Natural killer (NK) cells are innate lymphoid cells (ILCs) that participate to the clearance of pathogen-infected cells and tumour cells. NK cells and subsets of ILCs express the natural cytotoxicity receptors (NCRs) NKp46, NKp44 and NKp30 at their surface. NCRs have been shown to recognize a broad spectrum of ligands ranging from viral-, parasite- and bacterial-derived ligands to cellular ligands; however, the full identification of NCR ligands remains to be performed and will undoubtedly contribute to a better understanding of NK cell and ILC biology.
In this study the phenotype and function of tumor-associated NK cells from peritoneal fluids of a selected cohort of patients with seropapillary ovarian carcinoma were analyzed. In > 50% of these patients, the expression of the activating receptor NKp30 in tumor-associated NK cells was substantially reduced as compared to autologous peripheral blood (PB) NK cells. The impaired expression of this receptor was associated with the presence of one of its cellular ligands (B7-H6), which was detectable as a surface/cytosolic molecule in tumor cells and as a soluble molecule in the peritoneal fluid. NK cells from patients expressing this NKp30low phenotype displayed an impaired interferon-gamma (IFNγ) production and cytolytic function when tested against target cells expressing surface B7-H6. Our data also suggest that in these patients, the defective expression and function of NKp30 may be induced by the chronic engagement of this receptor by soluble B7-H6 or by tumor cells expressing this ligand. The impairment of NK cell functions described herein could represent a novel mechanism by which the tumor microenvironment may contribute to the escape from immune surveillance.
The immunosurveillance mechanisms governing high-risk neuroblastoma (HR-NB), a major pediatric malignancy, have been elusive. We identify a potential role for natural killer (NK) cells, in particular the interaction between the NK receptor NKp30 and its ligand, B7-H6, in the metastatic progression and survival of HR-NB after myeloablative multimodal chemotherapy and stem cell transplantation. NB cells expressing the NKp30 ligand B7-H6 stimulated NK cells in an NKp30-dependent manner. Serum concentration of soluble B7-H6 correlated with the down-regulation of NKp30, bone marrow metastases, and chemoresistance, and soluble B7-H6 contained in the serum of HR-NB patients inhibited NK cell functions in vitro. The expression of distinct NKp30 isoforms affecting the polarization of NK cell functions correlated with 10-year event-free survival in three independent cohorts of HR-NB in remission from metastases after induction chemotherapy (n = 196, P < 0.001), adding prognostic value to known risk factors such as N-Myc amplification and age >18 months. We conclude that the interaction between NKp30 and B7-H6 may contribute to the fate of NB patients and that both the expression of NKp30 isoforms on circulating NK cells and the concentration of soluble B7-H6 in the serum may be clinically useful as biomarkers for risk stratification.
• B7-H6 transcripts, B7-H6 cell-surface expression, and sB7-H6 can be induced in inflammatory conditions in vitro and in vivo.• B7-H6 is expressed on proinflammatory CD141 CD16 1 monocytes in sepsis conditions and is linked to an increased mortality.B7-H6, a member of the B7 family of immunoreceptors, is as a cell-surface ligand for the NKp30-activating receptor expressed on natural killer cells. B7-H6 is not detected in normal human tissues at steady state but is expressed on tumor cells. However, whether B7-H6 can be expressed in other conditions remains unknown. We analyzed here the pathways that lead to the expression of B7-H6 in nontransformed cells. In vitro, B7-H6 was induced at the surface of CD14 1 CD16 1 proinflammatory monocytes and neutrophils upon stimulation by ligands of Toll-like receptors or proinflammatory cytokines such as interleukin-1b and tumor necrosis factor a. In these conditions, a soluble form of B7-H6 (sB7-H6) was also produced by activated monocytes and neutrophils. In vivo, B7-H6 was expressed on circulating proinflammatory CD14 1 CD16 1 monocytes in a group of patients in sepsis conditions, and was linked to an increased mortality. sB7-H6 was selectively detected in the sera of patients with gram-negative sepsis and was associated with membrane vesicles that co-sedimented with the exosomal fraction. These findings reveal that B7-H6 is not only implicated in tumor immunosurveillance but also participates in the inflammatory response in infectious conditions. This trial was registered at www.clinicaltrials.gov as #NTC00699868. (Blood. 2013;122(3):394-404)
Summary:We investigated the use of 'prophylactic' donor lymphocyte infusions (DLI) containing 1 ؋ 10 7 CD3 ؉ cells, given at 30, 60 and 90 days post-allogeneic blood and marrow transplantation (BMT), following conditioning with fludarabine 30 mg/m 2 /4 days and melphalan 70 mg/m 2 /2 days. GVHD prophylaxis consisted of cyclosporin A (CsA) 2 mg/kg daily with early tapering by day 60. Our goals were the rapid achievement of chimerism and disease control, providing an immunological platform for DLIs to treat refractory patients with hematological malignancies. Twelve heavily pre-treated patients with life expectancy less than 6 months were studied; none were in remission. Diagnoses were AML (n ؍ 4), MDS (n ؍ 1), ALL (n ؍ 3), CML (n ؍ 3) and multiple myeloma (n ؍ 1). Response rate was 75%. Three patients are alive at a median of 450 days (range, 450-540). Two patients are in remission of CML in blast crisis and AML for more than 14 months. Median survival is 116 days (range, 25-648). Six patients received 12 DLIs; three patients developed acute GVHD after the first infusion and were excluded from further DLIs, but no GVHD occurred among patients receiving subsequent DLIs. One patient with CML in blast crisis went into CR after the first DLI. The overall incidence of acute GVHD was 70%. Primary causes of death were infections (n ؍ 3), acute GVHD (n ؍ 3), chronic GVHD (n ؍ 1) and disease relapse (n ؍ 2). We observed high response and chimerism rates at the expense of an excessive incidence of GVHD. DLI given at day ؉30 post BMT caused GVHD in 50% of the patients, and its role in this setting remains unclear. The therapeutic benefit of allogeneic BMT is in part related to an immunological graft-versus-leukemia (GVL) effect that frequently evolves in the context of graft-versus-host disease (GVHD). The ability of donor lymphocytes to induce remission in patients relapsing after allogeneic transplantation illustrates the potency of this effect.1 Establishing donor-recipient tolerance with less toxic regimens may provide the basis for further immunological manipulations in order to maximize the GVL effect. However, rapidly evolving diseases may not be amenable to this strategy, considering that the immune-mediated elimination of malignant cells may take weeks or months to occur. This fact suggests the need for strategies to reinforce the immune-mediated phenomena in the post-transplant period.Groups in Jerusalem and Houston pioneered the use of sub-lethal doses of fludarabine-based conditioning regimens. These regimens have been shown to be less toxic and to provide enough immunosuppression to prevent graft rejection and establish stable mixed or complete chimerism.2,3 The combination of melphalan and fludarabine has enabled allogeneic stem cell engraftment in the majority of patients treated, at least in the setting of HLA-identical transplantation. Patients with refractory relapses of advanced leukemias appear to benefit the least.
Background We examined prospective associations between atypical working hours, substance use and sugar and fat consumption. Methods In the French population-based CONSTANCES cohort, 47,288 men and 53,324 women currently employed included between 2012 and 2017 were annually followed for tobacco and cannabis use; among them, 35,647 men and 39,767 women included between 2012 and 2016 were also followed for alcohol and sugar and fat consumption. Three indicators of atypical working hours were self-reported at baseline: working at night, weekend work and non-fixed working hours. Generalized linear models computed odds of substance use and sugar and fat consumption at follow-up according to atypical working hours at baseline while adjusting for sociodemographic factors, depression and baseline substance use if appropriate. Results Working at night was associated with increased tobacco use in women [odds ratios ranging from 1.45 to 1.48], with increased cannabis use in men [from 1.40 to 1.54] and with increased alcohol use in both men and women [from 1.12 to 1.14]. Weekend work and non-fixed working hours were associated with increased tobacco and alcohol use in both men and women [from 1.15 to 1.54 and 1.12 to 1.14, respectively]. Dose-dependent relationships were found regarding the association between working at night and tobacco use in women as well as regarding non-fixed working hours and tobacco use in both men and women (P for trends <0.001). Conclusions The potential role of atypical working hours on substance use should be considered by public health policy makers and clinicians in information and prevention strategies. Key messages • Night shifts were associated with increased smoking in women with dose-dependent relationships, cannabis use in men and alcohol use in both. • Weekend work and non-fixed working hours were associated with increased alcohol and tobacco use with dose-dependent relationships in men and women.
e14225 Background: Activity of immune checkpoint inhibitors relies mainly on the presence of an immune response directed against neoantigens resulting from tumor specific mutations. The induction and/or amplification of such an immune response is expected to increase the activity of these therapies. We describe here a novel immunization platform developed for the purpose of personalized cancer immunotherapy. This platform integrates a DNA vector coding for neoantigens, a live modified vaccinia of strain Ankara (MVA) used as a physiologic adjuvant and anti-CTLA-4 as a locally acting early immune checkpoint blocker. Methods: Immune potency was assessed in C57BL6 mice injected subcutaneously three times five days apart with an ovalbumine (OVA) expressing DNA vector (100 µg), either alone or in combination with increasing doses of MVA (up to 2.5x107 plaque forming units, pfu) and increasing doses of anti-CTLA-4 (up to 100 µg). OVA specific immune responses were measured by ELISpot. Anti-tumor efficacy was then investigated with a similar administration scheme in a therapeutic B16F10 mice melanoma model with a DNA vector coding for the B16F10-M30 tumor neoantigen. Results: At an optimal dose of 2.5x106 pfu, MVA significantly improved OVA specific immune response up to 10 times higher as compared to vector alone. Addition of CTLA-4 blockade further increased the magnitude of response, up to 30 times higher than with vector alone. Both MVA and CTLA-4 demonstrated a bell-shaped dose dependent effect. In tumor-bearing animals, 80% experienced durable tumor-free survival when treated with the combination therapy as compared to less than 20% in untreated animals or animals treated with each component independently. Treatment appeared feasible and well-tolerated. Conclusions: Neoantigen coding DNA vector, MVA and CTLA-4 immune checkpoint blockade, when co-administered in immunocompetent C57BL6 mice, acted synergistically to induce a cellular immune response. The same approach translated into a strong anti-tumoral response in an aggressive melanoma model. This combined immunization platform appears as a potential novel way to enhance clinical benefit from current immune checkpoint inhibitors.
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