Enantiodivergence is an important concept in asymmetric catalysis that enables access to both enantiomers of a product relying on the same chiral source as reagent. This strategy is particularly ...appealing as an alternate approach when only one enantiomer of the required chiral ligand is readily accessible but both enantiomers of the product are desired. Despite the potential significance, general catalytic methods to effectively reverse enantioselectivity by changing an achiral reaction parameter remain underdeveloped. Herein we report our studies focused on elucidating the origin of metal-controlled enantioselectivity reversal in Lewis acid-catalysed Michael additions. Rigorous experimental and computational investigations reveal that specific Lewis and Brønsted acid interactions between the substrate and ligand change depending on the ionic radius of the metal catalyst, and are key factors responsible for the observed enantiodivergence. This holds potential to further our understanding of and facilitate the design of future enantiodivergent transformations.
Enantiodivergence is an important concept in asymmetric catalysis that enables access to both enantiomers of a product relying on the same chiral source as reagent.
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IJS, KILJ, NUK, UL, UM, UPUK
Background: The presence and role of follicular T-cell populations other than T follicular helper (Tfh) cells, such as T follicular regulatory (Tfr) and cytotoxic (Tfc) cells, are gaining increasing ...attention in certain pathological states. However, the ecosystem of follicular T cells in the tumor microenvironment (TME) has not been fully elucidated. In particular, the significance of minor follicular T-cell subsets in the neoplastic follicular environment remains elusive. Here, we aimed to reveal the landscape of follicular T-cell alterations in various cancers, with a particular emphasis on the follicular lymphoma (FL) TME. Methods: We analyzed single-cell RNA/TCR sequencing data of >500,000 human T cells from FL (obtained from four cohorts) and 25 other cancer types, as well as homeostatic and reactive lymph nodes (LNs), to construct a comprehensive single-T-cell atlas. We investigated differentially expressed genes, RNA velocity, and TCR clonality using this atlas. To determine the functions of neoplastic follicular regulatory (Tnfr) and cytotoxic (Tnfc) T cells, we performed in vitro cytokineproduction and co-culture assays, in combination with cell activation/suppression, cell division, and apoptosis assays, using human FL samples. With the PhenoCycler-Fusion system, we conducted multiplex digital spatial profiling (DSP) of 169 FL samples from two independent cohorts (now being extended to 242 FL samples from three cohorts) for >25 antibodies. We also performed single-cell spatial and protein expression profiling and prognostic analysis. Results: In FL, distinct minor neoplastic follicular T-cell subsets-Tnfr and CD4 (Tnfc4) and CD8 (Tnfc8) Tnfc cells-increased relative to homeostatic LNs. The TCR repertoire analysis revealed that Tnfr cells shared clonotypes with conventional effector regulatory T (Trg) and Tfh cells, whereas Tnfc4 and Tnfc8 cells shared clonotypes with Tfh cells and effector and exhausted (Tcex) cytotoxic CD8 T cells, respectively. In line with these findings, the RNA velocity survey suggested that Tnfr, Tnfc4, and Tnfc8 cells originated from Trg, Tfh, and naïve-like CD8 T cells, respectively. Tnfr and Tnfc cells expressed higher levels of effector genes, including those involved in cytokine release, chemokine response, migration, and PD-1 signaling, than their reactive LN counterparts. The pan-cancer survey revealed that Tfr and CD4 Tfc cells were exclusive to FL, whereas the prevalence and gene expression profiles of CD8 Tfc cells varied across cancers. Tnfr cells were marked by abundant expression of IL10 and IL21, whereas Tnfc cells displayed a unique phenotype, as they concomitantly expressed markers of effector Tfh (e.g., CXCL13, CXCR5, and PDCD1), naïve/stem (e.g., CCR7 and TCF7), central memory (e.g., CD27, CD28, and SELL), and tissue-resident memory (e.g., ITGAE) cells. Hierarchical clustering demonstrated that Tnfc8 cells had transcriptional profiles similar to those of melanoma TCF1 +PD-1 +CD8 + stem-like T cells. DSP of FL detected Tnfr and Tnfc cells frequently localized within and around neoplastic follicles, forming a cellular neighborhood that allowed them to interact closely. Tnfr cells were distributed predominantly near Tfh cells. The functional co-culture assays demonstrated that Tnfr cells suppressed Tfh-cell activation and division, thereby inhibiting Tfh-mediated malignant B-cell activation and survival. Tnfc8 cells showed a higher cell division capability than that of Tcex cells, suggesting that Tnfc8 cells function as a pool of CD8 T cells in neoplastic follicles. The prognostic analysis revealed that Tnfr and Tnfc cell proportions correlated with early disease relapse (i.e., POD24) and predicted a significantly longer time-to-relapse ( P <0.05 for Tnfr and <0.001 for Tnfc cells) in FL. In the multivariate analysis, the prognostic impact of these two cell subsets was independent of the FLIPI. The prognostic analysis findings were confirmed using a validation cohort. Conclusions: Our multi-omics approach identified the expansion of minor neoplastic follicular T-cell subsets that carry unique transcriptional and functional profiles and robust prognostic impacts. These findings deepen our understanding of the biological and immunological roles of non-Tfh follicular T cells in the lymphoma TME and highlights their clinical potential for patient risk stratification and future therapeutic interventions.
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IJS, IMTLJ, KILJ, NLZOH, NUK, SAZU, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
T follicular helper (T
) cell lymphomas (TFHLs) are characterized by T
-like properties and accompanied by substantial immune-cell infiltration into tumor tissues. Nevertheless, the comprehensive ...understanding of tumor-cell heterogeneity and immune profiles of TFHL remains elusive. To address this, we conducted single-cell transcriptomic analysis on 9 lymph node (LN) and 16 peripheral blood (PB) samples from TFHL patients. Tumor cells were divided into 5 distinct subclusters, with significant heterogeneity observed in the expression levels of T
markers. Copy number variation (CNV) and trajectory analyses indicated that the accumulation of CNVs, together with gene mutations, may drive the clonal evolution of tumor cells towards T
-like and cell proliferation phenotypes. Additionally, we identified a novel tumor-cell-specific marker, PLS3. Notably, we found a significant increase in exhausted CD8
T cells with oligoclonal expansion in TFHL LNs and PB, along with distinctive immune evasion characteristics exhibited by infiltrating regulatory T, myeloid, B, and natural killer cells. Finally, in-silico and spatial cell-cell interaction analyses revealed complex networking between tumor and immune cells, driving the formation of an immunosuppressive microenvironment. These findings highlight the remarkable tumor-cell heterogeneity and immunoevasion in TFHL beyond previous expectations, suggesting potential roles in treatment resistance.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Activating mutations in the Vav guanine nucleotide exchange factor 1 (VAV1) gene are reported in various subtypes of mature T-cell neoplasms (TCNs). However, oncogenic activities associated with VAV1 ...mutations in TCNs remain unclear. To define them, we established transgenic mice expressing VAV1 mutants cloned from human TCNs. Although we observed no tumors in these mice for up to a year, tumors did develop in comparably aged mice on a p53-null background (p53−/−VAV1-Tg), and p53−/−VAV1-Tg mice died with shorter latencies than did p53-null (p53−/−) mice. Notably, various TCNs with tendency of maturation developed in p53−/−VAV1-Tg mice, whereas p53−/− mice exhibited only immature TCNs. Mature TCNs in p53−/−VAV1-Tg mice mimicked a subtype of human peripheral T-cell lymphoma (PTCL-GATA3) and exhibited features of type 2 T helper (Th2) cells. Phenotypes seen following transplantation of either p53−/−VAV1 or p53−/− tumor cells into nude mice were comparable, indicating cell-autonomous tumor-initiating capacity. Whole-transcriptome analysis showed enrichment of multiple Myc-related pathways in TCNs from p53−/−VAV1-Tg mice relative to p53−/− or wild-type T cells. Remarkably, amplification of the Myc locus was found recurrently in TCNs of p53−/−VAV1-Tg mice. Finally, treatment of nude mice transplanted with p53−/−VAV1-Tg tumor cells with JQ1, a bromodomain inhibitor that targets the Myc pathway, prolonged survival of mice. We conclude that VAV1 mutations function in malignant transformation of T cells in vivo and that VAV1-mutant–expressing mice could provide an efficient tool for screening new therapeutic targets in TCNs harboring these mutations.
•Expression of VAV1 mutants on a p53-null background accelerated development of various types of TCNs.•Myc pathway activation is marked in TCNs with VAV1 mutants, accompanying focal somatic copy-number alterations of the Myc locus.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Introductions:
Loss-of-function TET2 mutations are frequent in clonal hematopoiesis in patients with solid cancers as well as that in healthy individuals. It remains to be elucidated whether and how ...TET2-mutated immune cells affect cancer progression in patients with TET2-mutated clonal hematopoiesis. Here, we assessed activity of Tet2-deficient immune cells using a mouse lung cancer model.
Methods:
Lewis Lung Carcinoma (LLC) cells were subcutaneously transplanted into blood-specific Mx-Cre or myeloid-specific LysM-Cre x Tet2 f/f mice (Tet2 -/- or Tet2 mye-) or control mice (CT). Single-cell RNA sequencing (scRNA-seq) was performed to determine the immune-cell profiles and mediators in tumors of Tet2 -/- mice (Tet2 -/- tumors). Whole transcriptome analysis (WTA) was also performed for granulocytic myeloid-derived cells (GMD), monocytic myeloid-derived cells (MMD), and tumor associated macrophages (TAM), as well as LLC cells sorted from Tet2 -/- tumors and CT tumors.
Results:
We found that tumor growth was enhanced in both Tet2 -/- and Tet2 mye- comparing to CT. Unsupervised clustering of scRNA-seq data identified 14 cell clusters: GMD into 3 (GMD1, GMD2, and GMD3), MMD into 5 (MMD1, MMD2, MMD3, MMD4, and MMD5), TAMs into 4 (TAM1, TAM2, TAM3, and TAM4), and DCs into 2 (DC1 and DC2). Notably, among all subclusters, the proportions of GMD1, GMD3, TAM3 and TAM4 were markedly expanded in Tet2 -/- tumors comparing to CT. Differentially expressed gene (DEG) analysis of scRNA-seq data found that S100a8 and S100a9 were highly expressed in Tet2-deficient GMD1 compared to CT. Furthermore, S100a8/S100a9 proteins were elevated in plasmas of Tet2 -/- comparing to those of CT. Pathway analysis using DEGs (p < 0.05) from WTA of GMD determined interleukin 1b (Il1b) signaling as upstream of S100a8/S100a9 activity. Gene set enrichment analysis (GSEA) also showed that 6 pathways related to Il1b were enriched in Tet2-deficient group compared to CT group. Gene ontology analysis (GO) for DEGs of GMD, MMD, and TAMs by WTA as well as 13 subclusters by scRNA-seq revealed that the “cellular response to IL-1” pathway was enriched in Tet2-deficient group compared to CT group. To define the downstream effectors in LLC cells, we performed WTA for LLC cells sorted from Tet2 -/- and CT tumors. We found that Vegfa, encoding a mediator for angiogenesis was highly upregulated in LLC cells sorted from Tet2 -/- tumors comparing to CT tumors. GSEA for WTA further identified that multiple Vegfa-related pathways as well as MAPK cascade were enriched in LLC cells from Tet2 -/- tumors comparing to those from CT tumors . Furthermore, S100a8/S100a9 induced Vegfa secretion from LLC cells in vitro. Remarkably, the area of blood vessels was increased in Tet2 -/- tumors comparing to CT tumors. Immunostaining exhibited that the number of Ly6g +GMD foci (>1000 px 2) expressing S100a8/S100a9 was increased in Tet2 -/- tumors comparing to CT tumors. Furthermore, LLC cells surrounding GMD foci highly expressed Vegfa in Tet2 -/- tumors. Finally, administration of an antibody against Emmprin, a receptor for S100a8/S100a9 inhibited the tumor growth in Tet2 -/-. Notably, the area of blood vessels in Tet2 -/- tumors with anti-Emmprin group was decreased at 2-fold compared to that seen in isotype group (p < 0.05). Consistently, S100A8/S100A9 induced VEGFA production in human lung cancer cells in vitro.
Conclusions:
Tet2-deificient immune cells promote lung cancer progression through S100a8/S100a9-Emmprin-Vegfa axis. Our study suggests a novel role of TET2-mutated clonal hematopoiesis in cancer progression and even provides a novel therapeutic target.
No relevant conflicts of interest to declare.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Objectives
Immunosuppressive therapy (IST) with antithymocyte globulin (ATG) and cyclosporin A is the standard treatment for aplastic anemia (AA). However, the efficacy of repeated IST with rabbit ...ATG (rATG) as salvage therapy remains unclear in patients with relapsed or refractory AA.
Methods
We retrospectively evaluated the efficacy and safety of IST2 with rATG (IST2‐rATG) in 19 consecutive patients with relapsed or refractory AA who received first‐line IST with rATG in two centers between 2009 and 2020.
Results
The overall 6‐month response rate of the patients was 58%. The response rates were similar between patients with relapsed and refractory AA. The presence of glycophosphatidylinositol‐deficient blood cells was associated with a better response to IST2‐rATG. Despite retreatment with the same rATG, serum disease and severe allergic reactions were not observed.
Conclusion
IST2‐rATG is effective and safe for the treatment of adult patients with relapsed and refractory AA after receiving first‐line IST with rATG.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Graft failure and delayed hematopoietic recovery are the major limitations of cord-blood transplantation (CBT). Romiplostim, a thrombopoietin-receptor agonist, promotes megakaryopoiesis and ...multilineage hematopoiesis in aplastic anemia. The decreased number of hematopoietic stem cells in the early phase after CBT and aplastic anemia share certain characteristics. Therefore, we hypothesized that romiplostim administration immediately after CBT may promote multilineage hematopoietic recovery. We investigated the safety and preliminary efficacy of administering romiplostim a day after CBT. This phase 1 dose-escalation study included six adults with hematologic malignancies in remission. Romiplostim was administered subcutaneously within 7 days after single-unit CBT, initially at doses of 5 µg/kg or 10 µg/kg in three patients, then once a week for 14 weeks or until platelet recovery. The maximum dose was 20 µg/kg. The median number of romiplostim administrations was 6 (range, 3–15). Romiplostim-related adverse events included bone pain (3/6) and injection site reaction (1/6). Non-hematological grade ≥ 3 toxicities were observed in four patients; febrile neutropenia was the most common (4/6). All patients achieved neutrophil engraftment and the median time was 14 days (range, 12–32). Platelet counts ≥ 50 × 10
9
/L were recorded in all patients except for one who died on day 48; the median time was 34 days (range, 29–98). No relapse, thrombosis, or bone marrow fibrosis was observed during a median follow-up of 34 months. Romiplostim may be safely administered in the early phase of CBT. Further phase 2 trial is warranted for its efficacy evaluation. Trial registration number: UMIN000033799, August 18, 2018.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Background: VAV1 is known as an important mediator of T-cell receptor (TCR) signaling through its guanine exchange factor (GEF)-dependent and independent functions. Recent studies identified ...activating VAV1 mutations in several types of T-cell malignancies including peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), ALK-negative anaplastic large cell lymphoma (ALCL), and adult T-cell lymphoma/leukemia (ATLL). However, the functions of VAV1 mutations in T-cell malignancies have not been clarified.
Objective: We aim to identify the oncogenic signaling of VAV1 mutations in T cells using genetically engineered mice.
Methods: Human VAV1 mutant (p.165_174del) (VAV1-Del) and VAV1-STAP2 fusion cDNAs, identified in our PTCL cohort (Fujisawa, Leukemia 2018) were cloned into a VA vector under the CD2 promoter. The vectors were injected into eggs to generate VAV1-Del and VAV1-STAP2 transgenic mice. The mice were further crossed with p53-/- mice to generate p53-/- x VAV1-Del or p53-/- x VAV1-STAP2 mice. Cell surface markers of tumor cells were analyzed by flowcytometry. Cell suspension of tumors were cultured, and were intraperitoneally injected into BALBc/nu mice to examine the cell-autonomous proliferative activity in vitro and tumor-initiating capacity in vivo, respectively. RNA sequencing was performed to clarify the downstream signaling of VAV1 mutations.
Results: The p53-/- mice expressing VAV1 mutants showed significantly poorer overall survival (OS) compared to p53-/- mice (p53-/- x VAV1-Del, median 16.6 weeks; p53-/- x VAV1-STAP2, median 18.6 weeks; vs p53-/-, median 33.7 weeks: p<0.001), while mice with VAV1 expression in the wild-type (WT) background as well as WT mice remained alive during the observation period (>50 weeks). p53-/- x VAV1-Del and p53-/- x VAV1-STAP2 mice developed either T-cell lymphoblastic leukemias (LBL) infiltrating into thymus, lung, spleen, and liver, or mature T-cell lymphomas (Lym) into lymph nodes, spleen, and liver. In contrast, p53-/- mice developed only T-LBL at thymus. Flow cytometric analysis showed that most of T-LBL cells developed in p53-/- mice with VAV1 mutants were CD8+ single positive (SP), while those in p53-/- mice were either CD4+CD8+ (double positive, DP) or CD8+ SP. Lym cells in p53-/- mice with VAV1 mutants were either CD4+ SP or CD4-CD8- (double negative, DN) (in p53-/- x VAV1-Del mice, 5/9 CD8+ SP T-LBL, 1/9 DP T-LBL , 2/9 CD4+ SP Lym , and 1/9 DN Lym; in p53-/- x VAV1-STAP2 mice, 9/13 CD8+ SP T-LBL, 1/13 CD4+ SP Lym , and 3/13 DN Lym; p53-/- mice, 3/7 CD8+ SP T-LBL and 4/7 DP T-LBL). T-LBL with or without VAV1 mutants were immortalized in vitro over 4 weeks without any cytokines, while Lym with VAV1 mutations could not be maintained in vitro. The BALBc/nu mice transplanted with cell suspension of either T-LBL or Lym with VAV1 mutants were succumbed to death around 10 or 15 weeks, respectively. All the tumor cells developed in transplanted mice showed the similar immunophenotype to those of donor cells. Gene set enrichment analysis (GSEA) following RNA sequencing showed that G2M check point, E2F targets, mitotic spindle, PI3K/Akt/mTOR signaling, and hedgehog signaling were enriched in CD8+ SP T-LBL with VAV1 mutants compared with DP T-LBL in p53-/- mice, while E2F targets, MYC targets, G2M checkpoint, Oxidative phosphorylation, and MTORC1 signaling were upregulated in CD4+ SP Lym with VAV1 mutants in comparison with WT CD4+ spleen cells. We previously reported that TCR and Tfh pathways were enriched in TET2-/-/RHOA G17V mice through activation of VAV1 (Tran, ASH 2018). Curiously, neither of them were enriched in CD4+ SP Lym with VAV1 mutants, while TCR pathway was enriched in T-LBL with VAV1 mutants. Cell viability assay using panels over 1400 drugs showed that PI3K/Akt/mTOR pathway inhibitors and cell-cycle inhibitors effectively suppressed the cell growth of T-LBL with VAV1 mutants in vitro.
Conclusions: Expression of VAV1 mutants promoted the development of T-cell malignancies in mice. Our mouse models may provide the efficient tools to screen new therapeutic targets in T-cell malignancies with VAV1 mutations.
Ohshima:NEC Corp.: Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Kyowa Kirin Co., Ltd.: Honoraria, Research Funding; Celgene Corp.: Honoraria, Research Funding; SRL, Inc.: Consultancy. Ogawa:Dainippon-Sumitomo Pharmaceutical, Inc.: Research Funding; RegCell Corporation: Equity Ownership; Asahi Genomics: Equity Ownership; Qiagen Corporation: Patents & Royalties; Kan Research Laboratory, Inc.: Consultancy; ChordiaTherapeutics, Inc.: Consultancy, Equity Ownership.
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IJS, IMTLJ, KILJ, NLZOH, NUK, SAZU, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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