistry ; Polyethyleneimine ; chemistry ; beta-Cyclodextrins ; chemistry ; tat Gene Products, Human Immunodeficiency Virus ; chemistry

BACKGROUND: Cytotoxic T lymphocytes (CTLs) appear to play an important role in the control and prevention of human cytomegalovirus (HCMV) infection. The pp65 antigen is a structural protein, which has been defined as a potential target for effective immunity against HCMV infection. Incorporation of an 11 amino acid region of the HIV TAT protein transduction domain (Tat) into protein facilitates rapid, efficient entry into cells. METHODS: To establish a strategy for the generation of HCMV-specific CTLs in vitro, recombinant truncated N- and C-terminal pp65 protein (pp65 N&C) and N- and C-terminal pp65 protein fused with Tat (Tat/pp65 N&C) was produced in E.coli system. Peripheral blood mononuclear cells were stimulated with dendritic cells (DCs) pulsed with pp65 N&C or Tat/pp65 N&C protein and immune responses induced was examined using IFN-gamma ELISPOT assay, cytotoxicity assay and tetramer staining. RESULTS: DCs pulsed with Tat/pp65N&C protein could induce higher T-cell responses in vitro compared with pp65N&C. Moreover, the DCs pulsed with Tat/pp65 N&C could stimulate both of CD8+ and CD4+ T-cell responses. The T cells induced by DCs pulsed with Tat/pp65 N&C showed higher cytotoxicity than that of pp65-pulsed DCs against autologous lymphoblastoid B-cell line (LCL) expressing the HCMV-pp65 antigen. CONCLUSION: Our results suggest that DCs pulsed with Tat/pp65 N&C protein effectively induced pp65-specific CTL in vitro. Tat fusion recombinant protein may be useful for the development of adoptive T-cell immunotherapy and DC-based vaccines.
B-Lymphocytes ; Cytomegalovirus ; Dendritic Cells ; Enzyme-Linked Immunospot Assay ; HIV ; Humans ; Immunotherapy ; T-Lymphocytes ; T-Lymphocytes, Cytotoxic ; tat Gene Products, Human Immunodeficiency Virus ; Vaccines

The PTD-NPY fusion gene derived from HIV-1 TAT protein transduction domain and rat neuropeptide Y was amplified by overlap extension PCR, digested and subcloned into yeast expression vector pPICZ alpha A to construct recombinant expression plasmid pPICZ alpha-PTD-NPY. The cloned PTD-NPY fusion gene was identified by PCR and restriction enzyme digestion and sequenced. The exact recombinant plasmid was linearized by Sac I and integrated by electrotransformation into the genome of Pichia pastoris GS115 cells. Then, these positive recombinant yeast cells were induced by 10 mL/L methanol to express soluble PTD-NPY fusion protein. After 120 h of methanol induction, the SDS-PAGE electrophoresis result indicated PTD-NPY fusion protein was efficiently secreted into the medium. Western blotting analysis proved that the expressed fusion protein had specific NPY binding activity. The successful expression of PTD-NPY fusion protein in Pichia pastoris provided basis for its further application study.
Animals ; Cloning, Molecular ; Gene Fusion ; Genetic Vectors ; genetics ; Neuropeptide Y ; genetics ; Pichia ; genetics ; metabolism ; Polymerase Chain Reaction ; methods ; Rats ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; Transduction, Genetic ; tat Gene Products, Human Immunodeficiency Virus ; genetics

Gene therapy offers the promise of curing the HIV-infected patients. Specific, potent, and sustained short hairpin RNA (shRNA)-mediated gene silencing is crucial for the successful application of RNA interference technology to therapeutic interventions. To reduce the probability of viral escape mutants, in this study, we constructed lentiviral vector containing vpr and tat shRNA, respectively, furthermore the bispecific lentiviral vector harboring vpr and tat shRNA expression cassettes from U6 promotor and H1 promotor was cotransfected with recombinant plasmid expressing the vpr and tat gene. The result showed that the bispecific lentiviral vector plvx-vpr-tatshRNA could inhibit the vpr and tat effectively,with ratios of 89.20% and 62.00% respectively. When cotransfected with pNL4-3 in 293T cell, plvx-vpr-tatshRNA showed higher efficacy in down regulating the HIV NL4-3 packaging production than the plvx-vprshRNA or plvx-tatshRNA individually. MT4 cell clones transduced with recombinant lentiviral vectors were screened and challenged with HIV NL4-3. P24 ELISA test showed that MT4 transduced with the combinational lentiviral vector could inhibit virus replication efficiently.
Cell Line ; Down-Regulation ; Genetic Therapy ; Genetic Vectors ; genetics ; metabolism ; HIV Infections ; therapy ; virology ; HIV-1 ; genetics ; metabolism ; Humans ; Lentivirus ; genetics ; metabolism ; RNA Interference ; RNA, Small Interfering ; genetics ; metabolism ; therapeutic use ; tat Gene Products, Human Immunodeficiency Virus ; genetics ; metabolism ; vpr Gene Products, Human Immunodeficiency Virus ; genetics ; metabolism

We constructed a phage-displayed random mutation library of Tat38-61(51N/55N), for studying the molecular evolution screening of HIV-1 Tat38-61 epitope. We used primers containing the random nucleotide sequences, and introduced the random mutations at the sites of 51 and 55 amino acids coding sequences into full-length Tat sequences by overlapping PCR. With the randomly mutated full-length Tat as template, the Tat38-61(51N/55N) mutants which contained recognition sequences for the Xba I in both ends were amplified by PCR using the designed primers. The mutants were cloned into Xba I site in the phagemid vector pCANTAB5S, then the recombinants were transformed into E. coli TG1, a phage-displayed the random mutation library of Tat38-61(51N/55N) was constructed by the rescue of help virus M13KO7. The results showed that the library consisted of about 5.0 x 10(6) colonies and the phage library titer was 2.65 x 10(12) TU/mL. More than 56.50% colonies in the library were positive for insertion. Sequence analysis showed that the nucleotides encoding amino acids at the sites of 51 and 55 distributed randomly. The constructed mutation library could meet the requirements for the following molecular evolution screening, and might prepare the Tat mutants for the further study of new Tat vaccine candidates.
AIDS Vaccines ; immunology ; Escherichia coli ; genetics ; metabolism ; HIV-1 ; genetics ; Humans ; Mutation ; Peptide Fragments ; biosynthesis ; genetics ; immunology ; Peptide Library ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; tat Gene Products, Human Immunodeficiency Virus ; biosynthesis ; genetics ; immunology

Host cell protein phosphatase-1 (PP1) is an important regulator of human immunodeficiency virus-1 (HIV-1) transcription. PP1 is involved in the regulation of HIV-1 transcription, and dephosphorylates RNA polymerase II C-terminal domain (RNAPII CTD) or CycT1-dependent kinase 9 (CDK9) to increase Tat-dependent HIV-1 transcription. In this review, we discuss the action of PP1 in Tat-induced HIV-1 transcription and related to PP1 inhibitors.
Anti-HIV Agents ; pharmacology ; Enzyme Inhibitors ; pharmacology ; HIV-1 ; genetics ; Humans ; Okadaic Acid ; pharmacology ; Protein Phosphatase 1 ; antagonists & inhibitors ; chemistry ; physiology ; Pyrans ; pharmacology ; Spiro Compounds ; pharmacology ; Transcription, Genetic ; tat Gene Products, Human Immunodeficiency Virus ; physiology

HIV-1 trans-activator of transcription (Tat) plays a critical role in HIV-1 transcription. Based on the beta-turn motif present in HIV-1 Tat, a series of novel benzodiazepine analogs were designed as beta-turn mimetics and prepared from p-chloro-nitrobenzene/2-phenylacetonitrile, p-toluidine/benzoyl chloride, or (Z)-7-nitro-5-phenyl-1H-benzo[e][1, 4]diazepin-2(3H)-one (nitrazepam) through different synthetic routes. Preliminary biological evaluation indicated that compound 30 exhibited inhibitory activity on HIV-1 tat-mediated LTR transcription with EC50 of 25.0 micromol x L(-1) and showed no obvious cytotoxic effects on TZM-BI cells under the concentration of 100 micromol x L(-1).
Benzodiazepinones ; chemical synthesis ; chemistry ; pharmacology ; Cell Line, Tumor ; HIV Long Terminal Repeat ; genetics ; HIV-1 ; genetics ; Humans ; Transcription, Genetic ; drug effects ; tat Gene Products, Human Immunodeficiency Virus ; antagonists & inhibitors

Gelatin-siloxane nanoparticles (GS NPs) have been considered to be good gene carrier candidate in vitro, since they have several advantages such as low toxicity, easy preparation and surface modification. In this study, the Tat-PEG-GS NPs were synthesized by the gelatin-siloxane, surface-modified with the polyethylene glycol (H2 N-PEG-COOH) and Tat peptide (KYGRRRQRRKKRGC) and thus constructed a delivery system which can cross BBB (Blood-brain barrier). The morphology, diameter, and zeta potential of Tat-PEG-GS NPs carrier system were characterized with transmission electron microscopy (TEM) and Nano-ZS zetasizer dynamic light scattering Detector. The organ distribution and dynamic evolution localized in the brain parenchyma of Tat-PEG-GS NPs in vivo was investigated with Cri in vivo imaging system and TEM. The obtained Tat-PEG-GS NPs were approximately spherical in shape with average particle size of 150-200 nm and zeta potentials of (32.27 +/- 2.47) mV. In vivo imaging results showed that the accumulation of Tat-PEG-GS NPs was higher in the brain than the accumulation of PEG-GS NPs, but the accumulation of Tat-PEG-GS NPs was lower in the liver than the accumulation of PEG-GS NPs. These differences are statistically significant. The nanocomplex could cross the BBB and reach the neural tissues tested with TEM. The Tat-PEG-GS NPs could cross the BBB and escape the arrest of the reticuloendothelial system (RES), and it would be potential nano-carrier systems for central delivery.
Animals ; Blood-Brain Barrier ; metabolism ; Drug Delivery Systems ; Female ; Gelatin ; administration & dosage ; chemistry ; pharmacokinetics ; Male ; Mice ; Mice, Nude ; Nanoparticles ; chemistry ; Peptide Fragments ; chemistry ; Polyethylene Glycols ; chemistry ; Siloxanes ; administration & dosage ; chemistry ; pharmacokinetics ; tat Gene Products, Human Immunodeficiency Virus ; chemistry