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New 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.The 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.We 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.Hydrocarbon-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.

To investigate distinctive features in drug-resistant mutations (DRMs) and interpretations for reverse transcriptase inhibitors (RTIs) between proviral DNA and paired viral RNA in HIV-1-infected patients.Forty-three HIV-1-infected individuals receiving first-line antiretroviral therapy were recruited to participate in a multicenter AIDS Cohort Study in Anhui and Henan Provinces in China in 2004. Drug resistance genotyping was performed by bulk sequencing and deep sequencing on the plasma and whole blood of 77 samples, respectively. Drug-resistance interpretation was compared between viral RNA and paired proviral DNA.Compared with bulk sequencing, deep sequencing could detect more DRMs and samples with DRMs in both viral RNA and proviral DNA. The mutations M184I and M230I were more prevalent in proviral DNA than in viral RNA (Fisher's exact test, P0.05). Considering 'majority resistant variants', 15 samples (19.48%) showed differences in drug resistance interpretation between viral RNA and proviral DNA, and 5 of these samples with different DRMs between proviral DNA and paired viral RNA showed a higher level of drug resistance to the first-line drugs. Considering 'minority resistant variants', 22 samples (28.57%) were associated with a higher level of drug resistance to the tested RTIs for proviral DNA when compared with paired viral RNA.Compared with viral RNA, the distinctive information of DRMs and drug resistance interpretations for proviral DNA could be obtained by deep sequencing, which could provide more detailed and precise information for drug resistance monitoring and the rational design of optimal antiretroviral therapy regimens.

To review the mechanisms by which HIV evades different components of the host immune system.This review is based on data obtained from published articles from 1991 to 2012. To perform the PubMed literature search, the following key words were input: HIV and immune evasion.Articles containing information related to HIV immune evasion were selected.Although HIV is able to induce vigorous antiviral immune responses, viral replication cannot be fully controlled, and neither pre-existing infected cells nor latent HIV infection can be completely eradicated. Like many other enveloped viruses, HIV can escape recognition by the innate and adaptive immune systems. Recent findings have demonstrated that HIV can also successfully evade host restriction factors, the components of intrinsic immune system, such as APOBEC3G (apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G), TRIM5α (tripartite motif 5-α), tetherin, and SAMHD1 (SAM-domain HD-domain containing protein).HIV immune evasion plays an important role in HIV pathogenesis. Fully understanding the tactics deployed by HIV to evade various components of the host immune systems will allow for the development of novel strategies aimed toward the prevention and cure of HIV/AIDS.

To design and construct an HIV-1 subunit vaccine containing the N-terminal heptad repeat (NHR) domain N51 in gp41 of the HIV-1 CRF01_AE recombinant subtype in China and study its immunogenicity.Two pairs of primers were designed to amplify DNA fragment encoding N51Fd gene, which was then subcloned into pFUSE-hIgG1-Fc2 vector. The recombinant plasmid pFUSE/N51Fd was confirmed by DNA sequencing. Western blotting was used to measure the correct expression of the recombinant protein N51FdFc-AE. The N51FdFc-AE protein was used to immunize BALB/c mice, and the specific antibody response was measured by ELISA.A recombinant plasmid pFUSE/N51Fd was successfully constructed and the N51FdFc-AE recombinant protein was expressed effectively in 293T cells. The purified N51FdFc-AE recombinant protein (35 kD) was detected by Western blotting with rabbit anti-gp41 N/C peptide antibodies. The mouse anti-sera could specifically recognize the antigens derived from gp41 NHR. The titers of the specific antibodies were up to 1:102 400 with an average titer of 1:51 200.The recombinant N51FdFc-AE protein can effectively induce the gp41 NHR-specific immune responses in BALB/c mice and could be used as an immunogen for design of HIV-1 subunit vaccine.

Twenty seven new diarylbenzimidazole derivatives (A1-A21, B1-B6) were designed, synthesized, and evaluated in MT-2 cell line as potential HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) agents with a new skeleton based on molecular modeling technique and hit 1,2-diarylbenzimidazole A1 (EC50 69.9 miromol x L(-1)). Hence, 1,2-diarylbenzimidazoles A6 and B3, and 1,6-diarylbenzimidazole B6 showed obvious potency against HIV-1 replication in MT-2 cell line with EC50 values of 15.33, 9.81 and 1.37 micromol x L(-1) respectively. All target compounds were synthesized commonly from substituted 2-nitroanilines by 1-3 steps under mild reaction conditions. Current studies provided preliminary SAR, thus indicating that 1,6-diaryl substitution on the benzimidazole ring would be a right direction for further modification. Furthermore, the docking studies demonstrated that B6 could fit well into the HIV-1 NNRTI binding pocket with a similar binding orientation and conformation to that of TMC278, a promising NNRTI candidate inclinical trial III, Therefore, active compound B6 could serve as a new starting point to develop a series of 1,6-diarylbenzimidazole derivatives as HIV-1 NNRTI agents with a novel skeleton.

To investigate the inhibitory activities of caffeoyl glucopyranoses purified from Balanophora japonica Makino on HIV entry and their mechanism.HIV-1 Env pseudovirus was used to evaluate the anti-HIV-1 activity of those compounds. ELISA and molecular docking were used to study the mechanism of the actions of the active compounds.We used the HIV-1 Env pseudovirus to test the anti-HIV-1 activity of the six phenolic compounds (final concentration 25 microg/ml), and found that only 1,2,6-Tri-O-caffeoyl-beta-D-glucopyranose (TCGP) and 1,3-Di-O-caffeoyl-4-O-galloyl-beta-D- glucopyranose (DCGGP) could effectively inhibit the entry of HIV-1 Env pseudovirus into the target cells in a dose-dependent manner, with IC(50) values of 5.5-/+0.2 and 5.3-/+0.1 microg/ml, respectively. These two compounds could also blocked the gp41 six-helix bundle formation. Molecular docking analysis suggested that they might bind to the hydrophobic cavity of the gp41 N-trimeric coiled-coil.TCGP and DCGGP are potent HIV-1 entry inhibitors targeting gp41 and can serve as lead compounds for developing novel anti-HIV-1 microbicides for prevention of sexual HIV-1 transmission.

To 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.TGGP 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.TGGP 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.The 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.

To investigate the mechanism by which tannin inhibits HIV-1 entry into target cells.The inhibitory activity of tannin on HIV-1 replication and entry was detected by p24 production and HIV-1-mediated cell fusion, respectively. The inhibitory activity on the gp41 six-helix bundle formation was determined by an improved sandwich ELISA.Tannins from different sources showed potent inhibitory activity on HIV-1 replication, HIV-1-mediated cell fusion, and the gp41 six-helix bundle formation.Tannin inhibits HIV-1 entry into target cells by interfering with the gp41 six-helix bundle formation, thus blocking HIV-1 fusion with the target cell.