Adenovirus-mediated transfer of a gene encoding acyloxyacyl hydrolase (AOAH) into mice increases tissue and plasma AOAH activity

Although the host response to gram-negative bacterial infection follows largely from the interactions of bacterial lipopolysaccharides (LPS or endotoxin) with host cells, little information is available concerning the mechanisms by which the host eliminates or detoxifies LPS. Acyloxyacyl hydrolase (AOAH) is an enzyme, found in phagocytic cells, that catalyzes the enzymatic deacylation of the lipid A moiety of LPS. Enzymatically deacylated LPS is much less potent than LPS at inducing responses in human cells, and it can antagonize the ability of LPS to activate human macrophages, neutrophils, and endothelial cells. Despite these observations, the physiologic role of LPS deacylation remains undefined. To investigate the ability of AOAH to carry out LPS deacylation in vivo, we produced a recombinant adenovirus carrying a gene encoding AOAH (Ad.CMV-AOAH) and employed this vector to elicit transient overexpression of AOAH in mice. Mice infected with Ad.CMV-AOAH expressed high levels of the enzyme in plasma, liver, spleen, and kidney. Although adenovirus-induced hepatitis reduced hepatic uptake of intravenously injected [H-3]LPS, animals expressing the transgene deacylated a larger fraction of the [3H]LPS taken up by their livers than did mice infected with a control adenovirus. These studies indicate that AOAH can catalyze the deacylation of LPS in vivo, and they provide evidence that the rates of hepatic LPS uptake and deacylation are not closely linked

Atorvastatin induces associated reductions in platelet P-selectin, oxidized low-density lipoprotein, and interleukin-6 in patients with coronary artery diseases.

The development and progression of atherosclerosis comprises various processes, such as endothelial dysfunction, chronic inflammation, thrombus formation, and lipid profile modification. Statins are 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors that have pleiotropic effects in addition to cholesterol-lowering properties. However, the mechanisms of these effects are not completely understood. Here, we investigated whether atorvastatin affects the levels of malondialdehyde-modified low-density lipoprotein (MDALDL), an oxidized LDL, the proinflammatory cytokine interleukin-6 (IL-6), or platelet P-selectin, a marker of platelet activation, relative to that of LDL cholesterol (LDL-C). Forty-eight patients with coronary artery disease and hyperlipidemia were separated into two groups that were administered with (atorvastatin group) or without (control group) atorvastatin. The baseline MDA-LDL level in all participants significantly correlated with LDL-C (r = 0.71, P < 0.01) and apolipoprotein B levels (r = 0.66, P < 0.01). Atorvastatin (10 mg/day) significantly reduced the LDL-C level within 4 weeks and persisted for a further 8 weeks of administration. Atorvastatin also reduced the MDA-LDL level within 4 weeks and further reduced it over the next 8 weeks. Platelet P-selectin expression did not change until 4 weeks of administration and then significantly decreased at 12 weeks, whereas the IL-6 level was gradually, but not significantly, reduced at 12 weeks. In contrast, none of these parameters significantly changed in the control group within these time frames. The reduction (%) in IL-6 between 4 and 12 weeks after atorvastatin administration significantly correlated with that of MDALDL and of platelet P-selectin (r = 0.65, P < 0.05 and r = 0.70, P < 0.05, respectively). These results suggested that the positive effects of atorvastatin on the LDL-C oxidation, platelet activation and inflammation that are involved in atherosclerotic processes are exerted in concert after lowering LDL-C

Highly-parallelized simulation of a pixelated LArTPC on a GPU

The rapid development of general-purpose computing on graphics processing units (GPGPU) is allowing the implementation of highly-parallelized Monte Carlo simulation chains for particle physics experiments. This technique is particularly suitable for the simulation of a pixelated charge readout for time projection chambers, given the large number of channels that this technology employs. Here we present the first implementation of a full microphysical simulator of a liquid argon time projection chamber (LArTPC) equipped with light readout and pixelated charge readout, developed for the DUNE Near Detector. The software is implemented with an end-to-end set of GPU-optimized algorithms. The algorithms have been written in Python and translated into CUDA kernels using Numba, a just-in-time compiler for a subset of Python and NumPy instructions. The GPU implementation achieves a speed up of four orders of magnitude compared with the equivalent CPU version. The simulation of the current induced on 10^3 pixels takes around 1 ms on the GPU, compared with approximately 10 s on the CPU. The results of the simulation are compared against data from a pixel-readout LArTPC prototype

Endogenous regulation of a therapeutic transgene restores homeostasis in arthritic joints

The treatment of chronic inflammatory diseases is complicated by their unpredictable, relapsing clinical course. Here, we describe a new strategy in which an inflammation-regulated therapeutic transgene is introduced into the joints to prevent recurrence of arthritis. To this end, we designed a recombinant adenoviral vector containing a two-component, inflammation-inducible promoter controlling the expression of human IL-10 (hIL-10) cDNA. When tested in vitro, this system had a low-level basal activity and was activated four to five orders of magnitude by various inflammatory stimuli, including TNF-α, IL-1β, IL-6, and LPS. When introduced in joints of rats with recurrent streptococcal cell wall–induced arthritis, the IL-10 transgene was induced in parallel with disease recurrence and effectively prevented the influx of inflammatory cells and the associated swelling of the joints. Levels of inflammation-inducible hIL-10 protein within the joints correlated closely with the severity of recurrence. An endogenously regulated therapeutic transgene can thus establish negative feedback and restore homeostasis in vivo while minimizing host exposure to the recombinant drug

C3-Tat/HIV-regulated intraarticular human interleukin-1 receptor antagonist gene therapy results in efficient inhibition of collagen-induced arthritis superior to cytomegalovirus-regulated expression of the same transgene.

Item does not contain fulltextOBJECTIVE: To achieve disease-inducible expression of recombinant antiinflammatory proteins in order to allow autoregulation of drug dose by natural homeostatic mechanisms. METHODS: We compared the inducible 2-component expression system (C3-human immunodeficiency virus/transactivator of transcription [C3-Tat/HIV]) with the constitutive cytomegalovirus (CMV) promoter in the polyarticular collagen-induced arthritis (CIA) model in mice. DBA/1 mice were immunized with bovine type II collagen and were given boosters on day 21. On day 22, mice were injected intraarticularly with the adenoviral vectors AdCMVLuc, AdCMVhIL-1Ra, AdC3-Tat/HIV-Luc, or AdC3-Tat/HIV-hIL-1Ra. The injected knee joints and hind paws were then scored for signs of arthritis, and knee joint histology was compared. RESULTS: The CMV-driven interleukin-1 receptor antagonist (IL-1Ra) expression resulted in a high constitutive expression and amelioration of CIA. C3-Tat/HIV-driven IL-1Ra expression could be detected only on days 24, 29, and 35. Fourteen days after injection of the vectors, CIA was significantly better inhibited by the C3-Tat/HIV-driven IL-1Ra expression compared with the CMV-driven IL-1Ra expression. Moreover, prevention of CIA in the knee joints also prevented CIA in the untreated hind paws. CONCLUSION: Our data demonstrate for the first time the feasibility of an inducible expression system for local production of IL-1Ra for treatment of arthritis in the CIA model