Effects of valproic acid on histone deacetylase inhibition in vitro and in glioblastoma patient samples

Background: The antiepileptic drug valproic acid (VPA) inhibits histone deacetylase in glioblastoma cells in vitro, which influences several oncogenic pathways and decreases glioma cell proliferation. The clinical relevance of these observations remains unclear, as VPA does not seem to affect glioblastoma patient survival. In this study, we analyzed whether the in vitro effects of VPA treatment on histone acetylation are also observed in tumor tissues of glioblastoma patients. Methods: The in vitro effects of VPA treatment on histone acetylation were assessed with immunofluorescence and western blotting. On tissue microarrays and in fresh-frozen glioblastoma tissues we investigated the histone acetylation patterns of patients who were either treated with VPA or did not receive antiepileptic drugs at the time of their surgery. We also performed mRNA expression-based and gene set enrichment analyses on these tissues. Results: VPA increased the expression levels of acetylated histones H3 and H4 in vitro, in agreement with previous reports. In tumor samples obtained from glioblastoma patients, however, VPA treatment affected neither gene (set) expression nor histone acetylation. Conclusions: The in vitro effects of VPA on histone acetylation status in glioblastoma cells could not be confirmed in clinical tumor samples of glioblastoma patients using antiepileptic doses of VPA, which reflects the lack of effect of VPA on the clinical outcome of glioblastoma patients

Autotaxin impedes anti-tumor immunity by suppressing chemotaxis and tumor infiltration of CD8+ T cells

Artículo publicado en revista Cell Reports, 2021 Nov 16;37(7):110013. doi: 10.1016/j.celrep.2021.110013.Autotaxin (ATX; ENPP2) produces lysophosphatidic acid (LPA) that regulates multiple biological functions via cognate G protein-coupled receptors LPAR1-6. ATX/LPA promotes tumor cell migration and metastasis via LPAR1 and T cell motility via LPAR2, yet its actions in the tumor immune microenvironment remain unclear. Here, we show that ATX secreted by melanoma cells is chemorepulsive for tumor-infiltrating lymphocytes (TILs) and circulating CD8+ T cells ex vivo, with ATX functioning as an LPA-producing chaperone. Mechanistically, T cell repulsion predominantly involves Gα12/13-coupled LPAR6. Upon anti-cancer vaccination of tumor-bearing mice, ATX does not affect the induction of systemic T cell responses but, importantly, suppresses tumor infiltration of cytotoxic CD8+ T cells and thereby impairs tumor regression. Moreover, single-cell data from melanoma tumors are consistent with intratumoral ATX acting as a T cell repellent. These findings highlight an unexpected role for the pro-metastatic ATX-LPAR axis in suppressing CD8+ T cell infiltration to impede anti-tumor immunity, suggesting new therapeutic opportunities.This work was supported by private funding to W.H.M. and grants from the Dutch Cancer Society (NKI 2013-5951 and 10764 to I.V. and NKI 2017-10894 to J.B. and I.V.), the German Research Foundation (DFG) (ME 4924/1-1 to A. Mazzocca), and the NIH (P30 GM127211 to A.J.M.). E.M.-R. is supported by a ‘‘Ramo ´n y Cajal’’ Award (RYC2019-027950-I) from Ministerio de Ciencia e Innovacio´n (MICINN), Spain

Radiotherapy and Cisplatin Increase Immunotherapy Efficacy by Enabling Local and Systemic Intratumoral T-cell Activity

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Autotaxin impedes anti-tumor immunity by suppressing chemotaxis and tumor infiltration of CD8+ T cells

To improve the efficacy of immunotherapy, it is essential to better understand how cytotoxic CD8+ T cells infiltrate into tumors. Here, we examine a role for autotaxin (ATX) in this process. ATX (encoded by ENPP2) is a secreted phospholipase that produces the lipid mediator lysophosphatidic acid (LPA) to regulate multiple biological functions via specific G protein-coupled receptors, termed LPAR1-6. ATX/LPA promotes tumor cell migration via LPAR1 and T-cell motility via LPAR2, yet its actions in the tumor microenvironment remain unclear. Here, we show that tumor-intrinsic ATX suppresses T-cell infiltration to impede anti-tumor immunity, and identify LPAR6 as a T-cell migration inhibitory receptor. Hence, ATX inhibition may show clinical benefit for patients with cancer. We find that ATX secreted by melanoma cells is a chemo-repellent for ex vivo expanded tumor-infiltrating lymphocytes (TILs) and peripheral CD8+ T cells, overruling chemokine activity. Mechanistically, T-cell repulsion is mediated by G12/13-coupled LPAR6, which is highly expressed in immune cells. Contrary to prevailing notions, secreted ATX is bioactive at physiologically insignificant steady-state LPA levels, revealing its secondary function as an LPA carrier or chaperone. Upon anti-cancer vaccination of tumor-bearing mice, tumor-intrinsic ATX does not affect the induction of systemic T-cell responses but, importantly, suppresses tumor infiltration of cytotoxic CD8+ T cells and thereby impairs tumor immune control. Moreover, ENPP2 expression in melanoma tumors – in both malignant and stromal cells – is associated with reduced T-cell infiltration, as inferred from single-cell transcriptomics. These findings highlight an unexpected role for the pro-metastatic ATX-LPAR axis in suppressing CD8+ T cell infiltration and anti-tumor immunity

Characterization and modulation of anti-alpha beta TCR antibodies and their respective binding sites at the beta TCR chain to enrich engineered T cells

T cell engineering strategies offer cures to patients and have entered clinical practice with chimeric antibody-based receptors; αβT cell receptor (αβTCR)-based strategies are, however, lagging behind. To allow a more rapid and successful translation to successful concepts also using αβTCRs for engineering, incorporating a method for the purification of genetically modified T cells, as well as engineered T cell deletion after transfer into patients, could be beneficial. This would allow increased efficacy, reduced potential side effects, and improved safety of newly to-be-tested lead structures. By characterizing the antigen-binding interface of a good manufacturing process (GMP)-grade anti-αβTCR antibody, usually used for depletion of αβT cells from stem cell transplantation products, we developed a strategy that allows for the purification of untouched αβTCR-engineered immune cells by changing 2 amino acids only in the TCRβ chain constant domain of introduced TCR chains. Alternatively, we engineered an antibody that targets an extended mutated interface of 9 amino acids in the TCRβ chain constant domain and provides the opportunity to further develop depletion strategies of engineered immune cells

Autotaxin impedes anti-tumor immunity by suppressing chemotaxis and tumor infiltration of CD8+ T cells

Autotaxin (ATX; ENPP2) produces lysophosphatidic acid (LPA) that regulates multiple biological functions via cognate G protein-coupled receptors LPAR1-6. ATX/LPA promotes tumor cell migration and metastasis via LPAR1 and T cell motility via LPAR2, yet its actions in the tumor immune microenvironment remain unclear. Here, we show that ATX secreted by melanoma cells is chemorepulsive for tumor-infiltrating lymphocytes (TILs) and circulating CD8+ T cells ex vivo, with ATX functioning as an LPA-producing chaperone. Mechanistically, T cell repulsion predominantly involves Gα12/13-coupled LPAR6. Upon anti-cancer vaccination of tumor-bearing mice, ATX does not affect the induction of systemic T cell responses but, importantly, suppresses tumor infiltration of cytotoxic CD8+ T cells and thereby impairs tumor regression. Moreover, single-cell data from melanoma tumors are consistent with intratumoral ATX acting as a T cell repellent. These findings highlight an unexpected role for the pro-metastatic ATX-LPAR axis in suppressing CD8+ T cell infiltration to impede anti-tumor immunity, suggesting new therapeutic opportunities

Autotaxin impedes anti-tumor immunity by suppressing chemotaxis and tumor infiltration of CD8+ T cells

Autotaxin (ATX; ENPP2) produces lysophosphatidic acid (LPA) that regulates multiple biological functions via cognate G protein-coupled receptors LPAR1-6. ATX/LPA promotes tumor cell migration and metastasis via LPAR1 and T cell motility via LPAR2, yet its actions in the tumor immune microenvironment remain unclear. Here, we show that ATX secreted by melanoma cells is chemorepulsive for tumor-infiltrating lymphocytes (TILs) and circulating CD8+ T cells ex vivo, with ATX functioning as an LPA-producing chaperone. Mechanistically, T cell repulsion predominantly involves Gα12/13-coupled LPAR6. Upon anti-cancer vaccination of tumor-bearing mice, ATX does not affect the induction of systemic T cell responses but, importantly, suppresses tumor infiltration of cytotoxic CD8+ T cells and thereby impairs tumor regression. Moreover, single-cell data from melanoma tumors are consistent with intratumoral ATX acting as a T cell repellent. These findings highlight an unexpected role for the pro-metastatic ATX-LPAR axis in suppressing CD8+ T cell infiltration to impede anti-tumor immunity, suggesting new therapeutic opportunities.This work was supported by private funding to W.H.M. and grants from the Dutch Cancer Society (NKI 2013-5951 and 10764 to I.V. and NKI 2017-10894 to J.B. and I.V.), the German Research Foundation (DFG) (ME 4924/1-1 to A. Mazzocca), and the NIH (P30 GM127211 to A.J.M.). E.M.-R. is supported by a ‘‘Ramón y Cajal’’ Award (RYC2019-027950-I) from Ministerio de Ciencia e Innovación (MICINN), Spain.Ye