Restriction of HIV-1 Replication in Monocytes Is Abolished by Vpx of SIVsmmPBj

Background: Human primary monocytes are refractory to infection with the human immunodeficiency virus 1 (HIV-1) or transduction with HIV-1-derived vectors. In contrast, efficient single round transduction of monocytes is mediated by vectors derived from simian immunodeficiency virus of sooty mangabeys (SIVsmmPBj), depending on the presence of the viral accessory protein Vpx. Methods and Findings: Here we analyzed whether Vpx of SIVsmmPBj is sufficient for transduction of primary monocytes by HIV-1-derived vectors. To enable incorporation of PBj Vpx into HIV-1 vector particles, a HA-Vpr/Vpx fusion protein was generated. Supplementation of HIV-1 vector particles with this fusion protein was not sufficient to facilitate transduction of human monocytes. However, monocyte transduction with HIV-1-derived vectors was significantly enhanced after delivery of Vpx proteins by virus-like particles (VLPs) derived from SIVsmmPBj. Moreover, pre-incubation with Vpx-containing VLPs restored replication capacity of infectious HIV-1 in human monocytes. In monocytes of non-human primates, single-round transduction with HIV-1 vectors was enabled. Conclusion: Vpx enhances transduction of primary human and even non-human monocytes with HIV-1-derived vectors, only if delivered in the background of SIVsmmPBj-derived virus-like particles. Thus, for accurate Vpx function the presence of SIVsmmPBj capsid proteins might be required. Vpx is essential to overcome a block of early infection steps in primary monocytes

Purification of adenovirus and adeno-associated virus: comparison of novel membrane-based technology to conventional techniques

Adenovirus (Ad) and Adeno-associated virus (AAV) are efficient gene delivery systems; manipulation of the wild-type genome allows their use as vectors for the overexpression of desirable transgenes. Generation and purification of such viral vectors can be labour intensive, costly and require specialized equipment, but a new generation of membrane-mediated ion exchange kits for purification of recombinant virus may facilitate this process. Here, we examine the yields, transgene expression and purity of preparations of Ad and AAV purified using commercially available kits in comparison to other established techniques for purification of recombinant viral vectors. We demonstrate comparable results for Ad and AAV respectively in all parameters investigated, with a substantial reduction in purification time for the kit-based technology. Such approaches are attractive methods for small-scale purification of recombinant Ad and AAV viral vectors

Epigallocatechin gallate (EGCG) decorating soybean seed ferritin as a rutin nanocarrier with prolonged release property in the gastrointestinal tract

Strappe, P ORCiD: 0000-0003-0100-0558The instability and low bioavailability of polyphenols limit their applications in food industries. In this study, epigallocatechin gallate (EGCG) and soybean seed ferritin deprived of iron (apoSSF) were fabricated as a combined double shell material to encapsulate rutin flavonoid molecules. Firstly, due to the reversible assembly characteristics of phytoferritin, rutin was successfully encapsulated within apoSSF to form a ferritin-rutin complex (FR) with an average molar ratio of 28.2: 1 (rutin/ferritin). The encapsulation efficiency and loading capacity of rutin were 18.80 and 2.98 %, respectively. EGCG was then bound to FR to form FR-EGCG composites (FRE), and the binding number of EGCG was 27.30 ± 0.68 with a binding constant K of (2.65 ± 0.11) × 10(4) M(-1). Furthermore, FRE exhibited improved rutin stability, and displayed prolonged release of rutin in simulated gastrointestinal tract fluid, which may be attributed to the external attachment of EGCG to the ferritin cage potentially reducing enzymolysis in GI fluid. In summary, this work demonstrates a novel nanocarrier for stabilization and sustained release of bioactive polyphenols.Associated Grant:National Nature Science Foundation of China (No. 31501489), Nature Science Foundation of Tianjin (youth program) (16JCQNJC14500), Nature Science Foundation of China (No. 31471701), and Tianjin Research Program of Application Foundation and Advanced Technology (15JCZDJC34300)

Responses of fecal bacterial communities to resistant starch intervention in diabetic rats

Strappe, P ORCiD: 0000-0003-0100-0558Recent studies have revealed that diabetes mellitus caused gut bacterial dysbiosis, and intervention studies aiming to selectively alter the composition and metabolism of the gut microbiota are crucial next steps for investigating the links between the microbiome and diabetes. The sequences encompassing V1–3 16S rDNA hypervariable regions were PCR amplified from rat fecal samples fed with resistant starch (RS). In total, 13 different phyla and 107 different genus were obtained with a 3% distance cut off. The microbiota profile of normal rats was significantly different from that of rats in diabetic control and RS intervention group. The most prominent phyla were Firmicutes and Bacteroidetes in the three groups. The proportion of Proteobacteria was significantly higher in the rats of diabetic control compared to normal group, and RS intervention could inhibit the proliferation of Proteobacteria phyla, including a wide variety of pathogenic species, such as Escherichia-Shige, Klebsiella, and Pseudomona. At genus level, Lactobacillus in the diabetic control was significantly lower than that in the normal group, whereas the feeding of RS increased the amount of Lactobacillus. More importantly, the consumption of RS reduced the composition of Ruminococcus and increased S24-7 norank comparing with the diabetic control. This study might indicate that RS is an effective food ingredient for manipulating the gut microbiota