Clear cell renal cell carcinomas (RCC) frequently display inactivation of von Hippel-Lindau (VHL) gene leading to increased level of hypoxia-inducible factors (HIF). In this study, we investigated ...the potential role of HIF2α in regulating RCC susceptibility to natural killer (NK) cell-mediated killing. We demonstrated that the RCC cell line 786-0 with mutated VHL was resistant to NK-mediated lysis as compared with the VHL-corrected cell line (WT7). This resistance was found to require HIF2α stabilization. On the basis of global gene expression profiling and chromatin immunoprecipitation assay, we found ITPR1 (inositol 1,4,5-trisphosphate receptor, type 1) as a direct novel target of HIF2α and that targeting ITPR1 significantly increased susceptibility of 786-0 cells to NK-mediated lysis. Mechanistically, HIF2α in 786-0 cells lead to overexpression of ITPR1, which subsequently regulated the NK-mediated killing through the activation of autophagy in target cells by NK-derived signal. Interestingly, both ITPR1 and Beclin-1 silencing in 786-0 cells inhibited NK-induced autophagy and subsequently increased granzyme B activity in target cells. Finally, in vivo ITPR1 targeting significantly enhanced the NK-mediated tumor regression. Our data provide insight into the link between HIF2α, the ITPR1-related pathway, and natural immunity and strongly suggest a role for the HIF2α/ITPR1 axis in regulating RCC cell survival.
Accumulating evidence highlights natural killer (NK) cell parameters as potential prognostic factors in cancer patients, which provides a strong rationale for developing therapeutic strategies aiming ...at restoring NK cell. However, reaching this point warrants better characterization of tumor-induced NK cell alterations. Our group recently reported heterogeneous NK maturation in acute myeloid leukemia (AML) patients. However, the clinical significance of such observations remained to be assessed on a larger cohort of patients. NK maturation based on expression of CD56, CD57, and KIR was assessed by flow cytometry in newly diagnosed AML patients (
= 87 patients from GOELAMS-LAM-IR-2006 multicenter trial). Clinical outcome was evaluated with regard to NK maturation profiles. Unsupervised integrated analysis of NK maturation markers confirmed the existence of three distinct groups of patients hypomaturation (24.1%), intermediate maturation (66.7%), and hypermaturation (9.2%). In univariate analysis, significant differences in overall survival (OS) (
= 0.0006) and relapse-free survival (RFS) (
< 0.0001) were observed among these different groups. Patients with hypomaturation profile had reduced OS, with 3-year OS rates of 12.5 vs 57.1 and 57.4% for patients with intermediate and hypermaturation, respectively. Consistently, patients with hypomaturation profile had reduced RFS, with 3-year RFS rates of 0 vs 52.6 and 73.3% for patients with intermediate and hypermaturation, respectively. In multivariate Cox regression models, NK hypomaturation remained significantly associated with reduced OS and RFS, independent of other factors hazard ratio (HR) = 4.15,
= 0.004 and HR = 8.23,
= 0.003, respectively. NK maturation defects were further explored by mass cytometry and revealed that NK hypomaturation profile is associated with a reduced frequency of memory-like NK cells. In conclusion, besides classical alterations of NK triggering and inhibitory receptors expression in AML, we confirm that the homeostasis of NK maturation can be modified in the context of AML, notably with a deep maturation blockade in almost 10% patients.
Immunomodulatory drugs (IMiDs) are anticancer drugs with immunomodulatory, anti-angiogenesis, anti-proliferative, and pro-apoptotic properties. IMiDs are currently used for the treatment of multiple ...myeloma, myelodysplastic syndrome, and B-cell lymphoma; however, little is known about efficacy in acute myeloid leukemia (AML). We proposed in this study to investigate the relevance of IMiDs therapy for AML treatment. We evaluated the effect of IMiDs on primary AML blasts (
= 24), and the impact in natural killer (NK) cell-mediated immunosurveillance of AML. Using primary AML cells and an immunodeficient mouse leukemia xenograft model, we showed that IMiDs induce AML cell death
and impair leukemia progression
. In addition, treatment of AML blasts with IMiDs resulted in enhanced allogeneic NK cell anti-leukemia reactivity. Treatment by pomalidomide of AML blasts enhanced lysis, degranulation, and cytokine production by primary allogeneic NK cells. Furthermore, the treatment with lenalidomide of patients with myeloid malignancies resulted in NK cell phenotypic changes similar to those observed
. IMiDs increased CD56 and decreased NKp30, NKp46, and KIR2D expression on NK cells. Finally, AML blasts treatment with IMiDs induced phenotypic alterations including downregulation of HLA-class I. The effect of pomalidomide was not correlated with cereblon expression and A/G polymorphism in AML cells. Our data revealed, a yet unobserved, dual effects on AML affecting both AML survival and their sensitivity to NK immunotherapy using IMiDs. Our study encourages continuing investigation for the use of IMiDs in AML, especially in combination with conventional therapy or immunotherapy strategies.
The success of immunotherapy has highlighted the critical role of the immune microenvironment in acute lymphoblastic leukemia (ALL); however, the immune landscape in ALL remains incompletely ...understood and most studies have focused on conventional T cells or NK cells. This study investigated the prognostic impact of circulating γδ T-cell alterations using high-dimensional analysis in a cohort of newly diagnosed adult ALL patients (10 B-ALL; 9 Philadelphia
ALL; 9 T-ALL). Our analysis revealed common alterations in CD8
T cells and γδ T cells of relapsed patients, including accumulation of early stage differentiation and increased expression of BTLA and CD73. We demonstrated that the circulating γδ T-cell signature was the most discriminating between relapsed and disease-free groups. In addition, Vδ2 T-cell alterations strongly discriminated patients by relapse status. Taken together, these data highlight the role of ɣδ T cells in adult ALL patients, among whom Vδ2 T cells may be a pivotal contributor to T-cell immunity in ALL. Our findings provide a strong rationale for further monitoring and potentiating Vδ2 T cells in ALL, including in the autologous setting.
NKp46 is a major determinant of natural killer (NK) cell function and it is implicated in tumor immune surveillance in acute myeloid leukemia (AML). The purpose of this study was to investigate the ...prognostic significance of NKp46 expression in an independent cohort of patients with AML, and to investigate the impact of NKp46 on clinical outcome after allogeneic stem cell transplantation (allo-SCT).
NKp46 expression was assessed at diagnosis on NK cells by flow cytometry (N = 180 patients). Clinical outcome was evaluated with regard to NKp46 expression. Patients with NKp46
high
phenotype at diagnosis had better progression-free survival (PFS) and overall survival (OS) than patients with NKp46
low
phenotype (74.3% vs. 46.6%, p = 0.014; 82.6% vs. 57.1%, p = 0.010, respectively). In multivariate analysis, high NKp46 was an independent factor for improved OS (HR = 0.409, p = 0.010) and PFS (HR = 0.335, p = 0.011). Subgroup analysis revealed that allo-SCT had a favorable impact on PFS in patients with NKp46
high
phenotype (p = 0.025). By contrast, allo-SCT did not impact PFS in patients with low NKp46 expression (p = 0.303).
In conclusion, we validate the prognostic value of NKp46 expression at diagnosis in AML. However, the prognostic value of NKp46 expression is limited to patients treated with allo-SCT, thus suggesting that NKp46 status may be predictive for allo-SCT responsiveness.
A better characterization of T-cell subsets in the microenvironment of classical Hodgkin lymphoma (cHL) would help to develop immunotherapies. Using multicolor flow cytometry, we identified in 6 of ...43 cHL tissue samples a previously unrecognized subset of CD8 T cells coexpressing CXCR5 and inducible T-cell costimulator (ICOS) molecules (CD8CXCR5+ICOS+). These cells shared phenotypic features with follicular helper T (TFH) cells including low CCR7 expression together with high expression of B-cell lymphoma-6, programmed cell death 1, B and T lymphocyte attenuator, CD200, and OX40. They had deficient cytotoxicity, low interferon-γ secretion, and common functional properties with intratumoral CD4+ TFH cells, such as production of interleukin-4 (IL-4), IL-21, CXCL13, and capacity to sustain B cells. Gene profiling analysis showed a significant similarity between the signatures of CD8CXCR5+ICOS+ T cells and CD4+ TFH cells. Benign lymphadenitis tissues (n = 8) were devoid of CD8CXCR5+ICOS+ cells. Among the 35 B-cell lymphoma tissues analyzed, including follicular lymphomas (n = 13), diffuse large cell lymphomas (n = 12), marginal zone lymphomas (MZLs; n = 3), mantle cell lymphomas (n = 3), and chronic lymphocytic leukemias (n = 4), only 1 MZL sample contained CD8CXCR5+ICOS+ cells. Lymphoma tumors with CD8CXCR5+ICOS+ cells shared common histopathological features including residual germinal centers, and contained high amounts of activated CD8CXCR5−ICOS+ cells. These data demonstrate a CD8 T-cell differentiation pathway leading to the acquisition of some TFH similarities. They suggest a particular immunoediting process with global CD8 activation acting mainly, but not exclusively, in HL tumors.
•A subset of CD8 T cells in some Hodgkin lymphomas shares phenotypic and functional features with CD4 TFH cells.
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Vγ9Vδ2 cells, the major γδ T-cell subset in human peripheral blood, represent a T-cell subset that displays reactivity against microbial agents and tumors. The biology of Vγ9Vδ2 T cells remains ...poorly understood. We show herein that the interaction between B- and T-lymphocyte attenuator (BTLA) and herpesvirus entry mediator (HVEM) is a major regulator of Vγ9Vδ2 T-cell proliferation control. BTLA was strongly expressed at the surface of resting Vγ9Vδ2 T cells and inversely correlated with T-cell differentiation. BTLA-HVEM blockade by monoclonal antibodies resulted in the enhancement of Vγ9Vδ2 T-cell receptor–mediated signaling, whereas BTLA-HVEM interaction led to a decrease in phosphoantigen-mediated proliferation by inducing a partial S-phase arrest. Our data also suggested that BTLA-HVEM might participate in the control of γδ T-cell differentiation. In addition, the proliferation of autologous γδ T cells after exposition to lymphoma cells was dramatically reduced through BTLA-HVEM interaction. These data suggest that HVEM interaction with BTLA may play a role in lymphomagenesis by interfering with Vγ9Vδ2 T-cell proliferation. Moreover, BTLA stimulation of Vγ9Vδ2 T cells appears as a new possible mechanism of immune escape by lymphoma cells.
•BTLA-HVEM interaction negatively regulates the proliferation of LTγδ.•BTLA-HVEM interaction appears as a new possible mechanism of immune escape by lymphoma cells.
Significance
This work provides a report of accumulation of unconventional CD56
−
CD16
+
NK cells in nonvirally induced malignancies. Increased frequency of CD56
−
CD16
+
NK cells is associated with ...adverse clinical outcome in AML, as well as other maturation defects, and might contribute to a defective control of AML progression. Pseudotime analysis highlights a disruption in the maturation process of conventional NK cells in AML patients, leading to a bifurcation point absent in healthy subjects. This analysis, combined with the reduced frequency of conventional NK cells observed in AML patients, suggests that unconventional CD56
−
CD16
+
NK cells derive from an aberrant maturation of conventional NK cells. Overall, accumulation of CD56
−
CD16
+
NK cells could be an important feature of immune escape from innate immunity.
Natural killer (NK) cells are major antileukemic immune effectors. Leukemic blasts have a negative impact on NK cell function and promote the emergence of phenotypically and functionally impaired NK cells. In the current work, we highlight an accumulation of CD56
−
CD16
+
unconventional NK cells in acute myeloid leukemia (AML), an aberrant subset initially described as being elevated in patients chronically infected with HIV-1. Deep phenotyping of NK cells was performed using peripheral blood from patients with newly diagnosed AML (
n
= 48, HEMATOBIO cohort, NCT02320656) and healthy subjects (
n
= 18) by mass cytometry. We showed evidence of a moderate to drastic accumulation of CD56
−
CD16
+
unconventional NK cells in 27% of patients. These NK cells displayed decreased expression of NKG2A as well as the triggering receptors NKp30 and NKp46, in line with previous observations in HIV-infected patients. High-dimensional characterization of these NK cells highlighted a decreased expression of three additional major triggering receptors required for NK cell activation, NKG2D, DNAM-1, and CD96. A high proportion of CD56
−
CD16
+
NK cells at diagnosis was associated with an adverse clinical outcome and decreased overall survival (HR = 0.13;
P
= 0.0002) and event-free survival (HR = 0.33;
P
= 0.018) and retained statistical significance in multivariate analysis. Pseudotime analysis of the NK cell compartment highlighted a disruption of the maturation process, with a bifurcation from conventional NK cells toward CD56
−
CD16
+
NK cells. Overall, our data suggest that the accumulation of CD56
−
CD16
+
NK cells may be the consequence of immune escape from innate immunity during AML progression.
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