Autologous T cell therapy for MAGE-A4 solid cancers in HLA-A*02 patients: a phase 1 trial.

Affinity-optimized T cell receptors can enhance the potency of adoptive T cell therapy. Afamitresgene autoleucel (afami-cel) is a human leukocyte antigen-restricted autologous T cell therapy targeting melanoma-associated antigen A4 (MAGE-A4), a cancer/testis antigen expressed at varying levels in multiple solid tumors. We conducted a multicenter, dose-escalation, phase 1 trial in patients with relapsed/refractory metastatic solid tumors expressing MAGE-A4, including synovial sarcoma (SS), ovarian cancer and head and neck cancer ( NCT03132922 ).

Systemic and local immunity following adoptive transfer of NY-ESO-1 SPEAR T cells in synovial sarcoma.

Background: Gene-modified autologous T cells expressing NY-ESO-1, an affinity-enhanced T-cell receptor (TCR) reactive against the NY-ESO-1-specific HLA-A*02-restricted peptide SLLMWITQC (NY-ESO-1 SPEAR T-cells; GSK 794), have demonstrated clinical activity in patients with advanced synovial sarcoma (SS). The factors contributing to gene-modified T-cell expansion and the changes within the tumor microenvironment (TME) following T-cell infusion remain unclear. These studies address the immunological mechanisms of response and resistance in patients with SS treated with NY-ESO-1 SPEAR T-cells.

Antitumor Activity Associated with Prolonged Persistence of Adoptively Transferred NY-ESO-1 T Cells in Synovial Sarcoma.

We evaluated the safety and activity of autologous T cells expressing NY-ESO-1, an affinity-enhanced T-cell receptor (TCR) recognizing an HLA-A2-restricted NY-ESO-1/LAGE1a-derived peptide, in patients with metastatic synovial sarcoma (NY-ESO-1T cells). Confirmed antitumor responses occurred in 50% of patients (6/12) and were characterized by tumor shrinkage over several months. Circulating NY-ESO-1T cells were present postinfusion in all patients and persisted for at least 6 months in all responders.

Distinct gene expression program dynamics during erythropoiesis from human induced pluripotent stem cells compared with adult and cord blood progenitors.

Background: Human-induced pluripotent stem cells (hiPSCs) are a potentially invaluable resource for regenerative medicine, including the in vitro manufacture of blood products. HiPSC-derived red blood cells are an attractive therapeutic option in hematology, yet exhibit unexplained proliferation and enucleation defects that presently preclude such applications. We hypothesised that substantial differential regulation of gene expression during erythroid development accounts for these important differences between hiPSC-derived cells and those from adult or cord-blood progenitors.

A network including TGFβ/Smad4, Gata2, and p57 regulates proliferation of mouse hematopoietic progenitor cells.

Transforming growth factor β (TGFβ) is a potent inhibitor of hematopoietic stem and progenitor cell proliferation. However, the precise mechanism for this effect is unknown. Here, we have identified the transcription factor Gata2, previously described as an important regulator of hematopoietic stem cell function, as an early and direct target gene for TGFβ-induced Smad signaling in hematopoietic progenitor cells.

Distinct mechanisms of inadequate erythropoiesis induced by tumor necrosis factor alpha or malarial pigment.

The role of infection in erythropoietic dysfunction is poorly understood. In children with P. falciparum malaria, the by-product of hemoglobin digestion in infected red cells (hemozoin) is associated with the severity of anemia which is independent of circulating levels of the inflammatory cytokine tumor necrosis alpha (TNF-α).

Dynamic analysis of gene expression and genome-wide transcription factor binding during lineage specification of multipotent progenitors.

We used the paradigmatic GATA-PU.1 axis to explore, at the systems level, dynamic relationships between transcription factor (TF) binding and global gene expression programs as multipotent cells differentiate. We combined global ChIP-seq of GATA1, GATA2, and PU.

Single-cell gene expression analysis reveals genetic associations masked in whole-tissue experiments.

Gene expression in multiple individual cells from a tissue or culture sample varies according to cell-cycle, genetic, epigenetic and stochastic differences between the cells. However, single-cell differences have been largely neglected in the analysis of the functional consequences of genetic variation. Here we measure the expression of 92 genes affected by Wnt signaling in 1,440 single cells from 15 individuals to associate single-nucleotide polymorphisms (SNPs) with gene-expression phenotypes, while accounting for stochastic and cell-cycle differences between cells.

Methods for qPCR gene expression profiling applied to 1440 lymphoblastoid single cells.

The stochastic nature of generating eukaryotic transcripts challenges conventional methods for obtaining and analyzing single-cell gene expression data. In order to address the inherent noise, detailed methods are described on how to collect data on multiple genes in a large number of single cells using microfluidic arrays. As part of a study exploring the effect of genotype on Wnt pathway activation, data were collected for 96 qPCR assays on 1440 lymphoblastoid cells.

Inferring rules of lineage commitment in haematopoiesis.

How the molecular programs of differentiated cells develop as cells transit from multipotency through lineage commitment remains unexplored. This reflects the inability to access cells undergoing commitment or located in the immediate vicinity of commitment boundaries. It remains unclear whether commitment constitutes a gradual process, or else represents a discrete transition.

GATA-2 mediated regulation of normal hematopoietic stem/progenitor cell function, myelodysplasia and myeloid leukemia.

Unremitting blood cell production throughout the lifetime of an organism is reliant on hematopoietic stem cells (HSCs). A rare and relatively quiescent cell type, HSCs are, on entry into cell cycle fated to self-renew, undergo apoptosis or differentiate to progenitors (HPCs) that eventually yield specific classes of blood cells. Disruption of these HSC fate decisions is considered to be fundamental to the development of leukemia.

High GATA-2 expression inhibits human hematopoietic stem and progenitor cell function by effects on cell cycle.

Evidence suggests the transcription factor GATA-2 is a critical regulator of murine hematopoietic stem cells. Here, we explore the relation between GATA-2 and cell proliferation and show that inducing GATA-2 increases quiescence (G(0) residency) of murine and human hematopoietic cells. In human cord blood, quiescent fractions (CD34(+)CD38(-)Hoechst(lo)Pyronin Y(lo)) express more GATA-2 than cycling counterparts.

GATA-2 regulates granulocyte-macrophage progenitor cell function.

The zinc finger transcription factor GATA-2 has been implicated in the regulation of hematopoietic stem cells. Herein, we explored the role of GATA-2 as a candidate regulator of the hematopoietic progenitor cell compartment. We showed that bone marrow from GATA-2 heterozygote (GATA-2(+/-)) mice displayed attenuated granulocyte-macrophage progenitor function in colony-forming cell (CFC) and serial replating CFC assays.

Impaired embryonic haematopoiesis yet normal arterial development in the absence of the Notch ligand Jagged1.

Specific deletion of Notch1 and RBPjkappa in the mouse results in abrogation of definitive haematopoiesis concomitant with the loss of arterial identity at embryonic stage. As prior arterial determination is likely to be required for the generation of embryonic haematopoiesis, it is difficult to establish the specific haematopoietic role of Notch in these mutants. By analysing different Notch-ligand-null embryos, we now show that Jagged1 is not required for the establishment of the arterial fate but it is required for the correct execution of the definitive haematopoietic programme, including expression of GATA2 in the dorsal aorta.

Novel compounds with antiproliferative activity against imatinib-resistant cell lines.

Chronic myelogenous leukemia is caused by the Bcr-Abl hybrid gene that encodes the p210Bcr-Abl chimeric oncoprotein. Although it reduces the total body burden of leukemia cells, the use of imatinib mesylate as a single agent may be accompanied by the evolution of resistance due mainly to the acquisition of point mutations. Imatinib has been combined with drugs that inhibit both the active and the inactive states of the p210Bcr-Abl kinase.

ETO-2 associates with SCL in erythroid cells and megakaryocytes and provides repressor functions in erythropoiesis.

Lineage specification and cellular maturation require coordinated regulation of gene expression programs. In large part, this is dependent on the activator and repressor functions of protein complexes associated with tissue-specific transcriptional regulators. In this study, we have used a proteomic approach to characterize multiprotein complexes containing the key hematopoietic regulator SCL in erythroid and megakaryocytic cell lines.

Modulation of the p38 MAPK (mitogen-activated protein kinase) pathway through Bcr/Abl: implications in the cellular response to Ara-C.

The chimaeric protein Bcr/Abl, the hallmark of chronic myeloid leukaemia, has been connected with several signalling pathways, such as those involving protein kinase B/Akt, JNK (c-Jun N-terminal kinase) or ERKs (extracellular-signal-regulated kinases) 1 and 2. However, no data about the p38 MAPK (mitogen-activated protein kinase) have been reported. Here, we present evidence showing that Bcr/Abl is able to modulate this signalling pathway.

Comparative gene expression profile of chronic myeloid leukemia cells innately resistant to imatinib mesylate.

Objective: Resistance to imatinib mesylate monotherapy is clearly a barrier to successful treatment of chronic myeloid leukemia (CML) patients. In some patients, resistance arises due to powerful selective pressure on rare cells that carry amplified copies of the BCR-ABL fusion oncogene or point mutations in the Bcr-Abl tyrosine kinase domain that affect binding of the drug to the oncoprotein. However, in a proportion of patients neither mechanism operates, and resistance appears to be a priori, existing prior to exposure to the drug.

Imatinib mesylate in combination with other chemotherapeutic drugs: in vitro studies.

Imatinib mesylate (Gleevec) (formerly STI571) has secured a definitive role in the treatment of chronic myeloid leukemia (CML) due to its specificity and efficacy. Although some patients become resistant to the drug, it may still be possible to control the leukemia with imatinib-containing regimens. Front-line treatment with such combinations may indeed minimize the risk that resistance, and hence relapse, occurs.