BackgroundCorticosteroids are routinely utilized to alleviate edema in patients with intracranial lesions and are first-line agents to combat immune-related adverse events (irAEs) that arise with immune checkpoint blockade treatment. However, it is not known if or when corticosteroids can be administered without abrogating the efforts of immunotherapy. The purpose of this study was to evaluate the impact of dexamethasone on lymphocyte activation and proliferation during checkpoint blockade to provide guidance for corticosteroid use while immunotherapy is being implemented as a cancer treatment.MethodsLymphocyte proliferation, differentiation, and cytokine production were evaluated during dexamethasone exposure. Human T cells were stimulated through CD3 ligation and co-stimulated either directly by CD28 ligation or by providing CD80, a shared ligand for CD28 and CTLA-4. CTLA-4 signaling was inhibited by antibody blockade using ipilimumab which has been approved for the treatment of several solid tumors. The in vivo effects of dexamethasone during checkpoint blockade were evaluated using the GL261 syngeneic mouse intracranial model, and immune populations were profiled by flow cytometry.ResultsDexamethasone upregulated CTLA-4 mRNA and protein in CD4 and CD8 T cells and blocked CD28-mediated cell cycle entry and differentiation. Naïve T cells were most sensitive, leading to a decrease of the development of more differentiated subsets. Resistance to dexamethasone was conferred by blocking CTLA-4 or providing strong CD28 co-stimulation prior to dexamethasone exposure. CTLA-4 blockade increased IFNγ expression, but not IL-2, in stimulated human peripheral blood T cells exposed to dexamethasone. Finally, we found that CTLA-4 blockade partially rescued T cell numbers in mice bearing intracranial gliomas. CTLA-4 blockade was associated with increased IFNγ-producing tumor-infiltrating T cells and extended survival of dexamethasone-treated mice.ConclusionsDexamethasone-mediated T cell suppression diminishes naïve T cell proliferation and differentiation by attenuating the CD28 co-stimulatory pathway. However, CTLA-4, but not PD-1 blockade can partially prevent some of the inhibitory effects of dexamethasone on the immune response.Electronic supplementary materialThe online version of this article (10.1186/s40425-018-0371-5) contains supplementary material, which is available to authorized users.

Glycogen synthase kinase 3 (GSK3), a serine/threonine kinase, is involved in diverse cellular processes ranging from nutrient and energy homeostasis to proliferation and apoptosis. Its role in glioblastoma multiforme has yet to be elucidated. We identified GSK3 as a regulator of glioblastoma multiforme cell survival using microarray analysis and small-molecule and genetic inhibitors of GSK3 activity. Various molecular and genetic approaches were then used to dissect out the molecular mechanisms responsible for GSK3 inhibitioninduced cytotoxicity. We show that multiple small molecular inhibitors of GSK3 activity and genetic down-regulation of GSK3A/B significantly inhibit glioma cell survival and clonogenicity. The potency of the cytotoxic effects is directly correlated with decreased enzyme activity-activating phosphorylation of GSK3A/B Y276/Y216 and with increased enzyme activity inhibitory phosphorylation of GSK3A S21. Inhibition of GSK3 activity results in c-MYC activation, leading to the induction of Bax, Bim, DR4/DR5, and tumor necrosis factor-related apoptosis-inducing ligand expression and subsequent cytotoxicity. Additionally, down-regulation of GSK3 activity results in alteration of intracellular glucose metabolism resulting in dissociation of hexokinase II from the outer mitochondrial membrane with subsequent mitochondrial destabilization. Finally, inhibition of GSK3 activity causes a dramatic decrease in intracellular nuclear factor-KB activity. Inhibition of GSK3 activity results in c-MYC-dependent glioma cell death through multiple mechanisms, all of which converge on the apoptotic pathways. GSK3 may therefore be an important therapeutic target for gliomas. Future studies will further define the optimal combinations of GSK3 inhibitors and cytotoxic agents for use in gliomas and other cancers. [Cancer Res 2008;68(16):6643-51]

No curative treatment exists for glioblastoma, with median survival times of less than 2 years from diagnosis. As an approach to develop immune-based therapies for glioblastoma, we sought to target antigens expressed in glioma stem cells (GSCs). GSCs have multiple properties that make them significantly more representative of glioma tumors than established glioma cell lines. Epidermal growth factor receptor variant III (EGFRvIII) is the result of a novel tumor-specific gene rearrangement that produces a unique protein expressed in approximately 30% of gliomas, and is an ideal target for immunotherapy. Using PCR primers spanning the EGFRvIII-specific deletion, we found that this tumor-specific gene is expressed in three of three GCS lines. Based on the sequence information of seven EGFRvIII-specific monoclonal antibodies (mAbs), we assembled chimeric antigen receptors (CARs) and evaluated the ability of CAR-engineered T cells to recognize EGFRvIII. Three of these anti-EGFRvIII CAR-engineered T cells produced the effector cytokine, interferon-c, and lysed antigen-expressing target cells. We concentrated development on a CAR produced from human mAb 139, which specifically recognized GSC lines and glioma cell lines expressing mutant EGFRvIII, but not wild-type EGFR and did not recognize any normal human cell tested. Using the 139-based CAR, T cells from glioblastoma patients could be genetically engineered to recognize EGFRvIII-expressing tumors and could be expanded ex vivo to large numbers, and maintained their antitumor activity. Based on these observations, a c-retroviral vector expressing this EGFRvIII CAR was produced for clinical application.

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Summary The haemophagocytic syndrome (HPS) is a rare but frequently fatal disorder of immune regulation caused by hypercytokinemia. Using cytometric bead array technique, the serum T‐helper cell type 1 (Th1) and 2 (Th2) cytokines including interferon‐γ (IFN‐γ), tumour necrosis factor (TNF), interleukin (IL)‐10, IL‐6, IL‐4 and IL‐2 were determined in 24 children with de novo HPS and 87 children as control. The median levels of serum IFN‐γ, IL‐10 and IL‐6 in the acute phase of HPS were 901·7, 879·0 and 63·8 pg/ml, respectively, significantly higher than those after remission, and in the healthy volunteers and patients with viral infection. IL‐4 was slightly elevated while IL‐2 and TNF were within normal range in acute phase. Patients with bacterial sepsis showed an extremely high level of IL‐6 and moderate level of IL‐10, whereas IFN‐γ was only slightly elevated. Five patients were diagnosed with HPS according to the Th1/Th2 cytokine pattern 3–13 d earlier than they fulfilled the relevant diagnostic criteria. IL‐10 level >2000 pg/ml was an unfavorable prognostic factor for HPS treatment response (P = 0·033) and outcome (P = 0·009). We conclude that the significant increase of IFN‐γ and IL‐10 and a slightly increased level of IL‐6 is an early, specific and prognostic cytokine pattern for childhood HPS.