Wtjmc. Hermens et al., TRANSIENT GENE-TRANSFER TO NEURONS AND GLIA - ANALYSIS OF ADENOVIRAL VECTOR PERFORMANCE IN THE CNS AND PNS, Journal of neuroscience methods, 71(1), 1997, pp. 85-98
In this paper a detailed protocol is presented for neuroscientists pla
nning to start work on first generation recombinant adenoviral vectors
as gene transfer agents for the nervous system. The performance of a
prototype adenoviral vector encoding the bacterial lacZ gene as a repo
rter was studied, following direct injection in several regions of the
central and peripheral nervous system. The distribution of the cells
expressing the transgene appears to be determined by natural anatomica
l boundaries and possibly by the degree of myelinization of a particul
ar brain region. In highly myelinated areas with a compact cellular st
ructure (e.g. the cortex and olfactory bulb) the spread of the viral v
ector is limited to the region close to the injection needle, while in
areas with a laminar structure (e.g. the hippocampus and the eye) mor
e widespread transgene expression is observed. Retrograde transport of
the viral vector may serve as an attractive alternative route of tran
sgene delivery. A time course of expression of P-galactosidase in neur
al cells in the facial nucleus revealed high expression during the fir
st week after AdLacZ injection. However, a significant decline in tran
sgene expression during the second and third week was observed. This m
ay be caused by an immune response against the transduced cells or by
silencing of the cytomegalovirus promoter used to drive transgene expr
ession. Taken together, the data underscore that for each application
of adenoviral vectors as gene transfer agents in the nervous system it
is important to examine vector spread in and infectability of the neu
ral structure that is subject to genetic modification.