Myeloid-derived cells comprising the tumor stroma represent a heterogeneous population of cells critical to the structure, function and growth of established cancers. We have recently found that engineering tumor-specific CD8+ T cells to secrete IL-12 (IL-12TD) can lead to striking improvements in T-cell activity against established melanomas in murine models. Surprisingly, IL-12-dependent enhancement of CD8+ T-cell anti-tumor function did not occur through direct ligation of receptors on lymphocytes or NK cells. Instead, IL-12 sensitized host bone marrow-derived tumor-stromal cells, partly through interferon-gamma, to indirectly enhance the effects of adoptively-transferred T cells. Direct presentation of antigen by tumor was not necessary, but MHC class I expression on endogenous cells was essential for IL-12 mediated anti-tumor enhancements. Upon successful treatment with IL-12TD cells, we observed the selective elimination of tumor-infiltrating CD11b+ F4/80+ macrophages, CD11b+/ClassII+/CD11c+ dendritic cells and CD11b+/Ly6C+/Ly6G- but not CD11b+/Ly6C+/Ly6G+ myeloid-derived suppressor cells within regressing lesions. These results are consistent with a model whereby IL-12 triggers the maturation of myeloid-derived cells into competent antigen cross-presenting cells. Licensed recognition of these antigens by effector T cells may in turn trigger the collapse of the tumor stroma and aid in the regression of large vascularized lesions.
IL-12 triggers a programmatic change in dysfunctional myeloid-derived cells within mouse tumors.
Specimen part, Disease, Disease stage
View SamplesMouse CD8+ T cells affected by ID3 (Inhibitor of DNA binding 3) display patterns of gene expression suggesting enhanced persistance and survival. In this study, we identified genes differentially expressed between ID32a transduced and mock transduced, and ID32a knockout and wild type mouse CD8+ T cells. Most prominent functions of differentially expressed genes include DNA replication-associated repair, maintenance of chromosome stability and mitotic cell divison machinery. Overall, these data suggest that ID3 acts in favor of maintained survival in CD8+ mouse T cells.
Repression of the DNA-binding inhibitor Id3 by Blimp-1 limits the formation of memory CD8+ T cells.
Treatment
View SamplesAdoptive immunotherapy using ex vivo expanded tumor reactive lymphocytes can mediate durable cancer regression in selected melanoma patients. Analyses of these trials have associated the in vivo engraftment ability of the transferred cells with their anti-tumor efficacy. Thus, there is significant clinical interest in the prospective isolation of tumor specific T cells that can reliably persist after transfer. Animal studies have suggested that central memory CD8+ T cells (TCM) have divergent capabilities including effector differentiation to target antigen and stem cell-like self renewal that enable long term survival after adoptive transfer. In this study, we sought to isolate human melanoma specific TCM to define their in vivo fate and function after autologous therapeutic transfer to metastatic patients. To facilitate the high throughput identification of these rare cells from patients, we report that TCM have a defined stoichiometric production of IL-2 and IFN-g mRNA after antigen stimulation. Melanoma specific T cells screened for high relative IL-2 production possessed a TCM phenotype and superior in vitro proliferative capacity compared to cells with low IL-2 production. To investigate in vivo effector function and self renewal capability, melanoma specific TCM underwent in vitro expansion and differentiation into lytic effector clones and then were adoptively transferred back into their hosts. These clones targeted skin melanocytes in all five patients and persisted long term and reacquired parental TCM attributes in four patients after transfer. These findings demonstrate the favorable engraftment fitness for human TCM-derived clones, but further efforts to improve their anti-tumor efficacy are still necessary.
The stoichiometric production of IL-2 and IFN-γ mRNA defines memory T cells that can self-renew after adoptive transfer in humans.
Specimen part
View SamplesEffector cells for adoptive immunotherapy can be generated by in vitro stimulation of nave or memory subsets of CD8+ T cells. While the characteristics of CD8+ T cell subsets are well defined, the heritable influence of those populations on their effector cell progeny is not well understood. We studied effector cells generated from nave or central memory CD8+ T cells and found that they retained distinct gene expression signatures and developmental programs. Effector cells derived from central memory cells tended to retain their CD62L+ phenotype, but also to acquire KLRG1, an indicator of cellular senescence. In contrast, the effector cell progeny of nave cells displayed reduced terminal differentiation, and, following infusion, they displayed greater expansion, cytokine production, and tumor destruction. These data indicate that effector cells retain a gene expression imprint conferred by their nave or central memory progenitors, and they suggest a strategy for enhancing cancer immunotherapy.
Adoptively transferred effector cells derived from naive rather than central memory CD8+ T cells mediate superior antitumor immunity.
Specimen part
View SamplesCancer cells must evade immune responses at distant sites to establish metastases. The lung is a frequent site for metastasis. We hypothesized that lung-specific immunoregulatory mechanisms create an immunologically permissive environment for tumor colonization. We found that T cell-intrinsic expression of the oxygen-sensing prolyl-hydroxylase (PHD) proteins is required to maintain local tolerance against innocuous antigens in the lung, but powerfully licenses colonization by circulating tumor cells. PHD proteins limit pulmonary type helper (Th)-1 responses, promote CD4+-regulatory T (Treg) cell induction, and restrain CD8+ T cell effector function. Tumor colonization is accompanied by PHD protein-dependent induction of pulmonary Treg cells and suppression of IFN-g-dependent tumor clearance. T cell-intrinsic deletion or pharmacological inhibition of PHD proteins limits tumor colonization of the lung and improves the efficacy of adoptive cell transfer immunotherapy. Collectively, PHD proteins function in T cells to coordinate distinct immunoregulatory programs within the lung that are permissive to cancer metastasis. Overall design: RNA expression was measured by RNA-Seq at day 4 following stimulation of naïve FACS-sorted CD4+ T cells with anti-CD3 and anti-CD28 antibodies in the presence of indicated doses of TGF-b. Gene expression was analysed separately in control Cd4Cre (WT) and Egln1fl/fl Egln2fl/fl Egln3fl/fl Cd4Cre (tKO) cells, or in cells treated with the pharmacological PHD inhibitor dimethyloxaloylglycine (DMOG) and control vehicle-treated cells.
Oxygen Sensing by T Cells Establishes an Immunologically Tolerant Metastatic Niche.
Specimen part, Treatment, Subject
View SamplesTo better elucidate epigenetic mechanisms that correlate with the dynamic gene expression program observed after T cell activation, we investigated the genomic landscape of histone modifications in antigen-experienced CD8+ T cells. Using a ChIP-Seq approach coupled with global gene expression profiling, we generated genome-wide histone H3 lysine 4 (H3K4me3) and H3 lysine 27 (H3K27me3) trimethylation maps in distinct subsets of CD8+ T cells-nave, stem cell memory, central memory, and effector memory-to gain insight into how histone architecture is remodeled during the differentiation of activated T cells. We show that H3K4me3 histone modifications are associated with activation of genes, while H3K27me3 is negatively correlated with gene expression at canonical loci and enhancers regions associated with T cell metabolism, effector function, and memory. Our results also reveal histone modifications and gene expression signatures that distinguish the recently identified stem cell memory T cell from other antigen-experienced CD8+ T cell subsets. Taken together, our results suggest that antigen-experienced T cells may undergo chromatin remodeling in a progressive fashion that may have implications for our understanding of peripheral T cell ontogeny and the formation of immunological memory.
Lineage relationship of CD8(+) T cell subsets is revealed by progressive changes in the epigenetic landscape.
Specimen part
View SamplesAdoptive immunotherapies using genetically-redirected T cells expressing a chimeric antigen receptor (CAR) or T cell receptor (TCR) are poised to enter mainstream clinical practice. Despite encouraging results, some patients fail to respond to current therapies. In part, this phenomenon has been associated with infusion of a reduced number of early memory T cells. Herein, we report that pharmacologic disruption of AKT-signaling (AKTi) is compatible with the transduction of both CARs and TCRs into human T cells and promotes a minimally differentiated CD62L-expressing phenotype. Critically, this intervention did not compromise cell yield. Mechanistically, disruption of AKT-signaling preserved MAPK activation and promoted the intra-nuclear accumulation of FOXO1, a key transcriptional regulator of T-cell memory. Consequently, AKTi synchronized the T-cell transcriptional profile for FOXO1-dependent target genes across multiple donors. Expression of an AKT-resistant FOXO1 mutant phenocopied the influence of AKTi while addition of AKTi to T cells expressing mutant FOXO1 failed to further augment the frequency of CD62L-expressing cells. Finally, CD19 CAR-modified T cells transduced and expanded in AKTi treated established B-cell acute lymphoblastic leukemia superiorly to conventionally grown T cells in a murine xenograft model. Thus, inhibition of AKT-signaling represents a generalizable strategy to generate large numbers of receptor-modified T cells with an early memory phenotype.
Inhibition of AKT signaling uncouples T cell differentiation from expansion for receptor-engineered adoptive immunotherapy.
Treatment, Subject, Time
View SamplesTumours progress despite being infiltrated by effector T cells. Tumour necrosis is associated with poor survival in a variety of cancers. Here, we report that that necrosis causes release of an intracellular ion, potassium, into the extracellular fluid of human and mouse tumours. Surprisingly, elevated extracellular potassium ([K+]e) was sufficient to profoundly suppress mouse and human T cell anti-tumour function. Elevations in [K+]e acted to acutely impair T cell receptor (TCR) dependent Akt-mTOR phosphorylation and effector function. Potassium mediated suppression of Akt-mTOR signalling and T cell effector function required intact activity of PP2A, a serine/threonine phosphatase. The suppressive effect mediated by elevated [K+]e required a T cell-intrinsic increase in intracellular potassium ([K+]i) and was independent of changes in plasma membrane potential (Vm). Finally, ionic reprogramming of tumour-specific T cells via over-expression of the voltage-gated potassium channel Kv1.3 lowered [K+]i and improved effector functions in vitro and in vivo, with this gain of function being dependent on intact channel function. Consequently, Kv1.3 T cell expression enhanced tumour clearance and the survival of melanoma-bearing mice. These results uncover a previously undescribed ionic checkpoint against T cell function within tumours and identify new strategies for cancer immunotherapy. Overall design: RNA expression was measured by RNA-Seq on day 5 of cultures, maintained in individual biologial triplicates which were stimulated with immobilized anti-CD3/28 antibodies or kept in complete media (no stim) - with equivalent conditions treated with isotonic media containing elevated potassium.
Ionic immune suppression within the tumour microenvironment limits T cell effector function.
Sex, Age, Specimen part, Cell line, Treatment, Subject
View SamplesSerial comparison between Th1 and Th17 tumor-specific cells cultured in vitro and ex vivo after transferred into sublethaly irradiated B6.PL mice. Th17-derived cells acquire Th1-like properties in vivo but maintain a distinct molecular profile.
Th17 cells are long lived and retain a stem cell-like molecular signature.
Specimen part, Treatment
View SamplesT cell receptor (TCR) signaling is a critical process in immunity to infectious disease and cancer. Recently, a genome-wide association study has implicated polymorphisms in the CISH locus with susceptibility to infectious diseases. However, the role of Cish in the immune responses and its molecular underpinnings remains unclear. Here we demonstrate that Cish deletion resulted in protection against viral infection and enhanced CD8+ T cell tumor immunity. Transcriptome profiling revealed a hyper-TCR activation signature in Cish-deficient CD8+ T cells. Subsequent analysis revealed an inhibitory role for Cish in PLC1 activation, ensuing Ca2+ release and downstream signaling. In the steady-state Cish was found to physically interact with PLC1, however, PLC1 was only found to be ubiquitinated after acute TCR stimulation in the presence of Cish. These data implicate Cish as a potent negative regulator of TCR signaling and T cell immunity to infection and cancer and may have significant clinical applications.
Cish actively silences TCR signaling in CD8+ T cells to maintain tumor tolerance.
Specimen part, Treatment
View Samples