Using [F-18]FBAU for imaging brain tumor progression in an F98/tk-luc glioma-bearing rat model
ONCOLOGY REPORTS
Authors: Chien, Yi-Chun; Chen, John Chun-Hao; Lin, Wei-Chan; Ding, Hueisch-Jy; Wang, Hsin-Ell; Kao, Chih-Hao K.; Hwang, Jeng-Jong
Abstract
1-(2-Deoxy-2-[F-18]fluoro-beta-D-arabinofuranosyl)-5-bromouracil ([F-18]FBAU), a substitute for thymine, has been reported as an effective reporter probe by which to trace cellular metabolism with its positron emission. In the present study, a rat xenograft model bearing F98 glioma transfected with dual reporter genes, herpes simplex virus type 1 thymidine kinase (HSV1-tk) and firefly luciferase (luc) was used for monitoring tumor progression by multimodalities of molecular imaging using [F-18]FBAU and D-luciferase as probes. Rat F98 glioma cells were transfected with the pC1-tk-IRES-luc vectors. The selected stable clone was renamed as the F98/tk-luc cell line. Fischer 344 male rats bearing orthotropic F98/tk-luc gliomas in the left brain were used. On day 13 post tumor inoculation, biodistribution, positron emission tomography (PET), magnetic resonance imaging (MRI) and ex vivo autoradiography were performed. The surviving fraction of F98/tk-luc cells treated with 15 mu M ganciclovir (GCV) was 15.9%, and the uptake of [I-131]FIAU in these cells was significantly enhanced when compared with F98 cells. The correlation coefficient of tumor volume vs. the bioluminescence in the F98/tk-luc glioma-bearing rats was 0.90. The biodistribution showed that the accumulation ratios of [F-18]FBAU for glioma-to-normal brain were 9.16, 14.24, 5.7 and 13.7 at 30, 60, 90 and 120 min post i.v. injection, respectively. Consistent tumor enhancement of [F-18]FBAU/PET imaging was also noted from 30-90 min post injection. Ex vivo autoradiography also confirmed significant [F-18]FBAU uptake in tumors. In conclusion, [F-18]FBAU may be used as a PET probe for monitoring glioma progression in animal models and may have potential for clinical use as well.
The Effect of Helicobacter hepaticus Infection on Immune Responses Specific to Herpes Simplex Virus Type 1 and Characteristics of Dendritic Cells
COMPARATIVE MEDICINE
Authors: Gulani, Jatinder; Norbury, Christopher C.; Bonneau, Robert H.; Beckwith, Catherine S.
Abstract
Infection of mice with Helicobacter hepaticus is common in research colonies, yet little is known about how this persistent infection affects immunologic research. The goal of this study was to determine whether H. hepaticus infection status can modulate immune responses specific to herpes simplex virus type 1 (HSV1) and the phenotypic and functional characteristics of dendritic cells (130 of mice. We compared virus-specific antibody and T cell-mediated responses in H. hepaticus-infected and noninfected mice that were inoculated intranasally with HSV1. The effect of H. hepaticus on the HSV1-specific antibody and T cell-mediated immune responses in superficial cervical and tracheobronchal lymph nodes (LN) did not reach statistical significance. Surface expression of the maturation-associated markers CD40, CD80, CD86, and MHC II and percentages of IL12p40- and TNF alpha-producing DC from spleen and colic LN in H. hepaticus-infected mice and noninfected mice were measured in separate experiments. Expression of CD40, CD86, and MHC II and percentages of IL12p40- and TNF alpha-producing DC from colic LN were decreased in H. hepaticus-infected mice. In contrast, H. hepaticus infection did not reduce the expression of these molecules by splenic DC. Expression of CD40, CD80, CD86, and MHC II on splenic DC from H. hepaticus-infected mice was increased after in vitro lipopolysaccharide stimulation. These results indicate that H. hepaticus infection can influence the results of immunologic assays in mice and support the use of H. hepaticus-free mice in immunologic research.