IL-2 Signaling Research Articles

Early introduction of IL-10 weakens BCG revaccination’s protection by suppressing CD4+Th1 cell responses

BackgroundThe Bacillus Calmette-Guérin (BCG) vaccine, currently the sole authorized vaccine against tuberculosis (TB), demonstrates limited effectiveness in safeguarding adolescents and adults from active TB, even when administered as a booster with either BCG itself or heterologous vaccine candidates. To effectively control the persistent epidemic of adult TB, it is imperative to investigate the mechanisms responsible for the suboptimal efficacy of the BCG prime-boosting strategy against primary Mycobacterium tuberculosis (M.tb) infection.MethodsC57BL/6J mice were immunized with the BCG vaccine either once or twice, followed by analysis of lung tissue to assess changes in cytokine levels. Additionally, varying intervals between vaccinations and detection times were examined to study IL-10 expression across different organs. IL-10-expressing cells in the lungs, spleen, and lymph nodes were analyzed through FACS and intracellular cytokine staining (ICS). BCG-revaccinated IL-10−/− mutant mice were compared with wild-type mice to evaluate antigen-specific IgG antibody and T cell responses. Protection against M.tb aerosol challenge was evaluated in BCG-revaccinated mice, either untreated or treated with anti-IL-10R monoclonal antibody.ResultsIL-10 was significantly upregulated in the lungs of BCG-revaccinated mice shortly after the booster immunization. IL-10 expression peaked in the lungs 3–6 weeks post-revaccination and was also detected in lymph nodes and spleen as early as 2 weeks following the booster dose, regardless of the intervals between the prime and booster vaccinations. The primary sources of IL-10 in these tissues were identified as macrophages and dendritic cells. Blocking IL-10 signaling in BCG-revaccinated mice—either by using IL-10−/− mutant mice or administering anti-IL-10R monoclonal antibody increased levels of antigen-specific IFN-γ+ or IL-2+ CD4+ T cells, enhanced central and effector memory CD4+ T cell responses, and provided better protection against aerosol infection with 300 CFUs of M.tb.ConclusionOur findings are crucial for formulating effective immunization strategies related to the BCG vaccine and for developing efficacious adult TB vaccines.Graphical abstract

Real-World Evaluation of Dupilumab in the Long-Term Management of Eosinophilic Chronic Rhinosinusitis with Nasal Polyps: A Focus on IL-4 and IL-13 Receptor Blockade

Background and Objectives: Chronic rhinosinusitis (CRS) is a complex inflammatory condition of the nasal passages that severely impairs quality of life. Type 2 CRS is characterized by eosinophilic inflammation, driven by cytokines like IL-4, IL-5, and IL-13. These cytokines are key to CRS pathogenesis and contribute to a heavy disease burden, especially with comorbidities. This study assessed dupilumab, a monoclonal antibody targeting IL-4 and IL-13 signaling, to evaluate its efficacy in reducing the disease burden in patients with CRS with nasal polyps (CRSwNP). Materials and Methods: The patients received subcutaneous dupilumab for 42 weeks. The outcomes included Nasal Polyp Score (NPS); Sino-Nasal Outcome Test (SNOT-22), Numeric Rating Scale (NRS), and Visual Analog Scale (VAS) scores; total IgE; and olfactory function. Results: Significant improvements were observed across the NPS and SNOT-22, NRS, and VAS scores after 42 weeks. Their total IgE levels were reduced, though a transient increase in peripheral eosinophilia appeared at 16 weeks. The patients also reported substantial improvements in olfactory function and high satisfaction with the treatment, supporting dupilumab’s potential in reducing both symptom severity and inflammation in CRSwNP. Conclusions: These results indicate that dupilumab may be an effective treatment for CRSwNP, offering significant symptom relief, improved olfactory function, and enhanced quality of life. High satisfaction levels suggest that dupilumab may provide therapeutic advantages over the conventional CRS treatments, though further studies are warranted to confirm its long-term benefits.

The HSP90 Inhibitor Pimitespib Targets Regulatory T Cells in the Tumor Microenvironment.

Regulatory T (Treg) cells play key roles in cancer immunity by suppressing a range of antitumor immune responses and contributing to resistance to programmed death (PD)-1 blockade therapy. Given their critical roles in self-tolerance, local control of immunosuppression by Treg cells, such as in the tumor microenvironment (TME), has been intensively studied. Inhibition of heat shock protein 90 (HSP90), a chaperone with vital roles in regulating proteostasis in cancer cells, impedes cancer progression by interrupting oncogenic signaling pathways and potentially modulating antitumor immunity, but we have very little mechanistic insight into these immune modulatory effects. Here, we show that the number of Treg cells are selectively reduced by the HSP90 inhibitor pimitespib in animal models and patients with gastric cancer in a clinical trial (EPOC1704). Pimitespib reduced the highly immunosuppressive human FOXP3high effector Treg cells by inhibiting their proliferation and decreasing their expression of effector molecules, which improved the priming and activation of antigen-specific CD8+ T cells. Mechanistic studies revealed that pimitespib selectively degraded STAT5, a key transducer of the IL-2 signaling pathway, which is essential for Treg cell development and maintenance, and consequently compromised FOXP3 expression, leading to selective impairment of immunosuppression in the TME by Treg cells. Thus, pimitespib treatment combined with PD-1 blockade exhibited a far stronger antitumor effect than either treatment alone in animal models. Through these data, we propose that HSP90 inhibition is a promising therapeutic option for Treg cell-targeted cancer immunotherapy.

Dupilumab: Evaluating its role in atopic dermatitis, prurigo nodularis, eczemas, urticaria, alopecia areata and vesiculobullous disorders – Part I

Dupilumab is a fully human monoclonal IgG4 antibody that targets IL-4 and IL-13 signaling pathways. It is approved by the US-FDA for the treatment of atopic dermatitis and prurigo nodularis. Besides, it has shown efficacy in various off-label dermatologic conditions. Part I of this review will elaborate on the utility of dupilumab in atopic dermatitis, prurigo nodularis, eczemas, urticaria, alopecia areata and vesiculobullous disorders.

Interleukin-2-mediated NF-κB-dependent mRNA splicing modulates interferon gamma protein production.

Interferon-gamma (IFNγ) is a pleiotropic cytokine produced by natural killer (NK) cells during the early infection response. IFNγ expression is tightly regulated to mount sterilizing immunity while preventing tissue pathology. Several post-transcriptional effectors dampen IFNγ expression through IFNG mRNA degradation. In this study, we identify mRNA splicing as a positive regulator of IFNγ production. While treatment with the combination of IL-12 and IL-2 causes synergistic induction of IFNG mRNA and protein, defying transcription-translation kinetics, we observe that NK cells treated with IL-12 alone transcribe IFNG with introns intact. When NK cells are treated with both IL-2 and IL-12, IFNG transcript is spliced to form mature mRNA with a concomitant increase in IFNγ protein. We find that IL-2-mediated intron splicing occurs independently of nascent transcription but relies upon NF-κB signaling. We propose that while IL-12 transcriptionally induces IFNG mRNA, IL-2 signaling stabilizes IFNG mRNA by splicing detained introns, allowing for rapid IFNγ protein production. This study uncovers a novel role for cytokine-induced splicing in regulating IFNγ through a mechanism potentially applicable to other inflammatory mediators.

Abstract C019: IL27R signaling regulates neutrophils maturation, activation and function in colorectal cancer-liver metastases

Abstract Colorectal cancer (CRC) is the third most common cancer and fourth cause of cancer death worldwide. The liver is the most common organ for CRC metastasis, which is a major cause of death for CRC patients. Therefore, a better understanding of mechanisms facilitating CRC liver metastasis is in urgent need. IL27 is a member of IL6/IL12 cytokines superfamily which have a critical role in tumor microenvironment to affect tumorigenesis and metastasis. IL27 is secreted by activated macrophages and dendritic cells, and IL27R is expressed in various immune cells, mediating IL27-dependent pro-inflammatory or anti-inflammatory immune responses. However, the role of myeloid IL27 signaling in CRC-liver metastasis remains unclear. To study the role of IL27R signaling in myeloid cells, we generated Il27ra fl/fl mice and crossed them with LysM cre deleter to obtain LysM cre+ Il27ra f/f mice. Using MC-38 CRC cells portal vein injection model, we found that myeloid IL27Ra deletion leads to increased CRC-liver metastasis accompanied by increase in neutrophils, particularly Ly6G+Cxcr2-CD101- immature neutrophils, in circulation as well as tumors in LysM cre+ Il27ra f/f mice. Single-cell sequencing of tumor-infiltrating immune cells revealed that lack of IL27Ra in myeloid cells promoted neutrophil recruitment and degranulation as well as reactive oxygen species (ROS) and reactive nitrogen species (RNS) production but inhibited neutrophil maturation and production of pro-inflammatory chemokines and cytokines such as CXCL10, CSF1 and TNF. Furthermore, IL27Ra deficient neutrophils displayed heightened inflammatory response when stimulated with LPS in vitro. Collectively, our work reveals novel role of myeloid IL27Ra signaling that inhibits metastatic liver colonization by promoting neutrophil maturation, restricting neutrophil infiltration and degranulation. Citation Format: Jiani Zhu, Zhengzheng Shi, Ekaterina Koltsova. IL27R signaling regulates neutrophils maturation, activation and function in colorectal cancer-liver metastases [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C019.

Abstract C049: Implementing human bone marrow organoids to interrogate microenvironmental influences on the efficacy of blood cancer immunotherapies

Abstract Cancers perpetuate immunosuppressive niches that fuel progression and hinder the clinical utility of immunotherapies. Pre-clinical validation of immunotherapies often relies on 2D models that lack spatial complexity, or mouse models that do not fully recapitulate the human tumor microenvironment (TME). We recently developed a human induced pluripotent stem cell (iPSC)-derived bone marrow organoid platform, creating a robust system to interrogate cancer-stroma cross talk. Here, we further develop the model to create the first in vitro system for evaluation of blood cancer immunotherapies in a human tissue environment. We focused on targeting myeloproliferative neoplasms (MPNs) – chronic blood cancers affecting ∼400,000 individuals in the US that are currently largely incurable. 1/3 of MPNs are driven by a mutation in calreticulin (mutCALR), and the mutCALR oncoprotein is displayed on the cell surface of disease-initiating stem cells and fibrosis-driving megakaryocytes. MPNs are characterized by pronounced inflammation and fibrosis (“myelofibrosis”). Therapeutic antibodies have entered first-in-human trials, and we recently presented pre-clinical data for the first mutCALR-directed CAR-T cell therapy. However, it is unclear how the TME may limit the efficiency of these agents. To address this, we first tested the utility of the organoid platform to evaluate target killing of leukemic cell lines and cells from patients using the anti-CD33 antibody-drug conjugate (ADC) gemtuzumab. The ADC showed good penetration and potent target cell killing in organoids, with only minimal reduction in efficacy in TGFβ-rich/fibrotic microenvironments. We then developed more sophisticated ‘chimeroids’ comprising the iPSC organoid scaffold engrafted with malignant stem cells plus CAR-Ts. Addition of mutCALR-directed CAR-Ts induced highly selective killing of mutCALR+ stem/progenitor cells with minimal toxicity to non-malignant cells including niche cells (n=5 donors), replicating the highly specific and robust killing seen in 2D cultures. To evaluate the impact of TME perturbations on CAR-T phenotype and function, we generated a scRNAseq dataset of 161,970 cells from ‘healthy’ and ‘myelofibrotic’ organoids engrafted with patient-derived mutCALR+ cells plus CAR-Ts, pre-stimulating organoids with two immunoregulatory cytokines highly abundant in myelofibrosis -TGFβ and Galectin-1. CAR- Ts exposed to mutCALR+ cells showed a 2x expansion of CD8+ effector memory cells, with significant enrichment of IFNγ, TNFα and IL-2 signaling gene-sets. The proportion of immunosuppressive Tregs increased in a high TGFβ TME, but not with Galectin-1. Ongoing analyses are further interrogating crosstalk between CAR-T, target cells, and niche components, and exploring the pro-inflammatory impact of CAR-T killing on the marrow niche – a potential mediator of delayed hematopoietic recovery. These studies demonstrate the utility of human organoids to evaluate blood cancer-targeting immunotherapies within a relevant human TME, with broad relevance for mechanistic and translational studies. Citation Format: Zoë C. Wong, Yuqi Shen, Alex Rampotas, Isaac Gannon, Charlotte Brierley, Camelia Benlabiod, Nawshad Hayder, Eleanor Murphy, Aude-Anaïs Olijnik, Claire Roddie, Martin Pulé, Adam J. Mead, Abdullah O. Khan, Bethan Psaila. Implementing human bone marrow organoids to interrogate microenvironmental influences on the efficacy of blood cancer immunotherapies [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C049.

Divergent clinical and immunologic outcomes based on STK11 co-mutation status in resectable KRAS-mutant lung cancers following neoadjuvant immune checkpoint blockade.

Co-mutations of the KRAS and STK11 genes in advanced non-small cell lung cancer (NSCLC) are associated with immune checkpoint blockade (ICB) resistance. While neoadjuvant chemoimmunotherapy is now a standard of care treatment for resectable NSCLC, the clinical and immunologic impact of KRAS andSTK11 co-mutations in this setting are unknown. We evaluated and compared recurrence-free survival of resectable KRAS-mutated NSCLC tumors, with or without co-occuring STK11 mutations, treated with neoadjuvant ICB. Single cell transcriptomics was performed on tumor-infiltrating T cells from 7 KRASmut/STK11wttumors and 6 KRASmut/STK11mut tumors. Relative to KRASmut/STK11wttumors, KRASmut/STK11mut exhibited significantly higher recurrence risk. Single-cell transcriptomics showed enhanced oxidative phosphorylation with evidence of decreased PGE-2 signaling and increased IL-2 signaling in CD8+ tumor-infiltrating lymphocytes (TIL) from KRASmut/STK11mut tumors, a finding that was mirrored in KRASwt tumors that relapsed. TIL from KRASmut/STK11mut tumors expressed high levels of molecules associated with tumor residence, including CD39 and ZNF683 (HOBIT). These divergent T cell transcriptional fates suggest T cell maintenance and residence may be detrimental to anti-tumor immunity in the context of neoadjuvant ICB for resectable NSCLC, regardless of KRAS mutation status. Our work provides a basis for future investigations into the mechanisms underpinning PGE-2 and IL-2 signaling as they relate to T cell immunity to cancer and to divergent clinical outcomes in KRASmut/STK11mut NSCLC treated with neoadjuvant ICB.

Interleukin-10 inhibits important components of trained immunity in human monocytes.

Trained immunity induces antigen-agnostic enhancement of host defense and protection against secondary infections, but inappropriate activation can contribute to the pathophysiology of inflammatory diseases. Tight regulation of trained immunity is therefore needed to avoid pathology, but little is known about the endogenous processes that modulate it. Here, we investigated the potential of IL-10, a prototypical anti-inflammatory cytokine, to inhibit trained immunity. IL-10 induced tolerance and inhibited trained immunity in primary human monocytes at both functional and transcriptional levels. Inhibition of STAT3, a signaling route that mediates IL-10 signals, induced trained immunity. IL-10 downregulated glycolytic and oxidative metabolism in monocytes, but did not impact the metabolic effects of β-glucan-induced trained immunity. Furthermore, IL-10 prevented increased ROS production in BCG-induced training, but did not influence phagocytosis upregulation. In a cohort study of healthy volunteers vaccinated with BCG, genetic variants that influenced IL-10 or its receptor modulated BCG-induced trained immunity. Furthermore, circulating IL-10 concentrations were negatively correlated with induction of trained immunity after BCG vaccination in a sex-specific manner. In conclusion, IL-10 inhibited several, albeit not all, immunological functions amplified after induction of trained immunity. Follow-up studies should explore the precise molecular mechanism that mediate the effects of IL-10 on trained immunity. Addressing these knowledge gaps is an important step towards optimizing IL-10's potential as a therapeutic target in diseases characterized by inappropriate induction of trained immunity.

Transcriptional Profiling of Tofacitinib Treatment in Juvenile Idiopathic Arthritis: Implications for Treatment Response Prediction.

To assess changes in gene expression following tofacitinib treatment and investigate transcription patterns as potential predictors of treatment response in patients with active juvenile idiopathic arthritis (JIA). Whole blood samples were collected from JIA patients at baseline and after 18 weeks of open-label tofacitinib treatment (clinical trial NCT02592434). Patients who achieved a JIA-American College of Rheumatology (ACR) response of 70 or above at week 18 were classified as treatment-responders (TR) while those with at most a JIA-ACR30 response were classified as poor-responders (PR). Differential gene expression and gene ontology (GO) over-representation analyses were performed to compare RNA expression between week 18 and baseline samples, as well as between PR and TR samples at baseline. Samples from 67 patients at baseline and 60 at week 18 were analyzed. Following 18 weeks of tofacitinib treatment across all JIA subjects, 883 genes showed significant differential expression (week 18 - baseline). The most strongly downregulated genes were over-represented within IL-7, type I, and type II interferon pathways, while upregulated genes were enriched in ontologies related to neuronal cell processes and cell signaling. Comparing PR and TR at baseline, 663 genes showed differential expression. Upregulated genes were over-represented within ontologies including activation of MAPK activity (p=9.40x10-5), myeloid cell development (p=8.13 x10-5), activation of GTPase activity (p=0.00015), and organelle transport along microtubules (p=0.00021). Tofacitinib treatment in JIA downregulated genes in interferon and IL-7 signaling pathways regardless of effectiveness. Furthermore, baseline upregulation of MAPK signaling may predict poor response to tofacitinib treatment in JIA.

Gut-homing and intestinal TIGITnegCD38+ memory T cells acquire an IL-12-induced, ex-Th17 pathogenic phenotype in a subgroup of Crohn’s disease patients with a severe disease course

CD4+ memory T cell (TM) reactivation drives chronicity in inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis. Defects driving loss of TM regulation likely differ between patients but remain undefined. In health, approximately 40 % of circulating gut-homing CD38+TM express co-inhibitory receptor T-cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT). TIGIT+CD38+TM have regulatory function while TIGITnegCD38+TM are enriched in IFN-γ-producing cells. We hypothesized TIGITnegCD38+TM are inflammatory and drive disease in a subgroup of IBD patients. We characterized TIGIT+CD38+TM in a uniquely large cohort of pediatric IBD patients from time of diagnosis into adulthood. Circulating TIGITnegCD38+TM frequencies were higher in a subgroup of therapy-naïve CD patients with high plasma IFN-γ and a more severe disease course. TIGITnegCD38+TM were highly enriched in HLA-DR+ and ex-Th17/Th1-like cells, high producers of IFN-γ. Cultures of healthy-adult-stimulated TM identified IL-12 as the only IBD-related inflammatory cytokine to drive the pathogenic ex-Th17-TIGITnegCD38+ phenotype. Moreover, IL12RB2 mRNA expression was higher in TIGITnegCD38+TM than TIGIT+CD38+TM, elevated in CD biopsies compared to controls, and correlated with severity of intestinal inflammation. Overall, we argue that in a subgroup of pediatric CD, increased IL-12 signaling drives reprogramming of Th17 to inflammatory Th1-like TIGITnegCD38+TM and causes more severe disease.

IL-13 inhibition in the treatment of atopic dermatitis - new and emerging biologic agents.

Atopic dermatitis (AD) is a common, chronic, and recurrent inflammatory skin condition that affects a considerable portion of the population, and is particularly prevalent among children. The development of AD is influenced by environmental and genetic factors, which cause epidermal barrier dysfunction, immune dysregulation, and dysbiosis. In immune dysregulation, there is excessive production of cytokines. Among the cytokines, interleukin (IL)-13 plays a major role in the pathogenesis of AD. Searching for new and more selective treatments for moderate-to-severe cases is important because of the considerable effect of AD on the quality of life. Tralokinumab and lebrikizumab are selective IL-13 inhibitors that have demonstrated safety and efficacy as treatment options for AD in phase III trials. Tralokinumab is approved for use in Europe and the USA, while lebrikizumab is approved only in Europe. Cendakimab, which is another IL-13 selective inhibitor, has shown promising results in phase II trials, providing safe and effective outcomes. Eblasakimab, which disrupts IL-13 and IL-4 signaling pathways, is currently in phase II trials following well-tolerated administration in phase I studies. This narrative review aims to outline the current state of knowledge regarding the effectiveness and safety of these four biologic agents targeting IL-13 signaling.

Nrf2 Regulates Inflammation by Modulating Dendritic Cell-T Cell Crosstalk during Viral-Bacterial Superinfection.

Every year millions of people are infected with influenza, which can be complicated by secondary bacterial pneumonia. One factor that may contribute to increased susceptibility to secondary bacterial infection is the modulation of inflammatory cytokines. NF erythroid 2-related factor 2 (Nrf2) has been shown to be a master regulator of the antioxidant response and various inflammatory cytokines. To test the role of Nrf2 during viral-bacterial superinfection, we used a mouse model of influenza-Staphylococcus aureus superinfection with wild-type (WT) or Nrf2-deficient (Nrf2-/-) mice. Loss of Nrf2 reduced influenza burden and increased S. aureus burden during superinfection. Additionally, Nrf2-/- mice had increased abundance of conventional type 1 dendritic cells (DCs). We then tested the interaction between DCs and T cells using an invitro model of bone marrow-derived DCs with OVA and OT-II T cells. In this system, Nrf2-/- DCs promoted a Th2/regulatory T cell response as opposed to a Th1/Th17 response by WT DCs. This was recapitulated invivo with superinfected Nrf2-/- mice having increased regulatory T cell populations. We also observed an increased median survival time of Nrf2-/- superinfected mice, due at least in part to increased IL-10 signaling, as anti-IL-10R Ab treatment reduced median survival time to levels seen in WT mice. Overall, these data suggest that loss of Nrf2 promotes differential T cell skewing mediated by DCs that promote a regulatory phenotype, increasing superinfection survival time, despite increased bacterial burden.

Integrative analysis of gene expression, protein abundance, and metabolomic profiling elucidates complex relationships in chronic hyperglycemia-induced changes in human aortic smooth muscle cells

Type 2 diabetes mellitus (T2DM) is a major public health concern with significant cardiovascular complications (CVD). Despite extensive epidemiological data, the molecular mechanisms relating hyperglycemia to CVD remain incompletely understood. We here investigated the impact of chronic hyperglycemia on human aortic smooth muscle cells (HASMCs) cultured under varying glucose conditions in vitro, mimicking normal (5 mmol/L), pre-diabetic (10 mmol/L), and diabetic (20 mmol/L) conditions, respectively. Normal HASMC cultures served as baseline controls, and patient-derived T2DM-SMCs served as disease controls. Results showed significant increases in cellular proliferation, area, perimeter, and F-actin expression with increasing glucose concentration (p < 0.01), albeit not exceeding the levels in T2DM cells. Atomic force microscopy analysis revealed significant decreases in Young’s moduli, membrane tether forces, membrane tension, and surface adhesion in SMCs at higher glucose levels (p < 0.001), with T2DM-SMCs being the lowest among all the cases (p < 0.001). T2DM-SMCs exhibited elevated levels of selected pro-inflammatory markers (e.g., ILs-6, 8, 23; MCP-1; M-CSF; MMPs-1, 2, 3) compared to glucose-treated SMCs (p < 0.01). Conversely, growth factors (e.g., VEGF-A, PDGF-AA, TGF-β1) were higher in SMCs exposed to high glucose levels but lower in T2DM-SMCs (p < 0.01). Pathway enrichment analysis showed significant increases in the expression of inflammatory cytokine-associated pathways, especially involving IL-10, IL-4 and IL-13 signaling in genes that are up-regulated by elevated glucose levels. Differentially regulated gene analysis showed that compared to SMCs receiving normal glucose, 513 genes were upregulated and 590 genes were downregulated in T2DM-SMCs; fewer genes were differentially expressed in SMCs receiving higher glucose levels. Finally, the altered levels in genes involved in ECM organization, elastic fiber synthesis and formation, laminin interactions, and ECM proteoglycans were identified. Growing literature suggests that phenotypic switching in SMCs lead to arterial wall remodeling (e.g., change in stiffness, calcific deposits formation), with direct implications in the onset of CVD complications. Our results suggest that chronic hyperglycemia is one such factor that leads to morphological, biomechanical, and functional alterations in vascular SMCs, potentially contributing to the pathogenesis of T2DM-associated arterial remodeling. The observed differences in gene expression patterns between in vitro hyperglycemic models and patient-derived T2DM-SMCs highlight the complexity of T2DM pathophysiology and underline the need for further studies.

Abstract A031: Unhelpful CD4 help: Removal of conventional CD4+ T cells promotes priming of tumor antigen-specific CD8 T cells in the context of CD4-depletion therapy

Abstract Preclinical and clinical studies have used antibodies to deplete CD4-expressing cells to promote anti-tumor immunity. Specifically, a monoclonal anti-CD4 antibody (anti-CD4) has been employed to remove FOXP3+ CD4+ regulatory T cells (Tregs), which are known to impede anti-tumor immunity. Our previous studies demonstrated that administering anti-CD4 during B16 melanoma tumor growth in mice leads to the generation of tumor Ag-specific CD8 T cells that disseminate and form memory following surgical tumor excision. However, the importance of co-depleting other CD4-expressing cell compartments for anti-CD4 treatment efficacy are unknown. We utilized flow cytometry and single-cell RNA sequencing (scRNAseq) to evaluate the primary response of tumor Ag-specific CD8 T cells (pmel) in B16 melanoma tumor bearing mice treated with anti-CD4. Responses were compared to those induced by anti-PD1 and anti-CTLA4 dual immune checkpoint blockade (ICB). To determine the importance of homeostatic space in priming, homeostatic expansion and priming were decoupled, and neutralizing antibodies were administered. Treg-depleted (Foxp3-DTR) mice were used for comparison, and Batf3-/- mice and IL-2R blocking antibodies were used to determine requirements for CD8 T cell priming. Finally, scRNAseq was conducted on CD4 T cells from human melanoma tumors previously treated with ICB to characterize transcriptional properties of intratumoral CD4 T cells. Compared to ICB, anti-CD4 treatment elicited a more robust, disseminated, and persistent primary tumor Ag-specific CD8 T cell response. ScRNAseq revealed that anti-CD4 treatment induced more stem-like (TCF1+) memory precursor cells, whereas ICB induced more differentiated effector (Gzmb+) cells. Removal of homeostatic space or blockade of IL-7R and IL-15 during priming did not diminish pmel responses in anti-CD4 treated mice, indicating that homeostatic space was not required. Importantly, pmel cells were shown to produce their own IL-2, and pmel priming was significantly lower after IL-2 receptor blockade, suggesting dependence on autocrine IL-2 signals. Using DT-treated FOXP3-DTR mice, we found that targeted Treg depletion was insufficient for the pmel priming that disseminated and formed memory, indicating that total CD4 T cell depletion was required for this systemic response. Depletion of total CD4 T cells uniquely increased cDC1 proportions in tumor-draining LNs as well as their expression of CD86. However, treatment of tumor-bearing RAG-/- mice with anti-CD4 confirmed that depletion of CD4-expressing APC compartments does not contribute to anti-CD4 treatment efficacy. ScRNAseq of CD4 T cells from human melanoma tumors showed dominance of Tr1-like cells and other subsets without transcriptional evidence of helper differentiation, despite prior ICB. In mice, combination of anti-CD4 with dual ICB restored the systemic response of tumor-specific CD8 T cells. This study underscores the importance of eliminating conventional CD4 T cells in tumor-bearing hosts to elicit systemic primary and memory CD8 T cell responses. Citation Format: Christo P. C. Dragnev, Delaney E. Ramirez, Tyler G. Searles, Nathaniel Spicer, TIffany Chen, J. Louise Lines, Aaron R. Hawkes, Wilson L. Davis III, Asmaa Mohamed, Keisuke Shirai, Joesph D. Phillips, Pamela C. Rosato, Yina H. Huang, Mary Jo Turk. Unhelpful CD4 help: Removal of conventional CD4+ T cells promotes priming of tumor antigen-specific CD8 T cells in the context of CD4-depletion therapy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor Immunology and Immunotherapy; 2024 Oct 18-21; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2024;12(10 Suppl):Abstract nr A031.

Unique transcriptomic profile of peripheral blood monocytes in rheumatoid arthritis-associated interstitial lung disease.

Though interstitial lung disease (ILD) contributes to excess morbidity and mortality in rheumatoid arthritis (RA), RA-ILD pathogenesis remains incompletely defined. As intermediate, non-classical and suppressed CD14+ monocytes are expanded in RA-ILD, this study sought to characterize gene expression profiles of circulating monocytes in RA-ILD. Peripheral blood mononuclear cells were collected from patients with RA without lung disease (N = 5), RA-ILD (N = 5), idiopathic pulmonary fibrosis (IPF; N = 5), and controls without lung and autoimmune disease (N = 4). RNA was extracted from CD14+ isolated monocytes and subjected to transcriptional analysis of 1365 genes. Gene enrichment and pathway analyses were performed. Unsupervised clustering grouped patients with RA-ILD together with IPF for myeloid innate genes. For fibrosis genes, patients with RA-ILD clustered independent of comparator groups. There were 103, 66, and 64 upregulated and 66, 14, and 25 downregulated genes for RA-ILD, RA, and IPF, vs controls, respectively. For RA-ILD, there was increased expression of genes involved in regulating inflammation and fibrosis (SOCS3, CECAM1, LTB4R2, CLEC7A, IRF7, PHYKPL, GBP5, RAPGEF), epigenetic modification (KDM5D, KMT2D, OGT), and macrophage activation. Top canonical pathways included macrophage differentiation-activation, IL-12, neuroinflammatory, glucocorticoid receptor, and IL-27 signalling. Circulating monocytes in RA-ILD patients demonstrate unique gene expression profiles with innate immune gene features more aligned with IPF as opposed to RA in the absence of clinical lung disease with fibrosis gene expression that was distinct from RA and IPF. These studies are important for understanding disease pathogenesis and may provide information for future therapeutic targets in RA-ILD.

Eblasakimab, an Anti-IL‑13Rα1 Antibody, Reduces Atopy-Associated Serum Biomarkers in Moderate‑to‑Severe Atopic Dermatitis.

Eblasakimab, a first-in-class monoclonal antibody with a unique mechanism to target the interleukin (IL)-13 receptor alpha 1 (IL-13Rα1), inhibits IL-4/IL-13 signaling in the pathophysiology of atopic dermatitis (AD). This study investigates the impact of eblasakimab on type 2 inflammatory biomarkers in patients with moderate-to-severe AD. A double‑blind, multiple ascending dose, phase Ib study evaluated the effect of eblasakimab (200, 400, 600mg) or placebo administered subcutaneously once weekly for 8 weeks in patients with moderate‑to‑severe AD. Serum levels of thymus and activation-regulated chemokine (TARC), total immunoglobulin E (IgE), and lactate dehydrogenase (LDH) were assessed. Eblasakimab suppressed TARC, IgE, and LDH in the 400-mg and 600-mg groups over 8 weeks of treatment. Patients in the 400-mg and 600-mg groups experienced a reduction of 72.8% (p=0.004) and 62.9% (p=0.003), respectively, for TARC, 35.1% (p=0.006) and 20.9% (not significant; NS), respectively, for IgE, and 24.6% (NS) and 23.1% (NS), respectively, for LDH between baseline and Week 8. Reduction in serum TARC in the 400-mg group was significantly greater than placebo as early as Week 1, whereas reductions in total IgE were more gradual. Serum TARC and total IgE remained suppressed in the 400-mg and 600-mg eblasakimab groups for 4-6 weeks following the last administered dose. The effect of eblasakimab on circulating AD‑associated biomarker levels was accompanied by improvements in signs and symptoms of AD, consistent with the inhibition of IL-13 and IL-4 signaling via the type 2 receptor. NCT04090229.

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Ebi3 Blocks IFN-γ and IL-10 Signaling See article p. 1115 Thermal Regulation of WSSV Resistance See article p. 1187 ITPK1 Sensitizes Tumor Cells to IgA-Mediated Neutrophil Adcc See article p. 1244

LncRNA SNHG16 Inhibits Intracellular M. tuberculosis Growth Involving Cathelicidin Pathway, Autophagy, and Effector Cytokines Production.

Long noncoding small nucleolar RNA (LncRNA) host gene 16 (SNHG16) is associated with certain diseases, including cancers. However, its role and mechanism in Mycobacterium tuberculosis (Mtb) infection remain unclear. Here, we demonstrated that SNHG16 expression levels were suppressed in peripheral blood mononuclear cells (PBMCs) and CD14+ monocytes of tuberculosis (TB) patients. SNHG16 was up-regulated by acute Mtb infection of PBMCs from healthy control (HC) subjects. Such TB suppression of SNHG16 was consistent with an immunosuppressive-like state driven by IL-10 signaling as seen in TB patients. Notably, SNHG16 limited Mtb growth in macrophages/monocytes through autophagy and vitamin D receptor (VDR)-dependent cathelicidin (CAMP) antimicrobial pathways. Concurrently, SNHG16 was highly expressed in lymphocytes, including CD8+ and Vγ2 Vδ2 T-cell subsets in HCs. SNHG16 overexpression in lymphocytes allowed them to control Mtb infection in macrophages, and SNHG16 epigenetically increased the expression of anti-Mtb effector cytokines in lymphocytes by developing more accessible chromatin states in gene loci encoding IFN-γ, TNF-α, and Granzyme B. Furthermore, the adoptive transfer of SNHG16-overexpressing human PBMCs into Mtb-infected SCID mice conferred protective immunity against Mtb infection. Thus, SNHG16 drove the induction of pleiotropic effector functions that inhibited intracellular Mtb growth in vitro and in vivo, serving as an immunotherapy target in TB.

S1241 Guselkumab Binding to CD64+ IL-23–Producing Myeloid Cells Enhances Potency for Neutralizing IL-23 Signaling

S1241 Guselkumab Binding to CD64+ IL-23–Producing Myeloid Cells Enhances Potency for Neutralizing IL-23 Signaling