Cytokines TNF Research Articles

Combined effect of methotrexate and bifidobacteria metabolites on TNFα AND IFNγ production by human peripheral blood mononuclears

Methotrexate (Mtx) is a first-line drug for the treatment of numerous rheumatic and non-rheumatic disorders, including oncological disdiseases. However, therapeutic efficacy of Mtx is limited by severe toxicity to many organs (myelo-, hepato-, nephrotoxicity, mucositis, enteritis, dysbiosis at various human biotopes, etc.). Recently, a number of studies showed that some metabolites of Bifidobacteria and Lactobacilli are able to enhance effect of chemotherapeutic drugs and limit their toxic properties. The aim of the present work was to study the possible potentiating action of Bifidobacteria cell-free supernatants and methotrexate upon secretion of pro-inflammatory TNF and IFN cytokines by human peripheral blood mononuclear cells (PBMCs). The immunoregulatory effects upon production of TNF and IFNg was evaluated in the in vitro model of cultured PBMC supplemented with Bifidobacteria metabolites, methotrexate, or their combination. Analysis of the combined effect of Bifidobacteria metabolites and Mtx on the cytokine production revealed their synergism towards the key pro-inflammatory cytokines (TNF and IFN). We found an increase against the control cultures (with Mtx only), inhibition of the early pro-inflammatory cytokine TNF production. On the contrary, we revealed an increased secretion of IFN which regulates the effector cells. The results obtained with these cytokines suggest the presence of a potentiating effect of Bifidobacteria metabolites upon anti-inflammatory and immunoregulatory properties of methotrexate. Thus, Bifidobacteria metabolites can be considered a promising agent which potentiates the therapeutic action of methotrexate by suppressing TNF secretion and stimulating IFN by immunocompetent cells. Further studies of the combined effects of Mtx and metabolites from the intestinal microbiota upon the cytokine production by effector cells could be recommended, aiming to enhance therapeutic effect of methotrexate and limit its toxic properties using the Bifidobacteria metabolites.

TNF and TNF receptors as therapeutic targets for rheumatic diseases and beyond.

The cytokine TNF signals via two distinct receptors, TNF receptor 1 (TNFR1) and TNFR2, and is a central mediator of various immune-mediated diseases. Indeed, TNF-neutralizing biologic drugs have been in clinical use for the treatment of many inflammatory pathological conditions, including various rheumatic diseases, for decades. TNF has pleiotropic effects and can both promote and inhibit pro-inflammatory processes. The integrated net effect of TNF in vivo is a result of cytotoxic TNFR1 signalling and the stimulation of pro-inflammatory processes mediated by TNFR1 and TNFR2 and also TNFR2-mediated anti-inflammatory and tissue-protective activities. Inhibition of the beneficial activities of TNFR2 might explain why TNF-neutralizing drugs, although highly effective in some diseases, have limited benefit in the treatment of other TNF-associated pathological conditions (such as graft-versus-host disease) or even worsen the pathological condition (such as multiple sclerosis). Receptor-specific biologic drugs have the potential to tip the balance from TNFR1-mediated activities to TNFR2-mediated activities and enable the treatment of diseases that do not respond to current TNF inhibitors. Accordingly, a variety of reagents have been developed that either selectively inhibit TNFR1 or selectively activate TNFR2. Several of these reagents have shown promise in preclinical studies and are now in, or approaching, clinical trials.

PPARγ partial agonist LPSF/GQ-16 prevents dermal and pulmonary fibrosis in HOCl-induced systemic sclerosis (SSc) and modulates cytokine production in PBMC of SSc patients.

Thiazolidinediones (TZD) are synthetic molecules that have a range of biological effects, including antifibrotic and anti-inflammatory, and they may represent a promising therapeutic strategy for systemic sclerosis (SSc). The aim of this study was to investigate the immunomodulatory and antifibrotic properties of LPSF/GQ-16, a TZD derivative, in peripheral blood mononuclear cells (PBMC) from SSc patients and in a murine model of SSc HOCl-induced. The PBMC of 20 SSc patients were stimulated with phytohemagglutinin (PHA) and treated with LPSF/GQ-16 for 48h, later cytokines in the culture supernatants were quantified by sandwich enzyme-linked immunosorbent assay (ELISA) or cytometric bead array (CBA). Experimental SSc was induced by intradermal injections of hypochlorous acid (HOCl) for 6weeks. HOCl-induced SSc mice received daily treatment with LPSF/GQ-16 (30mg/kg) through intraperitoneal injections during the same period. Immunological parameters were evaluated by flow cytometry and ELISA, and dermal and pulmonary fibrosis were evaluated by RT-qPCR, hydroxyproline dosage and histopathological analysis. In PBMC cultures, it was possible to observe that LPSF/GQ-16 modulated the secretion of cytokines IL-2 (p < 0.001), IL-4 (p < 0.001), IL-6 (p < 0.001), IL-17A (p = 0.006), TNF (p < 0.001) and IFN-γ (p < 0.001). In addition, treatment with LPSF/GQ-16 in HOCl-induced SSc mice promoted a significant reduction in dermal thickening (p < 0.001), in the accumulation of collagen in the skin (p < 0.001), down-regulated the expression of fibrosis markers in the skin (Col1a1, α-Sma and Tgfβ1, p < 0.001 for all) and lungs (Il4 and Il13, p < 0.001 for both), as well as reduced activation of CD4 + T cells (p < 0.001), B cells (p < 0.001) and M2 macrophages (p < 0.001). In conclusion, LPSF/GQ-16 showed immunomodulatory and antifibrotic properties, demonstrating the therapeutic potential of this molecule for SSc.

Evaluation of the innate immune response of caprine neutrophils against Mycobacterium avium subspecies paratuberculosis in vitro

Neutrophils constitute an essential component of the innate immune response, readily killing most bacteria through phagocytosis, degranulation, and the release of neutrophil extracellular traps (NETs) among other mechanisms. These cells play an unclear role in mycobacterial infections such as Mycobacterium avium subspecies paratuberculosis (Map), the etiological agent of paratuberculosis, and its response is particularly understudied in ruminants. Herein, a wide set of techniques were adapted, or newly developed, to study the in vitro response of caprine neutrophils after Map infection. Immunofluorescence was used to demonstrate, simultaneously, chemotaxis, phagocytosis, degranulation, and NETs. The quantification of neutrophil phagocytic activity against Map at a 1:10 multiplicity of infection (MOI), through flow cytometry, showed values that varied from 4.54 to 5.63% of phagocyting neutrophils. By immunofluorescence, a 73.3 ± 14.5% of the fields showed NETs, and the mean release of DNA, attributable to NETosis, calculated through a fluorometric method, was 16.2 ± 3.5%. In addition, the RNA expression of TGF-β, TNF and IL-1β cytokines, measured through reverse transcription qPCR, was significantly higher in the two latter. Overall, neutrophil response was proportional to the number of bacteria. This work confirms that the simultaneous study of several neutrophil mechanisms, and the combination of different methodologies, are essential to reach a comprehensive understanding of neutrophil response against pathogens, demonstrates that, in vitro, caprine neutrophils display a strong innate response against Map, using their entire repertoire of effector functions, and sets the basis for further in vitro and in vivo studies on the role of neutrophils in paratuberculosis.

Paternal Expressed Gene 10 (PEG10) is decreased in early-onset preeclampsia

BackgroundPreeclampsia is a severe complication of pregnancy which is attributed to placental dysfunction. The retrotransposon, Paternal Expressed Gene 10 (PEG10) harbours critical placental functions pertaining to placental trophoblast cells. Limited evidence exists on whether PEG10 is involved in preeclampsia pathogenesis. This study characterised the expression and regulation of PEG10 in placentas from patients with early-onset preeclampsia compared to gestation-matched controls.MethodsPEG10 expression was measured in plasma and placentas collected from patients with early-onset preeclampsia (< 34 weeks’) and gestation-matched controls using ELISA (protein) and RT-qPCR (mRNA). First-trimester human trophoblast stem cells (hTSCs) were used for in vitro studies. PEG10 expression was measured during hTSC differentiation and hTSC exposure to hypoxia (1% O2) and inflammatory cytokines (IL-6 and TNFα) using RT-qPCR. Functional studies used PEG10 siRNA to measure the effect of reduced PEG10 on canonical TGF-beta signalling and proliferation using luciferase and xCELLigence assays, respectively.ResultsPEG10 mRNA expression was significantly reduced in placentas from patients with early-onset preeclampsia (< 34 weeks’ gestation) relative to controls (p = 0.04, n = 78 vs n = 18 controls). PEG10 protein expression was also reduced in preeclamptic placentas (p = 0.03, n = 5 vs n = 5 controls, blinded assessment of immunohistochemical staining), but neither PEG10 mRNA nor protein could be detected in maternal circulation. PEG10 was most highly expressed in hTSCs, and its expression was reduced as hTSCs differentiated into syncytiotrophoblasts (p < 0.0001) and extravillous trophoblasts (p < 0.001). Trophoblast differentiation was not altered when hTSCs were treated with PEG10 siRNA (n = 5 vs n = 5 controls).PEG10 was significantly reduced in hTSCs exposed to hypoxia (p < 0.01). PEG10 was also reduced in hTSCs treated with the inflammatory cytokine TNF alpha (p < 0.01), but not IL-6. PEG10 knocked down (siRNA) in hTSCs showed reduced activation of the canonical TGF-β signalling effector, the SMAD binding element (p < 0.05) relative to controls. PEG10 knockdown in hTSCs however was not associated with any significant alterations in proliferation.ConclusionsPlacental PEG10 is reduced in patients with early-onset preeclampsia. In vitro studies suggest that hypoxia and inflammation may contribute to PEG10 downregulation. Reduced PEG10 alters canonical TGF-beta signalling, and thus may be involved in trophoblast dysfunction associated with this pathway.

A relation between specific immune status indicators and activity of “lipid peroxidation — antioxidant defense” system in COVID-19 neonates

The 2019 coronavirus infection (COVID-19) has not been considered as a solved issue for public health. Pregnant women and newborns are specifically vulnerable to COVID-19 infection compared to older children and healthy young adults. Virtually no data on relation between diverse arms of immunity in patients in neonatal period and coronavirus infection are available. The obtained results can contribute to a better understanding of the pathogenetic mechanisms on reactivity of immune processes in young patients and corresponding formation of approaches for prevention and correction of such disorders. The aim of the study was to determine magnitude of specific altered parameters in immune system and their relation with lipid peroxidation parameters in COVID-19 newborns. Two groups of newborns (mean age 43.1 days) were examined: SARS-CoV-2-positive (COVID-19 patients, n = 44) and negative (control group, n = 80) PCR test of nasopharyngeal swab. All newborns were assessed for specific indicators of peripheral blood immune status and lipid peroxidation activity. The concentration of Th1-pro-inflammatory cytokines and Th2-anti-inflammatory interleukins was assessed by enzyme immunoassay method (a panel of monoclonal antibodies). Spectrophotometric, fluorometric and enzyme immunoassay methods to evaluate the lipid peroxidation system were used. According to our data, newborns with COVID-19 vs. healthy newborns had decreased CRP, pro-inflammatory cytokines TNF, IL-1, IL-6, IL-8, and anti-inflammatory factor (IL-4). Change in lipid peroxidation system in children with COVID-was 19 related to higher level of DC, KD and CT, TBARs, increased SOD activity and reduced GPO. Numerous intersystem dependencies in the group of newborns with COVID-19 (CRP Total AOA, IL-4 KD and CT, IL-4 TBARs, IL-4 Total AOA, IL-4 SOD, IL-8 SOD, IFN GSH) were noted. It can be concluded that in newborns with COVID-19, changes in the immune system are nonspecific and are accompanied by an increased intensity of lipid peroxidation reactions against the background of reduced values of pro- and anti-inflammatory cytokines. These results may contribute to a more accurate assessment of intensity and dynamics of emerging neonatal coronavirus infection, which should be an important arm in preventing subsequent complications.

Post-Effects of Time-Restricted Feeding against Adipose Tissue Inflammation and Insulin Resistance in Obese Mice.

Time-restricted feeding (TRF) has been shown to improve the disordered metabolic and immunologic functions associated with obesity, however little is known about its post-effects after the cessation of TRF practice. In the current study, we determined how long the effects of TRF persist, and whether the effects are tissue-dependent. There were four groups of mice in this study: overweight and obese mice were randomized into (1) TRF group (TRF for 6 weeks), (2) post-TRF group (TRF for 4 weeks and later ad libitum), (3) continuous ad libitum of high-fat diet (HFD-AL), and (4) the lean control-fed low-fat diet ad libitum. Blood, liver, and adipose tissues were collected to measure the metabolic, inflammatory, and immune cell parameters. The results showed that TRF withdrawal quickly led to increased body weight/adiposity and reversed fasting blood glucose. However, fasting insulin and insulin resistance index HOMA-IR remained lower in the post-TRF than in the HFD-AL group. In addition, TRF-induced reduction in blood monocytes waned in the post-TRF group, but the TRF effects on mRNA levels of proinflammatory immune cells (macrophages Adgre1 and Itgax) and cytokine (Tnf) in adipose tissue remained lower in the post-TRF group than in the HFD-AL group. Furthermore, the TRF group was protected from the down-regulation of Pparg mRNA expression in adipose tissue, which was also observed in the post-TRF group to a lesser extent. The post-TRF animals displayed liver mass similar to those in the TRF group, but the TRF effects on the mRNA of inflammation markers in the liver vanished completely. Together, these results indicate that, although the lasting effects of TRF may differ by tissues and genes, the impact of TRF on adipose tissue inflammation and immune cell infiltration could last a couple of weeks, which may, in part, contribute to the maintenance of insulin sensitivity even after the cessation of TRF.

Insight into crystal structures and identification of potential styrylthieno[2,3-b]pyridine-2-carboxamidederivatives against COVID-19 Mpro through structure-guided modeling and simulation approach

Anti-SARS-CoV-2 drugs are urgently needed to prevent the pandemic and for immunization. Their protease inhibitor treatment for COVID-19 has been used in clinical trials. In Calu-3 and THP1 cells, 3CL SARS-CoV-2 Mpro protease is required for viral expression, replication, and the activation of the cytokines IL-1, IL-6, and TNF-. The Mpro structure was chosen for this investigation because of its activity as a chymotrypsin-like enzyme and the presence of a cysteine-containing catalytic domain. Thienopyridine derivatives increase the release of nitric oxide from coronary endothelial cells, which is an important cell signaling molecule with antibacterial activity against bacteria, protozoa, and some viruses. Using DFT calculations, global descriptors are computed from HOMO-LUMO orbitals; the molecular reactivity sites are analyzed from an electrostatic potential map. NLO properties are calculated, and topological analysis is also part of the QTAIM studies. Both compounds 1 and 2 were designed from the precursor molecule pyrimidine and exhibited binding energies (-14.6708 kcal/mol and −16.4521 kcal/mol). The binding mechanisms of molecule 1 towards SARS-COV-2 3CL Mpro exhibited strong hydrogen bonding as well as Vdw interaction. In contrast, derivative 2 was bound to the active site protein’s active studied that several residues and positions, including (His41, Cys44, Asp48, Met49, Pro52, Tyr54, Phe140, Leu141, Ser144, His163, Ser144, Cys145, His164, Met165, Glu166, Leu167, Asp187, Gln189, Thr190, and GLn192) are critical for the maintenance of inhibitors inside the active pocket. Molecular docking and 100 ns MD simulation analysis revealed that Both compounds 1 and 2 with higher binding affinity and stability toward the SARS-COV-2 3CL Mpro protein. Binding free energy calculations and other MD parameters support the finding. Communicated by Ramaswamy H. Sarma

Investigating the role of "Immature Myeloid Cells" as Drivers of Inflammation and Disease Persistence in Psoriatic Arthritis.

Despite the development of treatments targeting T cell co-stimulation and cytokines TNF, IL-12/23, and IL-17, less than half of patients within clinical trials achieve high levels of clinical response. This fact, as well as the absence of prognostic biomarkers represents major unmet clinical needs that necessitate further investigation of the disease pathophysiology. Myeloid cells are critical components of PsA inflammatory mechanisms, being a highly prevalent immune population in biopsies of PsA target tissues, such as the skin and the synovium. Through their antigen-presenting capacity and their pro-angiogenic and pro-inflammatory properties myeloid cells could contribute to persistent inflammation in PsA leading to treatment-resistant disease. To this end, we have recently shown the expansion of monocytes in the blood of PsA patients compared to healthy subjects. Importantly, we have also identified an immature myeloid cell population in patients with highly active, refractory disease, indicating the presence of an "emergency myelopoiesis" process in PsA. In this research protocol, we aim to decipher the pro-inflammatory "myeloid signature" in patients with active PsA and explore the role of immature myeloid cells in disease pathophysiology and their potential as prognostic biomarkers. To address this, we will isolate and analyse monocytes and immature myeloid cells from PsA patients -before and after a 6-month treatment course- focusing on differences between responders and non-responders. In this context, we will perform a thorough phenotypic and functional analysis of these cells, identify their expression signature in an already established whole blood RNA-seq dataset and investigate their presence in target tissues, such as the skin and synovial fluid. This study will elucidate the role of myeloid cells in disease propagation by further defining the involvement of immature myeloid cells in PsA.

Itaconate-mediated inhibition of succinate dehydrogenase regulates cytokine production in LPS-induced inflammation

Itaconate is an immunoregulatory metabolite produced by myeloid cells and plays a key role in the regulation of the immune response. Itaconate, on the one hand, is able to suppress the activity of succinate dehydrogenase (SDH), thereby making a significant contribution to the metabolic reprogramming of the cell. On the other hand, itaconate can regulate the activity of a number of transcription factors and transcription regulators, thereby affecting gene expression. In most experimental studies, itaconate has been characterized predominantly as an anti-inflammatory agent. In particular, itaconate produced by activated macrophages inhibits the production of cytokines TNF, IL-1b, IL-6, IL-10. However, some evidence suggests a pro- inflammatory role for itaconate in a number of mouse disease models. Thus, the deletion of the Acod1 gene responsible for the production of itaconate leads to the suppression of the production of TNF and IL-6 in the mouse polymicrobial sepsis model, which means that in the context of inflammation in vivo, itaconate can act as an inducer of pro-inflammatory cytokines. The mechanism of itaconate regulation of cytokine production in systemic inflammation remains unexplored. In this work, we have shown that injection of itaconate and its derivative dimethyl itaconate into mice, followed by induction of inflammation by bacterial lipopolysaccharide (LPS), leads to changes in the content of cytokines in the blood. Interestingly, the systemic production of IL-6 and IL-10 in response to itaconate is increased, contrary to the results previously obtained in cell cultures. At the same time, IFNg production, on the contrary, is suppressed. Apparently, itaconate regulates the production of cytokines in vivo by suppressing the activity of SDH. Injection of the SDH inhibitor, dimethylmalonate, followed by induction of inflammation in mice, results in similar changes in blood cytokines observed in response to itaconate: increased production of IL-6, IL-10 and suppression of IFNg production. On the contrary, the addition of succinate, a SDH substrate, leads to the opposite effect on cytokine production. Thus, it can be assumed that the observed effects of itaconate on cytokine production in the model of LPS-induced inflammation are mediated by its ability to inhibit SDH. These results help to understand the controversial role of itaconate in inflammation and shed light on a previously undescribed relationship between SDH and cytokine production in inflammation in vivo.

In vivo CRISPR screens reveal Serpinb9 and Adam2 as regulators of immune therapy response in lung cancer

How the genetic landscape governs a tumor’s response to immunotherapy remains poorly understood. To assess the immune-modulatory capabilities of 573 genes associated with altered cytotoxicity in human cancers, here we perform CRISPR/Cas9 screens directly in mouse lung cancer models. We recover the known immune evasion factors Stat1 and Serpinb9 and identify the cancer testis antigen Adam2 as an immune modulator, whose expression is induced by KrasG12D and further elevated by immunotherapy. Using loss- and gain-of-function experiments, we show that ADAM2 functions as an oncogene by restraining interferon and TNF cytokine signaling causing reduced presentation of tumor-associated antigens. ADAM2 also restricts expression of the immune checkpoint inhibitors PDL1, LAG3, TIGIT and TIM3 in the tumor microenvironment, which might explain why ex vivo expanded and adoptively transferred cytotoxic T-cells show enhanced cytotoxic efficacy in ADAM2 overexpressing tumors. Together, direct in vivo CRISPR/Cas9 screens can uncover genetic alterations that control responses to immunotherapies.

A frameshift variant in the SIRPB1 gene confers susceptibility to Crohn's disease in a Chinese population.

Background: Crohn's disease (CD), a chronic gastrointestinal inflammatory disease, is increasing in China. With a focus on Han Chinese families with CD, the aim of this study was to find genetic variations that increase CD susceptibility by genome sequencing, genetic association, expression, and functional research. Materials and methods: We performed family-based genome sequencing (WGS) analysis on 24 patients with CD from 12 families and then filtered shared potential causal variants by incorporating association results from meta-analyses of CD GWAS and immunology genes and in silico variant effect prediction algorithms. Replication analyses were performed in an independent cohort including 381 patients with CD and 381 control subjects. Results: There were 92 genetic variants significantly associated with CD in Chinese individuals. Among them, 61 candidate loci were validated in replication analyses. As a result, patients carrying a rare frameshift variant (c.1143_1144insG; p. Leu381_Leu382fs) in gene SIRPB1 had significantly higher risk to develop CD (p = 0.03, OR 4.59, 95% CI 0.98-21.36, 81.82% vs. 49.53%). The frameshift variation induced tyrosine phosphorylation of Syk, Akt, and Jak2, elevated the expression of SIRPB1 at the mRNA and protein levels, activated DAP12, and controlled the activation of NF-κB in macrophages. Additionally, it promoted the synthesis of the pro-inflammatory cytokines IL-1, TNF-, and IL-6. Conclusion: Our results suggest that the rare gain-of-function frameshift variant in SIRPB1 is associated in Han Chinese patients with CD. The functional mechanism of SIRPB1 and its downstream inflammatory pathways was preliminarily explored in CD.

The expression IL1B correlates negatively with the clinical response to adalimumab in Crohn's disease patients: An ex vivo approach using peripheral blood mononuclear cells

AimsUnderstanding of the molecular mechanisms of anti-TNFα therapy non-response and reliable biomarkers are essential for personalized medicine in Crohn's disease (CD) patients. Using RNA-seq data adjusted for deconvoluted fractions of peripheral blood cells, we recently described MMD gene, coding for a monocyte to macrophage differentiation factor, as a biomarker of adalimumab (anti-TNFα) therapy response in CD. The results also suggest that cell subtype-specific biomarkers may be superior to those measured in bulk peripheral blood. Here, we used functional cell model to further investigate the role of the monocyte to macrophage differentiation in adalimumab treatment response and evaluate monocyte/macrophage specific expression of the inflammatory cytokines as potential biomarkers for (non)response to adalimumab in CD patients. Main methodsThe peripheral monocytes of CD patients responsive and non-responsive to adalimumab were isolated, differentiated into macrophages, and exposed to inflammation and concurrent adalimumab therapy in vitro. The results were correlated to the clinical response of the donor patients. Key findingsCorrelation is shown of the expression of two macrophage differentiation related genes- CD68 and MMD, with the expression of the inflammatory cytokines TNF, IL1B, IL6 and CXCL8. Monocytes and in vitro differentiated macrophages of adalimumab non-responders express more inflammatory cytokines than those of responders. The biggest difference was in the IL1B expression. Additionally, IL1B expression in the in vitro differentiated macrophages of CD patients correlates negatively with their clinical response to adalimumab. SignificanceWe propose the IL1B expression in the macrophages as a possible biomarker for adalimumab response in CD patients.

Complement C4-deficient mice have a high mortality rate during PTZ-induced epileptic seizures, which correlates with cognitive problems and the deficiency in the expression of Egr1 and other immediate early genes.

Complement system plays an important role in the immune defense against pathogens; however, recent studies demonstrated an important role of complement subunits C1q, C4, and C3 in normal functions of the central nervous system (CNS) such as non-functional synapse elimination (synapse pruning), and during various neurologic pathologies. Humans have two forms of C4 protein encoded by C4A and C4B genes that share 99.5% homology, while mice have only one C4B gene that is functionally active in the complement cascade. Overexpression of the human C4A gene was shown to contribute to the development of schizophrenia by mediating extensive synapse pruning through the activation C1q-C4-C3 pathway, while C4B deficiency or low levels of C4B expression were shown to relate to the development of schizophrenia and autism spectrum disorders possibly via other mechanisms not related to synapse elimination. To investigate the potential role of C4B in neuronal functions not related to synapse pruning, we compared wildtype (WT) mice with C3- and C4B- deficient animals for their susceptibility to pentylenetetrazole (PTZ)- induced epileptic seizures. We found that C4B (but not C3)-deficient mice were highly susceptible to convulsant and subconvulsant doses of PTZ when compared to WT controls. Further gene expression analysis revealed that in contrast to WT or C3-deficient animals, C4B-deficient mice failed to upregulate expressions of multiple immediate early genes (IEGs) Egrs1-4, c-Fos, c-Jus, FosB, Npas4, and Nur77 during epileptic seizures. Moreover, C4B-deficient mice had low levels of baseline expression of Egr1 on mRNA and protein levels, which was correlated with the cognitive problems of these animals. C4-deficient animals also failed to upregulate several genes downstream of IEGs such as BDNF and pro-inflammatory cytokines IL-1β, IL-6, and TNF. Taken together, our study demonstrates a new role of C4B in the regulation of expression of IEGs and their downstream targets during CNS insults such as epileptic seizures.

Intravenous BCG Induction of Innate Memory in Young Pigs

Abstract Exposure to vaccine strain of Mycobacterium bovis(M. bovis), Bacillus Calmette-Guerin (BCG), alters innate immune cells through epigenetic and metabolic modifications resulting in heightened responses to subsequent microbial insult (innate memory). As a biomedical model for human disease, pigs provide a critical space to study the role of innate memory in disease resistance. Young pigs were inoculated intravenous (IV) or intraperitoneal (IP) with either live or heat-inactivated BCG (IV-live, IP-live, IV-inactive, noBCG groups). At 2wks post BCG inoculation, monocyte production of IL-1β nor TNF cytokines following ex vivostimulation with LPS was not different in any BCG group compared to noBCG, i.e. no innate memory. As dose of live BCG was lower than anticipated, at 3wks post primary inoculation, all pigs were inoculated a second time with respective preparations and routes of BCG. Ex vivocytokine production in LPS stimulated monocytes was measured again at 5wks post primary inoculation (2wks post-secondary inoculation) and both IL-1β and TNF cytokines were elevated in IV-live (innate memory), but not IP-live or IV-inactive groups. Additionally, ex vivostimulation of PBMC with homologous recall antigen (purified proteins from M. bovis) resulted in a 3-fold higher IFNγ response in IP-live compared to IV-live and no IFNγ production in noBCG or IV-inactive. Together these data suggest that while BCG can induce a state of innate memory in monocytes of young pigs, induction of training cannot be inferred by T cell production of IFNγ to recall protein antigen. Additionally, data continue to highlight pigs as a valuable model as multiple BCG factors (i.e. route, dose, or viability) may need to be considered for induction of innate memory. USDA-ARS CRIS project 5030-32000-225-000D

Discovery of a molecular clock that controls CD8+ T cell function and exhaustion

Abstract During cancer and chronic viral infections, the persistence of antigen progressively causes CD8+ T cells to differentiate into a dysfunctional PD1+ “exhausted” state, with reduced production of inflammatory cytokines relative to effector cells that form during acute infections. Antigen and costimulation signals activate kinase cascades to induce distinct T cell transcription programs, but how T cells distinguish acute and chronic signals to program the exhausted or effector transcriptional states remains poorly understood. We found that members of the protein kinase C (PKC) family function together as a “molecular clock,” sensing acute or chronic agonism to drive distinct transcriptional programs. Continuous stimulation of PKC induces many features of T cell exhaustion, including a loss of production of the cytokines IFNγ and TNF, upregulation of inhibitory receptors and TOX, and altered expression of the proteins in the AP-1 family. Mechanistically, CD8+ T cells express several different PKC proteins, and chronic agonism of PKC leads to degradation of multiple family members and selective maintenance of only one PKC protein, PKC-η. This “PKC switch” alters downstream signaling to support the transcriptional reprogramming of T cells into a terminally exhausted state. In summary, continuous signaling through PKCs causes changes in the output from these kinases initially at the protein level, driving transcriptional changes downstream of PKC targets in the AP-1 transcription factor family and thus allowing further widespread transcriptional and functional changes that characterize T cell exhaustion. Supported by a Damon Runyon Cancer Research Fellowship (DRG-2358-19) and an NIH training grant, T32-CA009370.

Analysis of leukogram parameters and blood cytokine profile in tick-borne infections of various etiologies

Introduction. Studies aimed at identifying pathogenetic features of tick-borne natural focal infections depending on etiological agent are relevant to seek out for new associations of biomarkers characterizing the structural and functional phenotype of immune cells significant for the differential diagnosis and prognosis of diseases. The aim of the study was to evaluate the parameters of a leukogram with an expanded profile in relation to the parameters of cytokine status in patients with viral tick-borne encephalitis as well as erythemic tick-borne borreliosis at acute stage of the disease. Materials and methods. The study involved 28 patients with the non-erythemic tick-borne borreliosis and 27 patients with tick-borne encephalitis at the acute stage of the disease, as well as 16 healthy individuals (control group). Venous blood samples were examined using a Sysmex XN1000 analyzer based on reflex testing technology with extended profile allowing to characterize leukocyte reaction during infection and inflammation, including parameters such as the absolute and relative count of immature granulocytes (IG), neutrophil granularity index (NEUT-GI), neutrophil reactivity index (NEUT-RI), count of reactive lymphocytes (RE-LYMP), count of antibody-producing lymphocytes (AS-LYMP). Concentrationof IL-2, IL-4, IL-6, IL-8, IL-10, IFN and TNF in blood serum was determined by enzyme immunoassay using specific reagent kits (Vector-Best, Russia). Results. It was found that changes in the quantitative composition of blood leukocytes in patients with viral tick-borne encephalitis and non-erythemic form of tick-borne borreliosis have a unidirectional tendency characterized by increased count of metabolically active neutrophils (NEUT-RI) and a decreased count of reactive lymphocytes (RE-LYMP) compared to healthy individuals. Changes in the leukogram occur along with high blood concentration of proinflammatory cytokines IL-8 and TNF and a low level of IFN. A positive direct correlation was revealed between the fluorescence intensity parameter characterizing the metabolic activity of neutrophil granulocytes (NEUT-RI) and blood serum IL-8 level both in tick-borne encephalitis (r = 0.422, p 0.05) and non-erythemic form of tick-borne borreliosis (r = 0.551, p 0.05). Additionally, in the former, a positive correlation was established between the total leukocyte count (WBC) and concentration of TNF in the blood serum (r = 0.532, p 0.05).

Single-cell RNA sequencing deciphers the mechanism of sepsis-induced liver injury and the therapeutic effects of artesunate.

Liver, as an immune and detoxification organ, represents an important line of defense against bacteria and infection and a vulnerable organ that is easily injured during sepsis. Artesunate (ART) is an anti-malaria agent, that also exhibits broad pharmacological activities including anti-inflammatory, immune-regulation and liver protection. In this study, we investigated the cellular responses in liver to sepsis infection and ART hepatic-protective mechanisms against sepsis. Cecal ligation and puncture (CLP)-induced sepsis model was established in mice. The mice were administered ART (10 mg/kg, i.p.) at 4 h, and sacrificed at 12 h after the surgery. Liver samples were collected for preparing single-cell RNA transcriptome sequencing (scRNA-seq). The scRNA-seq analysis revealed that sepsis-induced a dramatic reduction of hepatic endothelial cells, especially the subtypes characterized with proliferation and differentiation. Macrophages were recruited during sepsis and released inflammatory cytokines (Tnf, Il1b, Il6), chemokines (Ccl6, Cd14), and transcription factor (Nfkb1), resulting in liver inflammatory responses. Massive apoptosis of lymphocytes and abnormal recruitment of neutrophils caused immune dysfunction. ART treatment significantly improved the survival of CLP mice within 96 h, and partially relieved or reversed the above-mentioned pathological features, mitigating the impact of sepsis on liver injury, inflammation, and dysfunction. This study provides comprehensive fundamental proof for the liver protective efficacy of ART against sepsis infection, which would potentially contribute to its clinical translation for sepsis therapy. Single cell transcriptome reveals the changes of various hepatocyte subtypes of CLP-induced liver injury and the potential pharmacological effects of artesunate on sepsis.

Abstract 5749: Core transcriptional regulatory circuitry in AML

Abstract Cell states are established by small sets of lineage-restricted transcription factors (TFs). A generally accepted model posits that core regulatory TFs positively regulate their own and each other’s genes, forming a network of interconnected feed-forward loops termed core regulatory circuitry (CRC). Here, we sought to test the CRC concept by defining the direct gene-regulatory programs of the critical oncogenic TFs in acute myeloid leukemia (AML). We employed a targeted protein degradation (dTag) strategy with a homozygous knock-in of the FKBP12F36V-coding DNA sequence into the endogenous TF-coding loci of 7 core myeloid TFs and 1 cofactor (MYB, PU.1/SPI1, GFI1, RUNX1, RUNX2, MEF2D, IRF8, IRF2BP2), all of which represent selective AML dependencies and display the canonical pattern of feed-forward CRC binding. Following complete degradation of TFs for 1-2 hours, we measured the genome-wide rates of nascent mRNA synthesis by SLAM-seq. Genes whose transcription rates change significantly and immediately after a TF’s degradation represent its direct transcriptional targets. Strikingly, each TF directly regulates only between 100-450 target genes. Furthermore, rather than forming a core regulatory circuit with fully interconnected feed-forward loops, the core TFs form a very sparsely interconnected hierarchy with a cascading regulatory structure. Each evaluated TF is capable of both direct gene activation and repression. For instance, MYB directly inhibits 135 genes, most of which are associated with myeloid differentiation and inflammation. Feed-forward loops appear to be much less common than previously anticipated. Indeed, we detected only 336 feed-forward loops formed by any combination of the 8 TFs genome-wide. GFI1 and IRF2BP2 negatively regulate their own expression, and the rest of the TFs show no evidence of direct self-regulation. The entire regulatory network converges on MYC and immune signaling. A time-course SLAM-seq experiment after MYB degradation highlighted the secondary nature of eventual global transcriptional collapse and revealed bi-phasic kinetic behavior of feed-forward loops that MYB forms with GFI1 and IRF2BP2. A pseudo-steady state of cellular transcription, ensuing 8-12 hours after MYB degradation, accurately predicts MYB-dependent gene expression patterns in human AML samples. Indeed, a much higher expression of inflammatory mediators and cytokines is observed in patients with low MYB expression, consistent with the observation that MYB directly regulates inflammatory pathways and potentially explaining the known survival benefit of high MYB expression in human AML. Accordingly, MYB degradation results in immediate release of the pro-inflammatory cytokines TNF and CCL2. Our data represent the first example of systematic elucidation of direct regulatory functions of multiple core regulatory TFs in a single cellular context and support a new model of core regulatory circuitry organization in human cells. Citation Format: Taku Harada, Monika Perez, Jeremie Kalfon, Kenneth Eagle, Flora Dievenich Braes, Rashad Batley, Kimberly Stegmaier, Stuart Orkin, Maxim Pimkin. Core transcriptional regulatory circuitry in AML. [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 5749.

Plant Polyphenol Gossypol Induced Cell Death and Its Association with Gene Expression in Mouse Macrophages

Gossypol is a complex plant polyphenol reported to be cytotoxic and anti-inflammatory, but little is known about its effect on gene expression in macrophages. The objective of this study was to explore gossypol's toxicity and its effect on gene expression involved in the inflammatory response, glucose transport and insulin signaling pathways in mouse macrophages. Mouse RAW264.7 macrophages were treated with multiple concentrations of gossypol for 2-24 h. Gossypol toxicity was estimated by MTT assay and soluble protein content. qPCR analyzed the expression of anti-inflammatory tristetraprolin family (TTP/ZFP36), proinflammatory cytokine, glucose transporter (GLUT) and insulin signaling genes. Cell viability was greatly reduced by gossypol, accompanied with a dramatic reduction in soluble protein content in the cells. Gossypol treatment resulted in an increase in TTP mRNA level by 6-20-fold and increased ZFP36L1, ZFP36L2 and ZFP36L3 mRNA levels by 26-69-fold. Gossypol increased proinflammatory cytokine TNF, COX2, GM-CSF, INFγ and IL12b mRNA levels up to 39-458-fold. Gossypol treatment upregulated mRNA levels of GLUT1, GLUT3 and GLUT4 genes as well as INSR, AKT1, PIK3R1 and LEPR, but not APP genes. This study demonstrated that gossypol induced macrophage death and reduced soluble protein content, which was accompanied with the massive stimulation of anti-inflammatory TTP family and proinflammatory cytokine gene expression, as well as the elevation of gene expression involved in glucose transport and the insulin signaling pathway in mouse macrophages.