Date of Award
Honors Bachelor of Arts
Dr. Susan Walsh
Dr. Jay Piecyznski
Dr. Paul Stephenson
Natural Killer (NK) cells are highly cytotoxic and specific towards certain types of cancer cells and are therefore a potential target for immunotherapy. In order to determine how NK cells acquire these traits, K562-mb15-41BBL cancer cells, specially modified leukemia cells designed to enhance NK cells for cancer eradication, were tagged with an Alexa Fluor 647 (A647) fluorescent dye and cultured with peripheral blood mononuclear cells (PBMCs) over a week. Non labeled K562-mb15-41BBL cells were used as a control. The co-incubation of PBMCs and K562s is intended to show which cells from the mixed PBMC culture interact directly with the cancer cells by way of A647 dye transfer. K562s can specify NK cells and increase cytotoxicity, but the using of whole K562 cell is inapplicable in a clinical setting. To test a new strategy, plasma membrane (PM) particles made from the K562-mb15-41BBL were labeled and cultured with PMBCs. Results were obtained by flow cytometry, utilizing specific antibodies CD56, CD14, and CD3 to identify labeled NK cells, natural killer-like T cells (NKT) and T cells. K562-mb15-41BBL cells labeled mostly (NKT) cells, with little expression of the A647 on pure NK cells, while PMs labeled NK cells and T cells at high rates, indicating that the first step of NK expansion involves direct contact with K562 cells. Further studies should be aimed at distinguishing the two culturing methods, to determine if the size of K562 cells inhibits the specification of NK cells and how to reduce T cell interaction with the K562-mb15-41BBL cells to allow for higher amounts of NK expansion. Determining how NK cells interact with K562-mb15-41BBL cells will allow for faster expansions of NK cells in the future, leading to improved and better treatments when this method of immunotherapy eventually moves to clinical trials.
Lindstrom, Ryan H., "NK cells expand and interact with K562-mb15-41BBL plasma membrane particles, but not with K562-mb15-41BBL cells" (2016). Honors Program Theses. 30.
Available for download on Wednesday, May 01, 2019