Incorporation of phosphatidylserine improves efficiency of lipid based gene delivery systems

The essential homeostatic process of dead cell clearance (efferocytosis) is used by viruses in an act of apoptotic mimicry. Among others, virions leverage phosphatidylserine (PS) as an essential "eat me" signal in viral envelopes to increase their infectivity. In a virus-inspired biomimetic approach, we demonstrate that PS can be incorporated into non-viral lipid nanoparticle (LNP) pDNA/mRNA constructs to enhance cellular transfection. The inclusion of the bioactive PS leads to an increased ability of LNPs to deliver nucleic acids in vitro to cultured HuH-7 hepatocellular carcinoma cells resulting in a 6-fold enhanced expression of a transgene. Optimal PS concentrations are in the range of 2.5 to 5% of total lipids. PS-decorated mRNA-LNPs show a 5.2-fold enhancement of in vivo transfection efficiency as compared to mRNA-LNPs devoid of PS. Effects were less pronounced for PS-decorated pDNA-LNPs (3.2-fold increase). Incorporation of small, defined amounts of PS into gene delivery vectors opens new avenues for efficient gene therapy and can be easily extended to other therapeutic systems

Zebrafish Larvae as an; in vivo; Model for Antimicrobial Activity Tests against Intracellular; Salmonella;

Blood infections from multi-drug-resistant; Salmonella; pose a major health burden. This is especially true because; Salmonella; can survive and replicate intracellularly, and the development of new treatment strategies is dependent on expensive and time-consuming; in vivo; trials. The aim of this study was to develop a; Salmonella; -infection model that makes it possible to directly observe; Salmonella; infections of macrophages; in vivo; and to use this model to test the effect of antimicrobials against intra- and extracellular; Salmonella; in order to close the gap between; in vitro; and rodent-infection models.; We established suitable; Salmonella; -infection conditions using genetically engineered zebrafish and; Salmonella; -expressing fluorescent proteins (; green fluorescent protein; (; GFP; ) and/or; mCherry; ).; We detected; Salmonella; inside and outside zebrafish larvae macrophages. Administration of the cell-impermeable antibiotic tobramycin removed; Salmonella; residing outside macrophages but did not affect; Salmonella; in macrophages, whereas ceftriaxone successfully cleared both types of; Salmonella; .; Salmonella; inside and outside macrophages experienced substantial DNA damage after administration of fluoroquinolones consistent with the excellent cell penetration of these antibiotics.; The zebrafish-larvae model enables testing of antimicrobials for efficacy against extra- and intracellular; Salmonella; in a complex; in vivo; environment. This model thus might serve for antimicrobial lead optimization prior to using rodent models

Genome-wide DNA profiling of marginal zone lymphomas identifies subtype-specific lesions with an impact on the clinical outcome

Marginal zone B-cell lymphomas (MZLs) have been divided into 3 distinct subtypes (extranodal MZLs of mucosa-associated lymphoid tissue [MALT] type, nodal MZLs, and splenic MZLs). Nevertheless, the relationship between the subtypes is still unclear. We performed a comprehensive analysis of genomic DNA copy number changes in a very large series of MZL cases with the aim of addressing this question. Samples from 218 MZL patients (25 nodal, 57 MALT, 134 splenic, and 2 not better specified MZLs) were analyzed with the Affymetrix Human Mapping 250K SNP arrays, and the data combined with matched gene expression in 33 of 218 cases. MALT lymphoma presented significantly more frequently gains at 3p, 6p, 18p, and del(6q23) (TNFAIP3/A20), whereas splenic MZLs was associated with del(7q31), del(8p). Nodal MZLs did not show statistically significant differences compared with MALT lymphoma while lacking the splenic MZLs-related 7q losses. Gains of 3q and 18q were common to all 3 subtypes. del(8p) was often present together with del(17p) (TP53). Although del(17p) did not determine a worse outcome and del(8p) was only of borderline significance, the presence of both deletions had a highly significant negative impact on the outcome of splenic MZLs