Development of optimized cytotoxicity assays for assessing the antitumor potential of CAR-T cells.

CAR-T cells are T cells expressing a chimeric antigen receptor (CAR) rendering them capable of killing tumor cells after recognition of a target antigen. CD19 CAR-T cells have revolutionized the treatment of hematological malignancies. Their function is typically assessed by cytotoxicity assays using human allogeneic cell lines expressing the target antigen CD19 such as Nalm-6.

Radiation therapy improves CAR T cell activity in acute lymphoblastic leukemia.

Autologous T cells engineered to express a chimeric antigen receptor (CAR) specific for CD19 are approved for the treatment of various CD19 hematological malignancies. While CAR T cells induce objective responses in a majority of patients, relapse frequently occurs upon loss of CD19 expression by neoplastic cells. Radiation therapy (RT) has been successfully employed to circumvent the loss of CAR targets in preclinical models of pancreatic cancer.

Case report: CAR-T cell therapy-induced cardiac tamponade.

Unlabelled: CD19-specific chimeric antigen receptor T (CAR-T) cell therapy has recently been shown to improve the prognosis of refractory diffuse large B-cell lymphoma (DLBCL). However, CAR-T cells may induce numerous adverse events, in particular cytokine release syndrome (CRS) which is frequently associated with cardiovascular manifestations. Among the latter, acute pericardial effusion represents less than 1% of cases and cardiac tamponade has only been reported once.

Generation of Pure Highly Functional Human Anti-Tumor Specific Cytotoxic T Lymphocytes With Stem Cell-Like Memory Features for Melanoma Immunotherapy.

Adoptive immunotherapy based on the transfer of anti-tumor cytotoxic T lymphocytes (CTLs) is a promising strategy to cure cancers. However, rapid expansion of numerous highly functional CTLs with long-lived features remains a challenge. Here, we constructed NIH/3T3 mouse fibroblast-based artificial antigen presenting cells (AAPCs) and precisely evaluated their ability to circumvent this difficulty.

Kidney Transplant T Cell-Mediated Rejection Occurring After Anti-CD19 CAR T-Cell Therapy for Refractory Aggressive Burkitt-like Lymphoma With 11q Aberration: A Case Report.

Post-transplant lymphoproliferative disorder is a growing complication of kidney transplantation and is associated with a poor prognosis. Anti-CD19 chimeric antigen receptor (CAR) T-cell therapy is an important new treatment option modifying the outcome of refractory hematological cancers. Here, we report the case of a 40-year-old kidney transplant recipient who developed a Burkitt-like lymphoma with 11q aberration 5 years after transplantation.

[Immunomonitoring of patients treated with CAR-T cells for hematological malignancy: Guidelines from the CARTi group and the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC)].

CAR-T cells represent a new anti-tumor immunotherapy which has shown its clinical efficacy in B-cell malignancies. The results of clinical trials carried out in this context have shown that certain immunological characteristics of patients before (at the time of apheresis) and after the administration of the treatment, or of the CAR-T cells themselves, are correlated with the response to the treatment or to its toxicity. However, to date, there are no recommendations on the immunological monitoring of patients treated in real life.

HLA-Class II Artificial Antigen Presenting Cells in CD4 T Cell-Based Immunotherapy.

CD4 T cells differentiate into various T helper subsets characterized by distinct cytokine secreting profiles that confer them effector functions adapted to a variety of infectious or endogenous threats. Regulatory CD4 T cells are another specialized subset that plays a fundamental role in the maintenance of immune tolerance to self-antigens. Manipulating effector or regulatory CD4 T cells responses is a promising immunotherapy strategy for, respectively, chronical viral infections and cancer, or severe autoimmune diseases and transplantation.

Cancer vaccines: designing artificial synthetic long peptides to improve presentation of class I and class II T cell epitopes by dendritic cells.

There is now a consensus that efficient peptide vaccination against cancer requires that peptides should (i) be exclusively presented by professional APC and (ii) stimulate both CD4 and CD8-specific T cell responses. To this aim, in recent trials, patients were vaccinated with pools of synthetic long peptides (SLP) (15-30 aa long) composed of a potential class I epitope(s) elongated at both ends with native antigen sequences to also provide a potential class II epitope(s). Using MELOE-1 as a model antigen, we present an alternative strategy consisting in linking selected class I and class II epitopes with an artificial cathepsin-sensitive linker to improve epitope processing and presentation by DC.

The ADAMTS13 peptide is a dominant HLA-DR1-restricted CD4 T-cell epitope.

Acquired thrombotic thrombocytopenic purpura is a rare and severe disease characterized by auto-antibodies directed against "A Disintegrin And Metalloproteinase with Thrombospondin type 1 repeats, 13 member" (ADAMTS13), a plasma protein involved in hemostasis. Involvement of CD4 T cells in the pathogenesis of the disease is suggested by the IgG isotype of the antibodies. However, the nature of the CD4 T-cell epitopes remains poorly characterized.

Heterogeneous epigenetic regulation of HACE1 in Burkitt- Lymphoma-derived cells.

We examined the consequences of 3-deazaneplanocin A (DZNep) on HACE1 expression in human Burkitt- Lymphoma-derived cells to investigate fundamental molecular mechanisms that control its expression. We treated the human Burkitt- Lymphoma-derived cells lines Ramos and Raji with DZNep and examined HACE1 mRNA expression by RT-PCR. We also studied the effect of DZNep on the methylation of lysine 9 and 27 of histone 3 (H3K27me3 and H3K9me2) associated with the CpG88 and CpG177 islands of the HACE1 promoters by chromatin immunoprecipitation and quantitative PCR.

Identification of a novel PD-L1 positive solid tumor transplantable in HLA-A*0201/DRB1*0101 transgenic mice.

HLA-A*0201/DRB1*0101 transgenic mice (A2/DR1 mice) have been developed to study the immunogenicity of tumor antigen-derived T cell epitopes. To extend the use and application of this mouse model in the field of antitumor immunotherapy, we described a tumor cell line generated from a naturally occurring tumor in A2/DR1 mouse named SARC-L1. Histological and genes signature analysis supported the sarcoma origin of this cell line.

Frameshift mutations, neoantigens and tumor-specific CD8(+) T cells in microsatellite unstable colorectal cancers.

Microsatellite unstable colorectal cancers (CRC) express frameshift mutation-derived tumor-specific neoantigens. We recently showed that: (i) frameshift mutations were correlated with tumor-infiltrating CD8(+) T cell density, (ii) neoantigen-specific cytotoxic T cells could be obtained in patients whose tumors harbored these mutations, underlining the interest of developing personalized immunotherapy strategies in these cancers.

HACE1 is a putative tumor suppressor gene in B-cell lymphomagenesis and is down-regulated by both deletion and epigenetic alterations.

HECT domain and ankyrin repeat containing E3 ubiquitin protein ligase 1, HACE1, located on chromosome 6q, encodes an E3 ubiquitin ligase and is downregulated in many human tumors. Here, we report HACE1 as a candidate tumor suppressor gene down-regulated by a combination of deletion and epigenetic mechanisms. HACE1 deletions were observed in 40% of B-cell lymphoma tumors.

Integrative Analyses of Colorectal Cancer Show Immunoscore Is a Stronger Predictor of Patient Survival Than Microsatellite Instability.

Microsatellite instability in colorectal cancer predicts favorable outcomes. However, the mechanistic relationship between microsatellite instability, tumor-infiltrating immune cells, Immunoscore, and their impact on patient survival remains to be elucidated. We found significant differences in mutational patterns, chromosomal instability, and gene expression that correlated with patient microsatellite instability status.

Artificial antigen-presenting cells expressing HLA class II molecules as an effective tool for amplifying human specific memory CD4(+) T cells.

Owing to their multiple immune functions, CD4(+) T cells are of major interest for immunotherapy in chronic viral infections and cancer, as well as for severe autoimmune diseases and transplantation. Therefore, standardized methods allowing rapid generation of a large number of CD4(+) T cells for adoptive immunotherapy are still awaited. We constructed stable artificial antigen-presenting cells (AAPCs) derived from mouse fibroblasts.

Correlation between Density of CD8+ T-cell Infiltrate in Microsatellite Unstable Colorectal Cancers and Frameshift Mutations: A Rationale for Personalized Immunotherapy.

Colorectal cancers with microsatellite instability (MSI) represent 15% of all colorectal cancers, including Lynch syndrome as the most frequent hereditary form of this disease. Notably, MSI colorectal cancers have a higher density of tumor-infiltrating lymphocytes (TIL) than other colorectal cancers. This feature is thought to reflect the accumulation of frameshift mutations in sequences that are repeated within gene coding regions, thereby leading to the synthesis of neoantigens recognized by CD8(+) T cells.

Direct Toll-Like Receptor 8 signaling increases the functional avidity of human CD8+ T lymphocytes generated for adoptive T cell therapy strategies.

Adoptive transfer of in vitro activated and expanded antigen-specific cytotoxic T lymphocytes (CTLs) is a promising therapeutic strategy for infectious diseases and cancers. Obtaining in vitro a sufficient amount of highly specific cytotoxic cells and capable of retaining cytotoxic activity in vivo remains problematic. We studied the role of Toll-Like Receptor-8 (TLR8) engagement on peripheral CTLs activated with melanoma antigen MART-1-expressing artificial antigen-presenting cells (AAPCs).

[Immunotherapy for colorectal cancer].

Recent studies have underlined the close link between immune response and prognosis of patients with colorectal cancer (CRC). Immune response understanding combined with biotechnology progress of the last years has allowed development of immunotherapy strategies in CRC. Immunotherapy strategies are divided in "active" or "passive" strategies (patients immune system stimulation or not) and considering the activation of antigen specific immune response or not.

Regulatory T lymphocytes are associated with less aggressive histologic features in microsatellite-unstable colorectal cancers.

Background: Colorectal cancers (CRCs) with microsatellite instability (MSI) are associated with a good prognosis and a high density of tumor-infiltrating lymphocytes (TILs). We have undertaken to determine the link between TIL densities and MSI CRC histologic features.

Patients And Methods: Using tissue microarrays, T-cell sub-population infiltration, including T cells (CD3), cytotoxic T cells (CD8) and regulatory T cells (FoxP3) were studied in 86 MSI CRCs.

Germline copy number variation of genes involved in chromatin remodelling in families suggestive of Li-Fraumeni syndrome with brain tumours.

Germline alterations of the tumour suppressor TP53 gene are detected approximately in 25% of the families suggestive of Li-Fraumeni syndrome (LFS), characterised by a genetic predisposition to a wide tumour spectrum, including soft-tissue sarcomas, osteosarcomas, premenopausal breast cancers, brain tumours, adrenocortical tumours, plexus choroid tumours, leukaemia and lung cancer. The aim of this study was to determine the contribution of germline copy number variations (CNVs) to LFS in families without detectable TP53 mutation. Using a custom-designed high-resolution array CGH, we evaluated the presence of rare germline CNVs in 64 patients fulfilling the Chompret criteria for LFS, but without any detectable TP53 alteration.

Genetic variations of the A13/A14 repeat located within the EGFR 3' untranslated region have no oncogenic effect in patients with colorectal cancer.

Background: The EGFR 3' untranslated region (UTR) harbors a polyadenine repeat which is polymorphic (A13/A14) and undergoes somatic deletions in microsatellite instability (MSI) colorectal cancer (CRC). These mutations could be oncogenic in colorectal tissue since they were shown to result into increased EGFR mRNA stability in CRC cell lines.

Methods: First, we determined in a case control study including 429 CRC patients corresponding to different groups selected or not on age of tumor onset and/or familial history and/or MSI, whether or not, the germline EGFR A13/A14 polymorphism constitutes a genetic risk factor for CRC; second, we investigated the frequency of somatic mutations of this repeat in 179 CRC and their impact on EGFR expression.

CRTAM receptor engagement by Necl-2 on tumor cells triggers cell death of activated Vγ9Vδ2 T cells.

Human Vγ9Vδ2 T cells exert potent in vitro and in vivo antitumor activities, making them promising candidates for immunotherapy strategies. Recognition of tumor cells by Vγ9Vδ2 T cells requires engagement of the TCR and/or NK receptors. Recently, one of the novel NK receptors, the class I-restricted T cell-associated molecule (CRTAM), has been described to promote cytotoxic function of NK cells and to lead to IFN-γ secretion by CD8(+) T cells through interaction with its ligand, Necl-2.