Ncluding T cells, macrophages and dendritic cells [4]. VIP and PACAP have

Ncluding T cells, macrophages and dendritic cells [4]. VIP and PACAP have well-characterized effects on the immune system and anti-inflammatory properties, including inhibition of macrophage adherence and down-regulation of inflammatory cytokines and reactive oxygen species [9,10?4]. Moreover, they can induce production of the anti-inflammatory cytokine IL-10 [12,14]. Due to their immunomodulatory properties, both neuropeptides have been considered as promising therapeutic agents for a range of pathologies [15?7]. Macrophages play a central role in the pathogenesis of the 10457188 human immunodeficiency virus type 1 (HIV-1) infection due to their ability to resist HIV-1-mediated cytopathic effects and tocontinuously produce virus even in the presence of antiretrovirals [18?0]. They function as an HIV-1 reservoir and contribute in HIV-1 transmission to CD4+ T cells and virus propagation in lymphoid tissues [21,22]. Considering that HIV-1 replication in macrophages can be modulated by a variety of inflammatory mediators and cytokines [23?5], identifying factors that influence HIV-1 growth in these cells is Title Loaded From File essential to understand the immunopathogenesis of HIV-1 infection and to design novel strategies to control HIV-1 propagation. We recently reported that the neuroimmunomodulatory molecule Nerve Growth Factor (NGF) stimulates HIV-1 replication in primary monocyte-derived macrophages [26], and we now address whether the immunosuppressive neuropeptides VIP and PACAP, which also regulate the functioning of the neuro-immune-endocrine system, could also Title Loaded From File affect HIV-1 production in those cells. Few studies have addressed the biological effects of VIP and PACAP during HIV-1 infection, which have mainly focused on the repercussion of VIP and PACAP receptor ligation on HIV-1 production, describing that VPAC1 facilitates productive HIV-1 infection in CD4+ T cell lines [27], and that VPAC2 stimulation diminishes HIV-1 production in peripheral blood mononuclear cells (PBMCs) and in CD4+ T cell lines [28]. These findings suggest that the sole activation of VPAC1 or VPAC2 receptors can lead to opposite effects on HIV-1 replication, but the consequence of the simultaneous ligation of these receptors and PAC1 by their natural ligands on viral production is unknown. Therefore, because the existent data regarding the influence of VIP andVIP and PACAP Inhibit HIV-1 InfectionPACAP receptors on HIV-1 infection were obtained in T cells using selective receptor agonists, we analyzed whether these neuropeptides could directly modulate the viral production in HIV-1-infected monocyte-derived macrophages, a possibility that has not been pursued thus far. We found that VIP and PACAP increased macrophage resistance to HIV-1 replication by inducing the synthesis of b-chemokines and IL-10 following preferential activation of the receptors VPAC2 and PAC1.HIV-1 infectionMacrophages were exposed for 16?8 h to viral suspensions containing 5?0 ng/mL of HIV-1 p24 antigen, as previously described [29]. The infected cells were then washed, replenished with fresh medium and maintained under standard culture conditions. HIV-1 replication was evaluated in cell culture supernatants after 12?4 days using an ELISA kit for HIV-1 p24 antigen (ZeptoMetrix Corp, NY, USA). Due to the common donor-to-donor variation of HIV-1 replication in primary cells [30], some HIV-1 inhibition results are presented normalized to viral production by macrophages maintained only in culture medium, with the absolu.Ncluding T cells, macrophages and dendritic cells [4]. VIP and PACAP have well-characterized effects on the immune system and anti-inflammatory properties, including inhibition of macrophage adherence and down-regulation of inflammatory cytokines and reactive oxygen species [9,10?4]. Moreover, they can induce production of the anti-inflammatory cytokine IL-10 [12,14]. Due to their immunomodulatory properties, both neuropeptides have been considered as promising therapeutic agents for a range of pathologies [15?7]. Macrophages play a central role in the pathogenesis of the 10457188 human immunodeficiency virus type 1 (HIV-1) infection due to their ability to resist HIV-1-mediated cytopathic effects and tocontinuously produce virus even in the presence of antiretrovirals [18?0]. They function as an HIV-1 reservoir and contribute in HIV-1 transmission to CD4+ T cells and virus propagation in lymphoid tissues [21,22]. Considering that HIV-1 replication in macrophages can be modulated by a variety of inflammatory mediators and cytokines [23?5], identifying factors that influence HIV-1 growth in these cells is essential to understand the immunopathogenesis of HIV-1 infection and to design novel strategies to control HIV-1 propagation. We recently reported that the neuroimmunomodulatory molecule Nerve Growth Factor (NGF) stimulates HIV-1 replication in primary monocyte-derived macrophages [26], and we now address whether the immunosuppressive neuropeptides VIP and PACAP, which also regulate the functioning of the neuro-immune-endocrine system, could also affect HIV-1 production in those cells. Few studies have addressed the biological effects of VIP and PACAP during HIV-1 infection, which have mainly focused on the repercussion of VIP and PACAP receptor ligation on HIV-1 production, describing that VPAC1 facilitates productive HIV-1 infection in CD4+ T cell lines [27], and that VPAC2 stimulation diminishes HIV-1 production in peripheral blood mononuclear cells (PBMCs) and in CD4+ T cell lines [28]. These findings suggest that the sole activation of VPAC1 or VPAC2 receptors can lead to opposite effects on HIV-1 replication, but the consequence of the simultaneous ligation of these receptors and PAC1 by their natural ligands on viral production is unknown. Therefore, because the existent data regarding the influence of VIP andVIP and PACAP Inhibit HIV-1 InfectionPACAP receptors on HIV-1 infection were obtained in T cells using selective receptor agonists, we analyzed whether these neuropeptides could directly modulate the viral production in HIV-1-infected monocyte-derived macrophages, a possibility that has not been pursued thus far. We found that VIP and PACAP increased macrophage resistance to HIV-1 replication by inducing the synthesis of b-chemokines and IL-10 following preferential activation of the receptors VPAC2 and PAC1.HIV-1 infectionMacrophages were exposed for 16?8 h to viral suspensions containing 5?0 ng/mL of HIV-1 p24 antigen, as previously described [29]. The infected cells were then washed, replenished with fresh medium and maintained under standard culture conditions. HIV-1 replication was evaluated in cell culture supernatants after 12?4 days using an ELISA kit for HIV-1 p24 antigen (ZeptoMetrix Corp, NY, USA). Due to the common donor-to-donor variation of HIV-1 replication in primary cells [30], some HIV-1 inhibition results are presented normalized to viral production by macrophages maintained only in culture medium, with the absolu.

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