Adoptive T-cell Therapy (ACT) involves using tumor-infiltrating lymphocytes (TIL) isolated from metastatic melanoma and expanding them ex vivo prior to infusion into lympho-depleted patients. This is one of the most promising approaches to treat metastatic melanoma, with the rates of clinical response between 48-50% based on studies done at NCI, M.D. Anderson Cancer Center (Houston, TX), and Sheba Medical Center (Tel Aviv, Israel). In the Phase II ACT Trial at M.D. Anderson Cancer Center , our group has uncovered an association between positive clinical response and the amount of CD8+ tumor-infiltrating lymphocytes expressing B and T Lymphocyte Attenuator (BTLA), a reported inhibitory receptor on T-cells.
BTLA marks a less-differentiated tumor-infiltrating lymphocyte subset in melanoma with enhanced survival properties.
Sex, Age, Specimen part, Subject
View SamplesPompe disease is caused by autosomal recessive mutations in the GAA gene, which encodes acid alpha-glucosidase. Although enzyme replacement therapy has recently improved patient survival greatly, the results in skeletal muscles and for advanced disease are still not satisfactory. Here, we report the derivation of Pompe disease induced pluripotent stem cells (PomD-iPSCs) and their potential for pathogenesis modeling, drug testing and disease marker identification. PomD-iPSCs maintained pluripotent features, and had low GAA activity and high glycogen content. Cardiomyocyte-like cells (CMLCs) differentiated from PomD-iPSCs recapitulated the hallmark Pompe disease pathophysiological phenotypes, including high levels of glycogen, abundant intracellular LAMP-1- or LC3-positive granules, and multiple ultrastructural aberrances. Drug rescue assessment showed that exposure of PomD-iPSC-derived CMLCs to rhGAA reversed the major pathologic phenotypes. Further, L-carnitine and 3- methyladenine treatment reduced defective cellular respiration and buildup of phagolysosomes, respectively, in the diseased cells. By comparative transcriptome analysis, we identified glycogen metabolism, lysosome and mitochondria related marker genes whose expression robustly correlated with the therapeutic effect of drug treatment in PomD-iPSC-derived CMLCs. Collectively, these results demonstrate that PomD-iPSCs are a promising in vitro disease model for development of novel therapeutic strategies for Pompe disease.
Human Pompe disease-induced pluripotent stem cells for pathogenesis modeling, drug testing and disease marker identification.
Specimen part
View SamplesThree of the melanoma cell lines show higher expression fold change after stimulation than the other 3.
Loss of IFN-γ Pathway Genes in Tumor Cells as a Mechanism of Resistance to Anti-CTLA-4 Therapy.
Specimen part
View SamplesTo understand why cancer vaccine-induced T cells often fail to eradicate tumors, we studied immune responses in mice vaccinated with gp100 peptide emulsified in incomplete Freund's adjuvant (IFA), commonly used in clinical cancer vaccine trials. After gp100 peptide/IFA vaccination, tumor-specific CD8+ T cells (adoptively transferred from gp100-specific TCR-transgenic pmel-1 mice) accumulated not in tumors but at the persisting, antigen-rich vaccination site. Once there, primed T cells became dysfunctional and underwent antigen-driven, IFN- and FasL-mediated apoptosis, resulting in systemic hyporesponsiveness to subsequent vaccination. Provision of anti-CD40 antibody, TLR7 agonist and interleukin-2 (covax) reduced T cell apoptosis but did not prevent vaccination site sequestration. A non-persisting vaccine formulation shifted T cell localization towards tumors, inducing superior anti-tumor activity. Short-lived formulation also reduced systemic T cell dysfunction and promoted memory formation, as shown by gene expression profiling and other measures. Persisting peptide/IFA vaccine depots, currently used to vaccinate cancer patients, can induce specific T cell sequestration at vaccination sites followed by dysfunction and deletion; short-lived depot formulations may overcome these limitations and result in greater therapeutic efficacy of peptide-based cancer vaccines.
Persistent antigen at vaccination sites induces tumor-specific CD8⁺ T cell sequestration, dysfunction and deletion.
Specimen part, Time
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