Project description:Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer. Transforming growth factor beta (TGF-β) is highly expressed in the liver tumor microenvironment and is known to inhibit immune cell activity. Here, we used human iPSCs to produce natural killer (NK) cells engineered to mediate improved anti-HCC activity. Specifically, we produced iPSC-NK cells with either knock out TGF-β receptor 2 (TGFBR2-KO) or expression of a dominant negative (DN) form of the TGF-β receptor 2 (TGFBR2-DN) combined with CARs that target either GPC3 or AFP. The TGFBR2-KO and TGFBR2-DN iPSC-NK cells are resistant to TGF-β inhibition and improved anti-HCC activity. However, expression of anti-HCC CARs on iPSC-NK cells did not lead to effective anti-HCC activity unless there was also inhibition of TGF-b activity. Our findings demonstrate that TGF-β signaling blockade is required for effective NK cell function against HCC and potentially other malignancies which express high levels of TGF-β.
Project description:CT26 tumors were implanted subcutaneously into syngeneic BALB/C mice and allowed to grow for 15-25 days. Tumors were collected, mechanically dissociated, and immune cells enriched using Percoll gradient. Cells were then stained with viability dye, CD45, CD3, and NKp46 to FACS sort for T cells (Live/CD45+/CD3+/NKp46-) and NK cells (Live/CD45+/CD3-/NKp46+). Isolated tumor infiltrating NK and T cells were then processed for RNA sequencing analysis.
Project description:ChIP-seq was conducted using freshly isolated (resting) splenic WT NK cells with anti-Runx3 antibody (Ab), anti-H3K4me1 Ab and non-immune serum (NIS) as control. Runx3 and H3K4me1 IP from splenic NK cells isolated by negative selection using NK cell isolation kit (R&D) followed by sorting of NKp46+ cells.
Project description:Natural killer cells are innate lymphocytes that play a pivotal role in the immune surveillance and elimination of transformed or virally infected cells. Using a combined chemico-genetic approach, we have identified that BET bromodomains BRD2 and BRD4 are central regulators of NK cell responses. We show that both BRD2 and BRD4 play a key regulatory function in controlling NK cell specific inflammatory responses. However, knockdown of BRD2 but not BRD4 impairs NK cell cytolytic response, highlighting a redundant role for BRD4 in regulating NK cell killing. We further show that the prototypic monovalent BET inhibitor impairs in vitro NK cell mediated killing of cancer target cells, while the bivalent BET bromodomain AZD5153 does not. We ascribe these differences to the preferential affinity of JQ1(+) to BRD2, while AZD5153 has a higher affinity for BRD4. Our work suggests that inhibiting BET bromodomains may be an effective therapeutic strategy for controlling inflammatory function. Given that BRD2 but not BRD4 inhibition can impair NK cell mediated killing, our findings also have clinical significance in light of the ongoing clinical application of BET bromodomains in oncology.
Project description:Tumor escape mechanisms for immunotherapy include deficiencies in antigen presentation, diminishing adaptive CD8+ T cell antitumor activity. Although innate NK cells are triggered by loss of MHC class I, their response is often inadequate. To increase tumor susceptibility to both innate and adaptive immune elimination, we performed parallel genome-wide CRISPR-Cas9 screens. This identified all components, RNF31, RBCK1, and SHARPIN, of the linear ubiquitination chain assembly complex (LUBAC). Genetic and pharmacologic ablation of RNF31, an E3 ubiquitin ligase, strongly sensitized melanoma, breast and colorectal cancer cells to both NK and CD8+ T cell killing. This occurred in a TNF-dependent manner, causing loss of A20 and non-canonical IKK complexes from TNF Receptor Complex I. Corroborating this preclinically, a small molecule RNF31 inhibitor sensitized human colon carcinoma organoids to TNF and greatly enhanced immune bystander killing of antigen-loss and antigen presentation machinery-deficient tumor cells. These results merit exploration of RNF31 inhibition as a clinical pharmacological opportunity for immunotherapy-refractory cancers.
Project description:Natural killer (NK) cells are NKp46+CD3- lymphocytes that can perform granule-dependent cytotoxicity and produce interferon-gamma, when isolated from blood, lymphoid organs, lung, liver and uterus. Here we identify in dermis, gut lamina propria and cryptopatches, very distinct populations of NKp46+CD3- cells with reduced ability to degranulate and to produce interferon-gamma. In gut, the transcription factor RORgamma-t and CD127 (IL-7R alpha) defined a novel subset of NKp46+CD3- that is reminiscent of lymphoid tissue inducer (LTi)-like cells. Gut ROR gamma t+NKp46+ cells produced IL-22 in contrast to ROR-gamma t-independent lamina propria and dermis NK cells. These data show that LTi-like cells and NK cells share unanticipated similarities and reveal the heterogeneity of NKp46+CD3- cells in innate immunity, lymphoid organization and local tissue repair.
Project description:ChIP-seq was conducted using freshly isolated splenic WT NK cells from IL-15/Ra treated mice with anti-Runx3 antibody (Ab) and non-immune serum (NIS) as control. Runx3 and NIS IP from splenic NK cells of IL-15/Ra treated WT mice, isolated by negative selection using NK cell isolation kit (R&D) followed by sorting of NKp46+ cells.
Project description:Discovery of immune tolerance mechanisms, which inhibit pre-existing autoimmune inflammation, may provide us with new strategies for treating autoimmune diseases. We have identified a CD8αα+MHC-II+ cell with professional APC capacity during our investigation on spontaneous recovery from autoimmune glomerulonephritis in a rat model. This cell actively invades inflamed target tissue to terminate an on-going autoimmune inflammation by selective killing of effector autoreactive T cells. Now, we showed that this cell used a cytotoxic machinery of Ly49s+ NK cells in killing of target T cells. Thus, this CD8αα+MHC-II+ cell, which previously was thought a professional APC, is an antigen presenting-NK (AP-NK) cell. Following its coupling with target T cells through antigen presentation, killing stimulatory receptor Ly49s6 and co-receptor CD8αα on this cell used non-classic MHC-I RT1CE16 on the target T cells as a ligand to initiate killing. Thus, activated effector T cells with elevated expression of RT1CE16 were highly susceptible to the killing by the CD8αα+ AP-NK cell. Granule cytolytic perforin/granzyme C from this cell subsequently mediated cytotoxicity, and thus, inhibition of granzyme C effectively attenuated the killing. As it can recognize and eliminate effector autoreactive T cells in the inflamed target tissue, CD8αα+ AP-NK cell not only represents a new type of immune cell involved in immune tolerance, but also is a potential candidate for developing a cell-based therapy for pre-existing autoimmune diseases.
Project description:To further characterize the global gene expression profiles of ITNKs, we conducted RNA-sequencing analysis of T cells, ITNKs (CD3+NKp46+) and NK cells (CD3-CD56+) (both the CB and the PBMC origins with > 90% purity) from the CB and PBMC . Principal component analysis (PCA) and unsupervised hierarchical cluster analysis revealed that ITNKs had transcriptomic features of both T cells and NK cells