NK Cells with KIR2DS2 Immunogenotype Have a Functional Activation Advantage To Efficiently Kill Glioblastoma and Prolong Animal Survival

Abstract

Glioblastomas (GBMs) are lethal brain cancers that are resistant to current therapies. We investigated the cytotoxicity of human allogeneic NK cells against patient-derived GBM in vitro and in vivo, as well as mechanisms mediating their efficacy. We demonstrate that KIR2DS2 immunogenotype NK cells were more potent killers, notwithstanding the absence of inhibitory killer Ig–like receptor (KIR)-HLA ligand mismatch. FACS-sorted and enriched KIR2DS2+ NK cell subpopulations retained significantly high levels of CD69 and CD16 when in contact with GBM cells at a 1:1 ratio and highly expressed CD107a and secreted more soluble CD137 and granzyme A. In contrast, KIR2DS2− immunogenotype donor NK cells were less cytotoxic against GBM and K562, and, similar to FACS-sorted or gated KIR2DS2− NK cells, significantly diminished CD16, CD107a, granzyme A, and CD69 when in contact with GBM cells. Furthermore, NK cell–mediated GBM killing in vitro depended upon the expression of ligands for the activating receptor NKG2D and was partially abrogated by Ab blockade. Treatment of GBM xenografts in NOD/SCID mice with NK cells from a KIR2DS2+ donor lacking inhibitory KIR-HLA ligand mismatch significantly prolonged the median survival to 163 d compared with vehicle controls (log-rank test, p = 0.0001), in contrast to 117.5 d (log-rank test, p = 0.0005) for NK cells with several inhibitory KIR-HLA ligand mismatches but lacking KIR2DS2 genotype. Significantly more CD56+CD16+ NK cells from a KIR2DS2+ donor survived in nontumor-bearing brains 3 wk after infusion compared with KIR2DS2− NK cells, independent of their proliferative capacity. In conclusion, KIR2DS2 identifies potent alloreactive NK cells against GBM that are mediated by commensurate, but dominant, activating signals.

Resistance to cytotoxicity and sustained release of interleukin-6 and interleukin-8 in the presence of decreased interferon-γ after differentiation of glioblastoma by human natural killer cells

“…Considering that NK-differentiated tumors are highly susceptible to chemotherapy, whereas their stem-like tumors are highly resistant, the combination of NK cell immunotherapy and chemotherapy may be effective in the treatment of GBM patients [10, 51, 52]. The most troubling outcome of GBM to overcome when considering therapies is the ability to deplete cytotoxic NK cells due to their immunosuppressive effect.…”

A novel antibody combination to identify KIR2DS2high natural killer cells in KIR2DL3/L2/S2 heterozygous donors

“…In contrast, much less is known about the activating KIR, although they have been shown to play a significant role in viral infections and cancer . The activating KIR, KIR2DS2, is of particular interest given its protective role in bone marrow and cord blood transplantation for various hematological malignancies and in glioblastoma models in vivo . In addition, KIR2DS2 has recently been shown to directly recognise viral helicase peptides in the context of HLA‐C and to be protective against chronic hepatitis C virus infection .…”

Identification of a Natural Killer Cell Receptor Allele That Prolongs Survival of Cytomegalovirus-Positive Glioblastoma Patients

“…We have previously demonstrated that NK cells infiltrating patient glioblastoma tumors highly express activating receptor NKG2D (43) and that NK cells derived from aKIRs KIR2DS4 þ and KIR2DS2 þ donors were more potent against glioblastoma stem-like cells (44). Thus, the specific association of KIR2DS4 Ã 00101 with HLA-C1 in the context of CMV seropositivity in glioblastoma patients but not healthy controls has intriguing implications for immune response, although the mechanisms underlying their association remain unknown.…”

“…We previously demonstrated that NK cells infiltrating patient glioblastoma tumors highly express NKG2D (43) and that subsets derived from KIR2DS4 immunogenotype donors were more potent against glioblastoma stem-like cells (44). Therefore, we hypothesized that altered distribution of NK cells' KIR-HLA ligand interactions as a result of CMV infections may influence malignant progression of glioblastoma.…”