CD56 Expression Marks Human Group 2 Innate Lymphoid Cell Divergence from a Shared NK Cell and Group 3 Innate Lymphoid Cell Developmental Pathway.

According to the established model of murine innate lymphoid cell (ILC) development, helper ILCs develop separately from natural killer (NK) cells. However, it is unclear how helper ILCs and NK cells develop in humans. Here we elucidated key steps of NK cell, ILC2, and ILC3 development within human tonsils using ex vivo molecular and functional profiling and lineage differentiation assays. We demonstrated that while tonsillar NK cells, ILC2s, and ILC3s originated from a common CD34-CD117+ ILC precursor pool, final steps of ILC2 development deviated independently and became mutually exclusive from those of NK cells and ILC3s, whose developmental pathways overlapped. Moreover, we identified a CD34-CD117+ ILC precursor population that expressed CD56 and gave rise to NK cells and ILC3s but not to ILC2s. These data support a model of human ILC development distinct from the mouse, whereby human NK cells and ILC3s share a common developmental pathway separate from ILC2s.

The role of interleukin-2, all-trans retinoic acid, and natural killer cells: surveillance mechanisms in anti-GD2 antibody therapy in neuroblastoma.

Although anti-disialoganglioside (GD2) antibodies are successfully used for neuroblastoma therapy, a third of patients with neuroblastoma experience treatment failure or serious toxicity. Various strategies have been employed in the clinic to improve antibody-dependent cell-mediated cytotoxicity (ADCC), such as the addition of interleukin (IL)-2 to enhance natural killer (NK) cell function, adoptive transfer of allogeneic NK cells to exploit immune surveillance, and retinoid-induced differentiation therapy. Nevertheless, these mechanisms are not fully understood. We developed a quantitative assay to test ADCC induced by the anti-GD2 antibody Hu14.18K322A in nine neuroblastoma cell lines and dissociated cells from orthotopic patient-derived xenografts (O-PDXs) in culture. IL-2 improved ADCC against neuroblastoma cells, and differentiation with all-trans retinoic acid stabilized GD2 expression on tumor cells and enhanced ADCC as well. Degranulation was highest in licensed NK cells that expressed CD158b (P < 0.001) and harbored a killer-cell immunoglobulin-like receptor (KIR) mismatch against the tumor-specific human leukocyte antigen (HLA; P = 0.016). In conclusion, IL-2 is an important component of immunotherapy because it can improve the cytolytic function of NK cells against neuroblastoma cells and could lower the antibody dose required for efficacy, thereby reducing toxicity. The effect of IL-2 may vary among individuals and a biomarker would be useful to predict ADCC following IL-2 activation. Sub-populations of NK cells may have different levels of activity dependent on their licensing status, KIR expression, and HLA-KIR interaction. Better understanding of HLA-KIR interactions and the molecular changes following retinoid-induced differentiation is necessary to delineate their role in ADCC.

CRISPR/Cas9 deletion of MIR155HG in human T cells reduces incidence and severity of acute GVHD in a xenogeneic model.

ABSTRACT: Acute graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic cell transplantation (allo-HCT). Using preclinical mouse models of disease, previous work in our laboratory has linked microRNA-155 (miR-155) to the development of acute GVHD. Transplantation of donor T cells from miR-155 host gene (MIR155HG) knockout mice prevented acute GVHD in multiple murine models of disease while maintaining critical graft-versus-leukemia (GVL) response, necessary for relapse prevention. In this study, we used clustered, regularly interspaced, short palindromic repeats (CRISPR)/Cas9 genome editing to delete miR-155 in primary T cells (MIR155HGΔexon3) from human donors, resulting in stable and sustained reduction in expression of miR-155. Using the xenogeneic model of acute GVHD, we show that NOD/SCID/IL2rγnull (NSG) mice receiving MIR155HGΔexon3 human T cells provide protection from lethal acute GVHD compared with mice that received human T cells with intact miR-155. MIR155HGΔexon3 human T cells persist in the recipients displaying decreased proliferation potential, reduced pathogenic T helper-1 cell population, and infiltration into GVHD target organs, such as the liver and skin. Importantly, MIR155HGΔexon3 human T cells retain GVL response significantly improving survival in an in vivo model of xeno-GVL. Altogether, we show that CRISPR/Cas9-mediated deletion of MIR155HG in primary human donor T cells is an innovative approach to generate allogeneic donor T cells that provide protection from lethal GVHD while maintaining robust antileukemic response.

A Phase 2 Trial of Ibrutinib and Nivolumab in Patients with Relapsed or Refractory Classical Hodgkin's Lymphoma.

BACKGROUND: Relapsed or refractory classical Hodgkin lymphoma (cHL) remains a difficult treatment challenge. Although checkpoint inhibitors (CPI) have provided clinical benefit for these patients, responses are generally not durable, and progression eventually occurs. Discovering combination therapies which maximize the immune response of CPI therapy may overcome this limitation. We hypothesized that adding ibrutinib to nivolumab will lead to deeper and more durable responses in cHL by promoting a more favorable immune microenvironment leading to enhanced T-cell-mediated anti-lymphoma responses. METHODS: We conducted a single arm, phase II clinical trial testing the efficacy of nivolumab in combination with ibrutinib in patients ≥18 years of age with histologically confirmed cHL who had received at least one prior line of therapy. Prior treatment with CPIs was allowed. Ibrutinib was administered at 560 mg daily until progression in combination with nivolumab 3 mg/kg IV every 3 weeks for up to 16 cycles. The primary objective was complete response rate (CRR) assessed per Lugano criteria. Secondary objectives included overall response rate (ORR), safety, progression free survival (PFS), and duration of response (DoR). RESULTS: A total of 17 patients from two academic centers were enrolled. The median age of all patients was 40 (range 20-84). The median number of prior lines of treatment was five (range 1-8), including 10 patients (58.8%) who had progressed on prior nivolumab therapy. Most treatment related events were mild (

Direct observation of space charge induced hydrogen ion insertion in nanoscale anatase TiO2.

Space charge induced 2H+ densities up to 2H+ (0.17)TiO2 are observed directly using neutron diffraction on two different nanoscale particle sizes of anatase TiO2 immersed in sulfuric acid, and consistent with experimental evidence modelling shows that these ions show rapid self diffusion.