Showing papers by "Lewis L. Lanier published in 2023"

Exhausted intratumoral Vδ2− γδ T cells in human kidney cancer retain effector function

Abstract: Gamma delta (γδ) T cells reside within human tissues including tumors, but their function in mediating antitumor responses to immune checkpoint inhibition is unknown. Here we show that kidney cancers are infiltrated by Vδ2- γδ T cells, with equivalent representation of Vδ1+ and Vδ1- cells, that are distinct from γδ T cells found in normal human tissues. These tumor-resident Vδ2- T cells can express the transcriptional program of exhausted αβ CD8+ T cells as well as canonical markers of terminal T-cell exhaustion including PD-1, TIGIT and TIM-3. Although Vδ2- γδ T cells have reduced IL-2 production, they retain expression of cytolytic effector molecules and co-stimulatory receptors such as 4-1BB. Exhausted Vδ2- γδ T cells are composed of three distinct populations that lack TCF7, are clonally expanded and express cytotoxic molecules and multiple Vδ2- T-cell receptors. Human tumor-derived Vδ2- γδ T cells maintain cytotoxic function and pro-inflammatory cytokine secretion in vitro. The transcriptional program of Vδ2- T cells in pretreatment tumor biopsies was used to predict subsequent clinical responses to PD-1 blockade in patients with cancer. Thus, Vδ2- γδ T cells within the tumor microenvironment can contribute to antitumor efficacy.

Hypoimmune induced pluripotent stem cells survive long term in fully immunocompetent, allogeneic rhesus macaques

Abstract: Genetic engineering of allogeneic cell therapeutics that fully prevents rejection by a recipient's immune system would abolish the requirement for immunosuppressive drugs or encapsulation and support large-scale manufacturing of off-the-shelf cell products. Previously, we generated mouse and human hypoimmune pluripotent (HIP) stem cells by depleting HLA class I and II molecules and overexpressing CD47 (B2M-/-CIITA-/-CD47+). To determine whether this strategy is successful in non-human primates, we engineered rhesus macaque HIP cells and transplanted them intramuscularly into four allogeneic rhesus macaques. The HIP cells survived unrestricted for 16 weeks in fully immunocompetent allogeneic recipients and differentiated into several lineages, whereas allogeneic wild-type cells were vigorously rejected. We also differentiated human HIP cells into endocrinologically active pancreatic islet cells and showed that they survived in immunocompetent, allogeneic diabetic humanized mice for 4 weeks and ameliorated diabetes. HIP-edited primary rhesus macaque islets survived for 40 weeks in an allogeneic rhesus macaque recipient without immunosuppression, whereas unedited islets were quickly rejected.

The CD16 and CD32b Fc-gamma receptors regulate antibody-mediated responses in mouse natural killer cells.

Abstract: Natural killer (NK) cells are innate lymphocytes capable of mediating immune responses without prior sensitization. NK cells express Fc-gamma receptors (FcγRs) that engage the Fc region of IgG. Studies investigating the role of FcγRs on mouse NK cells have been limited due to lack specific reagents. In this study, we characterize the expression and biological consequences of activating mouse NK cells through their FcγRs. We demonstrate that most NK cells express the activating CD16 receptor, and a subset of NK cells also expresses the inhibitory CD32b receptor. Critically, these FcγRs are functional on mouse NK cells and can modulate antibody-mediated responses. We also characterized mice with conditional knockout alleles of Fcgr3 (CD16) or Fcgr2b (CD32b) in the NK and innate lymphoid cell (ILC) lineage. NK cells in these mice did not reveal any developmental defects and were responsive to cross-linking activating NK receptors, cytokine stimulation, and killing of YAC-1 targets. Importantly, CD16-deficient NK cells failed to induce antibody-directed cellular cytotoxicity of antibody-coated B-cell lymphomas in in vitro assays. In addition, we demonstrate the important role of CD16 on NK cells using an in vivo model of cancer immunotherapy using anti-CD20 antibody treatment of B-cell lymphomas.

Abstract B031: Investigation of the ubiquitin ligase RNF31 as a mediator of immune evasion in advanced prostate cancer

Abstract: Background: Metastatic Castration-Resistance Prostate cancer (mCRPC) is a disease state associated with poor survival. Current FDA-approved therapies are non-curative and can only extend mCRPC patient survival by a few months. Therefore, there is an unmet need to improve therapies for patients with advanced disease. Immunotherapy is an effective treatment strategy for a number of cancers but showed limited success in mCRPC patients. Prostate cancer cells exhibit reduced surface expression of major histocompatibility complex (MHC) molecules as an evasive mechanism from cytotoxic CD8+ T-cells. Natural killer (NK) cells are another class of immune cells with anti-tumor characteristics and can target cancer cells independently of MHC expression. Increased NK cell infiltration and activity in prostate cancer has been associated with favorable patient outcomes, but cancer cells have evolved resistance mechanisms against NK cell targeting. We hypothesize that there are druggable pathways that can be exploited to enhance anti-tumor activities of NK cells and improve efficacy of immunotherapies. Methods: To investigate these pathways, we established and characterized an in vitro co-culture system between prostate cancer and NK cells. We conducted the first targeted pool CRISPR screen identifying genes that, when knockout (KO) in prostate cancer cells, enhance killing by NK cells. We validated the screen by individually KO the gene hits. To explore the potential resistance mechanisms conferred by these hits, we performed RNA seq in control and KO cells. Results: Our screen nominated several known ligands of NK cells including CD58 and PVRL2, as well as RNF31 as the top novel target in promoting NK-mediated kill of cancer cells. RNF31 is upregulated in prostate cancer and is part of a druggable linear ubiquitin chain assembly complex (LUBAC). Single sgRNA validation experiments confirmed that RNF31 KO significantly sensitized LNCaP cells to NK92-mediated depletion. Importantly, RNF31 KO did not affect cancer cell proliferation, suggesting that the observed effects are due to the actions of NK cells. We observed that immune response related genes were upregulated in the RNF31 KO cells compare to the wildtype cells. Furthermore, pharmacologic inhibiting RNF31 via LUBAC inhibitor Hopin-8 sensitizes LNCaP cell to NK cell mediated kill. Conclusions: We anticipate that results from this study will yield insights into a novel tumor-intrinsic mechanism of immune evasion in prostate cancer and evaluate the therapeutic potential of targeting this pathway. We hope this work will help identify new therapeutic options or combination treatments that can improve the efficacy of immunotherapy in prostate cancer and significantly extend the lives of patients with advanced prostate cancer. Acknowledgements: This study was supported by the DOD Early Investigator Research Award to TL. Citation Format: Tianyi Liu, Haolong Li, Tony Junjie Hua, Hyunjin Shin, Tanushree Shenoy, Martin Sjoestroem, Arian Lundberg, Luke Gilbert, David Quigley, Alan Ashworth, Lewis Lanier, Felix Feng. Investigation of the ubiquitin ligase RNF31 as a mediator of immune evasion in advanced prostate cancer [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr B031.