Standardized, Scalable, and Timely Flexible Adeno-Associated Virus Vector Production Using Frozen High-Density HEK-293 Cell Stocks and CELLdiscs.

Adeno-associated virus (AAV) vectors currently represent the most attractive platform for viral gene therapy and are also valuable research tools to study gene function or establish disease models. Consequently, many academic labs, core facilities, and biotech/pharma companies meanwhile produce AAVs for research and early clinical development. Whereas fast, universal protocols for vector purification (downstream processing) are available, AAV production using adherent HEK-293 cells still requires time-consuming passaging and extensive culture expansion before transfection. Moreover, most scalable culture platforms require special equipment or extensive method development. To tackle these limitations in upstream processing, this study evaluated frozen high-density cell stocks as a ready-to-seed source of producer cells, and further investigated the multilayered CELLdisc culture system for upscaling. The results demonstrate equal AAV productivity using frozen cell stock-derived cultures compared to conventionally cultured cells, as well as scalability using CELLdiscs. Thus, by directly seeding freshly thawed cells into CELLdiscs, AAV production can be easily upscaled and efficiently standardized to low-passage, high-viability cells in a timely flexible manner, potentially dismissing time-consuming routine cell culture work. In conjunction with a further optimized iodixanol protocol, this process enabled supply to a large-animal study with two high-yield AAV2 capsid variant batches (0.6-1.2 × 1015 vector genomes) in as little as 4 weeks.

In vitro anti-inflammatory and anticancer activities of extracts of Acalypha alopecuroidea (Euphorbiaceae).

More than 60% of conventional drugs are derived from natural compounds, some of the most effective pharmaceuticals (e.g. aspirin, quinine and various antibiotics) originate from plants or microbes, and large numbers of potentially valuable natural substances remain to be discovered. Plants with considerable medicinal potential include members of the genus Acalypha. Notably, extracts of A. platyphilla, A. fruticosa, A. siamensis, A. guatemalensis and A. wilkesiana have been recently shown to have antioxidant, antimicrobial and cytotoxic effects. In the study presented here we investigated the anti-inflammatory, anti-proliferative and pro-apoptotic activities of A. alopecuroidea, which is endemic in parts of Central America and is traditionally used by the Mopan- and Itza-Maya in the form of decoctions to treat skin conditions, and as a tea to treat stomach and urinary complaints. We demonstrate here that extracts of A. alopecuroidea can inhibit TNFalpha-induced E-selectin production, providing a mechanistic validation of its traditional use against inflammatory diseases. Furthermore, a fraction of A. alopecuroidea root extracts purified by solid phase extraction and separated by HPLC displayed strong cell cycle inhibitory activity by down-regulating and inactivating two proto-oncogenes (cyclin D1 and Cdc25A), and simultaneously inducing cyclin A, thereby disturbing orchestrated cell cycle arrest, and thus (presumably) triggering caspase 3-dependent apoptosis. The results of this study indicate that there are high prospects for purifying an active principle from A. alopecuroidea for further in vivo and preclinical studies.

In vitro anti-cancer activity of two ethno-pharmacological healing plants from Guatemala Pluchea odorata and Phlebodium decumanum.

Many traditional healing plants successfully passed several hundred years of empirical testing against specific diseases and thereby demonstrating that they are well tolerated in humans. Although quite a few ethno-pharmacological plants are applied against a variety of conditions there are still numerous plants that have not been cross-tested in diseases apart from the traditional applications. Herein we demonstrate the anti-neoplastic potential of two healing plants used by the Maya of the Guatemala/Belize area against severe inflammatory conditions such as neuritis, rheumatism, arthritis, coughs, bruises and tumours. Phlebodium decumanum and Pluchea odorata were collected, dried and freeze dried, and extracted with five solvents of increasing polarity. We tested HL-60 and MCF-7 cells, the inhibition of proliferation and the induction of cell death were investigated as hallmark endpoints to measure the efficiency of anti-cancer drugs. Western blot and FACS analyses elucidated the underlying mechanisms. While extracts of P. decumanum showed only moderate anti-cancer activity and were therefore not further analysed, particularly the dichloromethane extract of P. odorata inhibited the cell cycle in G2-M which correlated with the activation of checkpoint kinase 2, and down-regulation of Cdc25A and cyclin D1 as well as inactivation of Erk1/2. In HL-60 and MCF-7 cells this extract was a very strong inducer of cell death activating caspase-3 followed by PARP signature type cleavage. The initiating death trigger was likely the stabilization of microtubules monitored by the rapid acetylation of alpha-tubulin, which was even more pronounced than that triggered by taxol. The dichloromethane extract of P. odorata contains apolar constituents which inhibit inflammatory responses and exhibit anti-cancer activity. The strong proapoptotic potential warrants further bioassay-guided fractionation to discover and test the active principle(s).

Immature mouse dendritic cells enter inflamed tissue, a process that requires E- and P-selectin, but not P-selectin glycoprotein ligand 1.

Inflammatory processes are associated with the rapid migration of dendritic cells (DCs) to regional lymph nodes and depletion of these potent antigen-presenting cells (APCs) from the inflamed tissue. This study examined whether sites of cutaneous inflammation can be repopulated with DCs from a pool of immature DCs circulating in the blood. In adoptive transfer experiments with ex vivo-generated radioactively labeled primary bone marrow-derived DCs injected into mice challenged by an allergic contact dermatitis reaction, immature DCs were actively recruited from the blood to sites of cutaneous inflammation, whereas mature DCs were not. Immature, but not mature, DCs were able to adhere specifically to immobilized recombinant E- and P-selectin under static as well as under flow conditions. P-selectin-dependent adhesion of immature DCs correlates with their higher level of expression of the carbohydrate epitope cutaneous lymphocyte-associated antigen (CLA) and is blocked by a novel inhibitory antibody against mouse P-selectin glycoprotein ligand 1 (PSGL-1). Surprisingly, however, emigration of immature DCs into inflamed skin is retained in the presence of this anti-PSGL-1 antibody and is also normal when immature DCs are generated from fucosyltransferase (Fuc-T) Fuc-TVII-deficient mice. By contrast, emigration of wild-type immature DCs is reduced by adhesion-blocking anti-E- and P-selectin antibodies, and immature DCs generated ex vivo from Fuc-TVII/Fuc-TIV double-deficient mice emigrate poorly. Thus, fucosylated ligands of the endothelial selectins, determined in part by Fuc-TIV, and independent of PSGL-1, are required for extravasation of DCs into sites of cutaneous inflammation.