Project description:Natural killer (NK) cells support the anti-myeloma activity of daratumumab via antibody-dependent cellular cytotoxicity (ADCC) in multiple myeloma (MM). However, the different roles of heterogeneous NK cell subpopulations have not been elucidated in MM. Here, we delineate memory-like NK cells in the bone marrow (BM) of newly diagnosed MM (NDMM) patients using single-cell RNA sequencing, and further characterize their distinct immunophenotypic features and functions by multicolor flow cytometry. Memory-like NK cells exert robust daratumumab-mediated effector functions ex vivo, including cytokine production and degranulation, compared to conventional NK cells. The composition of memory-like NK cells in BM determines the daratumumab-mediated ex vivo functional activity of BM NK cells in NDMM patients. Unlike conventional NK cells, sorted memory-like NK cells from the BM of NDMM patients exert substantial cytotoxic activity against myeloma cells in the presence of daratumumab. Our findings indicate that memory-like NK cells are an important mediator of daratumumab-dependent effector functions in MM and support direct future efforts to better predict and improve the clinical efficacy of therapeutic antibodies by selectively employing memory-like NK cells.
Project description:Natural Killer cells (NK), a major constituent of innate immune system, have the ability to kill the transformed and infected cells without prior sensitization; can be put to immunotherapeutic use against various malignancies. NK cells discriminate between normal cells and transformed cells via a balance of inhibitory and activating signals induced by interactions between NK cell receptors and target cell ligands. Present study investigates whether expansion of NK cells could augment their anti-myeloma (MM) activity. For NK cell expansion, peripheral blood mononuclear cells from healthy donors and myeloma patients were co-cultured with irradiated K562 cells transfected with 4-1BBL and membrane-bound IL15 (K562-mb15-41BBL). A genome-wide profiling approach was performed to identify gene expression signature in expanded NK (ENK) cells and non-expanded NK cells isolated from healthy donors and myeloma patients. A specific set of genes involved in proliferation, migration, adhesion, cytotoxicity, and activation were up regulated post expansion, also confirmed by flow cytometry. Exp-NK cells killed both allogeneic and autologous primary MM cells more avidly than non-exp-NK cells in vitro. Multiple receptors, particularly NKG2D, natural cytotoxicity receptors, and DNAM-1 contributed to target lysis, via a perforin mediated mechanism. In summary, vigorous expansion and high anti-MM activity both in vitro and in vivo provide the rationale for testing exp-NK cells in a clinical trial for high risk MM. Differential gene expression profile in expanded natural killer (ENK) cells and non-expanded natural killer (NK) cells from healthy donors and myeloma patients Eight healthy donor and eight myeloma patients were used in the study. Non-expanded natural killer (NK) cells were isolated from PBMCs of healthy donors and myeloma patients. Expanded natural killer (ENK) cells were generated from same set of samples as mentioned in expansion protocol. All ENK and NK cells were used for gene expression profiling.
Project description:Natural Killer cells (NK), a major constituent of innate immune system, have the ability to kill the transformed and infected cells without prior sensitization; can be put to immunotherapeutic use against various malignancies. NK cells discriminate between normal cells and transformed cells via a balance of inhibitory and activating signals induced by interactions between NK cell receptors and target cell ligands. Present study investigates whether expansion of NK cells could augment their anti-myeloma (MM) activity. For NK cell expansion, peripheral blood mononuclear cells from healthy donors and myeloma patients were co-cultured with irradiated K562 cells transfected with 4-1BBL and membrane-bound IL15 (K562-mb15-41BBL). A genome-wide profiling approach was performed to identify gene expression signature in expanded NK (ENK) cells and non-expanded NK cells isolated from healthy donors and myeloma patients. A specific set of genes involved in proliferation, migration, adhesion, cytotoxicity, and activation were up regulated post expansion, also confirmed by flow cytometry. Exp-NK cells killed both allogeneic and autologous primary MM cells more avidly than non-exp-NK cells in vitro. Multiple receptors, particularly NKG2D, natural cytotoxicity receptors, and DNAM-1 contributed to target lysis, via a perforin mediated mechanism. In summary, vigorous expansion and high anti-MM activity both in vitro and in vivo provide the rationale for testing exp-NK cells in a clinical trial for high risk MM. Differential gene expression profile in expanded natural killer (ENK) cells and non-expanded natural killer (NK) cells from healthy donors and myeloma patients
Project description:Investigation of global gene expression levels between B cells, Natural killer cells and Natural killer B cells Gene expression profiling using sorted B cells, Natural killer cells and Natural killer B cells from WT mouse spleen. Total RNA extracted from WT cells were quantified by the NanoDrop ND-1000 and RNA integrity was assessed by standard denaturing agarose gel electrophoresis. The sample preparation and microarray hybridization were performed based on the NimbleGenâs standard protocols.
Project description:During the first trimester of pregnancy the uterus is massively infiltrated by decidual natural killer cells (dNK). These cells are not killers, but they rather provide a microenvironment that is propitious to healthy placentation. Human cytomegalovirus (HCMV) is the most common cause of intrauterine viral infections and a known cause of severe birth defects or fetal death. The rate of HCMV congenital infection is often low in the first trimester of pregnancy. The mechanisms controlling HCMV spreading during pregnancy are not yet fully revealed, but evidence indicating that the innate immune system plays a role in controlling HCMV infection in healthy adults exists. In this study, we investigated whether dNK cells could be involved in controlling viral spreading and in protecting the fetus against congenital HCMV infection. We found that freshly isolated dNK cells acquire major functional and phenotypic changes when they are exposed to HCMV-infected decidual autologous fibroblasts. Functional studies revealed that dNK cells, which are mainly cytokines and chemokines producers during normal pregnancy, become cytotoxic effectors upon their exposure to HCMV-infected autologous decidual fibroblasts. Both the NKG2D and the CD94/NKG2C or 2E activating receptors are involved in the acquired cytotoxic function. Moreover, we demonstrate that CD56(pos) dNK cells are able to infiltrate HCMV-infected trophoblast organ culture ex-vivo and to co-localize with infected cells in situ in HCMV-infected placenta. Taken together, our results present the first evidence suggesting the involvement of dNK cells in controlling HCMV intrauterine infection and provide insights into the mechanisms through which these cells may operate to limit the spreading of viral infection to fetal tissues.
Project description:Natural killer (NK) cells are multicompetent lymphocytes of the innate immune system that play a central role in host defense and immune regulation. Although increasing evidence suggests that innate immunity plays a key role in the pathogenesis of chronic rhinosinusitis (CRS), the role of NK cells in CRS has been poorly studied. This study aimed to characterize the peripheral blood NK cells from patients with CRS, and to compare the functions of these cells with those from non-CRS controls. The correlation between NK cell functional activity and prognosis was also assessed. Eighteen CRS patients and 19 healthy non-CRS controls were included. The patients with CRS were classified into two subgroups, namely a treatment-responsive group and recalcitrant group. NK cell degranulation was determined by measuring the cell surface expression of CD107a against 721.221 and K562 cells. Intracytoplasmic cytokine production was determined by flow cytometry. Compared to the controls, the NK cells of CRS group had an impaired ability to degranulate and to produce cytokines such as IFN-? and TNF-?. The recalcitrant subgroup showed the most severe defects in NK cell effector functions. Moreover, the decreased NK cell functions in patients with CRS were associated with poor prognostic factors such as concomitant asthma and peripheral blood eosinophilia. NK cells, which were originally named for their ability to mediate spontaneous cytotoxicity towards diseased cells including infected cells, may play an important role in regulating the inflammatory process in CRS pathogenesis.
Project description:Comparing global gene expression of neonatal and adult natural killer cells to determine if differences in gene expression suggest that different developmental pathways during hematopoiesis are followed in the fetal and adult mouse to produce mature natural killer cells.
Project description:Bach2 has been reported to regulate multiple immune cell development and function. Here we report that Bach2 is constitutively expressed in relatively immature NK subsets. Bach2 negatively regulates NK cell development and Bach2 deficiency results in NK cell with mature effector phenotype. Thus, Bach2 functions as a negative regulator of NK cell maturation and function.