Proteome profiling and vector yield optimization in a recombinant adeno-associated virus-producing yeast model.

Recent studies on recombinant adeno-associated viral (rAAV) vector production demonstrated the generation of infectious viral particles in Saccharomyces cerevisiae. Proof-of-concept results showed low vector yields that correlated with low AAV DNA encapsidation rates. In an attempt to understand the host cell response to rAAV production, we profiled proteomic changes throughout the fermentation process by mass spectrometry.

A rAAV2-producing yeast screening model to identify host proteins enhancing rAAV DNA replication and vector yield.

Recombinant adeno-associated viral vectors (rAAV) are promising therapies for genetic diseases. Although current platforms for recombinant vector production can generate drug material for pre-clinical and clinical studies, rAAV biomanufacturing will eventually face commercial supply challenges if per cell vector productivity and process scalability are not improved. Because considerable efforts have traditionally focused on optimizing rAAV plasmid design, herein we investigate the impact of host cell proteins on vector production to identify proteins that may enhance rAAV yield.

Molecular design for recombinant adeno-associated virus (rAAV) vector production.

Recombinant adeno-associated virus (rAAV) vectors are increasingly popular tools for gene therapy applications. Their non-pathogenic status, low inflammatory potential, availability of viral serotypes with different tissue tropisms, and prospective long-lasting gene expression are important attributes that make rAAVs safe and efficient therapeutic options. Over the last three decades, several groups have engineered recombinant AAV-producing platforms, yielding high titers of transducing vector particles.

Generation of infectious recombinant Adeno-associated virus in Saccharomyces cerevisiae.

The yeast Saccharomyces cerevisiae has been successfully employed to establish model systems for a number of viruses. Such model systems are powerful tools to study the virus biology and in particular for the identification and characterization of host factors playing a role in the viral infection cycle. Adeno-associated viruses (AAV) are heavily studied due to their use as gene delivery vectors.

Progress and prospects for stem cell engineering.

Stem cells offer tremendous biomedical potential owing to their abilities to self-renew and differentiate into cell types of multiple adult tissues. Researchers and engineers have increasingly developed novel discovery technologies, theoretical approaches, and cell culture systems to investigate microenvironmental cues and cellular signaling events that control stem cell fate. Many of these technologies facilitate high-throughput investigation of microenvironmental signals and the intracellular signaling networks and machinery processing those signals into cell fate decisions.

Nox2 redox signaling maintains essential cell populations in the brain.

Reactive oxygen species (ROS) are conventionally classified as toxic consequences of aerobic life, and the brain is particularly susceptible to ROS-induced oxidative stress and damage owing to its high energy and oxygen demands. NADPH oxidases (Nox) are a widespread source of brain ROS implicated in seizures, stroke and neurodegeneration. A physiological role for ROS generation in normal brain function has not been established, despite the fact that mice and humans lacking functional Nox proteins have cognitive deficits.

Akt increases sox2 expression in adult hippocampal neural progenitor cells, but increased sox2 does not promote proliferation.

Multiple extracellular factors have been shown to modulate adult hippocampal neural progenitor cell (NPC) proliferation and self-renewal, and we have previously shown that Akt is an important mediator of the effects of these extracellular factors on NPC proliferation and differentiation. However, very little work has investigated how and whether Akt is involved in maintaining the multipotency of these cells. Here we demonstrate that Akt promotes expression of Sox2, a core transcription factor important for the self-renewal of NPCs.

Viral packaging and transduction of adult hippocampal neural progenitors.

Genetic manipulation of adult hippocampal neural progenitor cells is a useful technique for exploring gene function through gain of function and loss of function mutations or RNAi. Furthermore, the introduction of new genes can "re-program" progenitor cell behavior to force a desired lineage in signaling environments that are not normally permissive for that cell fate. Additionally, by using a systems biology approach, neural progenitors can even be taught new behaviors and responses to signaling.

In vivo analysis of engrafted adult hippocampal neural progenitors.

A neural degenerative disease is characterized by the deterioration of neural tissue and subsequent loss of function. The in vivo engraftment of neural stem cells is a promising approach to the functional replacement of neural tissue with the ultimate goal of regaining lost function. In addition, by studying the behavior of engrafted neural stem cells in healthy and diseased tissue, insight can be gained into the extracellular and intracellular mechanisms which regulate stem cell behavior in vivo.

In vitro culture and analysis of adult hippocampal neural progenitors.

Adult hippocampal neural progenitor cell (AHNPC) culture is a useful technique for gaining insight into adult neurogenesis, studying disease, and high throughput drug screening. The ability of AHNPCs to proliferate and differentiate into the three cell lineages of the adult brain in cell culture provides the researcher a powerful platform to study the extracellular and intracellular regulatory mechanisms in a well-controlled environment. In this chapter, we describe some of the in vitro techniques necessary to study hippocampal progenitors in the adult rat.

Isolation of adult hippocampal neural progenitors.

Adult neurogenesis, or the creation of new neurons in adult organisms, is an exciting recent area of neurological research. The subgranular zone of the adult hippocampus is one area where hippocampal neural progenitors generate new neurons that functionally integrate into existing neuronal circuitry. Given the role that the hippocampus plays in learning and memory consolidation and its vulnerability to neurological diseases and conditions, such as Alzheimer's disease, understanding the mechanisms controlling the self-renewal and differentiation of neural progenitor cells is a critical first step in developing novel disease treatments.

Establishment of higher passage PER.C6 cells for adenovirus manufacture.

PER.C6 cells, an industrially relevant cell line for adenovirus manufacture, were extensively passaged in serum-free suspension cell culture to better adapt them to process conditions. The changes in cell physiology that occurred during this passaging were characterized by investigating cell growth, cell size, metabolism, and cultivation of replication-deficient adenovirus.

High-throughput screening of gene function in stem cells using clonal microarrays.

We describe a microarray-based approach for the high-throughput screening of gene function in stem cells and demonstrate the potential of this method by growing and isolating clonal populations of both adult and embryonic neural stem cells. Clonal microarrays are constructed by seeding a population of cells at clonal density on micropatterned surfaces generated using soft lithographic microfabrication techniques. Clones of interest can be isolated after assaying in parallel for various cellular processes and functions, including proliferation, signal transduction, and differentiation.

PI3K/Akt and CREB regulate adult neural hippocampal progenitor proliferation and differentiation.

The phosphoinositide 3-OH kinase (PI3K)/Akt pathway has been implicated in regulating several important cellular processes, including apoptosis, survival, proliferation, and metabolism. Using both pharmacological and genetic means, we demonstrate here that PI3K/Akt plays a crucial role in the proliferation of adult hippocampal neural progenitor cells. PI3K/Akt transduces intracellular signals from multiple mitogens, including basic fibroblast growth factor (FGF-2), Sonic hedgehog (Shh), and insulin-like growth factor 1 (IGF-1).

Large-scale propagation of a replication-defective adenovirus vector in stirred-tank bioreactor PER.C6 cell culture under sparging conditions.

Large-scale propagation of replication-defective adenovirus vectors has not been well studied to date. One of the challenges for efficient propagation at large scale is to overcome the sensitivity of virus infected cells to gas sparging required for oxygenation and CO(2) removal. In our initial experiments, it was observed that productivity of an adenovirus vector was significantly reduced under sparging conditions as compared to nonsparged, i.