Project description:We found that treatment with the TDB mosunetuzumab in patients resulted in natural killer (NK) cell activation in the peripheral blood. We modeled this phenomenon using PBMCs in vitro and found that TDB-mediated killing activated NK cells, increasing natural killing and antibody dependent cytotoxic (ADCC) function. To define TDB-mediated NK cell activation, we sorted NK cells from PBMCs at baseline and after TDB treatment and performed RNAseq.
Project description:Treatment of hematological malignancies by adoptive transfer of activated natural killer (NK) cells is limited by poor post-infusion persistence. We compared the ability of interleukin-2 (IL-2) and IL-15 to sustain human NK cell functions following cytokine withdrawal to model post-infusion performance. In contrasts to IL-2, IL-15 mediated stronger signaling through the IL-2/15 receptor complex and provided functional advantages. Genome-wide analysis of cytosolic and polysome-associated mRNA revealed cytokine dependent differential mRNA levels and translation during cytokine activation but also that most gene expression differences were primed by IL-15 and only manifested after cytokine withdrawal. IL-15 augmented mTOR signaling, which correlated with increased expression of genes related to cell metabolism and respiration. Consistently, mTOR inhibition abrogated IL-15-induced functional advantages. Moreover, mTOR-independent STAT-5 signaling contributed to improved NK cell function during cytokine activation but not following cytokine withdrawal. The superior performance of IL-15 stimulated NK cells was also observed using a clinically applicable protocol for NK cell expansion. Finally, expression of IL-15 correlated with cytolytic immune functions in patients with B cell lymphoma and favorable clinical outcome. These findings highlight the importance of mTOR regulated metabolic processes for immune cell functions and argue for implementation of IL-15 in adoptive NK cell cancer therapy. Freshly isolated NK cells from 6 donors were activated with IL-2 or IL-15 for 48 hours, followed by cytokine withdrawal for 24 hours, resulting in four RNA samples per donor. From each sample, both the cytosolic as well as the polysomal fraction were collected. Donor 3 contains activation and post withdrawal data from two different donors due to poor RNA-quality obtained for some samples which did not allow for processing of the complete set of 6 donors (resulting in a total of 40 samples).
Project description:Treatment of hematological malignancies by adoptive transfer of activated natural killer (NK) cells is limited by poor post-infusion persistence. We compared the ability of interleukin-2 (IL-2) and IL-15 to sustain human NK cell functions following cytokine withdrawal to model post-infusion performance. In contrasts to IL-2, IL-15 mediated stronger signaling through the IL-2/15 receptor complex and provided functional advantages. Genome-wide analysis of cytosolic and polysome-associated mRNA revealed cytokine dependent differential mRNA levels and translation during cytokine activation but also that most gene expression differences were primed by IL-15 and only manifested after cytokine withdrawal. IL-15 augmented mTOR signaling, which correlated with increased expression of genes related to cell metabolism and respiration. Consistently, mTOR inhibition abrogated IL-15-induced functional advantages. Moreover, mTOR-independent STAT-5 signaling contributed to improved NK cell function during cytokine activation but not following cytokine withdrawal. The superior performance of IL-15 stimulated NK cells was also observed using a clinically applicable protocol for NK cell expansion. Finally, expression of IL-15 correlated with cytolytic immune functions in patients with B cell lymphoma and favorable clinical outcome. These findings highlight the importance of mTOR regulated metabolic processes for immune cell functions and argue for implementation of IL-15 in adoptive NK cell cancer therapy.
Project description:This is a mathematical model comprised of non-linear ordinary differential equations describing the dynamic relationship between hypoxia-inducible factor-1 alpha (HIF-1a) mRNA, HIF-1a protein, and interleukin-15-mediated upstream signalling events in natural killer cells from human blood. Regulatory expressions are also included for mammalian target of rapamycin (mTOR), nuclear factor-kappa beta, and signal transducer and activator of transcription 3 (STAT3).
Project description:We report here the design of new antibody-based natural killer cell engager therapeutics (ANKET), single tetraspecific molecules engaging the NK cell activating receptors NKp46 and CD16, the β chain of the interleukin-2 receptor (IL-2R) and a tumor-associated antigen (TAA).
Project description:Interleukin-15 (IL-15) is essential for the development and maintenance of natural killer (NK) cells. IL-15 activates STAT5 proteins, which can form dimers or tetramers. We previously found that NK cell numbers are decreased in Stat5a-Stat5b tetramer-deficient double knockin (DKI) mice, but the mechanism was not investigated. Here we show that STAT5 dimers are sufficient for NK cell development, whereas STAT5 tetramers mediate NK cell maturation and the expression of maturation-associated genes. Unlike the defective proliferation of Stat5 DKI CD8+ T cells, Stat5 DKI NK cells have normal proliferation to IL-15 but are susceptible to death upon cytokine withdrawal, with lower Bcl2 and increased active caspases. These findings underscore the importance of STAT5 tetramers in maintaining NK cell homeostasis. Moreover, defective STAT5 tetramer formation could represent a cause of NK cell immunodeficiency, and interrupting STAT5 tetramer formation might serve to control NK leukaemia.