Researchers have developed a streamlined technology for the enrichment and expansion of tumor-specific lymphocytes for adoptive immunotherapy.
Recent research on the immune system has provided an in-depth look at how cancer progresses and offers new ways to stop it. As a result, cancer immunotherapy has become one of the most promising new cancer treatment approaches. Adoptive immunotherapy uses T cell-based cytotoxic responses to attack cancer cells. Typically, T cells that have a natural or genetically engineered reactivity to a patient’s cancer are generated in vitro and then transferred back into the patient. Adoptive immunotherapy using naturally occurring tumor-reactive lymphocytes has been shown to achieve complete, long-lasting remissions, with few or no side effects.
One major challenge for an effective adoptive immunotherapy is the production of large numbers of lymphocytes that will selectively target antigens expressed on cancer cells and not on normal tissue. Recently, researchers at Johns Hopkins University reported a new method using nanoscale artificial antigen-presenting cells (nano-aAPCs) to enrich for tumor-specific T cells . Nano-aAPCs are paramagnetic nanoparticles containing a major histocompatibility complex (MHC)-peptide to bind and activate antigen-specific T cell receptors, and a costimulatory anti-CD28 antibody to promote T cell stimulation. When passed through a magnetic column, tumor-specific T cells will bind to the nano-aAPCs and stick to the sides of the column, while other cells will be washed through and discarded. The magnetic field of the column also activates the T cells to proliferate, so once they are washed off, they can be expanded in culture.
The authors found that their strategy resulted in greater than 1000-fold expansion of both mouse and human tumor-specific T cells in one week. Enrichment prior to expansion conferred a proliferation advantage during both in vitro culture and following in vivo adoptive transfer. Since the cells can be expanded quickly enough to be therapeutically useful, this novel approach could lead to the development of personalized cancer immunotherapy for patients.
HemaCare provides T cells for research purposes and looks forward to the translation of this novel approach into the clinic.
 Perica, K. et al. Enrichment and Expansion with Nanoscale Artificial Antigen Presenting Cells for Adoptive Immunotherapy. ACS nano 9, 6861-6871, doi:10.1021/acsnano.5b02829 (2015).