OBJECTIVE: To explore the protective effect of SBi4211 (heptamidine), an inhibitor of S100B, against central nervous system injury induced by HIV-1 envelope protein gp120. METHODS: In an RESULTS: In the cell co-culture system, SBi4211 treatment significantly inhibited gp120-induced expression of S100B, RAGE and GFAP in U251 cells ( CONCLUSIONS SBi4211 can protect neurons from gp120-induced neurotoxicity possibly by inhibiting the S100B/ RAGE-mediated signaling pathway.
Animals ; Astrocytes ; Blotting, Western ; Central Nervous System ; HIV Envelope Protein gp120 ; Mice ; Neurons ; S100 Calcium Binding Protein beta Subunit ; Signal Transduction

OBJECTIVE: To construct a HIV-1 gp120 transgenic mice (gp120 Tg) with vimentin (VIM) gene knockout. METHODS: Female HIV-1 gp120 Tg mice were mated to VIM heterozygote mice (F0). All the offspring mice were derived from these original founders so that both genotypes had the same mixed genetic background. The F1 mice were bred to generate of VIM, VIM, VIM/gp120 Tg and VIM/gp120 Tg mice. PCR was performed for genotyping of the mice, and the expressions of VIM and gp120 in the brain tissues were examined using immunoblotting. RESULTS: The results of PCR showed the presence of the target bands in VIM, VIM, VIM/gp120 Tg and VIM/gp120 Tg mice. In VIM/gp120 Tg mice, gp120 expression was detected throughout the brain regions while no VIM expression was detected. CONCLUSIONS We generated gp120 transgenic mouse models with VIM gene knockout, which facilitate the exploration of the role of VIM in gp120-induced neurotoxicity.
Animals ; Brain ; Disease Models, Animal ; Female ; HIV Envelope Protein gp120 ; HIV-1 ; Mice ; Mice, Knockout ; Mice, Transgenic ; Vimentin

OBJECTIVENew rationally designed i,i+7-hydrocarbon-stapled peptides that target both HIV-1 assembly and entry have been shown to have antiviral activity against HIV-1 subtypes circulating in Europe and North America. Here, we aimed to evaluate the antiviral activity of these peptides against HIV-1 subtypes predominantly circulating in China.

METHODSThe antiviral activity of three i,i+7-hydrocarbon-stapled peptides, NYAD-36, NYAD-67, and NYAD-66, against primary HIV-1 CRF07_BC and CRF01_AE isolates was evaluated in peripheral blood mononuclear cells (PBMCs). The activity against the CRF07_BC and CRF01_AE Env-pseudotyped viruses was analyzed in TZM-bl cells.

RESULTSWe found that all the stapled peptides were effective in inhibiting infection by all the primary HIV-1 isolates tested, with 50% inhibitory concentration toward viral replication (IC50) in the low micromolar range. NYAD-36 and NYAD-67 showed better antiviral activity than NYAD-66 did. We further evaluated the sensitivity of CRF01_AE and CRF07_BC Env-pseudotyped viruses to these stapled peptides in a single-cycle virus infectivity assay. As observed with the primary isolates, the IC50s were in the low micromolar range, and NYAD-66 was less effective than NYAD-36 and NYAD-67.

CONCLUSIONHydrocarbon-stapled peptides appear to have broad antiviral activity against the predominant HIV-1 viruses in China. This finding may provide the impetus to the rational design of peptides for future antiviral therapy.

Amino Acid Sequence ; Anti-HIV Agents ; chemistry ; pharmacology ; China ; epidemiology ; HIV Envelope Protein gp120 ; genetics ; metabolism ; HIV Infections ; epidemiology ; virology ; HIV-1 ; drug effects ; genetics ; Humans ; Peptides, Cyclic ; administration & dosage ; pharmacology ; Phylogeny

To enhance the immunogenicity of DNA and adenoviral vector vaccines expressing HIV-1 subtype B gp160, human interleukin 15 (hIL15) DNA adjuvant (pVR-hIL15) was constructed. BALB/c mice received DNA prime/protein boost immunization with pVR-HIVgp160/Ad5-HIVgp160 alone or combined with pVR-hIL15. Cellular and humoral immune responses were evaluated by IFN-gamma enzyme-linked immunosorbent spot assay and enzyme-linked immunosorbent assay, respectively. Compared with those immunized with vaccines alone, the mice immunized with vaccines combined with pVR-hIL15 had significantly increased specific cellular response and antibody titer (P < 0.05). It suggests that the IL15 DNA adjuvant can enhance the immune responses induced by prime-boost regimen using DNA and adenoviral vector encoding HIV-1 subtype B gp160.
Adenoviridae ; genetics ; Adjuvants, Immunologic ; Animals ; Antibodies, Viral ; immunology ; Antibody Specificity ; Female ; Genetic Vectors ; genetics ; HIV Envelope Protein gp120 ; immunology ; HIV Envelope Protein gp160 ; genetics ; immunology ; HIV Envelope Protein gp41 ; immunology ; Humans ; Immunity, Cellular ; Immunity, Humoral ; Interleukin-15 ; genetics ; Mice ; Mice, Inbred BALB C ; Vaccines, DNA ; genetics ; immunology

To identify human monoclonal HIV-l-neutralizing antibodies from an HIV-1 CRF07BC specific phage display antibody library by cell-based screening. 293T cells were transfected by pCH064. 2-Env plas mid and then used to biopan the phage antibody library. The positive phage clones were screened by cell based ELISA and sequenced for the variable region of heavy (VH) and light (VL) chains. The expressed Fabs were purified by Ni(+2) -NTA column and analyzed by SDS-PAGE. The cell- and gp120 protein-based ELISA as well as flow cytometry were used to measure Fab's binding activity. The neutralizing activity of Fabs was assessed by HIV-1 pseudoviruses. After 4-round biopanning, the binding phages to transfected cells were enriched about 650-folds. A total of 28 positive clones were screened out by cell ELISA and sequence analysis identified 5 different Fabs possessing unique VH and VL (2801, 2837, 2863, 2870 and 2920). Interestingly, these Fabs reacted with the Env-transfected 293T cells but not soluble gp120 proteins, suggesting that they might target conformation-dependent epitopes presenting on viral Env complex. We found that three Fabs (2801, 2863, 2870) exhibited potent neutralizing activity against CRF07_BC isolate CH120. 6 with IC50 of 2.24, 0.89 and 3.09 microg/mL respectively, and that 2801 and 2863 cross-neutral ized the subtype B isolate SF162 at IC50 of 0.69 and 3.52 microg/mL respectively. In conclusion, the HIV-1 Env-transfected 293T cells can be used to efficiently enrich and screen the phage antibody library and isolate human monoclonal HIV-1-neutralizing Fabs that target the Env complex-dependent conformational epitopes. Therefore, our studies provide a powerful platform for exploring the mechanism of HIV-1 neu tralizing response and for designing AIDS vaccines.
Antibodies, Monoclonal ; genetics ; immunology ; Antibodies, Neutralizing ; genetics ; immunology ; Enzyme-Linked Immunosorbent Assay ; methods ; HEK293 Cells ; HIV Antibodies ; genetics ; immunology ; HIV Envelope Protein gp120 ; genetics ; immunology ; HIV Infections ; immunology ; virology ; HIV-1 ; genetics ; immunology ; isolation & purification ; Humans ; Immunoglobulin Fab Fragments ; genetics ; immunology ; Neutralization Tests ; Peptide Library ; Transfection

OBJECTIVETo screen the HIV-1 entry inhibitors targeting HIV-1 gp120 from the IBS natural product database by virtual screening based on the binding mode of the neutralizing antibody VRC01 with HIV-1 gp120 and investigate the anti-viral activities of the inhibitors and their action mechanisms.

METHODSThe binding interaction of the candidate molecules binding gp120 and changes of the binding free energy were analyzed by MM-PBSA calculation. The anti-HIV-1 activities of the tested compounds were detected by HIV-1 pseudotyped virus, laboratory-adapted HIV-1 and a cell-cell fusion assay. The cytotoxicity of the studied molecules was examined by XTT colorimetric assay. The mechanisms of the anti-viral activities of the candidate molecules were analyzed using enzyme-linked immunosorbent assay.

RESULTSA total of 19 molecules with distinct reduction of the binding free energy after binding with gp120 were screened from 40000 molecules. Among them, NC-2 showed anti-HIV-1 activities against HIV-1 pseudotyped virus and laboratory-adapted HIV-1, and was capable of blocking HIV-1 envelope-mediated cell-cell fusion. The IC50 of NC-2 for inhibiting HIV-1IIIB and pseudotyped HIV-1JRFL infection were 1.95∓0.44 µmol/L and 10.58∓0.13 µmol/L, respectively. The results of ELISA suggested that NC-2 could inhibit the binding of HIV-1 gp120 to CD4 without blocking the formation of gp41 six-helix bundle in vitro.

CONCLUSIONThis computer-based virtual screening method can be used to screen HIV-1 entry inhibitors targeting gp120. Using this virtual screening approach combined with anti-viral activity screening, we obtained a potent HIV-1 entry inhibitor NC-2 with novel structure.

Anti-HIV Agents ; pharmacology ; Antibodies, Monoclonal ; pharmacology ; Antibodies, Neutralizing ; pharmacology ; Binding Sites ; Cell Fusion ; Cell Line ; Drug Discovery ; Drug Evaluation, Preclinical ; HIV Antibodies ; pharmacology ; HIV Envelope Protein gp120 ; antagonists & inhibitors ; HIV-1 ; drug effects ; Humans ; Microbial Sensitivity Tests

BACKGROUNDHIV-1 infected and immune-activated macrophages and microglia secrete neurotoxins, such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), which play major role in the neuronal death. It has been shown that different HIV-1 variants have varying abilities to elicit secretion of TNF-α by peripheral blood mononuclear cell (PBMC); however, whether the difference of gp120 gene could affect the secretion of TNF-α and IL-1β by glial cells is unknown. The aim of this study was to explore the association between gene diversity and induction of neurotoxic cytokines.

METHODSIn this study, we constructed retroviral vectors MSCV-IRES-GFP/gp120 using HIV-1 gp120 genes isolated from four different tissues of one patient who died of AIDS dementia complex (ADC). Recombinant retroviruses produced by cotransfection of MSCV-IRES-GFP/gp120, pCMV-VSV-G and pUMVC into 293T cells were collected and added into U87 glial cells. Concentrations of TNF-α and IL-1β secreted by transduced U87 cells were assayed with ELISA separately.

RESULTSThe four HIV-1 gp120 were in the different branch of the neighbor-joining tree. Compared to the pMIG retrovirus (gp120-negative) or U87 cells, all the gp120-positive recombinant retroviruses induced more TNF-α (P < 0.01) and IL-1β (P < 0.01). In addition, compared with the L/MIG retrovirus, all the three brain gp120-positive recombinant retroviruses induced less TNF-α (P < 0.01) and IL-1β (P < 0.01).

CONCLUSIONSHIV-1 gp120 could induce U87 cells secret more TNF-α and IL-1β again. The more important is that difference of HIV-1 gp120, especially cell-tropism may account for the different ability in eliciting secretion of TNF-α and IL-1β, which might supply a novel idea helping understand the pathogenesis of ADC.

AIDS Dementia Complex ; metabolism ; virology ; Cell Line ; Cell Line, Tumor ; Enzyme-Linked Immunosorbent Assay ; HIV Envelope Protein gp120 ; genetics ; metabolism ; Humans ; Interleukin-1beta ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

Human immunodeficiency virus (HIV) infects the host cells by the fusion of viral and cell membranes. Blocking the combining between HIV and the receptors can prevent HIV from entering the host cells. We designed an invasion-inhibitor for HIV-1 targeting dendritic cell (DC), including 2 important HIV-1 receptors CD4 and CCR5, and 2 molecules Flt3-L and Mip-3alpha. With the synthetic gene of the inhibitor, 2 eukaryotic expression vectors pABK-CKR5-CD4/Flt3L-Mip3alpha (pABK-HIV-MF) and pABK-CKR5-CD4 (pABK-HIV-MT) were constructed and transfected into HEK 293 cells for expression. Results from RT-PCR, immunofluorescent assay, ELISA and Western blot approved that the invasion-inhibitor for HIV-1 was successfully and exactly expressed in the eukaryotic cells. Current study formed a solid base for the further research on the function of inhibitors for HIV-1 and elimination targeting DC.
Artificial Gene Fusion ; CD4 Antigens ; biosynthesis ; genetics ; Chemokine CCL20 ; biosynthesis ; genetics ; Dendritic Cells ; immunology ; metabolism ; Genetic Vectors ; genetics ; HEK293 Cells ; HIV Envelope Protein gp120 ; genetics ; HIV-1 ; physiology ; Humans ; Receptors, CCR5 ; biosynthesis ; genetics ; Receptors, HIV ; antagonists & inhibitors ; Transfection ; fms-Like Tyrosine Kinase 3 ; biosynthesis ; genetics

OBJECTIVETo develop an objective bioassay for quantitative detection of HIV-induced cell-cell fusion for screening HIV entry inhibitors.

METHODSHL2/3 cells expressing HIV envelope proteins gp120/gp41, Tat, and other HIV proteins were co-cultured with HeLa-CD4-LTR-beta-gal cells expressing CD4 receptor and HIV LTR triggered reporter gene beta-galactosidase. The enzyme activities of beta-galactosidase were detected by a chromogenic substrate, chlorophenol red-beta-galactopyranoside (CPRG). Specific HIV entry inhibitors were used to validate the established detecting method.

RESULTSNo syncytium was formed by mixing HL2/3 and HeLa-CD4-LTR-beta-gal cells. However, the membrane could be fused and the Tat expressed by HL2/3 cells could bind to HIV LTR on HeLa-CD4-LTR-beta-gal cells and trigger the expression of beta-galactosidase. CPRG allowed quantitative and sensitive detection of the activity of beta-galactosidase. Further studies showed that HIV entry inhibitors could inhibit the activity of beta-galactosidase in a dose-dependent manner.

CONCLUSIONWe have developed a simple, cheap, objective and quantitative non-infectious cell-cell fusion bioassay that can be used to screen for anti-HIV agents targeting the virus entry from natural and synthetic compound libraries.

Biological Assay ; Cell Fusion ; Cell Line ; Coculture Techniques ; Drug Evaluation, Preclinical ; methods ; HIV Envelope Protein gp120 ; metabolism ; HIV Envelope Protein gp41 ; metabolism ; HIV Fusion Inhibitors ; chemistry ; pharmacology ; Humans ; beta-Galactosidase ; metabolism

This review discusses recent progress in the development of anti-HIV agents, with emphasis on small molecule HIV-1 entry inhibitors. The entry inhibitors primarily target HIV-1 envelope glycoproteins or the cellular receptors, CD4 and chemokine receptors. Two of the entry inhibitors, enfuvirtide and maraviroc, have been approved by the US FDA for AIDS therapy. The drug resistance associated with some of the entry inhibitors will also be discussed.
Anti-HIV Agents ; chemistry ; pharmacology ; therapeutic use ; CCR5 Receptor Antagonists ; CD4 Antigens ; drug effects ; Cyclohexanes ; pharmacology ; therapeutic use ; Drug Resistance, Viral ; HIV Envelope Protein gp120 ; pharmacology ; HIV Envelope Protein gp41 ; pharmacology ; therapeutic use ; HIV Fusion Inhibitors ; chemistry ; pharmacology ; therapeutic use ; HIV Infections ; drug therapy ; HIV-1 ; drug effects ; Humans ; Molecular Structure ; Peptide Fragments ; pharmacology ; therapeutic use ; Receptors, CCR5 ; physiology ; Receptors, CXCR4 ; antagonists & inhibitors ; Receptors, Chemokine ; drug effects ; Triazoles ; pharmacology ; therapeutic use