Modulation Of Cytokine Production Research Articles

Xuebijing Injection Alleviates the Inflammatory Response in Patients with Venous-Arterial Extracorporeal Membrane Oxygenation: A Prospective Randomized Controlled Study.

Both acute myocardial infarction (AMI) and its salvage treatment, venoarterial-extracorporeal membrane oxygenation (VA-ECMO), may lead to the production of proinflammatory cytokines and further aggravate tissue damage. Xuebijing (XBJ) may modulate cytokine production involved in the inflammatory response. We aimed to determine the efficacy of XBJ in cardiogenic shock patients on VA-ECMO. This was a prospective, randomized trial carried out in an intensive care unit of a tertiary teaching hospital. Patients with cardiogenic shock after acute myocardial infarction undergoing percutaneous coronary intervention (PCI) with VA-ECMO support were randomly divided into a Xuebijing group and a control group. Cytokines, inflammatory factors and left ventricular ejection fraction (LVEF) were compared between the groups. 41 patients were enrolled in the study, with 21 in the Xuebijing group and 20 in the control group. 28 (68.3%) were male, and the average age was 64.71 ± 8.18 years old. There was no difference in APACHEII (acute physiology and chronic health evaluation II) score, LVEF, or cytokine and inflammatory factors collected before extracorporeal membrane oxygenation (ECMO) between the two groups. The levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in the Xuebijing group were lower than those in the control group in the first 24 hours, 48 hours and 72 hours after ECMO (p < 0.05). The LVEF in the Xuebijing group was higher than that of the control group at 48 hours (31.57 ± 3.43 vs. 28.35 ± 4.42, p = 0.013). This trend persisted at 72 hours. The duration of ECMO support in the Xuebijing group was 5.57 ± 2.11 days, which was shorter than that in the control group (p = 0.033). Xuebijing injection can reduce the inflammatory response and improve cardiac function in patients with acute myocardial infarction treated with VA-ECMO to a certain extent. Chinese Clinical Trial Registry (ChiCTR), ChiCTR2100054069, Registered 8, December 2021, https://www.chictr.org.cn/showproj.html?proj=142869.

Macrophages and autophagy: partners in crime.

Macrophages and autophagy are intricately linked, both playing vital roles in maintaining homeostasis and responding to disease. Macrophages, known for their 'eating' function, rely on a sophisticated digestion system to process a variety of targets, from apoptotic cells to pathogens. The connection between macrophages and autophagy is established early in their development, influencing both differentiation and mature functions. Autophagy regulates essential immune functions, such as inflammation control, pathogen clearance, and antigen presentation, linking innate and adaptive immunity. Moreover, it modulates cytokine production, ensuring a balanced inflammatory response that prevents excessive tissue damage. Autophagy also plays a critical role in macrophage polarization, influencing their shift between pro-inflammatory and anti-inflammatory states. This review explores the role of autophagy in macrophages, emphasizing its impact across various tissues and pathological conditions, and detailing the cellular and molecular mechanisms by which autophagy shapes macrophage function.

Basophils Induce Pro-Tumorigenic Cytokines from A549 Lung Adenocarcinoma via Mechanisms Requiring IgE, Galectin-3, and IL-3 Priming.

Galectin-3 (Gal-3) is implicated in innate immune cell activation in a host of diseases/conditions. We identified a unique response whereby human basophils secrete IL-4/IL-13 when co-cultured with A549 cells -a lung adenocarcinoma. While displaying parameters consistent with standard IgE-dependent activation, these Galectin-3-dependent responses occurred in the absence of specific IgE/allergen and required cell-to-cell contact. We now hypothesize that this mode of activation also impacts A549 function. Our findings show that cytokines are induced in basophil/A549 co-cultures that are not detected when either cell is cultured alone, in particular IL-6. As previously shown for IL-4/IL-13, IL-6 production also required cell-to-cell contact and was dependent on A549-Gal-3, since clones deficient of this lectin induced less cytokine. Using culture-derived basophils (CDBA), we demonstrate that the IL-6 response, and production of another tumorigenic factor, VEGF-A, are induced in CDBA/A549 co-cultures but only after passively sensitizing CDBA with IgE, in a manner similar to IL-4/IL-13. However, IgE-dependent activation of basophils/CDBA cultured alone failed to induce IL-6/VEGF. Importantly, IL-3-primed basophils, even those fixed with paraformaldehyde, readily induced IL-6/VEGF-A in co-cultures, thus verifying these cytokines are derived from A549. Overall, these results suggest a complex mechanism whereby Gal-3/IgE interactions between IL-3-primed basophils and A549 have the potential to modulate cytokine production by both cells. With Gal-3 implicated in many diseases ranging from asthma to cancer, but also in normal physiological conditions, such as wound healing, these findings are predicted to provide insight into the molecular mechanisms by which this lectin (and IgE) functions in these processes.

Bifidobacterium and the Immune System: A Key Player Against Gastrointestinal Cancers

: Gastrointestinal (GI) cancers pose a significant global health challenge, with rising incidence and mortality rates. Recent studies suggest that gut microbiota, particularly Bifidobacterium, plays a crucial role in modulating immune responses and influencing cancer progression. Understanding how Bifidobacterium interacts with the immune system may offer novel therapeutic strategies. A comprehensive review of recent literature was conducted, focusing on the role of Bifidobacterium in defending against GI cancers. The findings indicate that Bifidobacterium enhances the immune response by promoting regulatory T-cell activity and modulating cytokine production. Specific strains of Bifidobacterium have been shown to induce apoptosis in cancer cells and improve the effectiveness of immunotherapy and chemotherapy. Moreover, alterations in gut microbiota composition, particularly the presence of Bifidobacterium, are associated with reduced tumor growth and improved patient outcomes in various cancer models. In conclusion, Bifidobacterium emerges as a promising candidate for therapeutic interventions in GI cancers, with the potential to enhance immune responses and treatment efficacy. However, further research is needed to elucidate its specific mechanisms of action and to optimize the use of Bifidobacterium strains in clinical settings. Future studies should focus on personalized approaches and the integration of Bifidobacterium into existing cancer treatment protocols to improve patient outcomes.

Interactions that define the arrangement of sugar-binding sites in BDCA-2 and dectin-2 dimers.

The sugar-binding receptors dectin-2 and blood dendritic cell antigen 2 (BDCA-2) bind oligosaccharide ligands through extracellular carbohydrate-recognition domains (CRDs) and initiate intracellular signaling through Fc receptor γ adapters (FcRγ). Dectin-2 stimulates macrophages in response to pathogen binding while BDCA-2 modulates cytokine production in plasmacytoid dendritic cells. The oligomeric states of these receptors and the orientations of their CRDs have been investigated by analysis of a naturally occurring disulfide-bonded variant of BDCA-2 and by replacement of transmembrane domains with N-terminal dimerization domains to create extracellular domain dimers of both dectin-2 and BDCA-2. Analysis of these constructs, as well as previously described crystal structures of the CRDs from these proteins and a novel structure of an extended version of the extracellular domain of dectin-2, showed that there is only limited interaction of the CRDs in the dimers, but interactions can be stabilized by the presence of the neck region. The resulting orientation of sugar-binding sites in the dimers would favor crosslinking of multiple dimers by oligosaccharide ligands, causing clustering of FcRγ to initiate signaling.

Therapeutic Potential of Olax subscorpioidea Root Extracts in Managing Inflammatory Conditions: A Preclinical Study

Olax subscorpioidea, a plant species endemic to tropical Africa, has long been utilized in traditional medicine for its purported anti-inflammatory and analgesic properties. This preclinical study evaluates the therapeutic potential of Olax subscorpioidea root extracts in managing inflammatory conditions, specifically in a Freund’s adjuvant (CFA)-collagen type II induced arthritis model in albino rats. Both aqueous and ethanol extracts were prepared and assessed for their effects on inflammatory parameters, including cytokine levels, paw edema, joint swelling, and histopathological changes. The study found that both extracts significantly reduced inflammation and clinical signs of arthritis, with the ethanol extract demonstrating a broader range of bioactive compounds and potentially greater efficacy. Mechanistic insights suggest that the extracts exert their effects through inhibition of pro-inflammatory enzymes, modulation of cytokine production, and enhancement of antioxidant activity. Safety and toxicity assessments confirmed the non-toxic nature of the extracts at tested doses. These findings validate the traditional use of Olax subscorpioidea for inflammatory conditions and support its potential integration into modern therapeutic regimens. Future research should focus on dosage optimization, long-term effects, and clinical trials to further establish the efficacy and safety of Olax subscorpioidea root extracts in human subjects. Keywords: Olax subscorpioidea, Root Extracts, Inflammatory Conditions, Preclinical Study.

Wound Closure Promotion by Leucine-Based Pseudo-Proteins: An In Vitro Study.

Our research explores leucine-based pseudo-proteins (LPPs) for advanced wound dressings, focusing on their effects on wound healing in an in vitro model. We assessed three types of LPP films for their ability to enhance wound closure rates and modulate cytokine production. They all significantly improved wound closure compared to traditional methods, with the 8L6 and copolymer films showing the most pronounced effects. Notably, the latter exhibited an optimal cytokine profile: an initial burst of pro-inflammatory TNF-α, followed by a controlled release of IL-6 during the proliferative phase and a significant increase in anti-inflammatory IL-10 during remodeling. This balanced cytokine response suggests that the copolymer film not only accelerates wound closure but also supports a well-regulated healing process, potentially reducing fibrosis and abnormal scarring, underscoring the potential of copolymer LPPs as advanced wound dressing materials. Future research will aim to elucidate the specific signaling pathways activated by the copolymer LPP to better understand its mechanism of action. Overall, LPP films offer a promising approach to improving wound care and could lead to more effective treatments for complex wounds.

Vitamin D treatment distinctly modulates cytokine production by peripheral blood mononuclear cells among patients with chronic cardiac and indeterminate clinical forms of Chagas disease.

Chagas disease is caused by the protozoan Trypanosoma cruzi and is clinically divided into acute and chronic phases. Chronic Chagas cardiomyopathy is the most studied manifestation of the disease. Vitamin D deficiency has been suggested as a risk factor for cardiovascular disease. No studies demonstrate the action of this hormone in the cells of patients with chronic Chagas heart disease. To evaluate the in vitro immunomodulatory effect of vitamin D on peripheral blood mononuclear cellsof patients with the different chronic clinical forms of Chagas disease. Evaluating vitamin D's in vitro effect on blood cells by producing cytokines. Thirteen patients of the undetermined form (IND), 13 of the mild cardiac form (CARD1) and 14 of the severe cardiac form (CARD2) of Chagas disease, and 12 with idiopathic heart disease (CARDid) were included. The cells obtained from peripheral blood were treated in vitro with vitamin D (1 × 10-7 M) for 24 h and cytokines were dosed in the culture supernatant. Although it was not possible to demonstrate statistically significant differences between the groups studied, our data showed that the cells treated with vitamin D modify (p < .05) the production of interferon-γ(IFN-γ) (decrease in IND), tumor necrosis factor-α (TNF-α) (decreased in CARD1 and CARDid),interleukin(IL)-6 (increased in all groups), and IL-10 (decreased in CARD1, CARD2, and CARDid) when compared to untreated cells. In vitro treatment with vitamin D distinctly modulated the production of cytokines by mononuclear cells of peripheral blood among patients with chronic and indeterminate cardiac clinical forms of Chagas disease.

The combination of sitagliptin and bee honey extract potentiates the anti-proliferative properties of 5-fluorouracil on Caco-2 cell line without detectable inflammatory events

BackgroundColon cancer originates in the colon, specifically the large intestine. It carries a poor prognosis and high mortality rate due to late diagnosis and migration. ObjectiveHere our objective was to evaluate the anticancer effects of sitagliptin (Sita) in colon cancer using Caco-2 cells. Additionally, we examined the role of bee honey extract in modulating cancer cell division and necrotic events commonly observed during drug treatments. MethodsWe monitored cell viability rate to evaluate the effect of bee honey extract compared to 5-fluorouracil (5-Fu), Sita, and their combinations. To gain further foresights into the implicated molecular interaction, we assessed the expression outline of Raf-1 and MEK, as proliferation effectors. Additionally, we examined the expression outline of p53 and Caspase 3, which are associated with programmed cell death (PCD), through western blot analysis. ResultsWe identified the Raf-1 expression pattern as a likely target for the drug combination and bee honey extract (HE), which effectively controlled colon cancer cell proliferation. Our study demonstrates that honey extract, either alone or in combination with drugs, can induce PCD by restoring the p53 and CASP-3 proteins. This was accompanied by a synergistic effect on the production of apoptotic cytokines, particularly interlukine-6 (IL-6) and IL-8, in cancer cells. Moreover, the treatment modulated the levels of pro-inflammatory cytokines, including IL-1α and IL-1β and anti-inflammatory cytokines, including IL-4 and IL-10. ConclusionOur findings shed light on honey extract and its combinations with 5-Fu and Sita in stimulating PCD and modulating cytokine production in Caco-2 cells.

Toll-like receptor 4 (TLR4) is the major pattern recognition receptor triggering the protective effect of a Candida albicans extracellular vesicle-based vaccine prototype in murine systemic candidiasis.

Systemic candidiasis remains a significant public health concern worldwide, with high mortality rates despite available antifungal drugs. Drug-resistant strains add to the urgency for alternative therapies. In this context, vaccination has reemerged as a prominent immune-based strategy. Extracellular vesicles (EVs), nanosized lipid bilayer particles, carry a diverse array of native fungal antigens, including proteins, nucleic acids, lipids, and glycans. Previous studies from our laboratory demonstrated that Candida albicans EVs triggered the innate immune response, activating bone marrow-derived dendritic cells (BMDCs) and potentially acting as a bridge between innate and adaptive immunity. Vaccination with C. albicans EVs induced the production of specific antibodies, modulated cytokine production, and provided protection in immunosuppressed mice infected with lethal C. albicans inoculum. To elucidate the mechanisms underlying EV-induced immune activation, our study investigated pathogen-associated molecular patterns (PAMPs) and pattern recognition receptors (PRRs) involved in EVs-phagocyte engagement. EVs from wild-type and mutant C. albicans strains with truncated mannoproteins were compared for their ability to stimulate BMDCs. Our findings revealed that EV decoration with O- and N-linked mannans and the presence of β-1,3-glucans and chitin oligomers may modulate the activation of specific PRRs, in particular Toll-like receptor 4 (TLR4) and dectin-1. The protective effect of vaccination with wild-type EVs was found to be dependent on TLR4. These results suggest that fungal EVs can be harnessed in vaccine formulations to selectively activate PRRs in phagocytes, offering potential avenues for combating or preventing candidiasis.IMPORTANCESystemic candidiasis is a serious global health concern with high mortality rates and growing drug resistance. Vaccination offers a promising solution. A unique approach involves using tiny lipid-coated particles called extracellular vesicles (EVs), which carry various fungal components. Previous studies found that Candida albicans EVs activate the immune response and may bridge the gap between innate and adaptive immunity. To understand this better, we investigated how these EVs activate immune cells. We demonstrated that specific components on EV surfaces, such as mannans and glucans, interact with receptors on immune cells, including Toll-like receptor 4 (TLR4) and dectin-1. Moreover, vaccinating with these EVs led to strong immune responses and full protection in mice infected with Candida. This work shows how harnessing fungal EVs might lead to effective vaccines against candidiasis.

Effects of Combustible Cigarettes and Heated Tobacco Products on Systemic Inflammatory Response in Patients with Chronic Inflammatory Diseases.

Smoke derived from combustible cigarettes (CCs) contains numerous harmful chemicals that can impair the viability, proliferation, and activation of immune cells, affecting the progression of chronic inflammatory diseases. In order to avoid the detrimental effects of cigarette smoking, many CC users have replaced CCs with heated tobacco products (HTPs). Due to different methods of tobacco processing, CC-sourced smoke and HTP-derived aerosols contain different chemical constituents. With the exception of nicotine, HTP-sourced aerosols contain significantly lower amounts of harmful constituents than CC-derived smoke. Since HTP-dependent effects on immune-cell-driven inflammation are still unknown, herein we used flow cytometry analysis, intracellular staining, and an enzyme-linked immunosorbent assay to determine the impact of CCs and HTPs on systemic inflammatory response in patients suffering from ulcerative colitis (UC), diabetes mellitus (DM), and chronic obstructive pulmonary disease (COPD). Both CCs and HTPs significantly modulated cytokine production in circulating immune cells, affecting the systemic inflammatory response in COPD, DM, and UC patients. Compared to CCs, HTPs had weaker capacity to induce the synthesis of inflammatory cytokines (IFN-γ, IL-1β, IL-5, IL-6, IL-12, IL-23, IL-17, TNF-α), but more efficiently induced the production of immunosuppressive IL-10 and IL-35. Additionally, HTPs significantly enhanced the synthesis of pro-fibrotic TGF-β. The continuous use of CCs and HTPs aggravated immune-cell-driven systemic inflammation in COPD and DM patients, but not in UC patients, suggesting that the immunomodulatory effects of CC-derived smoke and HTP-sourced aerosols are disease-specific, and need to be determined for specific immune-cell-driven inflammatory diseases.

Echinacea purpurea: An overview of mechanism, efficacy, and safety in pediatric upper respiratory infections and otitis media

Pediatric upper respiratory infections (URIs) and otitis media (OM) significantly impact the health of children globally. Echinacea purpurea, known for its immunomodulatory, anti-inflammatory, and antimicrobial properties, has been historically used to treat various ailments, suggesting its potential as an adjunctive treatment in pediatric respiratory conditions. This narrative review synthesizes literature from January 2000 to December 2023 on the efficacy and safety of E. purpurea in treating pediatric URIs, including OM. It focuses on clinical trials and empirical studies that explore the mechanisms of action, such as the modulation of cytokine production, inhibition of NF-κB signaling, and antimicrobial effects. The analysis reveals mixed outcomes regarding the efficacy of E. purpurea in pediatric populations, attributed partly to variability in study designs and lack of standardized treatment protocols. While some studies report reduced severity and duration of respiratory symptoms, others indicate minimal or no significant difference compared to placebo. The review also highlights the need for specifically designed products that cater to the unique physiological and metabolic needs of children. Rigorous, well-designed clinical trials are crucial for establishing clear guidelines on the use of E. purpurea in pediatric respiratory care, ensuring its safe and effective application in improving health outcomes for children.

The Mucus-Binding Factor Mediates Lacticaseibacillus rhamnosus CRL1505 Adhesion but Not Immunomodulation in the Respiratory Tract.

Lacticaseibacillus rhamnosus CRL1505 possesses immunomodulatory activities in the gastrointestinal and respiratory tracts when administered orally. Its adhesion to the intestinal mucosa does not condition its beneficial effects. The intranasal administration of L. rhamnosus CRL1505 is more effective than the oral route at modulating immunity in the respiratory tract. Nonetheless, it has not yet been established whether the adherence of the CRL1505 strain to the respiratory mucosa is needed to provide the immune benefits to the host. In this study, we evaluated the role of adhesion to the respiratory mucosa of the mucus-binding factor (mbf) knock-out L. rhamnosus CRL1505 mutant (Δmbf CRL1505) in the context of a Toll-like receptor 3 (TLR3)-triggered innate immunity response. In vitro adhesion studies in porcine bronchial epitheliocytes (PBE cells) indicated that L. rhamnosus Δmbf CRL1505 adhered weakly compared to the wild-type strain. However, in vivo studies in mice demonstrated that the Δmbf CRL1505 also reduced lung damage and modulated cytokine production in the respiratory tract after the activation of TLR3 to a similar extent as the wild-type strain. In addition, the mutant and the wild-type strains modulated the production of cytokines and antiviral factors by alveolar macrophages in the same way. These results suggest that the Mbf protein is partially involved in the ability of L. rhamnosus CRL1505 to adhere to the respiratory epithelium, but the protein is not necessary for the CRL1505 strain to exert its immunomodulatory beneficial effects. These findings are a step forward in the understanding of molecular interactions that mediate the beneficial effects of nasally administered probiotics.

The use of omics technologies in creating LBP and postbiotics based on the Limosilactobacillus fermentum U-21.

In recent years, there has been an increasing tendency to create drugs based on certain commensal bacteria of the human microbiota and their ingredients, primarily focusing on live biotherapeutics (LBPs) and postbiotics. The creation of such drugs, termed pharmacobiotics, necessitates an understanding of their mechanisms of action and the identification of pharmacologically active ingredients that determine their target properties. Typically, these are complexes of biologically active substances synthesized by specific strains, promoted as LBPs or postbiotics (including vesicles): proteins, enzymes, low molecular weight metabolites, small RNAs, etc. This study employs omics technologies, including genomics, proteomics, and metabolomics, to explore the potential of Limosilactobacillus fermentum U-21 for innovative LBP and postbiotic formulations targeting neuroinflammatory processes. Proteomic techniques identified and quantified proteins expressed by L. fermentum U-21, highlighting their functional attributes and potential applications. Key identified proteins include ATP-dependent Clp protease (ClpL), chaperone protein DnaK, protein GrpE, thioredoxin reductase, LysM peptidoglycan-binding domain-containing protein, and NlpC/P60 domain-containing protein, which have roles in disaggregase, antioxidant, and immunomodulatory activities. Metabolomic analysis provided insights into small-molecule metabolites produced during fermentation, revealing compounds with anti-neuroinflammatory activity. Significant metabolites produced by L. fermentum U-21 include GABA (γ-aminobutyric acid), niacin, aucubin, and scyllo-inositol. GABA was found to stabilize neuronal activity, potentially counteracting neurodegenerative processes. Niacin, essential for optimal nervous system function, was detected in vesicles and culture fluid, and it modulates cytokine production, maintaining immune homeostasis. Aucubin, an iridoid glycoside usually secreted by plants, was identified as having antioxidant properties, addressing issues of bioavailability for therapeutic use. Scyllo-inositol, identified in vesicles, acts as a chemical chaperone, reducing abnormal protein clumps linked to neurodegenerative diseases. These findings demonstrate the capability of L. fermentum U-21 to produce bioactive substances that could be harnessed in the development of pharmacobiotics for neurodegenerative diseases, contributing to their immunomodulatory, anti-neuroinflammatory, and neuromodulatory activities. Data of the HPLC-MS/MS analysis are available via ProteomeXchange with identifier PXD050857.

Protective effect of hesperidin on malathion-induced ovarian toxicity in mice: The role of miRNAs, inflammation, and apoptosis

Malathion, a widely used organophosphate, is known for its relatively low toxicity and extensive application. However, it has been found to act as a female reproductive toxicant by causing oxidative stress, apoptosis, autophagy, and hormonal imbalances. Hesperidin, a flavonoid belonging to the flavanone class, exhibits various beneficial properties such as antioxidant and anti-inflammatory effects, which can potentially counteract harmful effects. The objective of this study was to examine how hesperidin and malathion impact the expression of miRNAs and genes linked to apoptosis and inflammation. Balb/c mice (n = 40) were divided into four groups: hesperidin (20 mg/kg), malathion (3 mg/kg), hesperidin+malathion, and control. After a 35-day intraperitoneal treatment, the mice were sacrificed. The left ovaries were used for analyzing the expression of miRNA-146a-5p, miRNA-129-3p, miRNA-96-5p, NF-κB, Bax, and Bcl-2 through RT-qPCR, as well as the levels of several cytokines using the ELISA method. The right ovaries were examined through histological and immunohistochemical techniques using H&E and NF-κB staining. Malathion exposure led to an increased Bax/Bcl-2 ratio, upregulated expression of Bax and NF-κB, elevated levels of IFN-γ, IL-2, and IL-6, enhanced expression of miRNA-146a-5p, decreased expression of miRNA-129-3p and miRNA-96-5p, and reduced levels of IL-4 and IL-10. Additionally, malathion-exposed ovaries exhibited structural abnormalities and disrupted architecture, accompanied by heightened NF-κB immunoreactivity. Conversely, treatment with hesperidin showed its capacity to counteract the detrimental consequences of malathion on the ovaries by alleviating or reversing these changes. In conclusion, hesperidin showed protective effects against malathion-induced ovarian toxicity by modulating cytokine production, apoptosis, inflammation, and miRNA expression.

The Glycan Ectodomain of SARS-CoV-2 Spike Protein Modulates Cytokine Production and Expression of CD206 Mannose Receptor in PBMC Cultures of Pre-COVID-19 Healthy Subjects.

The ability of recombinant, SARS-CoV-2 Spike (S) protein to modulate the production of two COVID-19 relevant, pro-inflammatory cytokines (IL-6 and IFN-γ) in PBMC cultures of healthy, pre-COVID-19 subjects was investigated. We observed that cytokine production was largely and diversely modulated by the S protein depending on antigen or mitogen stimulation, as well as on the protein source, insect (S-in) or human (S-hu) cells. While both proteins co-stimulated cytokine production by polyclonally CD3-activated T cells, PBMC activation by the mitogenic lectin Concanavalin A (Con A) was up-modulated by S-hu protein and down-modulated by S-in protein. These modulatory effects were likely mediated by the S glycans, as demonstrated by direct Con A-S binding experiments and use of yeast mannan as Con A binder. While being ineffective in modulating memory antigenic T cell responses, the S proteins and mannan were able to induce IL-6 production in unstimulated PBMC cultures and upregulate the expression of the mannose receptor (CD206), a marker of anti-inflammatory M2 macrophage. Our data point to a relevant role of N-glycans, particularly N-mannosidic chains, decorating the S protein in the immunomodulatory effects here reported. These novel biological activities of the S glycan ectodomain may add to the comprehension of COVID-19 pathology and immunity to SARS-CoV-2.

Abstract 5297: CLN-619, a clinical stage MICA/B-specific hIgG1 monoclonal antibody, engages multiple immune effector cells to promote anti-tumor activity

Abstract CLN-619 is a humanized IgG1 monoclonal antibody that targets MICA and MICB (MICA/B) and is currently in phase 1 clinical development in cancer patients (NCT05117476). MICA/B serve as activating signals on target cells for recognition by the NKG2D receptor, which is expressed on NK cells and a subset of T cell populations. MICA/B expression is induced in response to stressed conditions, thereby enabling NKG2D-mediated elimination of target cells. On NK cells, NKG2D is one of many receptors in the complex network of activating and inhibitory receptors, whereby NKG2D pathway activation results in cytokine production, enhancement of ADCC and target cell death. On CD8 T cells, the NKG2D axis plays a costimulatory role in lowering the threshold for lysis upon TCR engagement, and may also drive direct CD8-mediated killing following prior TCR activation. MICA/B is expressed broadly on a range of solid and hematological malignancies. However, tumor cells evade NKG2D-mediated elimination by shedding MICA/B ligand from the cell surface via proteases present in the tumor microenvironment (TME). CLN-619 functions by binding to MICA/B and preventing shedding, thereby increasing MICA/B cell surface expression to restore the NKG2D-MICA/B axis to promote tumor cell killing by NK cells and T cells. Additionally, CLN-619 can mediate ADCC and ADCP by NK cells and macrophages. In preclinical xenograft models, doses as low as 0.03 mg/kg inhibited tumor outgrowth. We investigated the effects of CLN-619 on a variety of primary immune cells including NK cells, T cells and macrophages. In the evaluation of NK cells, we measured CLN-619 modulation of cytokine production and cytotoxicity in the presence of MICA/B expressing target cells. In addition, we demonstrated the contribution of Fc-mediated functions of CLN-619. In the context of T cells, we explored the requirement of TCR co-stimulation or prior antigen exposure in the activation of the NKG2D pathway by CLN-619. In the context of macrophages, we measured the ability of CLN-619 to mediate ADCP against MICA/B-expressing target cells. These data highlight the potential of CLN-619 to engage multiple immune cell types within the TME, which may lead to greater and broader efficacy compared to IO therapies targeting a single immune cell type. Citation Format: Kerry A. Whalen, Catherine C. Henry, Kavya Rakhra, Kristan Meetze, Jennifer S. Michaelson, Patrick A. Baeuerle. CLN-619, a clinical stage MICA/B-specific hIgG1 monoclonal antibody, engages multiple immune effector cells to promote anti-tumor activity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5297.

Anti-neuroinflammatory effect of hydroxytyrosol: a potential strategy for anti-depressant development.

Introduction: Depression is a complex psychiatric disorder with substantial societal impact. While current antidepressants offer moderate efficacy, their adverse effects and limited understanding of depression's pathophysiology hinder the development of more effective treatments. Amidst this complexity, the role of neuroinflammation, a recognized but poorly understood associate of depression, has gained increasing attention. This study investigates hydroxytyrosol (HT), an olive-derived phenolic antioxidant, for its antidepressant and anti-neuroinflammatory properties based on mitochondrial protection. Methods: In vitro studies on neuronal injury models, the protective effect of HT on mitochondrial ultrastructure from inflammatory damage was investigated in combination with high-resolution imaging of mitochondrial substructures. In animal models, depressive-like behaviors of chronic restraint stress (CRS) mice and chronic unpredictable mild stress (CUMS) rats were examined to investigate the alleviating effects of HT. Targeted metabolomics and RNA-Seq in CUMS rats were used to analyze the potential antidepressant pathways of HT. Results: HT protected mitochondrial ultrastructure from inflammatory damage, thus exerting neuroprotective effects in neuronal injury models. Moreover, HT reduced depressive-like behaviors in mice and rats exposed to CRS and CUMS, respectively. HT's influence in the CRS model included alleviating hippocampal neuronal damage and modulating cytokine production, mitochondrial dysfunction, and brain-derived neurotrophic factor (BDNF) signaling. Targeted metabolomics in CUMS rats revealed HT's effect on neurotransmitter levels and tryptophan-kynurenine metabolism. RNA-Seq data underscored HT's antidepressant mechanism through the BDNF/TrkB signaling pathways, key in nerve fiber functions, myelin formation, microglial differentiation, and neural regeneration. Discussion: The findings underscore HT's potential as an anti-neuroinflammatory treatment for depression, shedding light on its antidepressant effects and its relevance in nutritional psychiatry. Further investigations are warranted to comprehensively delineate its mechanisms and optimize its clinical application in depression treatment.

Genetic variation of FcγRIIa induces higher uptake of Leishmania infantum and modulates cytokine production by adherent mononuclear cells in vitro.

Single nucleotide variations (SNVs) are specific genetic variations that commonly occur in a population and often do not manifest phenotypically. However, depending on their location and the type of nucleotide exchanged, an SNV can alter or inhibit the function of the gene in which it occurs. Immunoglobulin G (IgG) receptor genes have exhibited several polymorphisms, including rs1801274, which is found in the FcgRIIa gene. The replacement of A with T results in a Histidine (H) to Arginine (R) substitution, altering the affinity of the IgG receptor for IgG subtypes and C-reactive protein (CRP). In this study, we analyzed rs1801274 and its functional implications concerning L. Infantum uptake and cytokine production. We genotyped 201 individuals from an endemic area for visceral leishmaniasis to assess the presence of rs1801274 using Taqman probes for a candidate gene study. Additionally, we included seventy individuals from a non-endemic area for a functional study. Subsequently, we isolated and cultivated one-week adherent mononuclear cells (AMCs) derived from the peripheral blood of participants residing in the non-endemic region in the presence of L. infantum promastigotes, with and without antigen-specific IgG and/or CRP. We analyzed the rate of phagocytosis and the production of nitric oxide (NO), tumor necrosis factor (TNF)-a, interleukin (IL)-10, IL-12 p70, IL-1b, IL- 6, and IL-8 in the culture supernatants. In participants from the endemic region, the A/G (H/R isoform) heterozygous genotype was significantly associated with susceptibility to the disease. Furthermore, SNVs induced a change in the phagocytosis rate in an opsonin-dependent manner. Opsonization with IgG increased the production of IL-10, TNF-a, and IL-6 in AMCs with the H/R isoform, followed by a decrease in NO production. The results presented here suggest that the rs1801274 polymorphism is linked to a higher susceptibility to visceral leishmaniasis.

Interactions of Corneal Endothelial Cells with Stromal Cells during Corneal Endothelial Injury

Purpose: To investigate the interaction of corneal endothelial cells (CECs) with corneal stromal cells (CSCs) on the healing of chemically induced corneal endothelial injury.Methods: Twenty-five rabbits were divided into two groups: rabbits exposed to NaOH and controls. Rabbits were clinically evaluated and sacrificed at 1 day, 1 week, 2 weeks, and 4 weeks after endothelial injury. Corneal endothelial cells and corneal stromal cells were cultured and the wound healing rate of the corneal endothelium and cytokines in the culture medium were analyzed with and without co-culture in the Transwell system.Results: Corneal edema and opacity scores were higher in all rabbits exposed to NaOH than in controls. Corneal endothelial apoptosis with little effect on CSCs was observed in rabbits exposed to NaOH at day 1. Two weeks after injury, CECs migrated from the periphery. CSCs were aligned in parallel to Descemet's membrane, which exhibited the presence of CECs. Transforming factor-β1 and interleukin-6 secretion was lower in the co-culture system than in individual cultures of CECs or CSCs.Conclusions: These results revealed intracameral NaOH injection is a model of corneal endothelial injury with minimal impact on the stroma. Communication between CECs and CSCs during wound healing may lead to the modulation of cytokine production, which is necessary for an enhanced healing process of corneal endothelial injury.