Background:
Immune reconstitution via adoptive transfer of pathogen specific T-cells (PSTs) can control viral infection in immune suppressed patients. We have developed a GMP compliant method for manufacture of enriched PST cell products for important opportunistic infections.
Method:
HPC-A samples from healthy donors were stimulated with peptide pools of proteins from cytomegalovirus (CMV), Epstein-Barr virus (EBV), adenovirus (AdV) and aspergillus fumigatus (AF) resulting in activation-induced surface expression of CD137. Positive selection of CD137+ cells was performed 16-24 hours post antigen stimulation. These were combined with irradiated CD137neg cells as feeder cells in a G-Rex®-6 device in media supplemented with cytokines IL-2, -7 and -15. Cultures were incubated for a total of 11 days.
Results:
47 T-cell products were generated specific for CMV (12), EBV (20), AdV (5) and multi-pathogen (CMV, EBV and AF; n=10). Product characteristics are summarised in Table 1.
Antigen specific responses (measured by CD107a/b mobilisation and IFN-γ/TNF-α secretion) are shown in Table 2. HLA restricted responses were present in 11/12 CMV-, 20/20 EBV- and 5/5 AdV-specific products. CMV responses were confirmed using tetramers for HLA-A*02:01 (mean 65.6%), A*24:02 (7.7%), B*07:02 (21.3%) and B*35:01 (5.4%).
Conclusion:
We generated a cell bank of CMV, EBV, AdV and multi-pathogen-specific T-cells, using a rapid manufacturing protocol that resulted in highly enriched T-cell products. Products from the cell bank are being utilised in several clinical trials of adoptive immunotherapy.