γδ T cells represent a substantial fraction of intestinal lymphocytes at homeostasis, but they also constitute a major lymphocyte population infiltrating colorectal cancers (CRCs); however, their ...temporal contribution to CRC development or progression remains unclear. Using human CRC samples and murine CRC models, we found that most γδ T cells in premalignant or nontumor colons exhibit cytotoxic markers, whereas tumor-infiltrating γδ T cells express a protumorigenic profile. These contrasting T cell profiles were associated with distinct T cell receptor (TCR)-Vγδ gene usage in both humans and mice. Longitudinal intersectional genetics and antibody-dependent strategies targeting murine γδ T cells enriched in the epithelium at steady state led to heightened tumor development, whereas targeting γδ subsets that accumulate during CRC resulted in reduced tumor growth. Our results uncover temporal pro- and antitumor roles for γδ T cell subsets.
Clinical outcomes in colorectal cancer (CRC) correlate with T cell infiltrates, but the specific contributions of heterogenous T cell types remain unclear. To investigate the diverse function of T ...cells in CRC, we profiled 37,931 T cells from tumors and adjacent normal colon of 16 patients with CRC with respect to transcriptome, TCR sequence, and cell surface markers. Our analysis identified phenotypically and functionally distinguishable effector T cell types. We employed single-cell gene signatures from these T cell subsets to query the TCGA database to assess their prognostic significance. We found 2 distinct cytotoxic T cell types. GZMK+KLRG1+ cytotoxic T cells were enriched in CRC patients with good outcomes. GNLY+CD103+ cytotoxic T cells with a dysfunctional phenotype were not associated with good outcomes, despite coexpression of CD39 and CD103, markers that denote tumor reactivity. We found 2 distinct Treg subtypes associated with opposite outcomes. While total Tregs were associated with good outcomes, CD38+ Tregs were associated with bad outcomes independently of stage and possessed a highly suppressive phenotype, suggesting that they inhibit antitumor immunity in CRC. These findings highlight the potential utility of these subpopulations in predicting outcomes and support the potential for novel therapies directed at CD38+ Tregs or CD8+CD103+ T cells.
Respiratory failure is the leading cause of death in patients with severe SARS-CoV-2 infection
, but the host response at the lung tissue level is poorly understood. Here we performed single-nucleus ...RNA sequencing of about 116,000 nuclei from the lungs of nineteen individuals who died of COVID-19 and underwent rapid autopsy and seven control individuals. Integrated analyses identified substantial alterations in cellular composition, transcriptional cell states, and cell-to-cell interactions, thereby providing insight into the biology of lethal COVID-19. The lungs from individuals with COVID-19 were highly inflamed, with dense infiltration of aberrantly activated monocyte-derived macrophages and alveolar macrophages, but had impaired T cell responses. Monocyte/macrophage-derived interleukin-1β and epithelial cell-derived interleukin-6 were unique features of SARS-CoV-2 infection compared to other viral and bacterial causes of pneumonia. Alveolar type 2 cells adopted an inflammation-associated transient progenitor cell state and failed to undergo full transition into alveolar type 1 cells, resulting in impaired lung regeneration. Furthermore, we identified expansion of recently described CTHRC1
pathological fibroblasts
contributing to rapidly ensuing pulmonary fibrosis in COVID-19. Inference of protein activity and ligand-receptor interactions identified putative drug targets to disrupt deleterious circuits. This atlas enables the dissection of lethal COVID-19, may inform our understanding of long-term complications of COVID-19 survivors, and provides an important resource for therapeutic development.
Constitutively activated STAT3 plays a critical role in non-small cell lung carcinoma (NSCLC) progression by mediating proliferation and survival. STAT3 activation in normal cells is transient, ...making it an attractive target for NSCLC therapy. The therapeutic potential of blocking STAT3 in NSCLC was assessed utilizing a decoy approach by ligating a double-stranded 15-mer oligonucleotide that corresponds to the STAT3 response element of STAT3-target genes, to produce a cyclic STAT3 decoy (CS3D). The decoy was evaluated using NSCLC cells containing either wild-type EGFR (201T) or mutant EGFR with an additional EGFRi resistance mutation (H1975). These cells are resistant to EGFR inhibitors and require an alternate therapeutic approach. CS3D activity was compared with an inactive cyclic control oligonucleotide (CS3M) that differs by a single base pair, rendering it unable to bind to STAT3 protein. Transfection of 0.3 μmol/L of CS3D caused a 50% inhibition in proliferation in 201T and H1975 cells, relative to CS3M, and a 2-fold increase in apoptotic cells. Toxicity was minimal in normal cells. CS3D treatment caused a significant reduction of mRNA and protein expression of the STAT3 target gene c-Myc and inhibited colony formation by 70%. The active decoy decreased the nuclear pool of STAT3 compared with the mutant. In a xenograft model, treatments with CS3D (5 mg/kg) caused a potent 96.5% and 81.7% reduction in tumor growth in 201T (
< 0.007) and H1975 models (
< 0.0001), respectively, and reduced c-Myc and p-STAT3 proteins. Targeting STAT3 with the cyclic decoy could be an effective therapeutic strategy for NSCLC.
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Production of amphiregulin (Areg) by regulatory T (Treg) cells promotes repair after acute tissue injury. Here, we examined the function of Treg cells in non-alcoholic steatohepatitis (NASH), a ...setting of chronic liver injury. Areg-producing Treg cells were enriched in the livers of mice and humans with NASH. Deletion of Areg in Treg cells, but not in myeloid cells, reduced NASH-induced liver fibrosis. Chronic liver damage induced transcriptional changes associated with Treg cell activation. Mechanistically, Treg cell-derived Areg activated pro-fibrotic transcriptional programs in hepatic stellate cells via epidermal growth factor receptor (EGFR) signaling. Deletion of Areg in Treg cells protected mice from NASH-dependent glucose intolerance, which also was dependent on EGFR signaling on hepatic stellate cells. Areg from Treg cells promoted hepatocyte gluconeogenesis through hepatocyte detection of hepatic stellate cell-derived interleukin-6. Our findings reveal a maladaptive role for Treg cell-mediated tissue repair functions in chronic liver disease and link liver damage to NASH-dependent glucose intolerance.
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•Treg cells are enriched and activated in human and mouse chronic liver disease•Treg cell-derived Areg promotes liver fibrosis and glucose intolerance•Areg from Treg cells activates hepatic stellate cells via EGFR signaling•Activated hepatic stellate cells promote hepatocyte gluconeogenesis via IL-6
Non-alcoholic fatty liver disease and its progressive form, non-alcoholic steatohepatitis (NASH), are a prevalent cause of chronic liver disease. Savage et al. demonstrate that regulatory T (Treg) cells are enriched in mouse and human NASH and find that production of the EGFR ligand amphiregulin by Treg cells promotes NASH-induced liver fibrosis and glucose intolerance through direct signaling to hepatic stellate cells.
In the prevailing model, Lgr5+ cells are the only intestinal stem cells (ISCs) that sustain homeostatic epithelial regeneration by upward migration of progeny through elusive upper crypt ...transit-amplifying (TA) intermediates. Here, we identify a proliferative upper crypt population marked by Fgfbp1, in the location of putative TA cells, that is transcriptionally distinct from Lgr5+ cells. Using a kinetic reporter for time-resolved fate mapping and Fgfbp1-CreERT2 lineage tracing, we establish that Fgfbp1+ cells are multi-potent and give rise to Lgr5+ cells, consistent with their ISC function. Fgfbp1+ cells also sustain epithelial regeneration following Lgr5+ cell depletion. We demonstrate that FGFBP1, produced by the upper crypt cells, is an essential factor for crypt proliferation and epithelial homeostasis. Our findings support a model in which tissue regeneration originates from upper crypt Fgfbp1+ cells that generate progeny propagating bi-directionally along the crypt-villus axis and serve as a source of Lgr5+ cells in the crypt base.
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•Intestinal epithelial regeneration originates from the upper crypt, not the crypt base•Fgfbp1 marks upper crypt homeostatic ISCs that regenerate all lineages and Lgr5+ cells•Fgfbp1+ and Lgr5+ CBC cells exhibit differential responses to niche signals•FGFBP1 secreted by upper crypt ISCs is essential for intestinal epithelial regeneration
A revised model of the cellular hierarchy during intestinal epithelial regeneration is presented, with the identification of multi-potent intestinal stem cells in the upper crypt zone. These cells are marked by Fgfbp1 and repopulate the intestinal epithelium, including the Lgr5+ crypt base columnar cells, under homeostatic conditions.
Abstract
Checkpoint blockade immunotherapy has shown great success in certain types of cancers, but are ineffective in most cancers. We do not understand why these therapies fail.
Here, we seek to ...better understand functional changes in T cells in responsive tumors through single cell TCR sequencing and high dimensional phenotypic analysis within single tumor-infiltrating T cells. Through surgical biopsy, we analyze the same tumor longitudinally before and after treatment, enabling us to track the fate of individual T cell clones.
Our data show that the CD4/CD8 ratio decreases upon treatment. T cells expressing inhibitory markers such as PD1, CTLA4, diminish post treatment. We see distinct clusters of effector CD4 and CD8 T cells in treated tumors, including effector CD4 populations with Tfh, Th1 and Th2 phenotypes. CD4 Tregs are greatly diminished upon successful treatment, and diminish through clonal contraction. Furthermore, TCR acts as a unique marker for T cell ancestry, which links T cell function to T cell specificity. Based on TCR clonality, we observe that expanded T cell clones before treatment do not share the same TCRs with expanded T cell clones after treatment. This implies new CD8 T cell clones are recruited into the tumor upon treatment.
From our data, we will be able to identify T cell clones that are phenotypically distinct and expanded in responsive tumors which is critical in understanding what makes for a successful T cell response after immunotherapy.
Celiac disease (CD) is a highly prevalent autoimmune disease in which intestinal inflammation is induced by dietary gluten. The means through which gluten-specific CD4+ T cell activation culminates ...in intraepithelial T cell (T-IEL) mediated intestinal damage remain unclear. Here, we performed multiplexed-single cell analysis of intestinal and gluten-induced peripheral blood T cells from patients with different celiac disease states and controls. Untreated, active CD (ACD) and potential CD (PCD) were associated with an enrichment of activated intestinal T cell populations including CD4+ follicular T-helper (TFH) cells, regulatory T cells (Tregs), and Natural CD8+ αβ and γδ T-IELs.
Natural CD8+ αβ and γδ T-IELs expressing activating Natural Killer Cell Receptors (NKRs) exhibited a distinct TCR repertoire in CD and persisted in patients on a gluten-free diet (GFD) without intestinal inflammation. Our data further show that NKR-expressing cytotoxic cells, which appear to mediate intestinal damage in CD, arise from a distinct NKR-expressing memory population of T-IELs. Following gluten ingestion, both αβ and γδ T cell clones from this memory population of T-IELs circulated systemically with gluten-specific CD4+ T cells and assumed a cytotoxic and activating NKR-expressing phenotype. In patient-derived organoid (PDO) model of CD, gluten exposure induced the presence of this cytotoxic, NKR-expressing population exclusively in PDOs generated from CD patients.
The increased abundance of cytotoxic, NKR-expressing T-IELs following gluten exposure corresponded to histologic observations of altered organoid morphology including degenerated organoid structures and the presence of infiltrating immune cells co-localized with apoptotic epithelial cells. Collectively, these findings suggest that these cytotoxic, NKR-expressing T cells in CD are rapidly mobilized in parallel with gluten-specific CD4+ T cells following gluten ingestion to mediate the destruction of intestinal epithelial cells in CD.
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