Abstracts (complete list) - Wissenschaft Online

Andreas Jeron, Susanne Pfoertner, Tanja Toepfer, Jan Buer, Robert Geffers, Andres J
Schrader
Analysis of regulatory T cells in renal cell carcinoma
In many cancer diseases an increased frequency of peripheral CD4+CD25+ regulatory T
cells (Treg) could be observed correlated with poor prognosis of cancer patients.
Therefore we characterized human Treg cells from patients with renal cell carcinoma
(RCC), which is known to be an immunogenic tumor.
Using magnetic cell separation we isolated highly pure CD4+CD25+ Treg and naïve CD4
+CD25- T cells from the peripheral blood of 12 RCC patients and 11 healthy donors. In
FACS analyses we confirmed elevated levels of peripheral CD4+CD25+ Treg cells in RCC
patients. These cells were further analysed for expression profiles on the Human Treg
Chip, a self-developed customized oligonucleotide microarray representing 350 Treg
associated genes.
Significant differentially expressed genes between CD4+CD25+ and naïve CD4+CD25-
T cells were conducted to gene ontology resulting in a functional clusterization of the
corresponding genes. We observed association to apoptosis, cell cycle, proliferation,
signal transduction and regulation of transcription as well as to categories like
cytokines, chemokines and surface receptors. Combining gene regulation and the
functional background of the affected molecules we concluded that Treg cells derived
from RCC patients might be less responsive to apoptotic stimuli, which might promote
their accumulation in the periphery and hereby also tumor immune escape.
Further experiments will compare peripheral Treg cells to tumor surrounding Treg cells
to identify new targets explaining a potential crosstalk between tumor and Treg cell.