Introduction and Objectives
Determine ratio of myeloid and plasmocytoid dendritic cells (DC) in patient blood, compare expression of CD83 and costimulatory molecules CD80 and CD86 by DCs in tumor and blood, and determine the fraction of regulatory T-lymphocytes.
Material and Methods
We defined percentage of myeloid and plasmocytoid DCs in the whole blood of 26 patients using flow cytometer (FACS Aria). In order to distinguish DC populations we stained blood with CD45, HLA-DR, BD lineage, CD11c and CD123. After isolation of peripheral blood mononuclear cells or tumor infiltrating cells on Ficoll-Paque we determined the expression of CD83, CD80 a CD86 on myeloid DCs using flow cytometer. Regulatory T-lymphocytes were detected as the cell population expressing CD4, CD25, FoxP3.
Myeloid DCs comprise 0.29% and plasmocytoid DCs 0.14% of peripheral blood leukocytes. Expression of maturation marker CD83 and costimulatory molecule CD86 is significantly higher in tumors (CD83 – blood 9.565%, tumor 24.85% p = 0.015, CD86 – blood 3.7%, tumor 11.59% p = 0.015). Expression of CD80 is higher in tumors (1% × 0.31%), however, this difference is not significant (p = 0.14). Regulatory T-lymphocytes represent 5.8% of blood leukocytes, but their number rises to 14% in tumors (p = 0.0002).
The portion of myeloid and plasmocytoid dendritic cells in the peripheral blood corresponds to healthy population. We observed partial maturation of DCs in tumors, however, the presence of higher number of regulatory T-lymphocytes point to the possibility of the suppression of local immune response aimed at tumor cells. All these findings will contribute to the preparation of DC vaccination protocol for patients with renal cell carcinoma. Supported by Grant Agency of Charles University no.7753/2007.
© 2009 European Association of Urology. Published by Elsevier Inc. All rights reserved.