Abstract
INTRODUCTION
Findings describing the existence of cytomegalovirus (CMV) antigens in glioblastoma have been controversial since first report in 2002 by Cobbs et al. Since this first publication, there were many studies to confirm the detection of CMV in malignant gliomas using a variety of methods such as immunohistochemistry, PCR, in situ hybridization, and immunofluorescence assay under confocal microscope. For confirming the presence of CMV proteins, we undertook immunofluorescence (IF) staining of CMV pp65 and IE-1 antigens in human primary malignant gliomas. Also, we investigated CMV specific CTL response on our primary cultured cells using pp65 or IE-1 specific CTLs obtained from healthy donors.
RESULTS
First, we analyzed serum CMV immunoglobulin M and G index, and CMV DNA copy numbers using real-time(RT) PCR from 20 malignant glioma patients. All of patients showed positivity of IgG index and negativity of IgM and CMV DNA copy numbers. Second, we stained 15 primary malignant glioma cell lines using pp65 or IE-a specific antibody and the expression of CMV antigens were visualized by confocal fluorescence microscope. We found all positive results (15/15) in primary malignant gliomas, using fibroblast as a negative control and CMV-infected U87 as a positive control. Third, we generated pp65 or IE-1 specific CTLs using mRNA-pulsed dendritic cells from HLA partially matched heathy donors. Using theses CTLs, we revealed positive IFN-gamma ELISPOT assay results.
CONCLUSION
We demonstrated not only the presence of CMV proteins (pp65, IE-1) in malignant gliomas but also elucidated that CMV could be an immuno-therapeutic target for adoptive cellular therapy.