InVivoMAb anti-mouse/human/rat/monkey/hamster/canine/bovine TGF-β

• Immunology and Microbiology
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Mucosal unadjuvanted booster vaccines elicit local IgA responses by conversion of pre-existing immunity in mice.

In Nature Immunology on 1 June 2025 by Kwon, D. I., Mao, T., et al.

Mucosal delivery of vaccine boosters induces robust local protective immune responses even without any adjuvants. Yet, the mechanisms by which antigen alone induces mucosal immunity in the respiratory tract remain unclear. Here we show that an intranasal booster with an unadjuvanted recombinant SARS-CoV-2 spike protein, after intramuscular immunization with 1 μg of mRNA-LNP vaccine encoding the full-length SARS-CoV-2 spike protein (Pfizer/BioNTech BNT162b2), elicits protective mucosal immunity by retooling the lymph node-resident immune cells. On intranasal boosting, peripheral lymph node-primed B cells rapidly migrated to the lung through CXCR3-CXCL9 and CXCR3-CXCL10 signaling and differentiated into antigen-specific IgA-secreting plasma cells. Memory CD4+ T cells in the lung served as a natural adjuvant for developing mucosal IgA by inducing the expression of chemokines CXCL9 and CXCL10 for memory B cell recruitment. Furthermore, CD40 and TGFβ signaling had important roles in mucosal IgA development. Repeated mucosal boosting with an unadjuvanted protein amplified anamnestic IgA responses in both the upper and the lower respiratory tracts. These findings help explain why nasal boosters do not require an adjuvant to induce robust mucosal immunity at the respiratory mucosa and can be used to design safe and effective vaccines against respiratory pathogens. © 2025. The Author(s).

Integrin-mediated mTOR signaling drives TGF-β overactivity and myxomatous mitral valve degeneration in hypomorphic fibrillin-1 mice.

In The Journal of Clinical Investigation on 20 May 2025 by Gao, F., Chen, Q., et al.

Mitral valve prolapse is often benign but progression to mitral regurgitation may require invasive intervention and there is no specific medical therapy. An association of mitral valve prolapse with Marfan syndrome resulting from pathogenic FBN1 variants supports the use of hypomorphic fibrillin-1 mgR mice to investigate mechanisms and therapy for mitral valve disease. mgR mice developed severe myxomatous mitral valve degeneration with mitral regurgitation by 12 weeks of age. Persistent activation of TGF-β and mTOR signaling along with macrophage recruitment preceded histological changes at 4 weeks of age. Short-term mTOR inhibition with rapamycin from 4 to 5 weeks of age prevented TGF-β overactivity and leukocytic infiltrates, while long-term inhibition of mTOR or TGF-β signaling from 4 to 12 weeks of age rescued mitral valve leaflet degeneration. Transcriptomic analysis identified integrins as key receptors in signaling interactions and serologic neutralization of integrin signaling or a chimeric integrin receptor altering signaling prevented mTOR activation. We confirmed increased mTOR signaling and a conserved transcriptome signature in human specimens of sporadic mitral valve prolapse. Thus, mTOR activation from abnormal integrin-dependent cell-matrix interactions drives TGF-β overactivity and myxomatous mitral valve degeneration, and mTOR inhibition may prevent disease progression of mitral valve prolapse.

• Cancer Research
,
• Immunology and Microbiology

Single-cell sequencing unveils the transcriptomic landscape of castration-resistant prostate cancer-associated fibroblasts and their association with prognosis and immunotherapy response.

In BMC Cancer on 30 April 2025 by Qiu, Y., Wang, Y., et al.

The tumor microenvironment (TME) is increasingly acknowledged as a determinant in the malignant transformation and progression of castration-resistant prostate cancer (CRPC). Cancer-associated fibroblasts (CAFs), as a pivotal stromal cellular component in TME, are implicated in tumor progression and immune escape. However, the molecular characteristics and biological functions of CRPC-CAFs in prostate cancer necessitate further investigation. We ascertained the differential transcriptomic profiles between CRPC-CAFs and PCa-CAFs through single-cell RNA-sequencing (scRNA-seq). Bulk RNA-seq data were employed to assess the prognostic implications of CRPC-CAFs in PCa. In addition, we examined the impact of CRPC-CAFs on the efficacy of immunotherapy and the composition of the tumor immune milieu. Furthermore, a subcutaneous PCa model was applied to determine the potential of TGF-β signaling blockade to augment the response to immunotherapeutic interventions. We observed a pronounced increase in the proportion of CAFs in CRPC compared to those in primary PCa. The functional pathways implicated in TGF-β signaling and ECM remodeling were remarkably upregulated in CRPC-CAFs. Moreover, gene regulatory network analysis uncovered substantial differences in the transcription factor activity profiles between CRPC-CAFs and PCa-CAFs. The elevated CRPC-CAFs abundance was associated with diminished recurrence-free survival and immunotherapy insensitivity. Substantially elevated infiltration of inhibitory immune cells and upregulated expression levels of immunosuppressive molecules were observed in patients with high CRPC-CAFs abundance. Importantly, administration of anti-TGF-β therapy remarkably potentiated the efficacy of anti-PD-1 immunotherapy through upregulating the anti-tumor immune response in the PCa model. Our results highlighted the impact of CRPC-CAFs on clinical prognosis and immunosuppressive tumor milieu, indicating that CRPC-CAFs may function as a promising therapeutic target for CRPC. © 2025. The Author(s).

• FC/FACS
,
• IHC
,
• Cancer Research
,
• Immunology and Microbiology

The Combination of Oncolytic Virus and Antibody Blockade of TGF-β Enhances the Efficacy of αvβ6-Targeting CAR T Cells Against Pancreatic Cancer in an Immunocompetent Model.

In Cancers on 30 April 2025 by Zhao, Z., Cutmore, L. C., et al.

CAR T cell therapy, as a rapidly advancing immuno-oncology modality, has achieved significant success in the treatment of leukaemia and lymphoma. However, its application in solid tumours remains limited. The challenges include the heterogeneity of tumours, local immunosuppression, poor trafficking and infiltration, life-threatening toxicity and the lack of precise representative immunocompetent research models. Considering its typically dense and immunosuppressive tumour microenvironment (TME) and early metastasis, pancreatic ductal adenocarcinoma (PDAC) was employed as a model to address the challenges that hinder CAR T cell therapies against solid tumours and to expand immunotherapeutic options for advanced disease. A novel murine A20FMDV2 (A20) CAR T cell targeting integrin αvβ6 (mA20CART) was developed, demonstrating efficient and specific on-target cytotoxicity. The mA20CART cell as a monotherapy for orthotopic pancreatic cancer in an immunocompetent model demonstrated modest efficacy. Therefore, a novel triple therapy regimen, combining mA20CART cells with oncolytic vaccinia virus encoding IL-21 and a TGF-β-blocking antibody was evaluated in vivo. The triple therapy improved overall survival, improved the safety profile of the CAR T cell therapy, attenuated metastasis and enhanced T cell infiltration. Notably, the potency of mA20CART was dependent on IL-2 supplementation. This study presents an αvβ6-targeting murine CAR T cell, offering a novel approach to developing CAR T cell technologies for solid tumours and a potential adjuvant therapy for pancreatic cancer.

Augmented expression of superoxide dismutase 2 mitigates progression and rupture of experimental abdominal aortic aneurysm.

In Theranostics on 11 April 2025 by Yan, H., Hu, Y., et al.

Rationale: Oxidative stress is implicated in the pathogenesis and progression of abdominal aortic aneurysm (AAA). It is suggested that an excess in reactive oxygen species (ROS) over endogenous antioxidant activities can lead to endothelial and mitochondrial dysfunction, which promotes tissue inflammation, extracellular matrix degradation, and cellular apoptosis, all pathologic features characteristic of AAA. While elevated levels of ROS in human and experimental AAA appear well established, the contribution of endogenous antioxidant systems to aneurysm formation and progression remains controversial. We demonstrate that the antioxidant enzyme superoxide dismutase 2 (SOD2), the resident mitochondrial form of SODs that protects against mitochondrial damage, is relatively deficient in established preclinical AAA. We hypothesize that augmented expression of SOD2 will protect against oxidative stress and mitigate aneurysm progression. Methods: Herein, we employ a peptide-based nanoplatform to overexpress a key modulator of oxidative stress, SOD2. The efficacy of systemic delivery of murine SOD2 mRNA as an antioxidant nanotherapeutic agent was studied in two different murine AAA models. Unbiased mass spectrometry-enabled proteomics and high-dimensional bioinformatics were used to examine pathways modulated by SOD2 overexpression. Results: Using two different murine models of AAA, we show that in vivo augmentation of SOD2 expression via mRNA-based nanotherapy mitigates the expansion of small aneurysms and largely prevents rupture. Mitigation of AAA is accompanied by concomitant suppression of ROS, ROS surrogate markers, and apoptotic cell death. Proteomic profiling of AAA tissue and gene set enrichment analysis show that SOD2 overexpression is associated with modulation of oxidative phosphorylation, respiratory electron transport, and fatty acid metabolism. In addition, SOD2 overexpression inhibits platelet activation, downregulates mitogen-activated protein kinase signaling, and augments levels of microRNAs miR-181a-5p and miR17-5p targets that regulate vascular inflammation and cell apoptosis, respectively. Conclusions: These results confirm that SOD2 plays a pivotal role in the pathogenesis of experimental AAA and identify its potential as a therapeutic target. © The author(s).

• Homo sapiens (Human)

Suppression of TGF-β/SMAD signaling by an inner nuclear membrane phosphatase complex.

In Nature Communications on 11 April 2025 by Ji, Z., Siu, W. S., et al.

Cytokines of the TGF-β superfamily control essential cell fate decisions via receptor regulated SMAD (R-SMAD) transcription factors. Ligand-induced R-SMAD phosphorylation in the cytosol triggers their activation and nuclear accumulation. We determine how R-SMADs are inactivated by dephosphorylation in the cell nucleus to counteract signaling by TGF-β superfamily ligands. We show that R-SMAD dephosphorylation is mediated by an inner nuclear membrane associated complex containing the scaffold protein MAN1 and the CTDNEP1-NEP1R1 phosphatase. Structural prediction, domain mapping and mutagenesis reveals that MAN1 binds independently to the CTDNEP1-NEP1R1 phosphatase and R-SMADs to promote their inactivation by dephosphorylation. Disruption of this complex causes nuclear accumulation of R-SMADs and aberrant signaling, even in the absence of TGF-β ligands. These findings establish CTDNEP1-NEP1R1 as the R-SMAD phosphatase, reveal the mechanistic basis for TGF-β signaling inactivation and highlight how this process is disrupted by disease-associated MAN1 mutations. © 2025. The Author(s).

• Cancer Research

LTA4H improves the tumor microenvironment and prevents HCC progression via targeting the HNRNPA1/LTBP1/TGF-β axis.

In Cell Reports Medicine on 18 March 2025 by Yang, S., Qiu, X., et al.

Leukotriene A4 hydrolase (LTA4H), an inflammatory mediator, has garnered attention for its role in the development of chronic lung diseases and various cancers. Our study highlights the protective role of LTA4H in hepatocellular carcinoma (HCC) occurrence and progression. LTA4H is downregulated in clinical and mouse HCC tumors. LTA4H deficiency exacerbates hepatocyte damage by restraining JNK activation and promotes CD206+ macrophage polarization through the upregulation of LTBP1 expression and downstream transforming growth factor β (TGF-β) secretion and activation. Mechanistically, LTA4H induces heterogeneous nuclear ribonucleoprotein A1 (HNRNPA1) phosphorylation, enhancing their interaction and leading to the functional inhibition of HNRNPA1 in regulating Ltbp1 mRNA maturation and processing in the nucleus. LTA4H-deficient patients exhibit poor prognosis and immunotherapy resistance. Combination therapy targeting TGF-β and PD-1 significantly improves the immunotherapy resistance of LTA4H-knockout Hepa1-6 tumors. Our findings reveal the previously unreported role of LTA4H in regulating the tumor microenvironment and provide insights into potential diagnostic and therapeutic strategies for patients with LTA4H-deficient HCC. Copyright © 2025 The Author(s). Published by Elsevier Inc. All rights reserved.

Single-cell and chromatin accessibility profiling reveals regulatory programs of pathogenic Th2 cells in allergic asthma.

In Nature Communications on 15 March 2025 by Khan, M., Alteneder, M., et al.

Lung pathogenic T helper type 2 (pTh2) cells are important in mediating allergic asthma, but fundamental questions remain regarding their heterogeneity and epigenetic regulation. Here we investigate immune regulation in allergic asthma by single-cell RNA sequencing in mice challenged with house dust mite, in the presence and absence of histone deacetylase 1 (HDAC1) function. Our analyses indicate two distinct highly proinflammatory subsets of lung pTh2 cells and pinpoint thymic stromal lymphopoietin (TSLP) and Tumour Necrosis Factor Receptor Superfamily (TNFRSF) members as important drivers to generate pTh2 cells in vitro. Using our in vitro model, we uncover how signalling via TSLP and a TNFRSF member shapes chromatin accessibility at the type 2 cytokine gene loci by modulating HDAC1 repressive function. In summary, we have generated insights into pTh2 cell biology and establish an in vitro model for investigating pTh2 cells that proves useful for discovering molecular mechanisms involved in pTh2-mediated allergic asthma. © 2025. The Author(s).

• Immunology and Microbiology
,
• Neuroscience

STING Deficiency Promotes Th17-Like Tfh to Aggravate the Experimental Autoimmune Uveitis.

In Investigative Ophthalmology & Visual Science on 3 March 2025 by Li, Z., Liu, X., et al.

The purpose of this study was to explore the underlying mechanism that Th17-like T follicular helper cells (Tfh) orchestrated by STING signaling have a pathogenic role in experimental autoimmune uveitis (EAU). The differences of transcriptome and gene ontology (GO) pathway of Tfh between EAU and control mice were analyzed by single-cell RNA sequence (scRNA-seq) and bulk RNA sequence. Additionally, draining lymph nodes (DLNs) were extracted to verify the expression of IL-17A and IFN-γ in Tfh from EAU and control mice by flow cytometry. Then, the scRNA-seq and flow cytometry were used to explore the different proportion of Tfh between STING deficiency (Sting-/-) mice and wild type (WT) mice. In vitro, naïve CD4+ T cells were isolated from Sting-/- mice and WT mice to induce the Tfh under the induction condition. In addition, flow cytometry was used to detect the different induction ratio and the IL-17A expression between 2 groups of naïve CD4+ T cells. Compared with control mice, marked increase of Tfh was observed in EAU, accompanied by elevated levels of Th1 and Th17 cells. Moreover, Th17-related genes, such as Rorc, Il22, Il23r, Il17a, and Il17f, and the corresponding GO pathways were upregulated in Tfh from EAU. The scRNA-seq showed that a higher proportion of Tfh was observed in the DLNs from Sting-/- mice than WT mice, which was verified by flow cytometry. When STING was knocked out, the Tfh was characterized with upregulated Th17-related phenotype in vivo, and there was a higher induction ratio of Tfh whose IL-17A expression was significantly increased in vitro. Notably, the STING expression of CD4+ T cells was downregulated in the EAU. STING-deficient EAU mice displayed more severe retinal inflammation, characterized by massive infiltration of CD4+ T cells, including Th1 and Th17 subsets. Importantly, treatment with a STING agonist alleviated inflammation of EAU. Th17-like Tfh cells play a pathogenic role in the EAU. STING deficiency promotes the differentiation and phenotypic transformation of Th17-like Tfh cells, exacerbating the inflammatory response in EAU. These findings highlight the potential of targeting STING to modulate Tfh cells as a therapeutic strategy for uveitis.

• Immunology and Microbiology

TBX3 shapes an immunosuppressive microenvironment and induces immunotherapy resistance.

In Theranostics on 3 February 2025 by Liu, Z., Zhang, C., et al.

Background: Identifying biomarkers that predict immunotherapy efficacy and discovering new targets for combination therapies are critical elements for improving the prognosis of bladder cancer (BLCA) patients. Methods: Firstly, we explored the expression patterns of TBX3 in normal and pan-cancer tissues and the correlation between TBX3 and the immune microenvironment using data from multiple public databases. Then, we combined various techniques, including bulk RNA sequencing, single-cell RNA sequencing, high-throughput cytokine arrays, functional experiments, ProcartaPlex multiplex immunoassays and TissueFAXS panoramic tissue quantification assays, to demonstrate that TBX3 shapes an immunosuppressive tumor microenvironment (TME) in BLCA. Results: We identified TBX3 as a key factor associated with the immunosuppressive microenvironment in BLCA through a systematic multi-omics analysis. We found that TBX3 is primarily expressed in malignant cells, where TBX3high tumor cells increase the secretion of TGFβ1, which promotes the infiltration of cancer-associated fibroblasts (CAFs), thereby forming an immunosuppressive microenvironment. We further demonstrated that TBX3 enhances TGFβ1 expression by binding to the TGFβ1 promoter, and blocking TGFβ1 counteracts the immunosuppressive effects of TBX3. Moreover, TBX3 reduced the cancer-killing efficiency of CD8+ T cells by decreasing the proportion of GZMB+ CD8+ T cells, and knocking down TBX3 combined with anti-PD-1 treatment increased CD8+ T cell infiltration and reduced CAFs in vivo. We also validated the inverse relationship between TBX3+ malignant cells and CD8+ T cells and the positive relationship with CAFs in tissue microarrays. Lastly, we found that TBX3 predicted immunotherapy efficacy in our real-world immunotherapy cohort and multiple public cohorts. Conclusion: In summary, TBX3 promotes BLCA progression and immunotherapy resistance by inducing an immunosuppressive microenvironment, and targeting TBX3 could enhance the efficacy of immunotherapy for BLCA. © The author(s).

• In Vivo
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• Mus musculus (House mouse)
,
• Cancer Research
,
• Cell Biology
,
• Immunology and Microbiology

Aberrant cytoplasmic expression of UHRF1 restrains the MHC-I-mediated anti-tumor immune response.

In Nature Communications on 3 October 2024 by Tan, L. M., Yin, T., et al.

Immunotherapy successfully complements traditional cancer treatment. However, primary and acquired resistance might limit efficacy. Reduced antigen presentation by MHC-I has been identified as potential resistance factor. Here we show that the epigenetic regulator ubiquitin-like with PHD and ring finger domains 1 (UHRF1), exhibits altered expression and aberrant cytosolic localization in cancerous tissues, where it promotes MHC-I ubiquitination and degradation. Cytoplasmic translocation of UHRF1 is induced by its phosphorylation on a specific serine in response to signals provided by factors present in the tumor microenvironment (TME), such as TGF-β, enabling UHRF1 to bind MHC-I. Downregulation of MHC-I results in suppression of the antigen presentation pathway to establish an immune hostile TME. UHRF1 inactivation by genetic deletion synergizes with immune checkpoint blockade (ICB) treatment and induces an anti-tumour memory response by evoking low-affinity T cells. Our study adds to the understanding of UHRF1 in cancer immune evasion and provides a potential target to synergize with immunotherapy and overcome immunotherapeutic resistance. © 2024. The Author(s).

Suppression of TGF-β/SMAD signaling by an inner nuclear membrane phosphatase complex

Preprint on BioRxiv : the Preprint Server for Biology on 23 September 2024 by Ji, Z., Siu, W. S., et al.

Cytokines of the TGF-β superfamily control essential cell fate decisions via receptor regulated SMAD (R-SMAD) transcription factors. Ligand-induced R-SMAD phosphorylation in the cytosol triggers their activation and nuclear accumulation. We determined how R-SMADs are inactivated by dephosphorylation in the cell nucleus to counteract signaling by TGF-β superfamily ligands. We showed that R-SMAD dephosphorylation is mediated by an inner nuclear membrane associated complex containing the scaffold protein MAN1 and the CTDNEP1-NEP1R1 phosphatase. Structural prediction, domain mapping and mutagenesis revealed that MAN1 binds independently to the CTDNEP1-NEP1R1 phosphatase and R-SMADs to promote their inactivation by dephosphorylation. Disruption of this complex led to nuclear accumulation of R-SMADs and aberrant signaling, even in the absence of TGF-β ligands. These findings establish CTDNEP1-NEP1R1 as the elusive R-SMAD phosphatase and reveal the mechanistic basis for TGF-β signaling inactivation and how this process is disrupted by disease-associated MAN1 mutations.

Adrenal gland macrophages regulate glucocorticoid production through Trem2 and TGF-β.

In JCI Insight on 13 June 2024 by Xu, Y., Patterson, M. T., et al.

Glucocorticoid synthesis by adrenal glands (AGs) is regulated by the hypothalamic-pituitary-adrenal axis to facilitate stress responses when the host is exposed to stimuli. Recent studies implicate macrophages as potential steroidogenic regulators, but the molecular mechanisms by which AG macrophages exert such influence remain unclear. In this study, we investigated the role of AG macrophages in response to cold challenge or atherosclerotic inflammation as physiologic models of acute or chronic stress. Using single-cell RNA sequencing, we observed dynamic AG macrophage polarization toward classical activation and lipid-associated phenotypes following acute or chronic stimulation. Among transcriptional alterations induced in macrophages, triggering receptor expressed on myeloid cells 2 (Trem2) was highlighted because of its upregulation following stress. Conditional deletion of macrophage Trem2 revealed a protective role in stress responses. Mechanistically, Trem2 deletion led to increased AG macrophage death, abolished the TGF-β-producing capacity of AG macrophages, and resulted in enhanced glucocorticoid production. In addition, enhanced glucocorticoid production was replicated by blockade of TGF-β signaling. Together, these observations suggest that AG macrophages restrict steroidogenesis through Trem2 and TGF-β, which opens potential avenues for immunotherapeutic interventions to resolve stress-related disorders.

• Cancer Research
,
• Immunology and Microbiology

Chemoradiotherapy-induced ACKR2+ tumor cells drive CD8+ T cell senescence and cervical cancer recurrence.

In Cell Reports Medicine on 21 May 2024 by Dai, D., Pei, Y., et al.

Tumor recurrence after chemoradiotherapy is challenging to overcome, and approaches to predict the recurrence remain elusive. Here, human cervical cancer tissues before and after concurrent chemoradiotherapy (CCRT) analyzed by single-cell RNA sequencing reveal that CCRT specifically promotes CD8+ T cell senescence, driven by atypical chemokine receptor 2 (ACKR2)+ CCRT-resistant tumor cells. Mechanistically, ACKR2 expression is increased in response to CCRT and is also upregulated through the ligation of CC chemokines that are produced by activated myeloid and T cells. Subsequently, ACKR2+ tumor cells are induced to produce transforming growth factor β to drive CD8+ T cell senescence, thereby compromising antitumor immunity. Moreover, retrospective analysis reveals that ACKR2 expression and CD8+ T cell senescence are enhanced in patients with cervical cancer who experienced recurrence after CCRT, indicating poor prognosis. Overall, we identify a subpopulation of CCRT-resistant ACKR2+ tumor cells driving CD8+ T cell senescence and tumor recurrence and highlight the prognostic value of ACKR2 and CD8+ T cell senescence for chemoradiotherapy recurrence. Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.

• Immunology and Microbiology

TGF-β1 induces PD-1 expression in macrophages through SMAD3/STAT3 cooperative signaling in chronic inflammation.

In JCI Insight on 5 March 2024 by Lei, Z., Tang, R., et al.

Programmed cell death protein 1 (PD-1), a coinhibitory T cell checkpoint, is also expressed on macrophages in pathogen- or tumor-driven chronic inflammation. Increasing evidence underscores the importance of PD-1 on macrophages for dampening immune responses. However, the mechanism governing PD-1 expression in macrophages in chronic inflammation remains largely unknown. TGF-β1 is abundant within chronic inflammatory microenvironments. Here, based on public databases, significantly positive correlations between PDCD1 and TGFB1 gene expression were observed in most human tumors. Of note, among immune infiltrates, macrophages as the predominant infiltrate expressed higher PDCD1 and TGFBR1/TGFBR2 genes. MC38 colon cancer and Schistosoma japonicum infection were used as experimental models for chronic inflammation. PD-1hi macrophages from chronic inflammatory tissues displayed an immunoregulatory pattern and expressed a higher level of TGF-β receptors. Either TGF-β1-neutralizing antibody administration or macrophage-specific Tgfbr1 knockdown largely reduced PD-1 expression on macrophages in animal models. We further demonstrated that TGF-β1 directly induced PD-1 expression on macrophages. Mechanistically, TGF-β1-induced PD-1 expression on macrophages was dependent on SMAD3 and STAT3, which formed a complex at the Pdcd1 promoter. Collectively, our study shows that macrophages adapt to chronic inflammation through TGF-β1-triggered cooperative SMAD3/STAT3 signaling that induces PD-1 expression and modulates macrophage function.

• Cancer Research

UPP1 promotes lung adenocarcinoma progression through the induction of an immunosuppressive microenvironment.

In Nature Communications on 8 February 2024 by Li, Y., Jiang, M., et al.

The complexity of the tumor microenvironment (TME) is a crucial factor in lung adenocarcinoma (LUAD) progression. To gain deeper insights into molecular mechanisms of LUAD, we perform an integrative single-cell RNA sequencing (scRNA-seq) data analysis of 377,574 cells from 117 LUAD patient samples. By linking scRNA-seq data with bulk gene expression data, we identify a cluster of prognostic-related UPP1high tumor cells. These cells, primarily situated at the invasive front of tumors, display a stronger association with the immunosuppressive components in the TME. Our cytokine array analysis reveals that the upregulation of UPP1 in tumor cells leads to the increased release of various immunosuppressive cytokines, with TGF-β1 being particularly prominent. Furthermore, this UPP1 upregulation also elevates the expression of PD-L1 through the PI3K/AKT/mTOR pathway, which contributes to the suppression of CD8 + T cells. Cytometry by time-of-flight (CyTOF) analysis provides additional evidence of the role of UPP1 in shaping the immunosuppressive nature of the TME. Using patient-derived organoids (PDOs), we discover that UPP1high tumors exhibit relatively increased sensitivity to Bosutinib and Dasatinib. Collectively, our study highlights the immunosuppressive role of UPP1 in LUAD, and these findings may provide insights into the molecular features of LUAD and facilitate the development of personalized treatment strategies. © 2024. The Author(s).

• Immunology and Microbiology

In PLoS Pathogens on 1 January 2024 by Rixon, J. A., Fong, K. D., et al.

PubMed

Chlamydia vaccine approaches aspire to induce Th1 cells for optimal protection, despite the fact that there is no direct evidence demonstrating Th1-mediated Chlamydia clearance from the female reproductive tract (FRT). We recently reported that T-bet-deficient mice can resolve primary Chlamydia infection normally, undermining the potentially protective role of Th1 cells in Chlamydia immunity. Here, we show that T-bet-deficient mice develop robust Th17 responses and that mice deficient in Th17 cells exhibit delayed bacterial clearance, demonstrating that Chlamydia-specific Th17 cells represent an underappreciated protective population. Additionally, Th2-deficient mice competently clear cervicovaginal infection. Furthermore, we show that sensing of IFN-γ by non-hematopoietic cells is essential for Chlamydia immunity, yet bacterial clearance in the FRT does not require IFN-γ secretion by CD4 T cells. Despite the fact that Th1 cells are not necessary for Chlamydia clearance, protective immunity to Chlamydia is still dependent on MHC class-II-restricted CD4 T cells and IL-12p40. Together, these data point to IL-12p40-dependent CD4 effector maturation as essential for Chlamydia immunity, and Th17 cells to a lesser extent, yet neither Th1 nor Th2 cell development is critical. Future Chlamydia vaccination efforts will be more effective if they focus on induction of this protective CD4 T cell population. Copyright: © 2024 Rixon et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

• Immunology and Microbiology

Kruppel-like factor 2+ CD4 T cells avert microbiota-induced intestinal inflammation.

In Cell Reports on 28 November 2023 by Shao, T. Y., Jiang, T. T., et al.

Intestinal colonization by antigenically foreign microbes necessitates expanded peripheral immune tolerance. Here we show commensal microbiota prime expansion of CD4 T cells unified by the Kruppel-like factor 2 (KLF2) transcriptional regulator and an essential role for KLF2+ CD4 cells in averting microbiota-driven intestinal inflammation. CD4 cells with commensal specificity in secondary lymphoid organs and intestinal tissues are enriched for KLF2 expression, and distinct from FOXP3+ regulatory T cells or other differentiation lineages. Mice with conditional KLF2 deficiency in T cells develop spontaneous rectal prolapse and intestinal inflammation, phenotypes overturned by eliminating microbiota or reconstituting with donor KLF2+ cells. Activated KLF2+ cells selectively produce IL-10, and eliminating IL-10 overrides their suppressive function in vitro and protection against intestinal inflammation in vivo. Together with reduced KLF2+ CD4 cell accumulation in Crohn's disease, a necessity for the KLF2+ subpopulation of T regulatory type 1 (Tr1) cells in sustaining commensal tolerance is demonstrated. Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.

• Mus musculus (House mouse)
,
• Cancer Research

TGF-β1 mediates tumor immunosuppression aggravating at the late stage post-high-light-dose photodynamic therapy.

In Cancer Immunology, Immunotherapy : CII on 1 September 2023 by Han, L., Huang, X., et al.

Photodynamic therapy (PDT) is an emerging clinical treatment that is expected to become an important adjuvant strategy for the immunotherapeutic cancer treatment. Recently, numerous works have reported combination strategies. However, clinical data showed that the anti-tumor immune response of PDT was not lasting though existing. The immune activation effect will eventually turn to immunosuppressive effect and get aggravated at the late stage post-PDT. So far, the mechanism is still unclear, which limits the design of specific correction strategies and further development of PDT. Several lines of evidence suggest a role for TGF-β1 in the immunosuppression associated with PDT. Herein, this study systematically illustrated the dynamic changes of immune states post-PDT within the tumor microenvironment. The results clearly demonstrated that high-light-dose PDT, as a therapeutic dose, induced early immune activation followed by late immunosuppression, which was mediated by the activated TGF-β1 upregulation. Then, the mechanism of PDT-induced TGF-β1 accumulation and immunosuppression was elucidated, including the ROS/TGF-β1/MMP-9 positive feedback loop and CD44-mediated local amplification, which was further confirmed by spatial transcriptomics, as well as by the extensive immune inhibitory effect of local high concentration of TGF-β1. Finally, a TGF-β blockade treatment strategy was presented as a promising combinational strategy to reverse high-light-dose PDT-associated immunosuppression. The results of this study provide new insights for the biology mechanism and smart improvement approaches to enhance tumor photodynamic immunotherapy. © 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Single-cell profiling uncovers regulatory programs of pathogenic Th2 cells in allergic asthma

Preprint on BioRxiv : the Preprint Server for Biology on 14 August 2023 by Khan, M., Alteneder, M., et al.

Lung pathogenic T helper type 2 (pTh2) cells are important drivers of allergic asthma, but fundamental questions remain regarding their regulation and heterogeneity. The differentiation and effector functions of immune cells are tightly regulated by epigenetic processes. Histone deacetylase 1 (HDAC1) is an important epigenetic regulator of T cells, however, its role in pTh2 cells is yet to be determined. Here we investigate immune regulation in allergic asthma by single-cell RNA sequencing (scRNA-seq) in mice challenged with house dust mite, in the presence and absence of HDAC1 function. Our analyses reveal two distinct subsets of lung pTh2 cells: pathogenic effector Th2 (peTh2) and pathogenic Th2 tissue-resident memory (Th2 Trm) cells. Both pTh2 cell subsets are highly proinflammatory and exhibit distinct transcriptional and phenotypic signatures as compared with other lung Th subsets. Based on our scRNA-seq analysis, we identify conditions to generate pTh2 cells in vitro and confirm that these in vitro generated pTh2 cells have a similar transcriptional profile as lung peTh2 cells. Using our new in vitro model, we demonstrate that the p38 mitogen-activated protein kinase pathway is critical for interleukin-5 (IL-5) and IL-13 expression in pTh2 cells. Our data further underline the importance of HDAC1 in limiting the pathogenicity of lung and in vitro pTh2 cells and in the formation of lung Th2 Trm cells. In summary, we have generated novel insights into pTh2 cell biology and established a new in vitro model for investigating pTh2 cells that will be useful for discovering molecular mechanisms involved in pTh2-mediated allergic asthma.