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Zippelius, A.

Publications and source records attributed to Zippelius, A..

11 recordsLinked to original sources

alpha2,3-sialylation on human naive T cells restrains bispecific engager-mediated anti-tumor immunity

Aberrantly elevated cell-surface sialylation, or hypersialylation, is a common feature of human cancers and contributes to immune evasion. Sialidase-based therapies have therefore emerged as a strategy to disrupt this glyco-checkpoint. Although the immunosuppressive role of tumor-associated sialylation is well established, how sialylation on human T cells shapes anti-tumor responses remains poorly defined. Here, we identify surface sialoglycans on T cells, particularly 2,3-linked structures, as a cell-intrinsic restraint on human T cell activation, proliferation, and effector function. In vitro, enzymatic desialylation enhanced T cell activation, proliferation, cytokine production, and bispecific T cell engager (TCE)-mediated tumor-cell killing in healthy donor PBMC co-cultures. In ex vivo cultures of primary chronic lymphocytic leukemia (CLL) PBMCs, sialidase treatment combined with the CD20-directed TCE glofitamab enhanced cytotoxic effector transcriptional programming in autologous T cells. Single-cell RNA sequencing combined with lectin-based CITE-seq linked treatment-induced transcriptional states to lectin-defined cell-surface glycan signatures within the same single-cell dataset. This integrated analysis revealed that naive and, to a lesser extent, central memory T cells combined elevated baseline 2,3-sialylation signatures with the clearest transcriptional responses to glofitamab plus sialidase treatment. CD43 emerged as a major carrier of 2,3-linked sialoglycans, and its deletion attenuated sialidase-enhanced T cell activation. Together, these findings identify sialylation of the T cell surface as a subset-specific restraint on human TCE responses and provide a rationale for testing sialidase-TCE combinations designed to engage less-differentiated T cell populations. One-sentence summaryDesialylation enhances bispecific T cell engager responses by relieving a sialoglycan-dependent restraint in human T cells.

immunology↗

Longitudinal profiling of tumor-reactive T cells during TIL therapy in metastatic melanoma

Adoptive cell therapy (ACT) with expanded autologous tumor-infiltrating lymphocytes (TILs) can induce durable responses in metastatic melanoma, yet many patients relapse. We profiled tumor-reactive T cell dynamics during TIL therapy using single-cell RNA and TCR sequencing from seven patients to elucidate underlying reasons. We found that tumor-reactive T cells preferentially expanded early during ex vivo TIL culture, transitioning from exhausted to reinvigorated effector states. Particularly, CD8+ exhausted T cells (Tex) and CD4+ follicular helper T cell (Tfh), but not CD4+ Tex, were efficiently reinvigorated. Further, we resolved the heterogeneity of tumor-reactive CD8+ and CD4+ subsets, defining unique signatures for their identification during TIL expansion. In addition, non-responders (NRs) exhibit increased levels of Type 17 T cells in TIL products, suggesting a potential association with resistance to therapy. After transfer, tumor-reactive clones rapidly extravasated and established a stem-like reservoir. However, in NRs, CD4+ regulatory T cells (Tregs) expanded de novo and tumor-reactive CD8+ T cells reacquired exhaustion markers, limiting their functionality. By contrast, responders (Rs) retained a pool of less differentiated, stem-like cells. Collectively, these data provide a comprehensive analysis of T cell fates during TIL-ACT providing the basis for new approaches to enhance therapeutic strategies.

immunology↗

Integrated single cell analysis identifies CD39+ tumor-associated NK cells with cytotoxic potential in lung cancer

Natural killer (NK) cell-targeting immunotherapies are emerging, yet the differentiation and functional states of tumor-infiltrating NK cells remain poorly understood. Using matched single-nucleus RNA and ATAC sequencing of non-small cell lung cancer (NSCLC) specimens, we resolved the transcriptional and epigenetic landscape of intratumoral NK cells. We identified two tumor-associated NK (taNK) cell subsets marked by ITGAE (CD103) and ITGA1 (CD49a) that display features of tissue residency and dysfunction while preserving cytotoxic function. Trajectory and regulon analyses revealed an inflammation-driven transition from early GZMK NKs toward an ENTPD1+ (CD39) effector state characterized by interferon-stimulated gene (ISG) programs. Functional profiling established CD39 taNK as the dominant cytotoxic NK cell population with superior killing capacity that is further potentiated by NKG2A blockade. This study offers mechanistic insights into NK cell differentiation in NSCLC and establishes CD39 taNK cells as a targetable effector population for immunotherapy. One sentence summaryMultiomic analysis identifies CD39+ tumor-associated NK cells as a cytotoxic effector state in NSCLC responsive to NKG2A blockade.

immunology↗

Targeting cancer-associated glycosylation for adoptive T cell therapy of gastro-intestinal and gynecological cancers

CAR-T cell therapy has provided a significant improvement for patients with chemotherapy-resistant B cell malignancies. However, CAR-T cell treatment of patients with solid cancers has been more difficult, in part because of the heterogeneous expression of tumor-specific cell surface antigens. Here, we describe the generation of a fully human CAR targeting altered glycosylation in secretory epithelial cancers. The expression of the target antigen - the truncated, sialylated O-glycan sialyl-Thomsen-Nouveau antigen (STn) - was studied with a highly STn-specific antibody across various different tumor tissues. Strong expression was found in a high proportion of gastro-intestinal cancers including pancreatic cancers and in gynecological cancers, in particular ovarian and endometrial tumors. T cells expressing anti-STn CAR were tested in vitro and in vivo. Anti-STn CAR-T cells showed activity in mouse models as well as in assays with primary ovarian cancer samples. No significant toxicity was observed in mouse models, although some intraluminal expression of STn was found in gastro-intestinal mouse tissue. Taken together, this fully human anti-STn CAR construct shows promising activity in preclinical tumor models supporting its further evaluation in early clinical trials.

cancer biology↗

Multimodal single-cell profiling of T cell specificity and reactivity in lung cancer

Adoptive transfer of autologous tumor-infiltrating lymphocyte T cells (TILs) offers one of the most promising approaches for cancer immunotherapy. However, high variability in patient responses highlight the need for an enhanced understanding of the transcriptional phenotypes of TILs and reactivity of their T cell receptors (TCR). Here, we employ single-cell multiomics approaches and TCR functional screening to investigate TILs from treatment-naive non-small cell lung cancer patients. This comprehensive analysis integrates scRNA-seq, scTCR-seq, and scATAC-seq, enabling a high-resolution examination of TILs within lung cancer tissue, as well as the adjacent non-tumor tissue. We apply a cellular functional screening platform to identify reactive TCRs that represent >1,000 TILs and have specificity towards a multitude of targets, including primary tumor cells, neoantigens, tumor-associated antigens, and viral antigens. Tumor-reactive TILs were primarily associated with dysfunctional phenotypes, whereas viral antigen-reactive TCRs were found in effector phenotype clusters. Key marker genes were identified and used to construct a tumor or viral reactivity score. Comparing clones shared in tumor and non-tumor tissue, a higher fraction of exhausted cells was observed in the tumor tissue, whereas non-tumor adjacent tissue possessed more effector cells, thus providing insight into potential sources for therapeutic T cells. Elucidating the specific T cell populations within TILs and their associated TCRs may support strategies to enhance the efficacy of TIL-based therapies. Graphical AbstractO_ST_ABSMultimodal single cell profiling and reactivity testing of TILsC_ST_ABS(A) CD8+ T cells of treatment naive non-small cell lung cancer patients and adjacent lung tissue were isolated by fluorescence-activated cell sorting (FACS) and were then subjected to scRNA-seq + scTCR-seq or scATAC-seq. (B) TCRs were functionally screened using a cellular platform (TnT cells) and target cells (tumor cells, antigen-pulsed antigen-presenting cells, PBMCs) by flow cytometry and deep sequencing. (C) scRNA-seq + scATAC-seq allowed trajectory inference of transcription factors and genes along pseudotime. (D) Gene scores for tumor- and virus-reactivity were developed by combining functional reactivity and transcriptomic profiling for each CD8+ T cell. (E) TIL scRNA-seq pre and post IL-2 treatment in tumor suspension displayed as alluvial plot shows change of clonal cell state composition. O_FIG O_LINKSMALLFIG WIDTH=196 HEIGHT=200 SRC="FIGDIR/small/560863v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@12fcc20org.highwire.dtl.DTLVardef@1027dccorg.highwire.dtl.DTLVardef@911711org.highwire.dtl.DTLVardef@18171e5_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

Engagement of sialylated glycans with Siglec receptors on myeloid suppressor cells inhibit anti-cancer immunity via CCL2

Overexpression of sialic acids on glycans, called hypersialylation is a common alteration found in cancer. Hypersialylation can, for example, enhance immune evasion via interaction with sialic acid-binding immunoglobulin-like lectin (Siglec) receptors on tumor-infiltrating immune cells. Here, we tested the role of sialic acid on myeloid-derived suppressor cells (MDSCs) and their interaction with Siglec receptors. We found that MDSCs derived from the blood of lung cancer patients and tumor-bearing mice strongly express inhibitory Siglec receptors. In murine cancer models of emergency myelopoiesis, Siglec-E knockout on myeloid cells resulted in prolonged survival and increased infiltration of activated T cells. Targeting suppressive myeloid cells by blocking Siglec receptors or desialylation led to strong reduction of their suppressive potential. We further identified CCL2 as mediator involved in T cell suppression upon interaction of sialoglycans and Siglec receptors on MDSCs. Our results provide mechanistic insights how sialylated glycans inhibit anti-cancer immunity by facilitating CCL2 expression. O_FIG O_LINKSMALLFIG WIDTH=142 HEIGHT=200 SRC="FIGDIR/small/547025v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@e7664forg.highwire.dtl.DTLVardef@1edd220org.highwire.dtl.DTLVardef@7e630dorg.highwire.dtl.DTLVardef@198ff40_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

13C tracer analysis reveals the landscape of metabolic checkpoints in human CD8+ T cell differentiation

Naive T cells remain in an actively maintained state of quiescence until activation by antigenic signals, upon which they start proliferation and generation of effector cells to initiate a functional immune response. Metabolic reprogramming is essential to meet the biosynthetic demands of the differentiation process, and failure to do so can promote the development of hypofunctional exhausted T cells. Here we used 13C metabolomics and transcriptomics to study the metabolic dynamics of CD8+ T cells in their complete course of differentiation from naive over stem-like memory to effector cells. The quiescence of naive T cells was evident in a profound suppression of glucose oxidation and a decreased expression of ENO1, downstream of which no glycolytic flux was detectable. Moreover, TCA cycle activity was low in naive T cells and associated with a downregulation of SDH subunits. Upon stimulation and exit from quiescence, the initiation of cell growth and proliferation was accompanied by differential expression of T cell regulatory genes and metabolic reprogramming towards aerobic glycolysis with high rates of nutrient uptake, respiration and lactate production. High flux in anabolic pathways imposed a strain on NADH homeostasis, which coincided with engagement of the proline cycle for mitochondrial redox shuttling. With acquisition of effector functions, cells increasingly relied on glycolysis as opposed to oxidative phosphorylation, which paradoxically was not linked to changes in mitochondrial abundance. We further investigated the metabolic phenotype of exhausted T cells, finding that decreased effector function concurred with a reduction in mitochondrial metabolism, glycolysis and amino acid import, and an upregulation of suppressive and quiescence-associated genes, including TXNIP and KLF2. Thus, these results identify multiple features critical for the metabolic reprogramming that supports quiescence, proliferation and effector function of CD8+ T cells during differentiation. Further, an impairment of the same processes in exhaustion suggests that targeting these control points may be useful for both modulation of differentiation and prevention of exhaustion.

immunology↗

Tumor-educated monocytes suppress T cells via adenosine and depletion of adenosine in the tumor microenvironment with adenosine deaminase enzyme promotes response to immunotherapy

Although immune checkpoint inhibitor (ICI) therapy has provided robust results in many cancer types such as melanoma and lung cancer, a large percentage of patients remain unresponsive to this therapy. Emerging evidence strongly suggests that one of the contributing factors in ICI resistance is monocytic myeloid derived suppressor cells (M-MDSCs) that accumulate in late-stage cancer patients. These M-MDSCs are a subset of innate immune cells and possess potent immunosuppressive activity against T lymphocytes. Here we provide evidence of a mechanism by which CD73-expressing M-MDSCs in the tumor microenvironment (TME) exhibit superior T cell suppressor function via adenosine. We show that tumor-derived PGE2, a prostaglandin frequently found at high levels in the TME, directly induces CD73 expression in M-MDSCs by initiating a signaling pathway that is mediated by both Stat3 and CREB. The resulting CD73 overexpression induces elevated levels of adenosine, a nucleoside with strong T cell suppressive activity, culminating in the suppression of CD8+ T cell-mediated anti-tumor responses. We also show that depletion of adenosine in the TME by the repurposed drug PEGylated Adenosine Deaminase (PEG-ADA) increases CD8+ T cell anti-tumor activity and enhances response to ICI therapy in preclinical models of cancer. Our results suggest that use of PEG-ADA is a viable therapeutic option to overcome ICI therapeutic resistance in advanced cancer patients.

cell biology↗

Successful IL-12 cancer immunotherapy requires NK cell-derived CCL5 for anti-tumor DC-T cell crosstalk

T cell-directed cancer immunotherapy often fails to generate lasting tumor control. Harnessing additional effectors of the immune response against tumors may strengthen the clinical benefit of immunotherapies. Here, we demonstrate that therapeutic targeting of the IFN{gamma}-IL-12 pathway relies on the ability of a population of tissue-resident NK (trNK) cells to orchestrate an anti-tumor microenvironment. Particularly, utilizing an engineered adenoviral platform, we show that paracrine IL-12 enhances functional DC-CD8 T cell interactions to generate adaptive anti-tumor immunity. This effect depends on the abundance of trNK cells and specifically their capacity to produce the cDC1-chemoattractant CCL5. Failure to respond to IL-12 and other IFN{gamma}-inducing therapies such as immune checkpoint blockade in tumors with low trNK cell infiltration could be overcome by intra-tumoral delivery of CCL5. Our findings reveal a novel barrier for T cell-focused therapies and offer mechanistic insights into how T cell-NK cell-DC crosstalk can be enhanced to promote anti-tumor immunity and overcome resistance. SignificanceWe identified the lack of CCL5-producing, tissue-resident NK (trNK) cells as a barrier to T cell-focused therapies. While IL-12 induces anti-tumoral DC-T cell crosstalk in trNK cellrich tumors, resistance to IL-12 or anti-PD-1 in trNK cellpoor tumors can be overcome by the additional delivery of CCL5.

immunology↗

Targeting cancer glycosylation repolarizes tumor-associated macrophages allowing effective immune checkpoint blockade

Immune checkpoint blockade (ICB) has significantly improved the prognosis of cancer patients, but the majority experience limited benefit, evidencing the need for new therapeutic approaches. Upregulation of sialic acid-containing glycans, termed hypersialylation, is a common feature of cancer-associated glycosylation, driving disease progression and immune escape via the engagement of Siglec-receptors on tumor-infiltrating immune cells. Here, we show that tumor sialylation correlates with distinct immune states and reduced survival in human cancers. The targeted removal of Siglec-ligands in the tumor microenvironment, using an antibody-sialidase conjugate, enhances anti-tumor immunity and halts tumor progression in several mouse tumor models. Using single-cell RNA sequencing, we reveal desialylation mechanistically to repolarize tumor-associated macrophages (TAMs) and identify Siglec-E on TAMs as the main receptor for hypersialylation. Finally, we show genetic and therapeutic desialylation, as well as loss of Siglec-E, to synergize with ICB. Thus, therapeutic desialylation represents a novel immunotherapeutic approach, shaping macrophage phenotypes and augmenting the adaptive anti-tumor immune response.

immunology↗

Hyperglycemia enhances cancer immune evasion by inducing alternative macrophage polarization through increased O-GlcNAcylation

Diabetes mellitus (DM) significantly increases the risk for cancer and cancer progression. Hyperglycemia is the defining characteristic of DM and tightly correlates with a poor prognosis in cancer patients. The hexosamine biosynthetic pathway (HBP) is emerging as a pivotal cascade linking high glucose, tumor progression and impaired immune function. Here we show that enhanced glucose flow through the HBP drives cancer progression and immune evasion by increasing O-GlcNAcylation in tumor-associated macrophages (TAMs). Increased O-GlcNAc skewed macrophage polarization to a M2-like phenotype. HBP or O-GlcNAcylation inhibition reprogrammed TAMs to an anti-tumoral phenotype. Finally, we found an upregulation of M2 markers on TAMs in DM2 patients with colorectal cancer compared to non-diabetic normoglycemic patients. Our results provide evidence for a new and targetable mechanism of cancer immune evasion in patients with hyperglycemia, advocating for strict control of hyperglycemia in cancer patients.\n\nSignificanceHyperglycemia increases O-GlcNAc levels in TAMs, programing them to a pro-tumorigenic phenotype (M2-like), contributing to cancer progression. Inhibition of O-GlcNAcylation could therefore be used to reprogram intratumoral macrophages to an anti-tumoral phenotype.

cancer biology↗