[In vivo migration and survival of donor-derived dendritic cell progenitors genetically modified using an adenoviral...

To investigate the migration and survival of B10 mouse bone marrow (BM)-derived DCs in C3H mice and if genetic modification of these DCs to overexpress TGF beta 1 may potentiate their tolerogenicity.

B10 mouse BM-derived DCs were propagated in GM-CSF and TGF beta(DC1), transduced DC1 with replication-deficient Ad vectors encoding genes for LacZ (DC2) or TGF beta 1(DC3). Cells of different groups were injected into one footpad of C3H mice. The mice were sacrificed on days 1, 2, 7, and 14, and spleens, thymuses, popliteal and mesenteric lymph nodes removed and stained with anti-IAb mAb. The incidences of B10 DC were determined by the mean number of IAb positive cells with dendriform morphology per low power field (x 100).

Transduction with Ad-LacZ or Ad-TGF beta 1 did not affect DC migration or distribution in C3H recipients, i.e. IAb+ cells were first observed under the capsule of popliteal LN (peak at d1), then migrated into the marginal T dependent area of spleens (peak at d7), and were found occasionally in the thymus. Transduction of Ad-LacZ reduced the numbers of IAb+ cells identified in both LN and spleens at all time points post injection, compared with injection of unmodified control DC, suggesting that Ad transduction itself can affect DC life span in allogeneic recipients. Overexpression of TGF beta 1 by transduction of Ad-TGF beta 1 not only fully reversed the reduction of DC numbers induced by Ad transduction, but also prolonged the life span of DC in spleen, as shown by the 2-fold increase in number of IAb+ cells in spleen at d14 compared with control DCs.

Mouse BM-derived TGF beta DCs can be transduced to express TGF beta 1 using an adenoviral vector, and exhibit the same migration characteristics as unmodified DC. The survival of TGF beta gene transduced DCs appears to be enhanced compared with unmodified or LacZ gene-transduced DCs.