BackgroundThe outcome of untreated HIV-1 infection is progression to AIDS and death in nearly all cases. Some important exceptions are the small number of patients infected with HIV-1 deleted for the accessory gene, nef. With these infections, disease progression is entirely suppressed or greatly delayed. Whether Nef is critical for high levels of replication or is directly cytotoxic remains controversial. The major problem in determining the role of Nef in HIV/AIDS has been the lack of tractable in vivo models where Nef’s complex pathogenic phenotype can be recapitulated.ResultsIntravenous inoculation (3000 to 600,000 TCIU) of BLT humanized mice with HIV-1LAI reproducibly establishes a systemic infection. HIV-1LAI (LAI) replicates to high levels (peak viral load in blood 8,200,000 ± 1,800,000 copies of viral RNA/ml, range 3,600,000 to 20,400,000; n = 9) and exhaustively depletes CD4+ T cells in blood and tissues. CD4+CD8+ thymocytes were also efficiently depleted but CD4+CD8- thymocytes were partially resistant to cell killing by LAI. Infection with a nef-deleted LAI (LAINefdd) gave lower peak viral loads (1,220,000 ± 330,000, range 27,000 to 4,240,000; n = 17). For fourteen of seventeen LAINefdd-infected mice, there was little to no loss of either CD4+ T cells or thymocytes. Both LAI- and LAINefdd-infected mice had about 8% of total peripheral blood CD8+ T cells that were CD38+HLA-DR+ compared <1% for uninfected mice. Three exceptional LAINefdd-infected mice that lost CD4+ T cells received 600,000 TCIU. All three exhibited peak viral loads over 3,000,000 copies of LAINefdd RNA/ml. Over an extended time course, substantial systemic CD4+ T cell loss was observed for the three mice, but there was no loss of CD4+CD8+ or CD4+CD8- thymocytes.ConclusionWe conclude Nef is necessary for elevated viral replication and as a result indirectly contributes to CD4+ T cell killing. Further, Nef was not necessary for the activation of peripheral blood CD8+ T cells following infection. However, CD4+CD8+ thymocyte killing was dependent on Nef even in cases of elevated LAINefdd replication and T cell loss. This depletion of thymic T cell precursors may be a significant factor in the elevated pathogenicity of CXCR4 trophic HIV-1.

Nonalcoholic steatohepatitis, a chronic liver disease without an approved therapy, is associated with lipotoxicity and insulin resistance and is a major cause of cirrhosis and hepatocellular carcinoma.Aramchol, a partial inhibitor of hepatic stearoyl-CoA desaturase (SCD1) improved steatohepatitis and fibrosis in rodents and reduced steatosis in an early clinical trial. ARREST, a 52-week, doubleblind, placebo-controlled, phase 2b trial randomized 247 non-alcoholic steatohepatitis (NASH) patients (101, 98, 48 in aramchol 400mg, 600mg, placebo, respectively; NCT 02279524). The primary endpoint was a decrease in hepatic triglycerides by magnetic resonance spectroscopy at 52 weeks with a dose of 600 mg of aramchol. Key secondary endpoints included liver histology and ALT. Aramchol 600 mg produced a placebo-corrected decrease in liver triglycerides without meeting the prespecified significance (-3.1, 95%CI -6.4 to 0.2, p=0.06), precluding further formal statistical analysis. NASH resolution without worsening fibrosis was achieved in 16.7% (13/78) of aramchol 600 mg versus 5% (2/40) of the placebo arm (OR=4.74, 95% CI:0.1-22.7) and fibrosis improvement Vlad Ratziu, Study Design, Patient Recruitment and Treatment, Data Analyses and Interpretation, member of study advisory committee, Manuscript Writing

Natural products have been used in medicine for many years. Many top-selling pharmaceuticals are natural compounds or their derivatives. These plant- or microorganism-derived compounds have shown potential as therapeutic agents against cancer, microbial infection, inflammation, and other disease conditions. However, their success in clinical trials has been less impressive, partly due to the compounds’ low bioavailability. The incorporation of nanoparticles into a delivery system for natural products would be a major advance in the efforts to increase their therapeutic effects. Recently, advances have been made showing that nanoparticles can significantly increase the bioavailability of natural products both in vitro and in vivo. Nanotechnology has demonstrated its capability to manipulate particles in order to target specific areas of the body and control the release of drugs. Although there are many benefits to applying nanotechnology for better delivery of natural products, it is not without issues. Drug targeting remains a challenge and potential nanoparticle toxicity needs to be further investigated, especially if these systems are to be used to treat chronic human diseases. This review aims to summarize recent progress in several key areas relevant to natural products in nanoparticle delivery systems for biomedical applications.

BackgroundThe HIV-1 accessory protein, Nef, is decisive for progression to AIDS. In vitro characterization of the protein has described many Nef activities of unknown in vivo significance including CD4 downregulation and a number of activities that depend on Nef interacting with host SH3 domain proteins. Here, we use the BLT humanized mouse model of HIV-1 infection to assess their impact on viral replication and pathogenesis and the selection pressure to restore these activities using enforced in vivo evolution.ResultsWe followed the evolution of HIV-1LAI (LAI) with a frame-shifted nef (LAINeffs) during infection of BLT mice. LAINeffs was rapidly replaced in blood by virus with short deletions in nef that restored the open reading frame (LAINeffs∆-1 and LAINeffs∆-13). Subsequently, LAINeffs∆-1 was often replaced by wild type LAI. Unexpectedly, LAINeffs∆-1 and LAINeffs∆-13 Nefs were specifically defective for CD4 downregulation activity. Viruses with these mutant nefs were used to infect BLT mice. LAINeffs∆-1 and LAINeffs∆-13 exhibited three-fold reduced viral replication (compared to LAI) and a 50% reduction of systemic CD4+ T cells (>90% for LAI) demonstrating the importance of CD4 downregulation. These results also demonstrate that functions other than CD4 downregulation enhanced viral replication and pathogenesis of LAINeffs∆-1 and LAINeffs∆-13 compared to LAINeffs. To gain insight into the nature of these activities, we constructed the double mutant P72A/P75A. Multiple Nef activities can be negated by mutating the SH3 domain binding site (P72Q73V74P75L76R77) to P72A/P75A and this mutation does not affect CD4 downregulation. Virus with nef mutated to P72A/P75A closely resembled the wild-type virus in vivo as viral replication and pathogenesis was not significantly altered. Unlike LAINeffs described above, the P72A/P75A mutation had a very weak tendency to revert to wild type sequence.ConclusionsThe in vivo phenotype of Nef is significantly dependent on CD4 downregulation but minimally on the numerous Nef activities that require an intact SH3 domain binding motif. These results suggest that CD4 downregulation plus one or more unknown Nef activities contribute to enhanced viral replication and pathogenesis and are suitable targets for anti-HIV therapy. Enforced evolution studies in BLT mice will greatly facilitate identification of these critical activities.

Background Post‐transplant diabetes mellitus (PTDM) is common after liver transplantation (LT). Yet, how PTDM relates to graft outcomes and survival needs elucidation as more individuals are transplanted for nonalcoholic fatty liver disease (NAFLD). Methods This single‐center, retrospective study of adult LT recipients (2003‐2016) identified PTDM incidence and associations with graft steatosis, rejection, and post‐LT patient survival. Multivariable analysis investigated predictors of PTDM. Kaplan‐Meier curves depicted patient survival 5 years post‐LT. Results Among 415 adult LT recipients, 23% had pre‐LT DM and 13% were transplanted for NAFLD. PTDM incidence was 34.7%, 46.9%, and 56.2% and overall survival was 90%, 80.9%, and 71.7% at 1, 3, and 5 years, respectively. Over a third of non‐NAFLD patients developed PTDM. Half of PTDM cases developed by 6 months and 75% by 12 months. The PTDM group had more rejection episodes compared to no PTDM (31.9% vs 21.8%, P = 0.055), with trends toward worse patient survival 5 years post‐LT (log‐rank test P = 0.254). Age was the only significant predictor of PTDM. Conclusions Post‐transplant diabetes mellitus occurs rapidly in the post‐LT period and is a significant problem for both NAFLD and non‐NAFLD LT recipients. Age is a significant risk factor for PTDM. Outcomes trended toward increased rejection and worse survival among PTDM individuals, suggesting the benefit of early strategies targeting glucose control.