The contribution of peroxynitrite generation in HIV replication in human primary macrophages

<p>Abstract</p> <p>Background</p> <p>Monocytes/Macrophages (M/M) play a pivotal role as a source of virus during the whole course of HIV-1 infection. Enhanced oxidative stress is involved in the pathogenesis of HIV-1 infection. HIV-1 regulatory proteins induce a reduction of the expression and the activity of MnSOD, the mitochondrial isoform leading to a sustained generation of superoxide anions and peroxynitrite that represent important mediators of HIV-1 replication in M/M. MnTBAP (Mn(III)tetrakis(4-benzoic acid)porphrin chloride), a synthetic peroxynitrite decomposition catalyst, reduced oxidative stress subsequent to peroxynitrite generation.</p> <p>Results</p> <p>Virus production was assessed by p24 ELISA, western blot, and electron microscopy during treatment with MnTBAP. MnTBAP treatment showed a reduction of HIV-1 replication in both acutely and chronically infected M/M: 99% and 90% inhibition of p24 released in supernatants compared to controls, respectively. Maturation of p55 and p24 was strongly inhibited by MnTBAP in both acutely and chronically infected M/M. EC₅₀and EC₉₀are 3.7 (± 0.05) μM and 19.5 (± 0.5) μM, in acutely infected M/M; 6.3 (± 0.003) μM and 30 (± 0.6) μM, in chronically infected M/M. In acutely infected peripheral blood limphocytes (PBL), EC₅₀and EC₉₀are 7.4 (± 0.06) μM and of 21.3 (± 0.6) μM, respectively. Treatment of acutely-infected M/M with MnTBAP inhibited the elevated levels of malonildialdehyde (MDA) together with the nitrotyrosine staining observed during HIV-1 replication. MnTBAP strongly reduced HIV-1 particles in infected M/M, as shown by electron microscopy. Moreover, in presence of MnTBAP, HIV-1 infectivity was reduced of about 1 log compared to control.</p> <p>Conclusion</p> <p>Results support the role of superoxide anions in HIV-1 replication in M/M and suggest that MnTBAP may counteract HIV-1 replication in combination with other antiretroviral treatments.</p

Different Patterns of HIV-1 Replication in MACROPHAGES is Led by Co-Receptor Usage

Background and objectives: To enter the target cell, HIV-1 binds not only CD4 but also a co-receptor &beta;-chemokine receptor 5 (CCR5) or &alpha; chemokine receptor 4 (CXCR4). Limited information is available on the impact of co-receptor usage on HIV-1 replication in monocyte-derived macrophages (MDM) and on the homeostasis of this important cellular reservoir. Materials and Methods: Replication (measured by p24 production) of the CCR5-tropic 81A strain increased up to 10 days post-infection and then reached a plateau. Conversely, the replication of the CXCR4-tropic NL4.3 strain (after an initial increase up to day 7) underwent a drastic decrease becoming almost undetectable after 10 days post-infection. The ability of CCR5-tropic and CXCR4-tropic strains to induce cell death in MDM was then evaluated. While for CCR5-tropic 81A the rate of apoptosis in MDM was comparable to uninfected MDM, the infection of CXCR4-tropic NL4.3 in MDM was associated with a rate of 14.3% of apoptotic cells at day 6 reaching a peak of 43.5% at day 10 post-infection. Results: This suggests that the decrease in CXCR4-tropic strain replication in MDM can be due to their ability to induce cell death in MDM. The increase in apoptosis was paralleled with a 2-fold increase in the phosphorylated form of p38 compared to WT. Furthermore, microarray analysis showed modulation of proapoptotic and cancer-related genes induced by CXCR4-tropic strains starting from 24 h after infection, whereas CCR5 viruses modulated the expression of genes not correlated with apoptotic-pathways. Conclusions: In conclusion, CXCR4-tropic strains can induce a remarkable depletion of MDM. Conversely, MDM can represent an important cellular reservoir for CCR5-tropic strains supporting the role of CCR5-usage in HIV-1 pathogenesis and as a pharmacological target to contribute to an HIV-1 cure

Deep Learning Can Differentiate IDH-Mutant from IDH-Wild GBM

Isocitrate dehydrogenase (IDH) mutant and wildtype glioblastoma multiforme (GBM) often show overlapping features on magnetic resonance imaging (MRI), representing a diagnostic challenge. Deep learning showed promising results for IDH identification in mixed low/high grade glioma populations; however, a GBM-specific model is still lacking in the literature. Our aim was to develop a GBM-tailored deep-learning model for IDH prediction by applying convoluted neural networks (CNN) on multiparametric MRI. We selected 100 adult patients with pathologically demonstrated WHO grade IV gliomas and IDH testing. MRI sequences included: MPRAGE, T1, T2, FLAIR, rCBV and ADC. The model consisted of a 4-block 2D CNN, applied to each MRI sequence. Probability of IDH mutation was obtained from the last dense layer of a softmax activation function. Model performance was evaluated in the test cohort considering categorical cross-entropy loss (CCEL) and accuracy. Calculated performance was: rCBV (accuracy 83%, CCEL 0.64), T1 (accuracy 77%, CCEL 1.4), FLAIR (accuracy 77%, CCEL 1.98), T2 (accuracy 67%, CCEL 2.41), MPRAGE (accuracy 66%, CCEL 2.55). Lower performance was achieved on ADC maps. We present a GBM-specific deep-learning model for IDH mutation prediction, with a maximal accuracy of 83% on rCBV maps. Highest predictivity achieved on perfusion images possibly reflects the known link between IDH and neoangiogenesis through the hypoxia inducible factor

The contribution of peroxynitrite generation in HIV replication in human primary macrophages-2

<p><b>Copyright information:</b></p><p>Taken from "The contribution of peroxynitrite generation in HIV replication in human primary macrophages"</p><p>http://www.retrovirology.com/content/4/1/76</p><p>Retrovirology 2007;4():76-76.</p><p>Published online 21 Oct 2007</p><p>PMCID:PMC2173904.</p><p></p>phages. Line 2: macrophages HIV-1 BaL infected and treated with MnTBAP (30 μM). Line 3: macrophages HIV-1 BaL infected

The contribution of peroxynitrite generation in HIV replication in human primary macrophages-0

<p><b>Copyright information:</b></p><p>Taken from "The contribution of peroxynitrite generation in HIV replication in human primary macrophages"</p><p>http://www.retrovirology.com/content/4/1/76</p><p>Retrovirology 2007;4():76-76.</p><p>Published online 21 Oct 2007</p><p>PMCID:PMC2173904.</p><p></p>ted with 300 TCID50/ml HIV-1 BaL and treated acutely (i.e. treated with drugs prior to virus challenge). Supernatants were collected day 14 after infection and tested for virus production by analysis of HIV-1 p24 gag Ag production with a commercially available kit ELISA

The contribution of peroxynitrite generation in HIV replication in human primary macrophages-1

<p><b>Copyright information:</b></p><p>Taken from "The contribution of peroxynitrite generation in HIV replication in human primary macrophages"</p><p>http://www.retrovirology.com/content/4/1/76</p><p>Retrovirology 2007;4():76-76.</p><p>Published online 21 Oct 2007</p><p>PMCID:PMC2173904.</p><p></p>ted with 300 TCID50/ml HIV-1 BaL and treated chronically (i.e. treated with drugs 10 days after infection) with MnTBAP at indicated doses, and Amprenavir (4 uM). Supernatants were collected at day 8, 10, 15, 20 after infection and tested for virus production by analysis of HIV-1 p24 gag Ag production with a commercially available kit ELISA

The contribution of peroxynitrite generation in HIV replication in human primary macrophages-6

<p><b>Copyright information:</b></p><p>Taken from "The contribution of peroxynitrite generation in HIV replication in human primary macrophages"</p><p>http://www.retrovirology.com/content/4/1/76</p><p>Retrovirology 2007;4():76-76.</p><p>Published online 21 Oct 2007</p><p>PMCID:PMC2173904.</p><p></p>ration, in cytoplasmatic vacuoles and in the extracellular space. By contrast in MnTBAP (30 μM) treated macrophages no viral particles are found. This observation support the hypothesis that MnTBAP treatment is able to prevent enveloped and unenveloped virions production

The contribution of peroxynitrite generation in HIV replication in human primary macrophages-3

<p><b>Copyright information:</b></p><p>Taken from "The contribution of peroxynitrite generation in HIV replication in human primary macrophages"</p><p>http://www.retrovirology.com/content/4/1/76</p><p>Retrovirology 2007;4():76-76.</p><p>Published online 21 Oct 2007</p><p>PMCID:PMC2173904.</p><p></p>nized MDA overproduction dose-dependently while AZT (0.05 μM) was not able to inhibit macrophages HIV-related MDA formation. † P < 0.001 when compared to control; * P < 0.05 and ** P < 0.001 when compared to HIV-infected cells

The contribution of peroxynitrite generation in HIV replication in human primary macrophages-4

<p><b>Copyright information:</b></p><p>Taken from "The contribution of peroxynitrite generation in HIV replication in human primary macrophages"</p><p>http://www.retrovirology.com/content/4/1/76</p><p>Retrovirology 2007;4():76-76.</p><p>Published online 21 Oct 2007</p><p>PMCID:PMC2173904.</p><p></p>. HIV-1 infection enhance the immunocytochemical expression of nitrotyrosine (Panel A) in compared to mock-infected macrophages (Panel B), indicating an increased production of peroxynitrite. Acute treatment with MnTBAP (30 μM) (Panel D), but not with AZT (0.05 μM) (Panel C) is able to inhibit in macrophages HIV-related peroxynitrite formation