Anti-Tumor Activity of Expanded PBMC-Derived NK Cells by Feeder-Free Protocol in Ovarian Cancer

Abstract

Natural killer (NK) cells have shown great therapeutic potential against a wide range of cancers due to their pan-specific target recognition. Numerous reports indicate that NK cell immunotherapy is an effective therapeutic approach for treating hematological malignancies, but shows limited effects against solid tumors. In this study, several models of ovarian cancer (OC) were used to test the anti-cancer effects of NK cells derived from human peripheral blood mononuclear cells and expanded using a feeder cell-free expansion system (eNKs). The results show that eNKs exhibit potent inhibitory activity on tumor growth in different ovarian cancer xenograft mice (i.e., solid tumors, abdominal metastatic tumors, and ascites), importantly, in a dose-dependent manner. Moreover, adoptive transfer of eNKs resulted in significant reduction in ascites formation in OC peritoneal tumor models, and especially in reducing intraperitoneal ascites. We found that eNKs could migrate to the tumor site, retain their activity, and proliferate to maintain high cell counts in cutaneous xenograft mice. In addition, when increased the infusion with a high dose of 12 × 107 cells/mouse, Graft-versus-host disease could be induced by eNK. These data show that eNK cell immunotherapy could be a promising treatment strategy for ovarian cancers, including solid tumors and ascites.

Development of an antibody-ligand fusion protein scFvCD16A-sc4-1BBL in Komagataella phaffii with stimulatory activity for Natural Killer cells

“…Our previous studies demonstrated that ex vivo expanded PBMC-derived NK cells by the defined feeder-free protocol effectively reduced the tumor burden and ascites in a xenograft murine OC model [ 29 ]. scFvCD16A-sc4-1BBL can stimulated the activation and expansion of NK cells from PBMCs in vitro .…”

“…Adoptive transfer of NK cells can recognize and kill tumor cells without MHC restriction, so it may be a better option to drive NK cells to treat ovarian cancer [ 63 , 67 , 68 ]. Previous studies in our laboratory showed that the adoptive transfer of PBMC-derived NK cells expanded by a feeder-free protocol combined with rhIL-2 effectively inhibited the growth of ovarian tumors in mice [ 29 ]. Here, we utilized this model and illustrated that scFvCD16A-sc4-1BBL enhanced the anti-solid tumor effect of NK cells without observed toxicity.…”

“…The K562 (RRID:CVCL_0004) cell line was purchased from the Cell Bank of the Chinese Academy of Sciences (Shanghai, China). The Ho8910-Luc cell line was constructed and cryopreserved in our laboratory [ 29 ]. All cell lines were maintained in modified RPMI medium (HyClone, SH30809.01) supplemented with 10% FBS (Biological Industries, Beit HaEmek, Israel), 100 U/mL penicillin and 100 µg/mL streptomycin (Sangon Biotech, Shanghai, China) at 37 °C in a 5% CO 2 incubator.…”

“…Cells were washed three times and resuspended in RPMI 1640 medium containing 10% FBS. In Paraller, the expanded NK cells were collected and purified with anti-CD56 beads (Miltenyi), as desribed previously [ 29 ]. They were subsequently suspended in RPMI 1640 containing 10% FBS at the indicated density and incubated with K562 cells for 3.5 h at 37 ℃.…”

“…And many activation-related receptors, including 4-1BB (tumor necrosis factor (TNF) receptor superfamily 9, CD137), CD25, CD69, NKG2D, and IL-21R, are upregulated [21,[25][26][27][28]. Immobilized anti-CD16 antibodies have been used for PBMC-derived NK cell expansion and activation ex vivo [29,30]. Some immunotherapy strategies target tumor antigens as well as CD16A receptors to boost NK cell bioactivity, achieving favourable outcomes [31][32][33].…”