Some opportunistic infections, such as Cytomegalovirus (CMV), occur after hematopoietic stem-cell transplantation and are hard to treat in patients undergoing immunosuppressive therapy. A solution for this problem is the transfer of pathogen-specific allogeneic T cells after in vitro stimulation. Antigen-specific T cells are able to propagate in vitro when stimulated with antigen and theyrespond to the viral pathogen after transfer to the live host. This selective separation of viral antigen-specific T cells can also be done by isolation of cells that have been activated by the pathogen and are secreting interferon gamma. This approach is called cytokine capture system and has some problems associated. It involves a time-consuming, taking 10 to 12 hours, and complex protocol, which limits its application.
Now, a new approach has been developed that uses Magnetic Activated Cell Sorting as a tool to rapidly isolate T cells. This method relies on a second-generation cell enrichment device, CliniMACSProdigy, which allows the automated generation of clinical grade products from magnetically labeled cells. This protocol isolates CMV pp65-specific T cells from a donor with CMV infection. The separation process starts by removing erythrocytes by apheresis, and then stimulation of T cells followed by separation and purification of viral-specific T cells based on a cytokine capture system. The activation of T cells is done by incubation of total nuclear cells with peptides from CMV pp65 antigen displayed in HLA, which induces secretion of interferon gamma by CMV-specific T cells. All the steps are fully automated,which limits the operator hands on time to 2 hours, and the resulting cells can be transferred to the patient immediately. The obtained cells are combined with thehematopoietic stem-cell transplantation and provide immunity against opportunistic CMV infection, all in the same procedure.
The development of this new method is important for clinical applications not only in the case of CMV infection but also for other immunological based therapies. This work highlights the versatility of magnetic separation in the clinical practice.
Automated Cell Enrichment of Cytomegalovirus-specific T cells for Clinical Applications using the Cytokine-capture System. Kumaresan, P., Figliola, M., Moyes, J. S., Huls, M. H., Tewari, P., Shpall, E. J., … Cooper, L. J. N. (2015). Journal of Visualized Experiments : JoVE, (104). doi:10.3791/52808
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