Selection of CMV-specific CD8+ and CD4+ T cells by mini-EBV-transformed B cell lines

✍ Scribed by Martina Wiesner; Caroline Zentz; Markus H. Hammer; Mark Cobbold; Florian Kern; Hans-Jochem Kolb; Wolfgang Hammerschmidt; Reinhard Zeidler; Andreas Moosmann

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 423 KB
• Volume: 35
• Category: Article
• ISSN: 0014-2980
• DOI: 10.1002/eji.200425936

✦ Synopsis

Efficient protocols to generate cytomegalovirus (CMV)-specific T cells are required for adoptive immunotherapy. Recombinant Epstein-Barr virus (EBV) vectors called mini-EBV can be used to establish permanent B cell lines in a single step, which present the CMV antigen pp65 in a constitutive manner. These B cell lines, coined pp65 mini-LCL, were successfully used to reactivate and expand CMV-specific cytotoxic T cells. Here we evaluate this pp65 mini-EBV system in closer detail, focusing on (1) the quantification of T cells with specific effector function and (2) the identification of CMV-specific CD4 + helper T cells. The co-expansion of various functional CMV epitope specificities was demonstrated by IFN-c enzyme-linked immunospot assay (ELISPOT) assays and HLApeptide tetramer staining. Single-cell cloning resulted in both CD4 + and CD8 + T cell clones, the majority of which was CMV specific. Thus, mini-LCL present the pp65 antigen on HLA class I and II, mobilizing both arms of the T cell response. Using a peptide library covering the pp65 sequence for further analysis of T cell clones, we identified new pp65 CD8 + and CD4 + T cell epitopes.