TNF-α Response Research Articles

Effect of aging on monocyte phagocytic and inflammatory functions, and on the ex vivo inflammatory responses to lipopolysaccharide, in horses

Studies investigating age-related changes in the function of monocytes are currently limited for horses. Thus, the main goal of this study was to determine the effect of aging on monocyte phagocytic capacity and pro-inflammatory cytokine responses to bacterial lipopolysaccharide (LPS). A second goal of this work was to examine the effect of aging on the inflammatory cytokine responses to LPS in a whole blood ex vivo model. Seven healthy young adult (4–6 years of age) and seven healthy senior horses (>20 years of age) were enrolled. Phagocytosis of E. coli, and pro-inflammatory cytokine (TNFα) responses to LPS, were measured in monocytes by flow cytometry. Gene expressions of pro-inflammatory cytokines (TNFα, IL-1β, IL-6, IL-8, IL-18, CCL-5, CCL-2) were measured in peripheral blood mononuclear cells (PBMCs) and whole blood by RT-qPCR post incubation for 2 h or 6 h with a low (0.01 µg/mL) or a high (1 µg/mL) dose of LPS. Two sets of statistical models were applied to compare the age groups, one adjusted, and one unadjusted for the horses’ body condition scores (BCS). The percentage of monocytes that phagocytosed E. coli after 2 h of incubation was significantly lower in senior compared to young adult horses in the BCS-adjusted model. In the senior group, the expression of IL-1β in 2 h-0.01 µg/mL LPS-stimulated PBMCs was significantly higher than in the young adult group (BCS-adjusted and unadjusted models). In senior horses, expressions of IL-8 and IL-6 in whole blood samples stimulated for 6 h with 0.01 µg/mL LPS and for 2 h with 1 µg/mL LPS, respectively, were significantly lower than in young adult horses (BCS-adjusted models). The results of this study suggest that the phagocytic function of monocytes, as well as their IL-1β response to LPS may be altered in senior horses. In addition, the whole blood IL-8 and IL-6 gene expression responses to LPS may be insufficient in senior horses. While investigation of the effect of BCS on monocyte functions and whole blood pro-inflammatory LPS-responses was not a major goal of this work, it appears that adiposity may play a role in innate immune cell function, as significant differences between the age groups were often not apparent until the models were adjusted for BCS.

Optimizing study design in LPS challenge studies for quantifying drug induced inhibition of TNFα response: Did we miss the prime time?

In this work we evaluate the study design of LPS challenge experiments used for quantification of drug induced inhibition of TNFα response and provide general guidelines of how to improve the study design. Analysis of model simulated data, using a recently published TNFα turnover model, as well as the optimal design tool PopED have been used to find the optimal values of three key study design variables – time delay between drug and LPS administration, LPS dose, and sampling time points – that in turn could make the resulting TNFα response data more informative. Our findings suggest that the current rule of thumb for choosing the time delay should be reconsidered, and that the placement of the measurements after maximal TNFα response are crucial for the quality of the experiment. Furthermore, a literature study summarizing a wide range of published LPS challenge studies is provided, giving a broader perspective of how LPS challenge studies are usually conducted both in a preclinical and clinical setting.

ANALYSIS OF THE PATHOGENESIS OF Aeromonas hydrophila IN THE AFRICAN CATFISH, Clarias gariepinus AND INVOLVEMENT OF THE TNF-a IN RESPONSE TO THE INFECTION

This research aimed to study the pathogenesis of Aeromonas hydrophila infection through two different routes of infection in African catfish and to find out the involvement of TNF-a in response to the infection. The experimental infection model was performed by clipping the caudal fin and immersing the fish in a medium with A. hydrophila and by intramuscular injection. Total plate count were used to investigate total and the distribution of A. hydrophila in the organs and TNF-a were observed using immune histochemistry. The results showed that the two types of infection were able to show typical A. hydrophila symptoms in experimental fish. Histological observation indicated that the two types of experimental infection resulted in systemic aeromoniasis infection. Total bacterial count results showed that A. hydrophila were detected three hours post-infection (hpi) in all organs, except for the kidney, in which detection started since hour 0, both in control and challenge fish. TNF-a were detected in all experimental fish and influenced by the number of bacteria, the function and tissue structure and of the organs. It can be concluded that artificial infection by clipping the caudal fin of Clarias gariepinus and immersing the fish in a medium with active A. hydrophila isolates cause systemic aeromoniasis infection in organs. Acute infection with Aeromonas hydrophila causes an increase in TNF-a production.

Natural Exposure- and Vaccination-Induced Profiles of Ex Vivo Whole Blood Cytokine Responses to Coxiella burnetii.

Q fever is a zoonotic disease caused by the highly infectious Gram-negative coccobacillus, Coxiella burnetii (C. burnetii). The Q fever vaccine Q-VAX® is characterised by high reactogenicity, requiring individuals to be pre-screened for prior exposure before vaccination. To date it remains unclear whether vaccine side effects in pre-exposed individuals are associated with pre-existing adaptive immune responses to C. burnetii or are also a function of innate responses to Q-VAX®. In the current study, we measured innate and adaptive cytokine responses to C. burnetii and compared these among individuals with different pre-exposure status. Three groups were included: n=98 Dutch blood bank donors with unknown exposure status, n=95 Dutch village inhabitants with known natural exposure status to C. burnetii during the Dutch Q fever outbreak of 2007-2010, and n=96 Australian students receiving Q-VAX® vaccination in 2021. Whole blood cytokine responses following ex vivo stimulation with heat-killed C. burnetii were assessed for IFNγ, IL-2, IL-6, IL-10, TNFα, IL-1β, IP-10, MIP-1α and IL-8. Serological data were collected for all three cohorts, as well as data on skin test and self-reported vaccine side effects and clinical symptoms during past infection. IFNγ, IP-10 and IL-2 responses were strongly elevated in individuals with prior C. burnetii antigen exposure, whether through infection or vaccination, while IL-1β, IL-6 and TNFα responses were slightly increased in naturally exposed individuals only. High dimensional analysis of the cytokine data identified four clusters of individuals with distinct cytokine response signatures. The cluster with the highest levels of adaptive cytokines and antibodies comprised solely individuals with prior exposure to C. burnetii, while another cluster was characterized by high innate cytokine production and an absence of C. burnetii-induced IP-10 production paired with high baseline IP-10 levels. Prior exposure status was partially associated with these signatures, but could not be clearly assigned to a single cytokine response signature. Overall, Q-VAX® vaccination and natural C. burnetii infection were associated with comparable cytokine response signatures, largely driven by adaptive cytokine responses. Neither individual innate and adaptive cytokine responses nor response signatures were associated retrospectively with clinical symptoms during infection or prospectively with side effects post-vaccination.

Characterization of Aspergillus terreus Accessory Conidia and Their Interactions With Murine Macrophages.

All Aspergillus species form phialidic conidia (PC) when the mycelium is in contact with the air. These small, asexual spores are ideally suited for an airborne dissemination in the environment. Aspergillus terreus and a few closely related species from section Terrei can additionally generate accessory conidia (AC) that directly emerge from the hyphal surface. In this study, we have identified galactomannan as a major surface antigen on AC that is largely absent from the surface of PC. Galactomannan is homogeneously distributed over the entire surface of AC and even detectable on nascent AC present on the hyphal surface. In contrast, β-glucans are only accessible in distinct structures that occur after separation of the conidia from the hyphal surface. During germination, AC show a very limited isotropic growth that has no detectable impact on the distribution of galactomannan. The AC of the strain used in this study germinate much faster than the corresponding PC, and they are more sensitive to desiccation than PC. During infection of murine J774 macrophages, AC are readily engulfed and trigger a strong tumor necrosis factor-alpha (TNFα) response. Both processes are not hampered by the presence of laminarin, which indicates that β-glucans only play a minor role in these interactions. In the phagosome, we observed that galactomannan, but not β-glucan, is released from the conidial surface and translocates to the host cell cytoplasm. AC persist in phagolysosomes, and many of them initiate germination within 24 h. In conclusion, we have identified galactomannan as a novel and major antigen on AC that clearly distinguishes them from PC. The role of this fungal-specific carbohydrate in the interactions with the immune system remains an open issue that needs to be addressed in future research.

Abstract 1383: Characterization of CD8 T cell responses to DNAJB1-PRKACA fusion neoantigens in fibrolamellar carcinoma

Abstract Fibrolamellar carcinoma (FLC) is a rare liver malignancy that has no known cure. Novel therapies for FLC are urgently needed to improve patient outcomes. The key genetic event in FLC tumorigenesis is a highly conserved gene fusion between the first exon of DNAJB1 and the last nine exons of PRKACA. This fusion gene is present in all FLC tumors, and more than 90% of patients express fusion proteins with identical amino acid sequences. Genetic mutations like this gene fusion can serve as important therapeutic vulnerabilities, in part because they may be processed and presented on the surface of tumor cells as neoantigens that can activate an anti-tumor T cell response. The purpose of our study was to test the hypothesis that DNAJB1-PRKACA fusion neoantigens could elicit T cell responses against FLC and serve as targets for novel immunotherapies. Spatial transcriptomic analyses of human FLC tumor samples indicated that CD8+ T cells could infiltrate these tumors, but often expressed markers of dysfunction and exhaustion, such as TOX. Nevertheless, we successfully expanded tumor-infiltrating T cells from FLC ex vivo and used intracellular cytokine staining (ICS) to identify a subset of FLC patient T cells that produced IFNγ and TNFα in response to stimulation with a fusion neoantigen. We used both peptide-MHC tetramer staining and functional response after stimulation to identify T cells in FLC patients and healthy donors that recognize fusion neoantigens. We then determined the paired T cell receptor (TCR) sequences using single-cell sequencing and expressed the TCRs in primary human T cells to test their potential utility in TCR-engineered immunotherapies. We validated the specificity and functionality of these TCRs using peptide-MHC tetramer staining, ICS, and in vitro cytotoxicity assays on the xCelligence and Berkeley Lights Lightning platforms. Primary T cells expressing fusion-specific TCRs bound to their cognate peptide-MHC tetramer, produced multiple cytokines in response to stimulation with their cognate fusion peptide, and specifically killed fusion-presenting target cells in vitro. Ongoing experiments will test whether T cells expressing these fusion-specific TCRs can control growth of fusion-presenting tumors in vivo. Collectively, these studies have defined the first reported fusion-specific T cell response in FLC, as well as fusion-specific TCRs that hold promise for use in adoptive T cell therapies. Our spatial transcriptomic analyses have also begun to illuminate the immune microenvironment in FLC and will inform future efforts to develop immunotherapies for this disease. Citation Format: Allison M. Kirk, Ching-Heng Chou, Jeremy Chase Crawford, Walid Awad, E. Kaitlynn Allen, Xiaoyu Zhang, Anthony E. Zamora, Scott E. Strome, Paul G. Thomas. Characterization of CD8 T cell responses to DNAJB1-PRKACA fusion neoantigens in fibrolamellar carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1383.

Abstract 5596: TNFα production by myeloid DCs in response to rituximab induces monocyte and NK cell proliferation and survival

Abstract Background: Rituximab is a central component of chemoimmunotherapy for B cell lymphomas. With over two decades in clinical use, new insights into its mechanisms of action continue to emerge. Rituximab infusion into patients results in elevated levels of TNFα in patient sera. However, our understanding of the mechanism of TNFα production in the context of rituximab and its role in anti-tumor immunity remain limited. In our study, we sought to determine the major producers of TNFα following rituximab treatment and the effect of rituximab-induced TNFα on anti-tumor effector cells. Methods: Peripheral blood mononuclear cells (PBMCs) from normal donors were cocultured in vitro with CD20-expressing Raji cells for 1 to 7 days. The coculture was treated with rituximab or non-specific antibody trastuzumab. Recombinant TNFα or TNFα blocking antibody infliximab were used to test the effect of TNFα in the rituximab- or trastuzumab-treated coculture system. ELISA was used to evaluate TNFα production in culture supernatant. Multicolor flow cytometry was used to evaluate for phenotypic and functional changes with TNFα treatment or blockade in various immune cell populations. Results: TNFα was robustly produced by PBMCs when treated with rituximab. This production was mediated by the Fc portion of rituximab antibody, as rituximab Fab elicited very little if any TNFα response from PBMCs. Myeloid dendritic cells (HLA-DR+CD123-CD11c+) were the key producers of TNFα in response to rituximab. In the absence of antibody therapy, recombinant TNFα treatment induced proliferation and survival of two major effector cells in the peripheral blood: monocytes and NK cells as determined by cell count and percent of Ki67+ cells. TNFα blockade using infliximab inhibited monocyte and NK cell proliferation and survival. TNFα blockade also protected Raji cells from rituximab-mediated killing. Conclusions: Rituximab-induced TNFα production promotes the proliferation and survival of monocytes and NK cells. Myeloid dendritic cells are necessary for TNFα production in this context. These results highlight the complexity of the immune response to rituximab treatment. Additional studies are ongoing exploring the role TNFa plays in the therapeutic response to rituximab. Citation Format: Nanmeng Yu, George J. Weiner. TNFα production by myeloid DCs in response to rituximab induces monocyte and NK cell proliferation and survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5596.

IL-4, IL-10, TNF-α and IFN-γ Cytokine Levels in Patients with Cystic Echinococcosis and Fascioliasis

Cytokines are protein substances involved in immune response and inflammation regulation, cell growth, tissue repair and natural and adaptive immunity events such as hematopoiesis. Changes in Th1 and Th2 immune responses provide information on the clinical presentation, pathology and diagnosis of diseases. This study was conducted on 142 patients, aged 18-95 yr and applied to Parasitology Laboratory of Van Yuzuncu Yil Hospital between Aug 2018 and May 2019. Fifty-one of the patients were serologically diagnosed with CE, 53 with a diagnosis of fascioliasis, and 38 as the control group. Serum samples were taken from patients and levels of IL-4, IL-10, TNF α and IFN γ parameters were investigated by ELISA method. Results were evaluated by spectrophotometer and observed which immunologic parameters increased in which infections. Cytokine results were also evaluated according to patient age groups and genders. Chi-square and/or Fisher's exact test were used to evaluate the results. IL-4 response was detected in 50.9%; IL-10 in 44.2%; TNF-α in 43.3% and IFN-γ in 43.3% of CE seropositive patients. IL-4, IL-10, TNF-α and IFN-responses detected in 50.9%, 44.2%, 43.3% and 43.3% of CE patients, and in 43%, 39.2%, 34.4% and 40.6% of fascioliasis patients, respectively. The presence of Th1 and Th2 responses were detected in both infections. There was a significant relationship between fascioliasis and IL-4 response and between CE and IL-4, IL-10 and TNF-α responses (P≤.05). These cytokine levels may provide information about the immune response to infections, and may be useful for early detection of disease and recurrence and monitoring of treatment.

Relationship between T-cell-dependent and T-cell-independent vaccines after neurotrauma; is the B-cell response preserved?

ABSTRACT Background After trauma and central nervous system (CNS) injury, trauma-induced immune deficiency syndrome (TIDS) and CNS injury-induced immune deficiency syndrome (CIDS) may negatively affect responses to T-cell-dependent vaccines, such as pneumococcal conjugate vaccine (PCV) recommended after basilar fracture. This study (NCT02806284) aimed to investigate whether there after neurotrauma is a correlation between T-cell-dependent and independent vaccine responses and, thus, if B-cell activity is similarly depressed and whether the T-cell-dependent response is possible to predict. Methods Adult patients with basilar fracture (n = 33) and those undergoing pituitary gland surgery (n = 23) were within 10 days vaccinated with a T-cell-dependent vaccine against Haemophilus influenzae type b (Hib) and a T-cell-independent pneumococcal polysaccharide vaccine (PPSV). Samples reflecting the systemic inflammatory response and pre- and post-vaccination antibody levels after 3–6 weeks against Hib and PPSV were collected and determined by enzyme immunoassays. Results High and significant correlations were detected in the responses to different pneumococcal serotypes, but none between the Hib and PPSV responses. No differences in trauma scores, C-reactive protein, IL-6, IL-10, pentraxin 3, fractalkine or calprotectin plasma concentrations or in ex vivo TNF-α, IL-6 or IL-10 responses to endotoxin were found between Hib vaccination responders and non-responders. Conclusions There was no correlation between the pneumococcal responses and that to Hib, indicating that B-cell function is not similarly depressed as T-cell function. Grading of the trauma or parameters reflecting the innate immune response could not predict the T-cell-dependent vaccine response. There is a need of further studies evaluating the vaccine response after neurotrauma.

Exosomal Transfer of DNA Methyl-Transferase mRNA Induces an Immunosuppressive Phenotype in Human Monocytes.

Survivors of sepsis exhibit persistent immunosuppression. Epigenetic events may be responsible for some of these immunosuppressive changes. During sepsis circulating exosomes contain large quantities of DNA methyltransferase (DNMT) mRNAs. We hypothesized that exosomes directly transfer DNMT mRNAs to recipient monocytes with resultant methylation events and immunosuppression. Exosomes containing DNMT mRNA were generated by stimulating monocytes with LPS. Confocal microscopy was used to determine uptake kinetics in the presence of pharmacologic inhibition. Expression and packaging of specific DNMT mRNA was controlled using DNMT siRNAs. Whole genome and gene specific methylation was assessed using bisulfite sequencing. Ingenuity pathway analysis was performed to determine the biological function of significance of differentially methylated regions. Exosomes effectively transferred DNMT mRNA to recipient monocytes. Pharmacologic inhibition of exosome uptake prevented this increase in DNMT mRNA expression. Recipient monocytes exhibited hypermethylation changes and gene suppression. siRNAs decreased the packaging of DNMT mRNAs and prevented TNFα gene suppression, restoring immunocompetence. These data support a role for exosome-mediated transfer of DNMT mRNA with resultant methylation and gene silencing. Pharmacologic uptake inhibition or targeted siRNA mediated DNMT gene silencing prevented DNMT mRNA transfer and maintained the cell's ability to express TNFα in response to LPS. This highlights the potential therapeutic value of targeting these exosome-mediated epigenetic events to maintain the host immune response during sepsis.

Comparison of biological responses between submerged, pseudo-air-liquid interface, and air-liquid interface exposure of A549 and differentiated THP-1 co-cultures to combustion-derived particles

Air liquid interface (ALI) exposure systems are gaining interest, and studies suggest enhanced response of lung cells exposed to particles at ALI as compared to submerged exposure, although the results have been somewhat inconsistent. Previous studies have used monocultures and measured particle deposition using assumptions including consistent particle deposition, particle density, and shape. This study exposed co-cultures of A549 and differentiated THP-1 cells to flame-generated particles using three exposure methods: ALI, pseudo-ALI, and submerged. The dose at ALI was measured directly, reducing the need for assumptions about particle properties and deposition. For all exposure methods an enhanced pro-inflammatory response (TNFα) and Cytochrome P450 (CYP1A1) gene expression, compared to their corresponding negative controls, was observed. ALI exposure induced a significantly greater TNFα response compared to submerged exposure. The submerged exposures exhibited greater induction of CYP1A1 than other exposure methods, although not statistically significant. Some of the factors behind the observed difference in responses for the three exposure methods include differences in physicochemical properties of particles in suspending media, delivered dose, and potential contribution of gas-phase species to cellular response in ALI exposure. However, given the difficulty and expense of ALI exposures, submerged exposure may still provide relevant information for particulate exposures.

CD8 T cell responses to conserved DNAJB1-PRKACA fusion neoantigens in fibrolamellar carcinoma

Abstract Fibrolamellar carcinoma (FLC) is an often-lethal liver malignancy of adolescents and young adults. No systemic therapies are currently approved for FLC, so novel treatments are needed to improve patient outcomes. A promising therapeutic vulnerability in FLC is a highly-conserved gene fusion between DNAJB1 and PRKACA. The resultant fusion protein is identical in more than 90% of patients, making it a potentially ideal neoantigen target for T cell-based immunotherapy. The goal of our study was to test if DNAJB1-PRKACA neoantigens could elicit T cell responses and serve as targets for immunotherapy. Spatial transcriptomic analyses of FLC tumor tissue indicated that CD8 T cells could infiltrate FLC tumors, but expressed exhaustion markers such as TOX. Nevertheless, we expanded T cells from an FLC patient tumor ex vivo and detected T cells that produced IFNγ and TNFα in response to stimulation with a fusion neoantigen. We then used functional response after peptide stimulation or peptide-MHC tetramer staining to identify fusion-specific T cell receptors (TCRs) in both FLC patients and healthy donors. We expressed these TCRs in primary human T cells and found that cells expressing fusion-specific TCRs bound to their cognate tetramer and produced IFNγ, TNFα, and IL-2 in response to stimulation with their cognate peptide. TCR-expressing cells also specifically killed target cells presenting their cognate fusion peptide in vitro. Ongoing experiments will test if cells expressing these TCRs can control growth of fusion-expressing tumors in vivo. Together, these studies have defined the first reported fusion-specific T cell response in an FLC patient, as well as fusion-specific TCRs that hold promise for development in adoptive T cell therapies. Supported by grants from NIH (R01 AI136514, F31 CA254423) and The Mark Foundation for Cancer Research (Aspire Award)

Differential CD4+ and CD8+ T cell recognition of mycobacteria antigens in pediatric versus adult TB

Abstract T cells from young children may be limited in capacity to mount pro-inflammatory responses to intracellular pathogens, thus contributing to vulnerability to TB disease. We compared CD4+ and CD8+ T cell cytokine production in response to mycobacterial antigens and mitogen SEB, between Ugandan children <5 yr (PedTB) and adults (ATB) with culture-confirmed pulmonary TB. HIV-uninfected children (n=12) and adults (n=41) had blood drawn for PBMC isolation prior to TB treatment. CD4+ and CD8+ T cell production of IFNγ, IL2, and TNFα in response to ESAT6/CFP10 (EC), ESXJ, PE12/13, PE3, PPE15, and PPE51 peptide pools, and SEB, were assessed by intracellular flow cytometry. Proportions and frequencies of CD4+ and CD8+ T cells producing cytokines were compared using Fisher’s Exact and Kruskal-Wallis tests, respectively, with adjusted p-values <0.05 significant. PedTB and ATB had equivalent CD4+ and CD8+ T cell production of IFNγ, IL2, and TNFα, including polyfunctional responses, to EC. T cell cytokine responses to ESXJ and PPE51 were equivalent; significant differences were noted in CD4+ T cell responses to PE3 and PPE15, and CD8+ T cell responses to PE12/13. Frequencies of CD4+ T cells producing IFNγ or IL2 in response to SEB were lower (p<0.0001) in PedTB versus ATB. Young children with PedTB exhibited adult-like capacity to generate Th-1 cytokines in response to EC, ESXJ, and PPE 51. Pediatric responses to PE3, PPE15, and PE12/13 were impaired, suggesting that the breath of antigen recognition differs between infants and adults with TB. Differential T cell recognition of mycobacterial antigens between adults and children should be considered in development of novel T cell based diagnostics and vaccines targeting pediatric TB. Supporting from grants by NIH: AI157807; HHSN272200900053C

Altered Trained immunity in AID−/− versus wild type mice following infection with Pneumocystis murina

Abstract Pneumocystis pneumonia continues to be a life-threatening infection in immunocompromised individuals. Dendritic cells are key antigen presenters to CD4+ T cells, which are critical to controlling Pneumocystis infection along with B cells. β-1,3 glucans are found in the cell wall of the cyst form of Pneumocystis. Glucans derived from other fungi have been shown to induce trained immunity. Therefore, we explored if Pneumocystis infection can induce a trained immunity response in C57Bl/6 (wild type) mice following exposure via a natural route of infection. We also tested activation-induced cytidine deaminase knockout mice (AID−/−), a deficiency that affects B cells, in the same infection model to determine whether a mutation known to affect the adaptive immune response can also alter the manifestation of trained immunity. We found that bone marrow derived dendritic cells (BMDCs) from C57BL/6 Pneumocystis exposed mice respond differently to homologous and heterologous antigen stimulation compared to BMDCs from naïve mice. Furthermore, although the differential response between cells from AID−/− exposed and naïve mice exists, specifically the TNFα response is opposite to that from C57BL/6 mice. In addition, when trained immunity was induced in BMDCs derived from naïve C57Bl/6 mice and AID−/− mice, the cytokine response was distinctive between the cells derived from C57BL/6 mice and AID−/− mice. These results suggest that not only can Pneumocystis infection induce trained immunity in BMDCs, this response is alterable by gene mutations traditionally thought to affect the adaptive immune response. Intramural Research Program of the NIH Clinical Center

CircHIPK3 alleviates inflammatory response and neuronal apoptosis via regulating miR-382-5p/DUSP1 axis in spinal cord injury

BackgroundSpinal cord injury (SCI) is one of the serious neurological diseases with high morbidity which may be treated with hematopoietic stem cell (HSC) transplants. Circular RNAs (circRNAs) play vital roles in SCI. The study aimed to reveal the function and mechanism of circRNA homeodomain interacting protein kinase 3 (HIPK3) in SCI. MethodsSCI model in vitro was established by treating neuronal cells AGE1.HN with oxygen-glucose deprivation (OGD) and CoCl2. The levels of circHIPK3, miR-382-5p and dual specificity phosphatase 1 (DUSP1) were examined using quantitative real-time PCR (qRT-PCR) or western blot assay. Enzyme linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors (IL-6 and TNF-α). Cell proliferation and apoptosis were evaluated by 5′-ethynyl-2′-deoxyuridine (EdU) assay and flow cytometry. Caspase-3 Colorimetric Assay Kit was used to detect aaspase-3 activity. The interactions among circHIPK3, miR-382-5p and DUSP1 were confirmed by dual-luciferase reporter and RNA immunoprecipitation assays. ResultsCircHIPK3 and DUSP1 were down-regulated, while miR-382-5p was up-regulated in OGD-induced AGE1.HN cells. Overexpression of circHIPK3 suppressed inflammatory response and cell apoptosis and promoted proliferation in OGD-induced AGE1.HN cells by sponging miR-382-5p. CircHIPK3 regulated DUSP1 expression by targeting miR-382-5p. MiR-382-5p inhibition hindered inflammatory response of IL-6 and TNF-α and neuronal apoptosis and promoted apoptosis via targeting DUSP1. ConclusionCircHIPK3 overexpression alleviated OGD-induced AGE1.HN cell inflammatory response and neuronal apoptosis via regulating miR-382-5p/DUSP1 axis, indicating that circHIPK3 might be a promising therapeutic target for SCI.

The Effects of Freshwater Clam (Corbicula fluminea) Extract on Serum Tumor Necrosis Factor-Alpha (TNF-α) in Prediabetic Patients in Taiwan.

Freshwater clam extract (FCE) is a functional food that regulates the immune system and has been demonstrated in numerous studies to display desirable anti–tumor necrosis factor-alpha (TNF-α) responses. In addition, excess TNF-α production is positively associated with type 2 diabetes. However, few longitudinal clinical studies evaluating the efficiency and toxicity of FCE are available. This article reports that patients with prediabetes who received FCE had a desirable outcome of a reduction in serum TNF-α for a long period. This was a double-blind, randomized, parallel clinical trial conducted using FCE intervention and placebo groups, and 36 patients with prediabetes were enrolled. Two grams of FCE or placebo was consumed daily for 180 consecutive days. The serum of the participants was collected at four time points (0M: before the intervention; 3M: after 3 months of intervention; 6M: after 6 months of intervention; 12M: 6 months after cessation of intervention at 6M). A serum TNF-α concentration higher than 4.05 pg/mL was defined as a cut-off value. FCE reduced serum TNF-α in all participants at 6M and 12M. Moreover, FCE significantly suppressed serum TNF-α concentrations at 6M and 12M and inhibited TNF-α release with time series in subjects with elevated TNF-α values. FCE intervention effectively reduced serum TNF-α and persistently sustained the effects for half a year in patients with prediabetes. Gas chromatography–mass spectrometry (GS-MS) analysis revealed that the major components of FCE were phytosterols and fatty acids, which exerted anti-inflammatory and anti-TNF-α abilities. Hence, FCE has the potential to be developed as a natural treatment for prediabetic patients in Taiwan.

Targeting TNFα-mediated cytotoxicity using thalidomide after experimental cardiac arrest in rats: An exploratory study.

Cardiac arrest (CA) results in a central and systemic cytokine and inflammatory response. Thalidomide has been reported to be neuroprotective by selectively decreasing TNFα synthesis. We hypothesized that thalidomide would decrease the systemic and organ-specific TNFα/cytokine response and biomarkers of injury in rats subjected to 10 min CA. Naïves, CA treated with vehicle (CA) and CA treated with thalidomide (50 mg/kg; CA+T) were studied (n=6 per group). TNFα and key cytokines were assessed at 3 h after resuscitation in the cortex, hippocampus, striatum, cerebellum, plasma, heart and lung. Neuron specific enolase (NSE), S100b, cardiac troponin T (cTnT) and intestinal fatty acid binding protein (IFABP) were used to assess neuronal, glial, cardiac and intestinal damage, respectively. CA increased TNFα and multiple pro-inflammatory cytokines in plasma and selected tissues with no differences between the CA and CA+T groups in any region. NSE, S100b, cTnT and IFABP were increased after CA or CA+T vs. in the naïve group (all P<0.05) without significant differences between the CA and CA+T groups. In conclusion, CA resulted in a TNFα and cytokine response, with increased biomarkers of organ injury. Notably, thalidomide at a dose reported to improve the outcome in in vivo models of brain ischemia did not decrease TNFα or cytokine levels in plasma, brain or extracerebral organs, or biomarkers of injury. Although CA at 3 h post resuscitation produces a robust TNFα response, it cannot be ruled out that an alternative dosing regimen or assessment at other time-points might yield different results. The marked systemic and regional cytokine response to CA remains a potential therapeutic target.

TNF-α derived from arsenite-induced microglia activation mediated neuronal necroptosis

Arsenic, an identified environmental toxicant, poses threats to the health of human beings through contaminated water and food. Recently, increasing reports focused on arsenic-induced nerve damage, however, the underlying mechanism remains elusive. Microglia are important immune cells in the nervous system, which produce a large number of inflammatory factors including TNF-α when activated. Recent reports indicated that TNF-α is involved in the process of necroptosis, a new type of programmed cell death discovered recently. Although there were evidences suggested that arsenic could induce both microglia activation and TNF-α production in the nervous system, the mechanism of arsenic-induced neurotoxicity due to microglia activation is rarely studied. In addition, the role of microglia-derived TNF-α in response to arsenic exposure in necroptosis has not been documented before. In this study, we found that arsenite induced microglial activation through p38 MAPK signaling pathway, leading to the production of TNF-α. Microglia-derived TNF-α further induced necroptosis in the neuronal cells. Our findings suggested that necroptosis induced by microglia-derived TNF-α upon arsenite exposure partially played a role in arsenic-induced cell death which underlie the fundamental event of arsenic-related neurotoxicity.

Innate lymphoid cells: NK and cytotoxic ILC3 subsets infiltrate metastatic breast cancer lymph nodes

ABSTRACT Innate lymphoid cells (ILCs) – which include cytotoxic Natural Killer (NK) cells and helper-type ILC – are important regulators of tissue immune homeostasis, with possible roles in tumor surveillance. We analyzed ILC and their functionality in human lymph nodes (LN). In LN, NK cells and ILC3 were the prominent subpopulations. Among the ILC3s, we identified a CD56+/ILC3 subset with a phenotype close to ILC3 but also expressing cytotoxicity genes shared with NK. In tumor-draining LNs (TD-LNs) and tumor samples from breast cancer (BC) patients, NK cells were prominent, and proportions of ILC3 subsets were low. In tumors and TD-LN, NK cells display reduced levels of NCR (Natural cytotoxicity receptors), despite high transcript levels and included a small subset CD127− CD56− NK cells with reduced function. Activated by cytokines CD56+/ILC3 cells from donor and patients LN acquired cytotoxic capacity and produced IFNg. In TD-LN, all cytokine activated ILC populations produced TNFα in response to BC cell line. Analyses of cytotoxic and helper ILC indicate a switch toward NK cells in TD-LN. The local tumor microenvironment inhibited NK cell functions through downregulation of NCR, but cytokine stimulation restored their functionality.

Modulation of Macrophage Response by Copper and Magnesium Ions in Combination with Low Concentrations of Dexamethasone.

Macrophages have been deemed crucial for correct tissue regeneration, which is a complex process with multiple overlapping phases, including inflammation. Previous studies have suggested that divalent ions are promising cues that can induce an anti-inflammatory response, since they are stable cues that can be released from biomaterials. However, their immunomodulatory potential is limited in a pro-inflammatory environment. Therefore, we investigated whether copper and magnesium ions combined with low concentrations of the anti-inflammatory drug, dexamethasone (dex), could have a synergistic effect in macrophage, with or without pro-inflammatory stimulus, in terms of morphology, metabolic activity and gene expression. Our results showed that the combination of copper and dex strongly decreased the expression of pro-inflammatory markers, while the combination with magnesium upregulated the expression of IL-10. Moreover, in the presence of a pro-inflammatory stimulus, the combination of copper and dex induced a strong TNF-α response, suggesting an impairment of the anti-inflammatory actions of dex. The combination of magnesium and dex in the presence of a pro-inflammatory stimulus did not promote any improvement in comparison to dex alone. The results obtained in this study could be relevant for tissue engineering applications and in the design of platforms with a dual release of divalent ions and small molecules.