Release Of GM-CSF Research Articles

Methotrexate promotes the release of granulocyte–macrophage colony-stimulating factor from rheumatoid arthritis fibroblast-like synoviocytes via autocrine interleukin-1 signaling

BackgroundActivated fibroblast-like synoviocytes (FLS) are drivers of synovitis and structural joint damage in rheumatoid arthritis (RA). Despite the use of disease-modifying drugs, only about 50% of RA patients reach remission in real-world settings. We used an unbiased approach to investigate the effects of standard-of-care methotrexate (MTX) and a Janus kinase inhibitor, tofacitinib (TOFA), on gene expression in RA-FLS, in order to identify untargeted disease mediators.MethodsPrimary RA-FLS were activated by stimulation with interleukin-1β (IL-1β) or platelet-derived growth factor + IL-1β in the presence or absence of MTX or TOFA, with or without additional inhibitors. Co-cultures of synovial cells were performed in direct and indirect systems. Cells were collected for RNA sequencing or qPCR, and supernatants were analyzed for protein concentrations.ResultsSix thousand three hundred fifty genes were differentially expressed, the majority being upregulated, in MTX-treated activated RA-FLS and 970 genes, the majority being downregulated, in TOFA-treated samples. Pathway analysis showed that MTX had largest effects on ‘Molecular mechanisms of cancer’ and TOFA on ‘Interferon signaling’. Targeted analysis of disease-associated genes revealed that MTX increased the expression of cell cycle-regulating genes but also of pro-inflammatory mediators like IL-1α (IL1A) and granulocyte–macrophage colony-stimulating factor, GM-CSF (CSF2). The MTX-promoted expression of CSF2 in activated RA-FLS peaked at 48 h, could be mediated via either NF-κB or AP-1 transcription factors, and was abrogated by IL-1 inhibitors (IRAK4 inhibitor and anakinra). In a co-culture setting, MTX-treatment of activated RA-FLS induced IL1B expression in macrophages.ConclusionsMTX treatment induces secretion of IL-1 from activated RA-FLS which by autocrine signaling augments their release of GM-CSF. This unexpected effect of MTX might contribute to the persistence of synovitis.

Abstract P20: Anti-CD123 CAR NK cells and cam161533 Trispecific Killer Engager have synergistic activity against Acute Myeloid Leukemia

Abstract P20: Anti-CD123 CAR NK cells and cam161533 Trispecific Killer Engager have synergistic activity against Acute Myeloid Leukemia

Paroxetine's effect on the proinflammatory cytokine stimulation and intracellular signaling pathways in J774.2 cells.

Paroxetine is extensively utilized in the management of depressive and anxious conditions. Paroxetine works by increasing serotonin levels in nerve cells in the brain. However, limited information is available regarding the direct effects of paroxetine on macrophage cells. Macrophages are a type of leukocytes involved in the body's immune response, playing a crucial role in combating infections. The impact of paroxetine on macrophages has been explored in research, although a comprehensive understanding is still pending. This study aimed to research the potential of administering paroxetine to J774.2 macrophage cells to stimulate the release of GM-CSF, TNF-α, IL-12p40, and IL-6 cytokines. Additionally, we examined the mechanisms of action of paroxetine on the p38 signaling pathway, which is involved in cytokine production, and the PI3K pathway, which is an important mechanism in intracellular signaling. Our findings revealed that paroxetine induced an inflammatory response in macrophages by promoting cytokine synthesis in a non-lipopolysaccharide (LPS) environment. We observed that paroxetine triggered the inflammatory response through the PI3K signaling pathway while suppressing the p38 signaling pathway.

Local radiotherapy for murine breast cancer increases risk of metastasis by promoting the recruitment of M-MDSCs in lung

BackgroundRadiotherapy is one of the effective methods for treatment of breast cancer; however, controversies still exist with respect to radiotherapy for patients with TNBC. Here, we intend to explore the mechanism by which local radiotherapy promotes the recruitment of M-MDSCs in the lung and increases the risk of lung metastasis in TNBC tumor-bearing mice.MethodsA single dose of 20 Gy X-ray was used to locally irradiate the primary tumor of 4T1 tumor-bearing mice. Tumor growth, the number of pulmonary metastatic nodules, and the frequency of MDSCs were monitored in the mice. Antibody microarray and ELISA methods were used to analyze the cytokines in exosomes released by irradiated (IR) or non-IR 4T1 cells. The effects of the exosomes on recruitment of MDSCs and colonization of 4T1 cells in the lung of normal BALB/c mice were observed with the methods of FCM and pathological section staining. T lymphocytes or 4T1 cells co-cultured with MDSCs were performed to demonstrate the inhibitory effect on T lymphocytes or accelerative migration effect on 4T1 cells. Finally, a series of in vitro experiments demonstrated how the exosomes promote the recruitment of M-MDSCs in lung of mice.ResultsEven though radiotherapy reduced the burden of primary tumors and larger lung metastatic nodules (≥ 0.4 mm2), the number of smaller metastases (< 0.4 mm2) significantly increased. Consistently, radiotherapy markedly potentiated M-MDSCs and decreased PMN-MDSCs recruitment to lung of tumor-bearing mice. Moreover, the frequency of M-MDSCs of lung was positively correlated with the number of lung metastatic nodules. Further, M-MDSCs markedly inhibited T cell function, while there was no difference between M-MDSCs and PMN-MDSCs in promoting 4T1 cell migration. X-ray irradiation promoted the release of G-CSF, GM-CSF and CXCl1-rich exosomes, and facilitated the migration of M-MDSCs and PMN-MDSCs into the lung through CXCL1/CXCR2 signaling. While irradiated mouse lung extracts or ir/4T1-exo treated macrophage culture medium showed obvious selective chemotaxis to M-MDSCs. Mechanistically, ir/4T1-exo induce macrophage to produce GM-CSF, which further promoted CCL2 release in an autocrine manner to recruit M-MDSCs via CCL2/CCR2 axis.ConclusionsOur work has identified an undesired effect of radiotherapy that may promote immunosuppressive premetastatic niches formation by recruiting M-MDSCs to lung. Further studies on radiotherapy combined CXCR2 or CCR2 signals inhibitors were necessary.

In vitro sepsis up-regulates Nociceptin/Orphanin FQ receptor expression and function on human T- but not B-cells.

In animal models of sepsis, increased activation of the Nociceptin/Orphanin FQ (N/OFQ) receptor NOP is associated with mortality and NOP antagonists improved survival. We have explored the role of the N/OFQ-NOP system in freshly isolated volunteer human B- and T-cells incubated with lipopolysaccharide (LPS) and peptidoglycan G (PepG) as a model of in vitro sepsis. B- and T-cell NOP expression was measured using the NOP fluorescent probe N/OFQATTO594 , N/OFQ content was measured using immunofluorescence, N/OFQ release was tracked using a CHOhNOPGαiq5 biosensor assay and NOP function was measured using transwell migration and cytokine/chemokine release using a 25-plex assay format. Cells were challenged with LPS/PepG. CD19-positive B-cells bound N/OFQATTO594 ; they also contain N/OFQ. Stimulation with CXCL13/IL-4 increased N/OFQ release. N/OFQ trended to reduced migration to CXCL13/IL-4. Surface NOP expression was unaffected by LPS/PepG, but this treatment increased GM-CSF release in an N/OFQ sensitive manner. CD3-positive T-cells did not bind N/OFQATTO594 ; they did contain N/OFQ. Stimulation with CXCL12/IL-6 increased N/OFQ release. When incubated with LPS/PepG, NOP surface expression was induced leading to N/OFQATTO594 binding. In LPS/PepG-treated cells, N/OFQ reduced migration to CXCL12/IL-6. LPS/PepG increased GM-CSF release in an N/OFQ sensitive manner. We suggest both a constitutive and sepsis-inducible N/OFQ-NOP receptor autocrine regulation of B- and T-cell function, respectively. These NOP receptors variably inhibit migration and reduce GM-CSF release. These data provide mechanistic insights to the detrimental role for increased N/OFQ signalling in sepsis and suggest a potential role for NOP antagonists as treatments.

89 Lung Single Cell Transcriptomics to Guide the Development of AOP Anchored Cell-Based Assays in Response to Nanoparticle Exposure

Abstract Inhaled nanoparticles (NP) can cause acute and chronic inflammation. Here we seek to identify NP-specific cellular perturbation pathways and the underlying key cell types to inform adverse outcome pathway (AOP) anchored in vitro studies, by single cell transcriptomics. We exposed mice intratracheally to carbon black (CNP), tangled double-walled (DWCNT) and rigid, multi-walled carbon nanotubes (MWCNT). All lungs underwent single-cell RNA sequencing (scRNA-seq), histology and BAL analysis. At the chosen doses all NPs caused comparable airspace neutrophilia at 12h, which increased until d6 for the CNTs but remained elevated until d28 only for MWCNT, indicating the key event (KE) acute and chronic inflammation. Comparing scRNA-seq and BAL cytokine levels at 12h, differentiated the fate of inflammation NP specifically. In agreement with airspace neutrophilia, CNP uniquely triggered GM-CSF and CXCL1 release, with Csf2 and Cxcl1 mRNAs being expressed mainly in alveolar epithelial cells. DWCNT caused CCL2, -3 and -4 release involving interstitial macrophages and monocytes, associated with acute high lung monocyte and at d6 high BAL macrophage numbers. MWCNT in contrast caused ample BAL cytokine increases involving different cell types and specifically caused a Th2 cytokine response (CCL11, IL10), a crucial KE of fibrosis AOPs. MWCNT triggered cell communication analysis uncovered NP-specific networks including epithelial cells, fibroblasts, macrophages, dendritic cells and endothelial cells. Our study uncovers early NP-specific cell perturbations and identified first specific cellular response pattern to guide AOP predictive cell-based testing strategies. Further analysis of the cellular dynamics shall enhance our understanding of NP specific cell circuits and related pathologies.

Abstract 4557: 3D-EXpress platform utilizing tumoroids from patients with MSS and MSI-H tumors allows rapid assessment of anti-tumor activity of immune checkpoint inhibitors and development of clinically relevant biomarkers of treatment response

Abstract Introduction: Recent studies showed that patients with deficient mismatch repair(dMMR)/microsatellite instability-high (MSI-H) tumors, have higher sensitivity to immune checkpointinhibitors (ICIs) compared to patients with microsatellite-stable (MSS)/microsatellite instability-low(MSI-L) tumors. However, the mechanisms of treatment responsiveness and resistance is not wellunderstood. Here, we used a novel 3D-EXpress ex vivo fresh patient tumoroid platform to assess theefficacy of nivolumab/ipilimumab combination therapy in tumors with known MSS/MSI-H status andperformed correlative studies. Materials and Methods: All tumor samples were obtained with patient consent and relevant IRBapproval. Tumoroids measuring 150 µm in size retaining tumor cell heterogeneity, tumor-residentimmune cells, stromal components, and cell-extracellular matrix interaction were prepared frompatients with endometrial and colorectal tumors among others. Tumoroid aliquots were cryopreservedin Nilogen’s tumoroid Biorepository for future studies. For the 3D-EXpress studies cryopreservedtumoroids were selected based on MSS/MSI-H status and treated ex vivo with nivolumab andipilimumab alone and in combinations for 72h. Tumor responses to treatments were evaluated by aproprietary tumor cell killing assay and changes in tumor immune microenvironment. Furthermore,tumor PD-L1 expression levels were analyzed on the associated TMA slides. Results: Treatment-induced tumor cell killing activity in intact tumoroids was assessed by a 3D high-content confocal imaging technique using a proprietary algorithm for data analysis. The impact of exvivo treatment by nivolumab and/or ipilimumab on tumor resident immune cell populations wasmonitored by a multiplex cytokine release assay analyzing release of GM-CSF, sCD137, IFNγ, sFas, sFasL,Granzyme A, Granzyme B, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, MIP-1α, MIP-1β, TNF-α, and Perforin usingculture supernatants isolated from treated tumoroid samples. Based on the ex vivo responses tumorswere assigned to treatment sensitive and resistant groups and correlative analyses were performed withindividual tumors’ innate and adaptive immune cell populations detected by a 21-color flow cytometrypanel, in addition to tumor MSS/MSI-H and p53 status, and detailed clinicopathologic data readilyavailable for the tumors cryopreserved in the Biorepository. Conclusion: The 3D-Express platform, using cryopreserved 3D tumoroids with intact TME is an effectivetool for the assessment of rational combinations which may prove relevant in the treatment of solidtumors. Furthermore, we believe this platform is a useful tool for the pre-clinical assessment of specifictherapeutic regimens designed for individualized patient care. Citation Format: Brittney Ruedlinger, Seth Currlin, Sharon Camacho, Alliyah Humphrey, Jared Ehrhart, Soner Altiok. 3D-EXpress platform utilizing tumoroids from patients with MSS and MSI-H tumors allows rapid assessment of anti-tumor activity of immune checkpoint inhibitors and development of clinically relevant biomarkers of treatment response. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4557.

Therapeutic implications of current Janus kinase inhibitors as anti-COVID agents: A review.

Severe cases of COVID-19 are characterized by hyperinflammation induced by cytokine storm, ARDS leading to multiorgan failure and death. JAK-STAT signaling has been implicated in immunopathogenesis of COVID-19 infection under different stages such as viral entry, escaping innate immunity, replication, and subsequent inflammatory processes. Prompted by this fact and prior utilization as an immunomodulatory agent for several autoimmune, allergic, and inflammatory conditions, Jakinibs have been recognized as validated small molecules targeting the rapid release of proinflammatory cytokines, primarily IL-6, and GM-CSF. Various clinical trials are under investigation to evaluate Jakinibs as potential candidates for treating COVID-19. Till date, there is only one small molecule Jakinib known as baricitinib has received FDA-approval as a standalone immunomodulatory agent in treating critical COVID-19 patients. Though various meta-analyses have confirmed and validated the safety and efficacy of Jakinibs, further studies are required to understand the elaborated pathogenesis of COVID-19, duration of Jakinib treatment, and assess the combination therapeutic strategies. In this review, we highlighted JAK-STAT signalling in the pathogenesis of COVID-19 and clinically approved Jakinibs. Moreover, this review described substantially the promising use of Jakinibs and discussed their limitations in the context of COVID-19 therapy. Hence, this review article provides a concise, yet significant insight into the therapeutic implications of Jakinibs as potential anti-COVID agents which opens up a new horizon in the treatment of COVID-19, effectively.

Ganoderma lucidum polysaccharides ameliorate lipopolysaccharide-induced acute pneumonia via inhibiting NRP1-mediated inflammation

Context Ganoderma lucidum polysaccharides (GLP), from Ganoderma lucidum (Leyss. ex Fr.) Karst. (Ganodermataceae), are reported to have anti-inflammatory effects, including anti-neuroinflammation and anti-colitis. Nevertheless, the role of GLP in acute pneumonia is unknown. Objective To explore the protective role of GLP against LPS-induced acute pneumonia and investigate possible mechanisms. Materials and methods GLP were extracted and used for high-performance liquid chromatography (HPLC) analysis after acid hydrolysis and PMP derivatization. Sixty C57BL/6N male mice were randomly divided into six groups: Sham, Model, LPS + GLP (25, 50 and 100 mg/kg/d administered intragastrically for two weeks) and LPS + dexamethasone (6 mg/kg/d injected intraperitoneally for one week). Acute pneumonia mouse models were established by intratracheal injection of LPS. Haematoxylin and eosin (H&E) staining was examined to evaluate lung lesions. ELISA and quantitative real-time PCR were employed to assess inflammatory factors expression. Western blots were carried out to measure Neuropilin-1 expression and proteins related to apoptosis and autophagy. Results GLP suppressed inflammatory cell infiltration. In BALF, cell counts were 1.1 × 106 (model) and 7.1 × 105 (100 mg/kg). Release of GM-CSF and IL-6 was reduced with GLP (25, 50 and 100 mg/kg) treatment. The expression of genes IL-1β, IL-6, TNF-α and Saa3 was reduced. GLP treatment also suppressed the activation of Neuropilin-1 (NRP1), upregulated the levels of Bcl2/Bax and LC3 and led to downregulation of the ratio C-Caspase 3/Caspase 3 and P62 expression. Discussion and conclusions GLP could protect against LPS-induced acute pneumonia through multiple mechanisms: blocking the infiltration of inflammatory cells, inhibiting cytokine secretion, suppressing NRP1 activation and regulating pneumonocyte apoptosis and autophagy.

Effectivity of polyphenolic polysaccharide-proteins isolated from medicinal plants as potential cellular immune response modulators.

Traditional medicinal herbs as Echinacea purpurea and Erigeron canadensis are recommended as a complementary supplementation for the treatment of diseases associated with immunological inflammation (e.g. common cold, coughs, bronchitis, upper respiratory infections, immunodeficiencies). This pathologic conditions are accompanied by the wide range of malfunctions or imbalances of the immune system, thus there is increased necessity for search of novel immunomodulation trends and immunopharmacologically active phytosubstances for effective pharmaco-immunomodulatory therapy. Anti-inflammatory immunobiological activity of polyphenolic polysaccharide-proteins of Echinacea purpurea and Erigeron canadensis are still not studied. Our results demonstrated the immunobiological effectivity of selected herbal polyphenolic polysaccharide-proteins isolated from flowers of medicinal plants Echinacea purpurea and Erigeron canadensis resulting into the significant immunostimulation of inflammatory TNF-α, IL-6, IL-1ß and IL-12 cytokines (p < 0.001). Both herbal polyphenolic polysaccharide-proteins triggered cell release of anti-inflammatory interleukin IL-10 (p < 0.001). Furthermore, the inductive cell release of growth factors M-CSF and GM-CSF has been demonstrated (p < 0.001). E. purpurea and E. canadensis polyphenolic polysaccharide-proteins accelerated the efficacy of cellular phagocytosis and free radical release, more pronounced with Erigeron treatment.

CD49a Identifies Polyfunctional Memory CD8 T Cell Subsets that Persist in the Lungs After Influenza Infection.

CD8 T cell memory offers critical antiviral protection, even in the absence of neutralizing antibodies. The paradigm is that CD8 T cell memory within the lung tissue consists of a mix of circulating TEM cells and non-circulating TRM cells. However, based on our analysis, the heterogeneity within the tissue is much higher, identifying TCM, TEM, TRM, and a multitude of populations which do not perfectly fit these classifications. Further interrogation of the populations shows that TRM cells that express CD49a, both with and without CD103, have increased and diverse effector potential compared with CD49a negative populations. These populations function as a one-man band, displaying antiviral activity, chemokine production, release of GM-CSF, and the ability to kill specific targets in vitro with delayed kinetics compared with effector CD8 T cells. Together, this study establishes that CD49a defines multiple polyfunctional CD8 memory subsets after clearance of influenza infection, which act to eliminate virus in the absence of direct killing, recruit and mature innate immune cells, and destroy infected cells if the virus persists.

Human Breast Milk Enhances Intestinal Mucosal Barrier Function and Innate Immunity in a Healthy Pediatric Human Enteroid Model.

Breastfeeding has been associated with long lasting health benefits. Nutrients and bioactive components of human breast milk promote cell growth, immune development, and shield the infant gut from insults and microbial threats. The molecular and cellular events involved in these processes are ill defined. We have established human pediatric enteroids and interrogated maternal milk’s impact on epithelial cell maturation and function in comparison with commercial infant formula. Colostrum applied apically to pediatric enteroid monolayers reduced ion permeability, stimulated epithelial cell differentiation, and enhanced tight junction function by upregulating occludin. Breast milk heightened the production of antimicrobial peptide α-defensin 5 by goblet and Paneth cells, and modulated cytokine production, which abolished apical release of pro-inflammatory GM-CSF. These attributes were not found in commercial infant formula. Epithelial cells exposed to breast milk elevated apical and intracellular pIgR and enabled maternal IgA translocation. Proteomic data revealed a breast milk-induced molecular pattern associated with tissue remodeling and homeostasis. Using a novel ex vivo pediatric enteroid model, we have identified distinct cellular and molecular events involved in human milk-mediated improvement of human intestinal physiology and immunity.

Abstract 1449: A live-cell imaging approach for assessing efficacy of immune-targeting therapies using high content imaging and analysis of 3D in vitro tumor models

Abstract Background: Immunotherapy has revolutionized cancer research, however limited clinical success to date underscores the need for novel therapeutic targets. Assessment of new targets has been challenging due to limitations of ex vivo animal platforms that only partially recapitulate tumor-intrinsic features and cell interactions. Here, we present a live-cell imaging approach for assessing efficacy of immune-targeting therapies using a 3D in vitro oncology platform in combination with high-content imaging and analysis (HCA) techniques. This study shows how effects of immune-targeting agents on tumor infiltration and killing by peripheral blood mononuclear cells (PBMCs) can be visualized and quantified with high-content endpoints. Aim: To develop and test a robust live-cell-imaging methodology for assessing efficacy of immuno-modulatory cancer therapies. Material &amp; Methods: Lung carcinoma cell-line models were generated using GFP-A549 cells in coculture with dermal fibroblasts and PBMCs. PDX cell suspensions of lung, breast and melanoma origin were self-aggregated with cancer-associated fibroblasts (CAFs) and labeled with live-cell dye for specific monitoring of tumor cell viability. Tumor killing activity and T-cell effector function were evaluated by measuring tumor model size using automatic stage fluorescence microscopy or confocal HCA instrument. Release of inflammatory cytokines IL-6, TNF, IFNγ and GM-CSF was measured with a multiplex cytokine panel. T cell infiltration into tumor models was quantified using fluorescent staining of CD3+ cells. To generate a pro-inflammatory tumor microenvironment, PBMCs were stimulated prior to coculture either with cytokines or anti-CD3/CD28. We monitored immune cell attack on tumors in realtime (56 timepoints) and in 3 dimensions without any discernable phototoxicity. Using cell centroid tools, we mapped physical locations of individual cells belonging to each population. Finally, we calculated tumor and immune cell volumes from individual image stacks to evaluate tumor killing and proliferation/infiltration of immune cells. Results: Our realtime confocal analysis of tumor-immune cell cocultures showed activation of PBMCs with either cytokines or CD3/CD28 increased proliferation/infiltration of immune cells and enhanced tumor killing. Conclusion: Proinflammatory tumor models combined with our novel, high-content imaging analysis endpoints offer a versatile solution for preclinical translational research and a promising approach for high-content screening of immune-targeting therapeutic agents and I-O studies involving engineered T cells (e.g., CAR-T) as well as for testing immunomodulatory agents, such as bispecific antibodies and immune checkpoint inhibitors. Citation Format: Irina Agarkova, Mahomi Suzuki, Silvan Strebel, Armin Wolf, Judith Wardwell-Swanson, Francesca Chiovaro. A live-cell imaging approach for assessing efficacy of immune-targeting therapies using high content imaging and analysis of 3D in vitro tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1449.

B-Cell Maturation Antigen (BCMA)-Specific, CentyrinTM-Based, PiggyBacTM-Transposed CAR-T Memory Stem Cells Are Effective Against p53-/- and Patient-Derived Multiple Myeloma Tumors

B-Cell Maturation Antigen (BCMA)-Specific, CentyrinTM-Based, PiggyBacTM-Transposed CAR-T Memory Stem Cells Are Effective Against p53-/- and Patient-Derived Multiple Myeloma Tumors

Screening immunotherapy cancer drugs in a scalable, physiologically relevant 3D in vitro tumor microenvironment model

Abstract Interaction of tumor cells with surrounding stromal and immune cells, secreted cytokines, and extracellular matrix proteins, collectively known as the tumor microenvironment (TME), is crucial for cancer progression and metastasis. Here, we present a novel 3D in vitro TME model to assess candidate drugs for cancer therapy. For this study, we prepared lung carcinoma spheroids from GFP-A549 cells co-cultured with cancer-associated fibroblasts (CAFs) and PBMCs. To simulate a pro-inflammatory tumor microenvironment, we activated PBMCs with cytokines and/or anti-CD3/CD28. We assessed the effect of PD-1 inhibitors in combination with cytokines for potential synergistic anti-cancer effects. We then developed a tumor model using melanoma PDX cells labeled with CellTracker to monitor tumor cell viability after exposure to activated PBMCs. We evaluated killing activity and effector function of T cells by measuring tumor microtissue size by automatic stage fluorescence microscopy and release of IL-6, TNFa, IFNγ and GM-CSF with a MAGPIXTM Luminex system over time. Immune cell infiltration and its effects on tumor were assessed by histological analysis using tumor, immune cell and apoptosis markers. Our results show combination treatment with cytokines and anti-PD-1 antibody led to higher secretion of IL-6/TNFa/IFNγ/GM-CSF, reduced tumor size, increased infiltration of the model by CD8+ T cells, stronger expression of Granzyme B resulting in enhanced tumor apoptosis and killing. This confirms our novel 3D in vitro TME model is a promising tool for studying cell-cell interactions and allows for HCS of novel candidates for anti-cancer drugs.

Neutrophils and IL-1α Regulate Surfactant Homeostasis during Cigarette Smoking.

Cigarette smoke exposure induces inflammation marked by rapid and sustained neutrophil infiltration, IL-1α, release and altered surfactant homeostasis. However, the extent to which neutrophils and IL-1α contribute to the maintenance of pulmonary surfactant homeostasis is not well understood. We sought to investigate whether neutrophils play a role in surfactant clearance as well as the effect of neutrophil depletion and IL-1α blockade on the response to cigarette smoke exposure. In vitro and in vivo administration of fluorescently labeled surfactant phosphatidylcholine was used to assess internalization of surfactant by lung neutrophils and macrophages during or following cigarette smoke exposure in mice. We also depleted neutrophils using anti-Ly-6G or anti-Gr-1 Abs, or we neutralized IL-1α using a blocking Ab to determine their respective roles in regulating surfactant homeostasis during cigarette smoke exposure. We observed that neutrophils actively internalize labeled surfactant both in vitro and in vivo and that IL-1α is required for smoke-induced elevation of surfactant protein (SP)-A and SP-D levels. Neutrophil depletion during cigarette smoke exposure led to a further increase in SP-A levels in the bronchoalveolar lavage and increased IL-1α, CCL2, GM-CSF, and G-CSF release. Finally, macrophage expression of Mmp12, a protease linked to emphysema, was increased in neutrophil-depleted groups and decreased following IL-1α blockade. Taken together, our results indicate that neutrophils and IL-1α signaling are actively involved in surfactant homeostasis and that the absence of neutrophils in the lungs during cigarette smoke exposure leads to an IL-1α-dependent exacerbation of the inflammatory response.

Abstract PO085: Cryogel-based cancer vaccine to treat acute myeloid leukemia

Abstract Acute myeloid leukemia (AML) is a hematopoietic malignancy with limited therapeutic options. Standard-of-care chemotherapy depletes AML cells to induce remission, but often precedes disease relapse. To promote robust and durable immunity against AML, we developed a macroporous cryogel-based vaccine which provided a sustained release of GM-CSF to concentrate dendritic cells (DCs), TLR agonist CpG-ODN, and leukemia antigen. Prophylactic vaccination in mice against AML cell lysates or peptide antigen induced a potent anti-tumor adaptive immune response and prevented the engraftment of AML cells. This immunity was transferable, as bone marrow transplanted from vaccinated mice immunized recipients against AML. In models of established disease, only the combination of chemotherapy and biomaterial vaccination entirely eradicated AML in all mice and generated long-term T cell immunity preventing relapse. Notably, in combination with chemotherapy, a cryogel vaccine delivering no antigen (only GM-CSF and CpG-ODN) generated robust AML-specific T cell immunity, depleted leukemia, and enabled long-term survival. In this setting, tumor antigens were likely sourced from chemotherapy-induced AML cell death, as AML cells expressing high levels of apoptotic markers were found in the vaccine site and draining lymph node, co-localizing with DCs activated by the vaccine. These results demonstrate the capacity of a biomaterial-based vaccine to induce a potent immune response depleting AML and preventing relapse, even without defined antigen targets. Citation Format: Alexander J. Najibi, Nisarg J. Shah, Ting-Yu Shih, Angelo S Mao, Azeem Sharda, David T. Scadden, David J. Mooney. Cryogel-based cancer vaccine to treat acute myeloid leukemia [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PO085.

The GM-CSF Released by Airway Epithelial Cells Orchestrates the Mucosal Adjuvant Activity of Flagellin.

The TLR5 agonist flagellin is a potent adjuvant and is currently being developed for use in vaccines. The mechanisms that drive flagellin's activity are influenced by its administration route. Previous studies showed that lung structural cells (especially epithelial cells lining the conducting airways) are pivotal for the efficacy of intranasally administered flagellin-containing vaccines. In this study, we looked at how the airway epithelial cells (AECs) regulate the flagellin-dependent stimulation of Ag-specific CD4+ T cells and the Ab response in mice. Our results demonstrate that after sensing flagellin, AECs trigger the release of GM-CSF in a TLR5-dependent fashion and the doubling of the number of activated type 2 conventional dendritic cells (cDC2s) in draining lymph nodes. Furthermore, the neutralization of GM-CSF reduced cDC2s activation. This resulted in lower of Ag-specific CD4+ T cell count and Ab titers in mice. Our data indicate that during pulmonary immunization, the GM-CSF released by AECs orchestrates the cross-talk between cDC2s and CD4+ T cells and thus drives flagellin's adjuvant effect.

Liposomes Encapsulating Neoantigens and Black Phosphorus Quantum Dots for Enhancing Photothermal Immunotherapy.

Colorectal cancer frustrates with high relapse after the traditional treatment including surgery and chemotherapy. Neoantigen-based therapeutic vaccine has achieved high response rate in the clinical trials rising the immunotherapy as a promising alternative for colorectal cancer. Herein, colon cancer cells derived neoantigen peptide Adpgk were employed to be co-encapsulated with black phosphorus quantum dots into liposome (Adpgk-BPQDs-liposome) as therapeutic vaccine. Adpgk-BPQDs-liposome were dispersed in F127 gel containing GM-CSF. The heat generated by black phosphorus (BP) under 808 nm near-infrared laser irradiation accelerates the F127 gel ablation and the release of GM-CSF, which recruit APC cells and prime the native T cells. The tumor bearing mice received the programmed cell death protein 1 (PD-1) checkpoint blockade antibody combined with photo-thermal gel intensively prevented the tumor progress. Furthermore, the tumor infiltrating CD8+ T cells were significantly increased which lead to the elimination of the tumor.

Anti-inflammatory steroidal sapogenins and a conjugated chalcone-stilbene from Dracaena usambarensis Engl.

Four new steroidal sapogenins, dracaenogenins CF (1–4), a new conjugated chalcone-stilbene, 3′′-methoxycochinchinenene H (5) together with eight known compounds namely, (25S)-spirosta-1,4-dien-3-one (6), trans-resveratrol (7), 4,4′-dihydroxy-3′-methoxychalcone (8), N-trans-coumaroyltyramine (9), N-trans-p-coumaroyloctopamine (10), N-trans-feruloyloctopamine (11), 7-hydroxy-1-(4-hydroxy-3-methoxyphenyl)-N2,N3-bis(4-hydroxyphenethyl)-6-methoxy-1,2-dihydronaphthalene-2,3-dicarboxamide (12) and grossamide (13) were isolated from the stems of Dracaena usambarensis Engl. from Kenya. It is important to note that compounds 12 and 13 are being reported from this genus for the first time. Structural elucidation of the isolated compounds was done using spectroscopic (NMR, UV, IR, optical rotation) and spectrometric (HRESIMS) techniques. The absolute and relative configurations of the isolated compounds were determined by employing single crystal X-ray crystallography analysis, NOESY correlations and coupling constants. The anti-inflammatory potencies of the isolated compounds were evaluated by measuring the levels of four cytokines (IL-1β, IL-2, GM-CSF and TNF-α) in the supernatant media of human peripheral blood mononuclear cells (PBMCs) stimulated by lipopolysaccharide (LPS). At the tested concentration of 100 μM, the new conjugated chalcone-stilbene 5, the dihydrochalcone, 8 and the lignanamide, 13 were substantially more potent than the standard drug, ibuprofen, inhibiting the release of all the cytokines, IL-1β, IL-2, GM-CSF and TNF-α from 0.06–58.04% compared to LPS control. These compounds should therefore be considered for development into anti-inflammatory drug candidates. Compound 7 significantly decreased the release of GM-CSF (6.11% of LPS control) and TNF-α (18.35% of LPS control). The cytokine TNF-α was sensitive to all the tested compounds 1-13.