ABSTRACT
Human natural killer (NK) cell-based therapies are under assessment for treating various cancers, but cryopreservation reduces both the recovery and function of NK cells, thereby limiting their therapeutic feasibility. Using cryopreservation protocols optimized for T cells, here we find that ~75% of NK cells die within 24 h post-thaw, with the remaining cells displaying reduced cytotoxicity. Using CRISPR-Cas9 gene editing and confocal microscopy, we find that cryopreserved NK cells largely die via apoptosis initiated by leakage of granzyme B from cytotoxic vesicles. Pretreatment of NK cells with a combination of Interleukins-15 (IL-15) and IL-18 prior to cryopreservation improves NK cell recovery to ~90-100% and enables equal tumour control in a xenograft model of disseminated Raji cell lymphoma compared to non-cryopreserved NK cells. The mechanism of IL-15 and IL-18-induced protection incorporates two mechanisms: a transient reduction in intracellular granzyme B levels via degranulation, and the induction of antiapoptotic genes.
Subject(s)
Apoptosis , Cryopreservation , Granzymes , Interleukin-15 , Interleukin-18 , Killer Cells, Natural , Granzymes/metabolism , Interleukin-15/metabolism , Killer Cells, Natural/immunology , Killer Cells, Natural/metabolism , Humans , Interleukin-18/metabolism , Animals , Cryopreservation/methods , Mice , Cell Line, Tumor , CRISPR-Cas SystemsABSTRACT
As a strategy to improve the therapeutic success of chimeric antigen receptor T cells (CART) directed against solid tumors, we here test the combinatorial use of CART and IMSA101, a newly developed stimulator of interferon genes (STING) agonist. In two syngeneic tumor models, improved overall survival is observed when mice are treated with intratumorally administered IMSA101 in addition to intravenous CART infusion. Transcriptomic analyses of CART isolated from tumors show elevated T cell activation, as well as upregulated cytokine pathway signatures, in particular IL-18, in the combination treatment group. Also, higher levels of IL-18 in serum and tumor are detected with IMSA101 treatment. Consistent with this, the use of IL-18 receptor negative CART impair anti-tumor responses in mice receiving combination treatment. In summary, we find that IMSA101 enhances CART function which is facilitated through STING agonist-induced IL-18 secretion.
Subject(s)
Interleukin-18 , Membrane Proteins , Receptors, Chimeric Antigen , Animals , Interleukin-18/metabolism , Membrane Proteins/agonists , Membrane Proteins/metabolism , Membrane Proteins/genetics , Mice , Receptors, Chimeric Antigen/metabolism , Receptors, Chimeric Antigen/immunology , Humans , Cell Line, Tumor , Mice, Inbred C57BL , T-Lymphocytes/immunology , T-Lymphocytes/drug effects , T-Lymphocytes/metabolism , Lymphocyte Activation/drug effects , Immunotherapy, Adoptive/methods , Female , Neoplasms/immunology , Neoplasms/therapy , Neoplasms/drug therapyABSTRACT
This year marks the tenth anniversary of cell therapy with chimeric antigen receptor (CAR)-modified T cells for refractory leukemia. The widespread commercial approval of genetically engineered T cells for a variety of blood cancers offers hope for patients with other types of cancer, and the convergence of human genome engineering and cell therapy technology holds great potential for generation of a new class of cellular therapeutics. In this Review, we discuss the goals of cellular immunotherapy in cancer, key challenges facing the field and exciting strategies that are emerging to overcome these obstacles. Finally, we outline how developments in the cancer field are paving the way for cellular immunotherapeutics in other diseases.
