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Synergistic Reactivation of Latent HIV Expression by Ingenol-3-Angelate, PEP005, Targeted NF-kB Signaling in Combination with JQ1 Induced p-TEFb Activation.

Jiang G, Mendes EA, Kaiser P, Wong DP, Tang Y, Cai I, Fenton A, Melcher GP, Hildreth JE, Thompson GR, Wong JK, Dandekar S - PLoS Pathog. (2015)

Bottom Line: Therefore, effective strategies for eradication of the HIV reservoirs are urgently needed.Furthermore, PEP005 and the P-TEFb agonist, JQ1, exhibited synergism in reactivation of latent HIV with a combined effect that is 7.5-fold higher than the effect of PEP005 alone.This anti-cancer compound is a potential candidate for advancing HIV eradication strategies.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Microbiology and Immunology, University of California, Davis, Davis, California, United States of America.

ABSTRACT
Although anti-retroviral therapy (ART) is highly effective in suppressing HIV replication, it fails to eradicate the virus from HIV-infected individuals. Stable latent HIV reservoirs are rapidly established early after HIV infection. Therefore, effective strategies for eradication of the HIV reservoirs are urgently needed. We report that ingenol-3-angelate (PEP005), the only active component in a previously FDA approved drug (PICATO) for the topical treatment of precancerous actinic keratosis, can effectively reactivate latent HIV in vitro and ex vivo with relatively low cellular toxicity. Biochemical analysis showed that PEP005 reactivated latent HIV through the induction of the pS643/S676-PKCδ/θ-IκBα/ε-NF-κB signaling pathway. Importantly, PEP005 alone was sufficient to induce expression of fully elongated and processed HIV RNAs in primary CD4+ T cells from HIV infected individuals receiving suppressive ART. Furthermore, PEP005 and the P-TEFb agonist, JQ1, exhibited synergism in reactivation of latent HIV with a combined effect that is 7.5-fold higher than the effect of PEP005 alone. Conversely, PEP005 suppressed HIV infection of primary CD4+ T cells through down-modulation of cell surface expression of HIV co-receptors. This anti-cancer compound is a potential candidate for advancing HIV eradication strategies.

No MeSH data available.


Related in: MedlinePlus

PEP005 down-modulates the expression of CD4, CCR5 and CXCR4 and inhibits HIV infection of primary CD4+ T cells ex vivo.(A) PEP005 inhibits expression of HIV receptors/co-receptors. The CD4+ T cells were isolated from the peripheral blood of HIV-negative uninfected controls and treated with 12 nM PEP005 for 72 hours. The expression of CD4, CCR5 and CXCR4 genes was evaluated using RT-qPCR after normalizing for GAPDH. (B) and (C) PEP005 inhibits HIV infection of primary CD4+ T cells ex vivo. Primary CD4+ T cells were pre-treated with 12 or 24 nM PEP005 overnight and infected with the virus. The CD4+ T cells were incubated for 5 days without PEP005. The cells were collected for RT-qPCR targeting the HIV LTR region (B), or supernatants were collected for p24 ELISA (C). *, p<0.05; **, p<0.01.
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ppat.1005066.g012: PEP005 down-modulates the expression of CD4, CCR5 and CXCR4 and inhibits HIV infection of primary CD4+ T cells ex vivo.(A) PEP005 inhibits expression of HIV receptors/co-receptors. The CD4+ T cells were isolated from the peripheral blood of HIV-negative uninfected controls and treated with 12 nM PEP005 for 72 hours. The expression of CD4, CCR5 and CXCR4 genes was evaluated using RT-qPCR after normalizing for GAPDH. (B) and (C) PEP005 inhibits HIV infection of primary CD4+ T cells ex vivo. Primary CD4+ T cells were pre-treated with 12 or 24 nM PEP005 overnight and infected with the virus. The CD4+ T cells were incubated for 5 days without PEP005. The cells were collected for RT-qPCR targeting the HIV LTR region (B), or supernatants were collected for p24 ELISA (C). *, p<0.05; **, p<0.01.

Mentions: Recent studies have shown that Prostratin and analogs down-modulate HIV receptor/co-receptor expression, which could have protective effects against the viral infection [52,53]. Conversely, SAHA, known to induce latent HIV expression in HIV infected individuals receiving ART, was reported to increase susceptibility of naive CD4+ T cells to HIV acquisition [54]. Diterpene compounds are known to inhibit expression of HIV receptors/co-receptors including CD4, CCR5, and CXCR4, which are important for the viral attachment and entry into immune cells [27,52,53,55,56]. We sought to examine the effect of PEP005 on the cell surface expression of HIV receptors and co-receptors in CD4+ T cells. Primary CD4+ T cells from peripheral blood samples of healthy HIV-negative donors were treated with 12 nM PEP005 and evaluated for the expression levels of CD4, CCR5, and CCXR4 using RT-qPCR. Our data showed that PEP005 treatment caused a significant reduction in the expression of all these HIV receptors/co-receptors, suggesting that PEP005 may not pose the risk of increasing susceptibility of CD4+ T cells to HIV infection during its reactivation of HIV latency (Fig 12A). Instead, PEP005 contribute to suppression of propagating HIV infection of CD4+ T cells following the reactivation of latent HIV. To investigate the potentially protective effects of PEP005, primary CD4+ T cells were infected with HIV with or without pre-treatment of 12 or 24 nM PEP005 for 24 hrs. The virological outcome in the CD4+ T cell cultures in vitro was monitored for 5 days. We observed that PEP005 dampened HIV gene expression as well as decreased the level of viral replication as determined at 3 and 5 days after HIV infection of primary CD4+ T cells (Fig 12B and 12C). These findings suggest that PEP005 may help prevent HIV infection of naive CD4+ T cells through down-modulation of HIV co-receptor expression (CD4, CXCR4 and CCR5) and that would be beneficial during the process of latent HIV reactivation.


Synergistic Reactivation of Latent HIV Expression by Ingenol-3-Angelate, PEP005, Targeted NF-kB Signaling in Combination with JQ1 Induced p-TEFb Activation.

Jiang G, Mendes EA, Kaiser P, Wong DP, Tang Y, Cai I, Fenton A, Melcher GP, Hildreth JE, Thompson GR, Wong JK, Dandekar S - PLoS Pathog. (2015)

PEP005 down-modulates the expression of CD4, CCR5 and CXCR4 and inhibits HIV infection of primary CD4+ T cells ex vivo.(A) PEP005 inhibits expression of HIV receptors/co-receptors. The CD4+ T cells were isolated from the peripheral blood of HIV-negative uninfected controls and treated with 12 nM PEP005 for 72 hours. The expression of CD4, CCR5 and CXCR4 genes was evaluated using RT-qPCR after normalizing for GAPDH. (B) and (C) PEP005 inhibits HIV infection of primary CD4+ T cells ex vivo. Primary CD4+ T cells were pre-treated with 12 or 24 nM PEP005 overnight and infected with the virus. The CD4+ T cells were incubated for 5 days without PEP005. The cells were collected for RT-qPCR targeting the HIV LTR region (B), or supernatants were collected for p24 ELISA (C). *, p<0.05; **, p<0.01.
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4520526&req=5

ppat.1005066.g012: PEP005 down-modulates the expression of CD4, CCR5 and CXCR4 and inhibits HIV infection of primary CD4+ T cells ex vivo.(A) PEP005 inhibits expression of HIV receptors/co-receptors. The CD4+ T cells were isolated from the peripheral blood of HIV-negative uninfected controls and treated with 12 nM PEP005 for 72 hours. The expression of CD4, CCR5 and CXCR4 genes was evaluated using RT-qPCR after normalizing for GAPDH. (B) and (C) PEP005 inhibits HIV infection of primary CD4+ T cells ex vivo. Primary CD4+ T cells were pre-treated with 12 or 24 nM PEP005 overnight and infected with the virus. The CD4+ T cells were incubated for 5 days without PEP005. The cells were collected for RT-qPCR targeting the HIV LTR region (B), or supernatants were collected for p24 ELISA (C). *, p<0.05; **, p<0.01.
Mentions: Recent studies have shown that Prostratin and analogs down-modulate HIV receptor/co-receptor expression, which could have protective effects against the viral infection [52,53]. Conversely, SAHA, known to induce latent HIV expression in HIV infected individuals receiving ART, was reported to increase susceptibility of naive CD4+ T cells to HIV acquisition [54]. Diterpene compounds are known to inhibit expression of HIV receptors/co-receptors including CD4, CCR5, and CXCR4, which are important for the viral attachment and entry into immune cells [27,52,53,55,56]. We sought to examine the effect of PEP005 on the cell surface expression of HIV receptors and co-receptors in CD4+ T cells. Primary CD4+ T cells from peripheral blood samples of healthy HIV-negative donors were treated with 12 nM PEP005 and evaluated for the expression levels of CD4, CCR5, and CCXR4 using RT-qPCR. Our data showed that PEP005 treatment caused a significant reduction in the expression of all these HIV receptors/co-receptors, suggesting that PEP005 may not pose the risk of increasing susceptibility of CD4+ T cells to HIV infection during its reactivation of HIV latency (Fig 12A). Instead, PEP005 contribute to suppression of propagating HIV infection of CD4+ T cells following the reactivation of latent HIV. To investigate the potentially protective effects of PEP005, primary CD4+ T cells were infected with HIV with or without pre-treatment of 12 or 24 nM PEP005 for 24 hrs. The virological outcome in the CD4+ T cell cultures in vitro was monitored for 5 days. We observed that PEP005 dampened HIV gene expression as well as decreased the level of viral replication as determined at 3 and 5 days after HIV infection of primary CD4+ T cells (Fig 12B and 12C). These findings suggest that PEP005 may help prevent HIV infection of naive CD4+ T cells through down-modulation of HIV co-receptor expression (CD4, CXCR4 and CCR5) and that would be beneficial during the process of latent HIV reactivation.

Bottom Line: Therefore, effective strategies for eradication of the HIV reservoirs are urgently needed.Furthermore, PEP005 and the P-TEFb agonist, JQ1, exhibited synergism in reactivation of latent HIV with a combined effect that is 7.5-fold higher than the effect of PEP005 alone.This anti-cancer compound is a potential candidate for advancing HIV eradication strategies.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Microbiology and Immunology, University of California, Davis, Davis, California, United States of America.

ABSTRACT
Although anti-retroviral therapy (ART) is highly effective in suppressing HIV replication, it fails to eradicate the virus from HIV-infected individuals. Stable latent HIV reservoirs are rapidly established early after HIV infection. Therefore, effective strategies for eradication of the HIV reservoirs are urgently needed. We report that ingenol-3-angelate (PEP005), the only active component in a previously FDA approved drug (PICATO) for the topical treatment of precancerous actinic keratosis, can effectively reactivate latent HIV in vitro and ex vivo with relatively low cellular toxicity. Biochemical analysis showed that PEP005 reactivated latent HIV through the induction of the pS643/S676-PKCδ/θ-IκBα/ε-NF-κB signaling pathway. Importantly, PEP005 alone was sufficient to induce expression of fully elongated and processed HIV RNAs in primary CD4+ T cells from HIV infected individuals receiving suppressive ART. Furthermore, PEP005 and the P-TEFb agonist, JQ1, exhibited synergism in reactivation of latent HIV with a combined effect that is 7.5-fold higher than the effect of PEP005 alone. Conversely, PEP005 suppressed HIV infection of primary CD4+ T cells through down-modulation of cell surface expression of HIV co-receptors. This anti-cancer compound is a potential candidate for advancing HIV eradication strategies.

No MeSH data available.


Related in: MedlinePlus