Vaccination med främmande vita blodkroppar som laddats med
tumörämnen förhindrar tillväxt av bröstcancerceller hos råttor
Vaccination with allogeneic monocyte-derived cells loaded with apoptotic tumor cells
elicits long-lasting protective immunity against breast cancer and significantly
suppresses tumor growth in a therapeutic setting
John Alder (1),Stefan Lange (2), Bengt Andersson (1), AnnaCarin Wallgren (3),Karin
Gustavsson (1), Eva Jennische (4), Luigi Pelletieri (5), Vincenzo d´Angelo (6), Peter S.
Eriksson (5), Alex Karlsson-Parra (1)
1 Avd för Klinisk Immunologi, Göteborgs Universitet. 2 Avd för Klinisk Bakteriologi, GU. 3
Avd för Endodonti, GU. 4 Avd för Anatomi och Cellbiologi, GU. 5 Avd för Neurovetenskap,
GU. 6 Ospedal Casa Sollievo, Italy.
Background: We have recently shown that addition of antigen-presenting cells (APCs) into
an allogeneic immune compartment in vitro elicits an inflammatory reaction (due to “direct”
allorecognition) that promotes maturation of bystander dendritic cells with T helper 1 (Th1)inducing capacity. This observation may explain the strong and Th1-deviated immunization
against “indirectly” presented alloantigens (derived from phagocytosed allogeneic cells) that
frequently occurs after organ transplantation despite continuous immunosuppressive therapy.
We hypothesized that all types of non-self antigens, including unique or shared tumor
antigens, within APCs will become targets of such strong and Th1-deviated immunity if
injected into an allogeneic recipient in vivo.
Material and methods: Fisher344 female rats were challenged subcutaneously (s.c.) with the
highly malignant tumor-cell line13762 MAT B III. This tumor line is poorly immunogenic in
syngeneic Fisher344 rats and successful prophylactic vaccinations with irradiated tumor cells,
with or without adjuvant such as BCG, have not been reported previously. The rats were
either vaccinated in a prophylactic (vaccine cells given s.c. 14 and 7 days before tumor
challenge) or therapeutic (vaccine cell given at the same day as the tumor cells and 7 days
after tumor challenge) setting. Vaccine cells consisted of peripheral monocytes from
allogeneic Sprague-Dawley rats cultivated for 2 days in culture media containing GM-CSF.
After 1 day the monocyte-derived cells were pulsed with apoptotic tumor cells with or
without addition of Vibrio cholerae neruraminidase (NAS), an enzyme known to enhance
alloreactivity in vitro.
Results: Four out of 5 (80%) non-vaccinated rats and 2 out of 5 (40%) rats given prophylactic
vaccinations with tumor-loaded allogneic vaccine cells developed subcutaneous tumors within
3 weeks. In rats given prophylactic vaccination with NAS-treated and tumor-loaded vaccine
cells only one out of 5 (20%) rats developed a tumor. This immunity was long-lasting since
challenge of tumor-rejecting rats with new tumor-cells 6 weeks later failed to induce any
tumor growth. In the therapeutic setting all rats developed tumors but tumor growth was
significantly reduced (p< 0,05) in rats given NAS-treated and tumor-loaded vaccine cells
compared to controls.
Conclusion: Our results indicate that NAS-treated allogeneic monocyte-derived cells may
act as antigen carrier as well as a potent adjuvant in cancer vaccination.
Framgångsrik framställning av vaccinceller mot cancer för kliniskt bruk
A preclinical protocol exploring mRNA-transfected allogeneic monocytes as a potential
cancer vaccine
Gustav Gaudenack (1), Li-Jun Mu (1), Stein Saeboe-Larsson (1), AnnaCarin Wallgren
(2), Bengt Andersson (2), Alex Karlsson-Parra (2), Gunnar Kvalheim (1)
1 Radiumhospitalet, Oslo, Norge. 2 Avd för Klinisk Immunologi, Göteborgs Universitet.
Background: We have recently shown that addition of human antigen-presenting cells into
an allogeneic compartment in vitro elicits an inflammatory reaction (due to “direct”
allorecognition) that promotes maturation of bystander dendritic cells with T helper 1 (Th1)inducing capacity. We have further shown that vaccination with tumor- pulsed and
neuraminidase-treated allogeneic monocytes in rats elicits long-lasting protective immunity
against breast cancer and significantly suppresses tumor growth in a therapeutic setting. The
aim of the present study was to develop a clinical grade protocol using human allogeneic
monocytes as a vehicle to deliver tumor antigens to dendritic cells (DCs) in vivo with the
rationale that activated allogneic monocytes would stimulate a potent alloagression when
injected into patients and subsequently be killed and taken up by resident DCs.
Methods: Enriched monocytes were obtained from leukapheresis products by Elutra. A
square wave electroporation procedure was employed to transfect fresh or frozen/thawed
monocytes with mRNA from fluorescent protein (EGFP) or telomerase (hTRET). After
transfection, cells were transferred to Teflon bags containing X-VIVO 20 medium
supplemented with GM-CSF. After culture for 24 h, cells were treated for 30 min with
neuraminidase from Vibrio Cholerae in order to enhance their allo-stimulatory capacity.
After washing the cells were frozen and stored at – 80°C until used. Electroporationefficiency was tested by flow cytometry with mRNA for EGFP, and by TRAP assay with
mRNA for hTERT. Immune responses were measured by an interferon-gamma ELISPOT
assay.
Results: Frozen/thawed monocytes gave a similar cell yield as fresh cells based on the initial
number of loaded cells. Electroporation was highly efficient with a telomerase activity
similar to that found in tumor cell lines with known high telomerase activity. Finally, priming
of peripheral blood mononuclear cells by neuraminidase-treated autologous or allogeneic
transfected monocytes and testing with transfected autologous monocytes generated a
significant T-cell response (interferon-gamma spots) specific for transfected mRNA.
Conclusion: Our results proved the basis for “on the shelf” cellular cancer vaccines made
from waste products of ordinary blood banking.
Obehandlade och behandlade tumörer
Brösttumörer uttagna från råttor som 12 dagar tidigare injicerats med tumörceller
(bröstcancer) under huden. Tumörerna till höger (5 st) kommer från råttor som dessutom
erhållit vaccinceller.
