Viral Manipulation of Neural Stem/Precursor Cells - Viral Vector Approaches in Neurobiology and Brain Diseases - page 258

Chapter 14

Viral Manipulation of Neural Stem/Precursor Cells

Nunzio Iraci, Giulia Elisabetta Tyzack, Chiara Cossetti,
Clara Alfaro-Cervello, and Stefano Pluchino

Abstract

Neural stem/precursor cells (NPCs) are defined according to their ability to self-renew and differentiate
into all the major cellular types of the central nervous system (CNS). They can survive and proliferate in
defined culture conditions as spherical aggregates (neurospheres) for a virtually indefinite number of pas-
sages, while remaining phenotypically and karyotypically stable. Besides classical stem cell-based approaches
for regenerative medicine, NPCs hold a great potential also as system for delivering secreted factors and/
or therapeutic genes in vivo, after transplantation. Solid evidence exist that NPCs survive transplantation
procedures within the host CNS, specifically migrate within the damaged tissue, and protect the nervous
system from inflammatory and other forms of damage. Viral vectors constitute a versatile tool for manipu-
lating and improving some of the NPC properties, including their migratory and differentiation capacities,
thus allowing a number of different possible applications. In this chapter, we have described some of the
methods for the preparation of NPCs, the production and titration of the lentiviral particles, and the
viral-mediated manipulation of NPCs, both ex vivo in organotypic slice cultures, as well as in vivo.

Key words Lentiviral vectors, Neural stem cells, Cell transplantation, Organotypic slice cultures,
Viral transduction, Animal models of neurological diseases

1 Introduction

Stem cells are defined as cells having the capacity to both self-renew
and differentiate into multiple cell types [ 1 , 2 ]. When this concept
is applied to the central nervous system (CNS), a neural stem cell is
a self-renewing progenitor/precursor that, at different develop-
mental stages, is able to differentiate into the tree main cell types
that constitute the brain: neurons, oligodendrocytes, and astro-
cytes [ 1 , 3 , 4 ]. Neural stem/precursor cells (NPCs) can be isolated
from both the developing and adult CNS, in rodents as well as in
humans [ 4 - 10 ]. In particular in the adult mammalian brain, new
neurons are generated primarily in the subventricular zone (SVZ)
of the lateral ventricles [ 11 ] and in the hippocampus, specifically in
the subgranular layer zone of the dentate gyrus (SGZ) [ 12 ]. NPCs
can survive and proliferate in vitro in defined culture conditions as