Received October 4, 2004
Revised October 20, 2004
Accepted after revision October 20, 2004
Differences in transductional tropism of adenoviral and
lentiviral vectors in the rat brainstem
Hanad Duale 1,
Sergey Kasparov 1,
Julian F.R. Paton 1,
Anja G Teschemacher 1*
1 University of Bristol
* To whom correspondence should be addressed. E-mail: anja.teschemacher{at}bristol.ac.uk.
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Abstract |
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Adenoviral vectors (AVV) and lentiviral vectors (LVV)
are highly useful research tools which can be used to
investigate the function of specific cell phenotypes in
the brain. The transductional tropism of viral vectors
has a critical impact upon the transgene expression in
different brain areas. This largely depends on the
properties of the viral particles, which for AVV are
most commonly analogous to the serotype 5 adenovirus
and, in the case of LVV, are determined by the envelope
used for pseudotyping, for example the vesicular
stomatitis virus coat (VSVG). We have created a matching
set of shuttle plasmids that allow a one-step transfer
of an entire expression cassette between the backbones
of AVV and LVV. This has permitted a fair assessment of
the impact of the vector type on tropism for both AVV
and LVV.
Thus, the aims of this study were twofold: (i) to
develop and demonstrate the validity of a
transgene "swap" system between AVV and LVV and, (ii)
using this system, to assess the tropism of AVV and LVV
for neuronal versus glial cell types. We have
constructed AVV and VSVG-coated LVV to express monomeric
red fluorescent protein (mRFP) driven by the human
cytomegalovirus promoter (hCMV). Transgene expression in
neurones and glia in the hypoglossal and dorsal vagal
motor nuclei of the rat brainstem was compared by
determining the co-localisation with immunostaining for
the neuronal marker NeuN (neuronal nuclear antigen) and
the glial marker GFAP (glial fibrillatory acidic
protein). We found that 55 % of mRFP-expressing cells
transduced with AVV were immunopositive for GFAP, while
only 38 % were NeuN-immunoreactive. In contrast, when
the same expression cassette was delivered by VSVG-
coated LVV, the neurone/glia ratio of mRFP expression
was reversed with 56 % of mRFP-positive cells identified
as neurones and 26 % as glia. Thus, the present study
provides compelling evidence that VSVG-coated LVV
significantly shift transgene expression towards
neurones while AVV transduction favours glia.
Key Words:
Brainstem, Fluorescence, Gene expression
