INVESTIGADORES
PUNTEL Mariana
congresos y reuniones científicas
Título:
High-Capacity Adenovirus Vector -mediated transfer of conditional cytotoxic (herpes simplex type 1-thymidine kinase [HSV1-TK] and immunostimulatory (Fms-like tyrosine kinase 3 ligand [Flt3L] transgenes elicits immune-mediated long-term survival in a synge
Autor/es:
PUNTEL; MUHAMMAD; KROEGER; CANDOLFI; YAGIZ; LIU; SALEM; BAKER; KAUR; KENNEDY; XIONG; LACAYO; PECHNICK; PALMER; NG; LOWENSTEIN; CASTRO
Lugar:
Buenos Aires
Reunión:
Simposio; II Simposio Franco-Argentino de Neurociencias; 2012
Institución organizadora:
SOCIEDAD ARGENTINA DE INVESTIGACION EN NEUROCIENCIAS
Resumen:
Glioblastoma multiforme (GBM) is a
malignant primary brain tumor associated with 5% survival at 5 years
post-diagnosis. Adenoviral (Ad)-mediated transfer of conditional cytotoxic,
HSV1-TK and immunostimulatory Flt3L transgenes elicited immune-mediated
long-term survival in a syngeneic intracranial GBM model in rodents. Helper
dependent, high-capacity Ad vectors (HC-Ads) have a significantly favorable
immunological profile due to the lack of Ad encoding sequences. Even in the
presence of a preexisting systemic anti-Ad immune response, transgene
expression from HC-Ads remains stable for up to 1 year.
In order to test efficacy, transgene
expression, distribution of vector genomes, and potential toxicity of the high
capacity vectors for the treatment of GBM we performed intratumoral delivery of
the combined therapy using HC-Ad-TK and HC-Ad-TetON-Flt3L co-administered with
gancyclovir and doxicycline. Three doses of the HC-Ads were administered intra-tumorally
and analyzed at 5 days, 30 days and 6 months after injection. Neuropathology
studies were conducted by immunocytochemistry of brain sections; distribution
of HC-Ads genomes were analyzed by qPCR as genome copy numbers within 13
different tissues including brain injection side and contra-lateral side,
spleen, and liver; FLt3L expression in brain tissue and plasma. Approximately
70% of the rats treated survived for long term when treated with the combined
therapy. At 5 days after treatment Flt3L was detected in brain tissue and serum;
strong infiltration of immune cells into the tumor mass was observed; an
average of 7.4x105, 1x106, and 7.2 x106 total
vector genomes were detected for the doses 5x108, 1x109 and
5x109 vp, respectively; the vector genomes were exclusively restricted
to the brain injection side for all the doses tested. At 30 days after
treatment, Flt3L was not detected in neither brain tissue nor serum; infiltration
of immune cells into the tumor mass was observed limited to the scar region
within the striatum; vector genomes were not detected at the doses tested.
Also, no toxic effects were found as
consequence of the treatment. Our data indicate that the combined administration
of HC-Ad vectors encoding TK and Flt3L was efficacious and safe for the
treatment of glioma in a syngeneic, intracranial rodent model. These results
will form the basis for further developments towards the implementation of HC-Ad
mediated combined gene therapy for the treatment of GBM in human patients.