BioProject

Granulocyte-colony stimulating factor (G-CSF) is used to boost granulocyte counts in immunocompromised patients, but its effects on the immune system may be counter productive. More...

Granulocyte-colony stimulating factor (G-CSF) is used to boost granulocyte counts in immunocompromised patients, but its effects on the immune system may be counter productive. We tested the hypothesis that G-CSF mobilized peripheral blood stem cell (PBSC) products are immunologically down regulated based on gene microarray analysis. Ten peripheral blood samples from normal donors for allogeneic PBSC transplantation were obtained before and after administration of G-CSF and tested on Affymetrix Human U133 Plus 2.0 GeneChip® microarrays. Significant changes in gene expression after G-CSF mobilization were reported by controlling the false discovery rate at 5%. Immune-related genes were isolated from the data set and categorized according to probe set annotations and a thorough, independent literature search. We found that G-CSF up-regulated inflammatory and neutrophil activation pathway gene expression; however, adaptive immune-related gene expression, such as antigen presentation, co-stimulation, T cell activation and cytolytic effector pathways, were generally down-regulated. Thus, despite significant increases in stem cells, lymphocytes and antigen presenting cells, G-CSF mobilized PBSC allografts exhibit a suppressive adaptive immune-related gene expression profile. Our data provides an explanation for the potentially immunosuppressive effects observed after G-CSF administration. Keywords: PBSCT, G-CSF, microarray, gene expression Overall design: This study was approved by the University of Florida Institutional Review Board. Five healthy donors (A-E) for allogeneic PBSC transplantation consented and were mobilized with rHu G-CSF at 10µ/kg/day for five days. Approximately 4mL of venous blood was collected before (Pre-G-CSF) and after (Post-G-CSF) mobilization. Whole blood leukocyte RNA was purified from each sample and used to generate cRNAs which were subsequently hybridized onto Affymetrix Human U133 Plus 2.0 GeneChip® microarrays. Representative genes were successfully validated with quantitative RT-PCR. Less...