High-fat diet exacerbates SIV pathogenesis and accelerates disease progression

Copyright: © 2019. American Society for Clinical Investigation.Consuming a high-fat diet (HFD) is a risk factor for obesity and diabetes; both of these diseases are also associated with systemic inflammation, similar to HIV infection. A HFD induces intestinal dysbiosis and impairs liver function and coagulation, with a potential negative impact on HIV/SIV pathogenesis. We administered a HFD rich in saturated fats and cholesterol to nonpathogenic (African green monkeys) and pathogenic (pigtailed macaques) SIV hosts. The HFD had a negative impact on SIV disease progression in both species. Thus, increased cell-associated SIV DNA and RNA occurred in the HFD-receiving nonhuman primates, indicating a potential reservoir expansion. The HFD induced prominent immune cell infiltration in the adipose tissue, an important SIV reservoir, and heightened systemic immune activation and inflammation, altering the intestinal immune environment and triggering gut damage and microbial translocation. Furthermore, HFD altered lipid metabolism and HDL oxidation and also induced liver steatosis and fibrosis. These metabolic disturbances triggered incipient atherosclerosis and heightened cardiovascular risk in the SIV-infected HFD-receiving nonhuman primates. Our study demonstrates that dietary intake has a discernable impact on the natural history of HIV/SIV infections and suggests that dietary changes can be used as adjuvant approaches for HIV-infected subjects, to reduce inflammation and the risk of non-AIDS comorbidities and possibly other infectious diseases.This study was funded through NIH/NHLBI/NIAID/NIDDK/ NCRR R01 grants HL117715 (to IP), HL123096 (to IP), AI119346 (to CA), DK113919 (to IP and CA), DK119936 (to CA), RR025781 (to CA and IP), and AI104373 (to RMR). RMR was funded by grant PTDC/ MAT-APL/31602/2017 from the Fundação para a Ciência e Tecnologia (Portugal). DNF and CCW were supported by the University of Colorado GI and Liver Innate Immunity Program. KDR and BBP were partly supported by the NIH Training Grant T32AI065380. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

Multi-dose Romidepsin Reactivates Replication Competent SIV in Post-antiretroviral Rhesus Macaque Controllers

<div><p>Viruses that persist despite seemingly effective antiretroviral treatment (ART) and can reinitiate infection if treatment is stopped preclude definitive treatment of HIV-1 infected individuals, requiring lifelong ART. Among strategies proposed for targeting these viral reservoirs, the premise of the “shock and kill” strategy is to induce expression of latent proviruses [for example with histone deacetylase inhibitors (HDACis)] resulting in elimination of the affected cells through viral cytolysis or immune clearance mechanisms. Yet, <i>ex vivo</i> studies reported that HDACis have variable efficacy for reactivating latent proviruses, and hinder immune functions. We developed a nonhuman primate model of post-treatment control of SIV through early and prolonged administration of ART and performed <i>in vivo</i> reactivation experiments in controller RMs, evaluating the ability of the HDACi romidepsin (RMD) to reactivate SIV and the impact of RMD treatment on SIV-specific T cell responses. Ten RMs were IV-infected with a SIVsmmFTq transmitted-founder infectious molecular clone. Four RMs received conventional ART for >9 months, starting from 65 days post-infection. SIVsmmFTq plasma viremia was robustly controlled to <10 SIV RNA copies/mL with ART, without viral blips. At ART cessation, initial rebound viremia to ~10⁶ copies/mL was followed by a decline to < 10 copies/mL, suggesting effective immune control. Three post-treatment controller RMs received three doses of RMD every 35–50 days, followed by <i>in vivo</i> experimental depletion of CD8⁺ cells using monoclonal antibody M-T807R1. RMD was well-tolerated and resulted in a rapid and massive surge in T cell activation, as well as significant virus rebounds (~10⁴ copies/ml) peaking at 5–12 days post-treatment. CD8⁺ cell depletion resulted in a more robust viral rebound (10⁷ copies/ml) that was controlled upon CD8⁺ T cell recovery. Our results show that RMD can reactivate SIV <i>in vivo</i> in the setting of post-ART viral control. Comparison of the patterns of virus rebound after RMD administration and CD8⁺ cell depletion suggested that RMD impact on T cells is only transient and does not irreversibly alter the ability of SIV-specific T cells to control the reactivated virus.</p></div

SIVsmmFTq reactivation after RMD administration in post-treatment controller RMs, as monitored by measuring the levels of PVLs and total CD4⁺ memory T cell-associated vDNA.

<p>(a) PVLs were measured using SCA, with a LOD of 1 copy/ml. Due to limitations in sample availability, the actual sensitivity of the SCA was of 5–10 copies (illustrated as a dashed line at 10 copies/ml). For comparison, the dynamics of PVLs at the cessation of ART are shown in shadow. (b) Total vDNA levels measured in memory CD4⁺ T cells from circulation. Times of the RMD administration are indicated with black arrows.</p

RMD administration does not significantly impact Env SIV-specific T cell responses or functionality in SIVsmmFTq post-treatment controller RM178.

<p>Serial monitoring of SIV-specific T cell polyfunctionality after two rounds of RMD administration was achieved by stimulating PBMCs with Env SIVmac239 peptide pools followed by intracellular cytokine staining. Cytokines tested include: TNF-α (T); IL-2 (2); IFN-γ (I); CD107α (7); and MIP-1β (M). Data are representative of all RMs. Absolute numbers of CD4⁺/CD8⁺ T cells/ml for each timepoint are presented beneath their respective pie graph. The pie charts depict functionality based on the combination of cytokines expressed, as illustrated in figure legends. The color scheme represents the number of cytokines that were produced by the SIV-specific T cells (listed as numbers in the figure legends) and the proportion of each is illustrated as a color-coded ring surrounding each pie chart to facilitate assessment of polyfunctionality.</p

Experimental ablation of CTL responses through experimental CD8⁺ cell depletion (with the M-T807R1 anti-CD8 monoclonal antibody) result in patterns of viral rebound and immune activation that are different from those observed after RMD administration.

<p>Changes in the levels of (a) CD8⁺ T cells; (b) PVLs; (c) CD4⁺ T cells; and (d) CD4⁺ T cell proliferation (Ki-67) after administration of the M-T807R1 monoclonal antibody. Times of M-T07R1 administration are depicted as a red arrow.</p

Study design.

<p>The timeline of the study indicates the days in which SIVsmmFTq infection was performed, ART was initiated, RMD was administered, as well as the experimental time point of the CD8⁺ cell depletion with M-T807R1 mAb. Sampling time points are not shown, as only blood was collected in this study and the time points of blood collection are too numerous to be shown. Please refer to the method section for information regarding the sampling schedule.</p

RMD administration does not significantly impact Gag SIV-specific T cell responses or functionality in SIVsmmFTq post-treatment controller RM178.

<p>Serial monitoring of SIV-specific T cell polyfunctionality after two rounds of RMD administration was achieved by stimulating PBMCs with Gag SIVmac239 peptide pools followed by intracellular cytokine staining. Cytokines tested include: TNF-α (T); IL-2 (2); IFN-γ (I); CD107α (7); and MIP-1β (M). Data are representative of all RMs. Absolute numbers of CD4⁺/CD8⁺ T cells/ml for each timepoint are presented beneath their respective pie graph. The pie charts depict functionality based on the combination of cytokines expressed, as illustrated in Fig legends. The color scheme represents the number of cytokines that were produced by the SIV-specific T cells (listed as numbers in the Fig legends) and the proportion of each is illustrated as a color-coded ring surrounding each pie chart to facilitate assessment of polyfunctionality.</p

Romidepsin increases the levels of acetylated histones in RMs.

<p>The levels of acetylated histones have been measured by flow cytometry prior to RMD administration, and at 4 hrs, 6 hrs, 2 days and 5 days after RMD administration. Testing was performed after the first, the second and the third RMD administration. Only the results from RM135 were shown, but data were representative for all animals receiving RMD.</p

Effect of RMD administration on the peripheral blood major T cell subsets.

<p>(a) The levels of the total lymphocyte population (as measured by the Trucount assay) dramatically, but transiently, decrease after each round of RMD administration, resulting in similarly dramatic decreases of both CD4⁺ T cell (b) and CD8⁺ T cell (c) counts. (d) Comparative analysis of the CD3⁺ and CD3^neg populations showed that the reduction in the CD3⁺ T cell counts was mirrored by a dramatic surge in the population of CD3^neg lymphocytes, suggesting the significant reduction in the lymphocyte counts were due to a downregulation of surface markers rather than a real depletion of cells. ART administration is highlighted as a light orange box in the graphs. Time of the RMD administration is illustrated with black arrows.</p

Rifaximin (RFX) + sulfasalazine (SFZ) therapy impacts the levels of inflammation during acute and early chronic SIVsab infection of pigtailed macaques (PTMs).

<p>Levels of proinflammatory cytokines were consistently lower in SIVsab-infected PTMs receiving RFX+SFZ (red) compared to untreated controls (black): (a) TNF-α; (b) I-TAC; and (c) C-reactive protein (CRP). Shown are the average values for each group and standard error of means.</p