Gene-Modified NK-92MI Cells Expressing A Chimeric CD16-BB-ζ Or CD64-BB-ζ Receptor Exhibit Enhanced Cancer-Killing Ability In Combination With Therapeutic Antibody

In order to investigate whether the high affinity FcγRI（CD64）gene modified NK-92MI cells（CD64-BB-ζNK-92MI）or the low affinity FcγRⅢa（CD16）gene modified NK-92MI cells（CD16-BB-ζNK-92MI）can improve the killing efficacy to the CD20+non-Hodgkin’s lymphoma cells in combination with rituximab（CD20 antibody）,comparing to the non-genetically modified NK-92MI cells.First,CD16-BB-ζand CD64-BB-ζfragment were constructed by PCR method and gene synthesis,then the CD16-BB-ζand CD64-BB-ζfragment were cloned into a new generation of lentiviral vector.After recombinant lentiviruses were prepared,NK-92MI cells were transduced by CD16-BB-ζor CD64-BB-ζlentivirus.The expression of NK-92MI^hCD16 and NK-92MI^hCD64was determined by flow cytometry.The stable cell lines NK-92MI^hCD16 and NK-92MI^hCD64were sorting by flow cytometry.Finally,cytotoxicity assay was performed to examine NK-92MI^hCD16 and NK-92MI^hCD64 cells to non-Hodgkin’s lymphoma cells in combination with rituximab.There was no enhanced cytotoxicity observed in the presence of rituximab in NK-92MI cells,while the NK-92MI^hCD16 and NK-92MI^hCD64 cells were capable of exerting enhanced cytotoxicity against rituximab-opsonized MAVER-1 cells and Raji cells.In contrast,NK-92MI^hCD16 and NK-92MI^hCD64 cells could not exert enhanced cytotoxicity against CD138 antibody-opsonized MAVER-1 cells.These results suggest that the chimeric receptor-expressing NK-92MI cells may enhance the clinical responses to currently available anticancer monoclonal antibodies.