Higher Levels Of IL-10 Research Articles

Immunological balance between Treg and Th17 lymphocytes as a key element of type 1 diabetes progression in children.

Type 1 diabetes (T1D) is autoimmune destruction of the beta cells of pancreatic islets. Due to complexity of that disease, the mechanisms leading to the tolerance breakdown are still not fully understood. Previous hypothesis of imbalance in the Th1 and Th2 cells as the main contributing factor has been recently changed towards role of other lymphocytes – regulatory (Treg) and IL-17A-producing (Th17). Our study aims to assess changes within Treg and Th17 cells in newly diagnosed T1D pediatric patients and their association with disease remission. Flow cytometry implementation allowed for Treg and Th17 analysis in studied groups and further combination with clinical and laboratory data. In addition, expression of diabetes-related genes was tested and evaluated in context of their association with studied lymphocytes. Initial results revealed that Treg and ratio Treg/Th17 are significantly higher in T1D than in healthy controls. Moreover, patients with lower HbA1c and daily insulin requirements demonstrated higher levels of Tregs. Similar tendency for insulin intake was also observed in reference to Th17 cells, together with high levels of these cells in patients demonstrating higher values for c-peptide after 2 years. In low-level Treg patients, that subset correlates with the c-peptide in the admission stage. In addition, higher levels of IL-10 were associated with its correlation with HbA1c and insulin dosage. In the context of gene expression, moderate associations were demonstrated in T1D subjects inter alia between CTLA4 and Treg or ratio Treg/Th17. Cumulatively, our data indicate a possible novel role of Treg and Th17 in mechanism of type 1 diabetes. Moreover, potential prognostic value of these populations has been shown in reference to diabetes remission.

Macrophage migration inhibitory factor contributes to immunopathogenesis during Plasmodium yoelii 17XL infection.

Macrophage migration inhibitory factor (MIF) is a cytokine recognized regulator of the inflammatory immune response associated with several immune cells that produce inflammatory cytokines such as IL-1β, IL-6, IL-12, IL-18, and TNF-α. This study aimed to understand the effect of MIF on the immune response and pathogenesis during Plasmodium infection. Wild-type (Wt) and MIF knockout (Mif -/-) mice were intravenously infected with 1×103 Plasmodium yoelii (Py) 17XL-parasitized red blood cells. Our data showed that Py17XL-infected Wt mice died 11 days postinfection, while Mif -/- mice showed reduced parasitemia and an increase in their survival at day 11 up to 58%, importantly they succumb up to day 21 postinfection. The increased survival rate in Mif -/- mice was associated with less severe cachexia and anemia as a result of a mixed Th1/Th2 cytokine profile, high levels of IL-12, IL-17/IL-4, and IL-10 in serum; and high levels of IL-4 and IL-10, and low levels of IFN-γ in spleen cells compared to Py17XL infected Wt mice. Moreover, macrophages (Mφs) from Mif -/- mice exhibited higher concentrations of IL-10 and IL-12 and reduced levels of TNF-α and nitric oxide (NO) compared to Py17XL-infected Wt mice. These results demonstrate that MIF has an important role in regulating the immune response associated with host pathogenesis and lethality, which is relevant to consider in preventing/reducing complications in Plasmodium infections.

Interleukin-10 levels and the risk of thromboembolism according to COMPASS-Cancer associated thrombosis score in breast cancer patients prior to undergoing doxorubicin-based chemotherapy.

Venous thromboembolism (VTE) is an important cause of morbidity/mortality in cancer patients, and COMPASS-CAT score must be used to VTE-risk prediction. There is a relationship between cytokines and thrombus formation and/or resolution. This study aimed to investigate the VTE risk and cytokines level in breast cancer patients prior to chemotherapy with doxorubicin (DOXO). Eighty women with breast cancer and indication for DOXO treatment were selected. TNF, IL-1β, IL-6, and IL-10 were measured after the diagnosis and immediately before DOXO treatment. All 80 patients presented a high risk for VTE when evaluated by COMPASS-CAT model (score ≥7). A positive correlation was observed between IL-10 plasma levels and VTE risk score. Our data showed that higher IL-10 levels before chemotherapy are associated to increased risk of VTE in breast cancer patients. This finding suggests that IL-10 levels and the combination with COMPASS-CAT score could be good markers to predict increased risk of VTE in these patients.

A Recombinant Chimeric Protein-Based Vaccine Containing T-Cell Epitopes from Amastigote Proteins and Combined with Distinct Adjuvants, Induces Immunogenicity and Protection against Leishmania infantum Infection.

Currently, there is no licensed vaccine to protect against human visceral leishmaniasis (VL), a potentially fatal disease caused by infection with Leishmania parasites. In the current study, a recombinant chimeric protein ChimT was developed based on T-cell epitopes identified from the immunogenic Leishmania amastigote proteins LiHyp1, LiHyV, LiHyC and LiHyG. ChimT was associated with the adjuvants saponin (Sap) or monophosphoryl lipid A (MPLA) and used to immunize mice, and their immunogenicity and protective efficacy were evaluated. Both ChimT/Sap and ChimT/MPLA induced the development of a specific Th1-type immune response, with significantly high levels of IFN-γ, IL-2, IL-12, TNF-α and GM-CSF cytokines produced by CD4+ and CD8+ T cell subtypes (p < 0.05), with correspondingly low production of anti-leishmanial IL-4 and IL-10 cytokines. Significantly increased (p < 0.05) levels of nitrite, a proxy for nitric oxide, and IFN-γ expression (p < 0.05) were detected in stimulated spleen cell cultures from immunized and infected mice, as was significant production of parasite-specific IgG2a isotype antibodies. Significant reductions in the parasite load in the internal organs of the immunized and infected mice (p < 0.05) were quantified with a limiting dilution technique and quantitative PCR and correlated with the immunological findings. ChimT/MPLA showed marginally superior immunogenicity than ChimT/Sap, and although this was not statistically significant (p > 0.05), ChimT/MPLA was preferred since ChimT/Sap induced transient edema in the inoculation site. ChimT also induced high IFN-γ and low IL-10 levels from human PBMCs isolated from healthy individuals and from VL-treated patients. In conclusion, the experimental T-cell multi-epitope amastigote stage Leishmania vaccine administered with adjuvants appears to be a promising vaccine candidate to protect against VL.

Placental Malaria is Associated with Higher LILRB2 Expression in Monocyte Subsets and Lower Anti-Malarial IgG Antibodies During Infancy.

BackgroundPlacental malaria (PM) is associated with a higher susceptibility of infants to Plasmodium falciparum (Pf) malaria. A hypothesis of immune tolerance has been suggested but no clear explanation has been provided so far. Our goal was to investigate the involvement of inhibitory receptors LILRB1 and LILRB2, known to drive immune evasion upon ligation with pathogen and/or host ligands, in PM-induced immune tolerance.MethodInfants of women with or without PM were enrolled in Allada, southern Benin, and followed-up for 24 months. Antibodies with specificity for five blood stage parasite antigens were quantified by ELISA, and the frequency of immune cell subsets was quantified by flow cytometry. LILRB1 or LILRB2 expression was assessed on cells collected at 18 and 24 months of age.FindingsInfants born to women with PM had a higher risk of developing symptomatic malaria than those born to women without PM (IRR=1.53, p=0.040), and such infants displayed a lower frequency of non-classical monocytes (OR=0.74, p=0.01) that overexpressed LILRB2 (OR=1.36, p=0.002). Moreover, infants born to women with PM had lower levels of cytophilic IgG and higher levels of IL-10 during active infection.InterpretationModulation of IgG and IL-10 levels could impair monocyte functions (opsonisation/phagocytosis) in infants born to women with PM, possibly contributing to their higher susceptibility to malaria. The long-lasting effect of PM on infants’ monocytes was notable, raising questions about the capacity of ligands such as Rifins or HLA-I molecules to bind to LILRB1 and LILRB2 and to modulate immune responses, and about the reprogramming of neonatal monocytes/macrophages.

Cytokine Profiles Associated With Acute COVID-19 and Long COVID-19 Syndrome.

The duration and severity of COVID-19 are related to age, comorbidities, and cytokine synthesis. This study evaluated the impact of these factors on patients with clinical presentations of COVID-19 in a Brazilian cohort. A total of 317 patients diagnosed with COVID-19 were included; cases were distributed according to clinical status as severe (n=91), moderate (n=56) and mild (n=170). Of these patients, 92 had acute COVID-19 at sample collection, 90 had already recovered from COVID-19 without sequelae, and 135 had sequelae (long COVID syndrome). In the acute COVID-19 group, patients with the severe form had higher IL-6 levels (p=0.0260). In the post-COVID-19 group, there was no significant difference in cytokine levels between groups with different clinical conditions. In the acute COVID-19 group, younger patients had higher levels of TNF-α, and patients without comorbidities had higher levels of TNF-α, IL-4 and IL-2 (p<0.05). In contrast, patients over age 60 with comorbidities had higher levels of IL-6. In the post-COVID-19 group, subjects with long COVID-19 had higher levels of IL-17 and IL-2 (p<0.05), and subjects without sequelae had higher levels of IL-10, IL-6 and IL- 4 (p<0.05). Our results suggest that advanced age, comorbidities and elevated serum IL-6 levels are associated with severe COVID-19 and are good markers to differentiate severe from mild cases. Furthermore, high serum levels of IL-17 and IL-2 and low levels of IL-4 and IL-10 appear to constitute a cytokine profile of long COVID-19, and these markers are potential targets for COVID-19 treatment and prevention strategies.

CD137 Costimulation Enhances the Antitumor Activity of Vγ9Vδ2-T Cells in IL-10-Mediated Immunosuppressive Tumor Microenvironment.

Although γδ-T cell-based tumor immunotherapy using phosphoantigens to boost γδ-T cell immunity has shown success in some cancer patients, the clinical application is limited due to the rapid exhaustion of Vγ9Vδ2-T cells caused by repetitive stimulation from phosphoantigens and the profoundly immunosuppressive tumor microenvironment (TME). In this study, using a cell culture medium containing human and viral interleukin-10 (hIL-10 and vIL-10) secreted from EBV-transformed lymphoblastoid B cell lines (EBV-LCL) to mimic the immunosuppressive TEM, we found that the antitumor activity of Vγ9Vδ2-T cells was highly suppressed by endogenous hIL-10 and vIL-10 within the TME. CD137 costimulation could provide an anti-exhaustion signal to mitigate the suppressive effects of IL-10 in TME by suppressing IL-10R1 expression on Vγ9Vδ2-T cells. CD137 costimulation also improved the compromised antitumor activity of Vγ9Vδ2-T cells in TME with high levels of IL-10 in Rag2-/- γc-/- mice. In humanized mice, CD137 costimulation boosted the therapeutic effects of aminobisphosphonate pamidronate against EBV-induced lymphoma. Our study offers a novel approach to overcoming the obstacle of the hIL-10 and vIL-10-mediated immunosuppressive microenvironment by costimulating CD137 and enhancing the efficacy of γδ-T cell-based tumor therapy.

Effects of dietary Glycyrrhiza polysaccharide supplementation on growth performance, intestinal antioxidants, immunity and microbiota in weaned piglets

The aim of this study was to evaluate the effects of dietary Glycyrrhiza polysaccharide (GCP) supplementation on growth performance, intestinal antioxidants, immunity and microbiota in weaned piglets. One hundred and twenty 28-day-old weaned piglets were randomly assigned into five groups (four replicates per group) and fed a basal diet with GCP at 0, 500, 1000, 2000 and 4000 mg/kg for four weeks, respectively. Results showed that 1000 mg/kg GCP improved piglets’ ADG and ADFI and reduced FCR (p < .05). Thus, the 0 and 1000 mg/kg GCP dose were selected for subsequent experiments. We found that 1000 mg/GCP increased SOD and T-AOC and decreased MDA in the jejunal mucosa (p < .05). Dietary 1000 mg/kg GCP also resulted in high levels of sIgA, IL-10 and TGF-β, whereas IL-2 dropped dramatically (p < .05). The relative expression levels of ZO-1, CLDN, OCLDN, TLR-4, IL-10, TGF-β, Nrf-2, SOD1 and CAT increased in the jejunal mucosa, whereas INF-γ decreased (p < .05). 1000 mg/kg GCP treatment altered the diversity and community composition of cecal microbiota in pigs, with increasing relative abundance of Bacteroidota and Lactobacillus at phylum and genus levels (p < .05), respectively. The results suggested that dietary 1000 mg/kg GCP could improve growth performance and intestinal health of weaned piglets.

Abstract 1360: CD8 T cells display distinct trajectories of T cell exhaustion in the bone marrow of mice with multiple myeloma

Abstract Multiple myeloma (MM) is the second most common hematological malignancy and despite the developments of novel therapies, it remains largely incurable. A minority of patients do achieve durable disease control after autologous stem cell transplantation (SCT), and we previously demonstrated the induction of profound T cell-mediated myeloma-specific immunity after SCT in preclinical models. Nonetheless, in both mice and patients, myeloma progression is associated with inhibitory receptor expression on CD8 T cells in the bone marrow (BM). Characterization of CD8 T cell exhaustion and the presence of precursor exhausted T cells (TPEX) has been limited to solid tumor models. Whether CD8 T cells exhibit the same trajectory of exhaustion from TPEX in the MM BM microenvironment after SCT was hitherto unknown. This is an important clinical question as immunotherapies are largely utilized in relapsed/refractory MM and currently do not target this patient population. We performed single cell RNA sequencing in mice with relapsed MM after SCT to provide in-depth characterization of CD8 T cell differentiation and exhaustion. CD8 T cells were sorted via flow cytometry based on CD38 and CD101 expression to capture diverse stages of differentiation. Notably, CD38+CD101+ CD8 T cells have been previously described as irreversibly exhausted and represent over 50% of polyclonal CD8 T cells in our model. We performed unsupervised clustering and identified ten CD8 T cell clusters that spanned T cell differentiation, including a TPEX population with a phenotype akin to solid tumor settings. We also observed two distinct exhausted T cell clusters that both expressed Tox, Pdcd1, and lacked Tcf7 while only one cluster expressed high levels of Prdm1 (Blimp-1), Havcr2 (TIM-3), Maf and Il10. Utilizing flow cytometry, we confirmed expression of TOX and PD-1, with loss of TCF-1, in mice with relapsed MM and expression of c-Maf was largely restricted to the TIM-3+ subset. We next sought to determine whether the exhausted clusters represented degrees of exhaustion or were distinct lineages. Thus, we performed RNA velocity analysis and noted a clear trajectory from the TPEX cluster towards the two exhausted clusters, confirming a common trajectory of CD8 T cell exhaustion states across solid and hematological malignancies. Surprisingly, there was a divergence point between the exhausted clusters suggesting that these could be distinct lineages. To address this, we performed bone marrow aspirates in mice from 3 weeks post-SCT to track exhaustion phenotypes over time in myeloma-bearing mice. We observed concurrent emergence of both exhausted T cell phenotypes from early post-SCT, supporting our hypothesis that these may represent distinct T cell exhaustion lineages. These data highlight a trajectory of CD8 T cell exhaustion from precursor subsets in MM that supports the utilization of immunotherapies in the early stages of disease. Citation Format: Simone A. Minnie, Nicole S. Nemychenkov, Olivia G. Waltner, Kathleen S. Ensbey, Christine R. Schmidt, Shruti S. Bhise, Scott N. Furlan, Geoffrey R. Hill. CD8 T cells display distinct trajectories of T cell exhaustion in the bone marrow of mice with multiple myeloma [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 1360.

Deciphering the balance of IL-6/IL-10 cytokines in severe to critical COVID-19 patients

The severity of COVID-19 is largely determined by the inflammatory response, a “Cytokine storm,” that involves both pro- and anti-inflammatory cytokines. In the current study we investigated the balance of pro- and anti-inflammatory status as represented by the levels of IL-6/IL-10 in severe to critical COVID-19 patients. 66 confirmed COVID-19 patients admitted to the ICU were categorized into groups according to the mortality and respiratory failure. Data were collected retrospectively in ICU, including a peripheral immune cells and infection-related biomarker CRP. The measurements of cytokine levels were performed by Immulite analyzer for IL-6 and ELISA sandwich for IL-10. In addition, longitudinal measurement of IL-6 was performed during 5 days post admission. Longitudinal assays showed that IL-6 was sustained at a medium level within 5 days post admission in severe cases who survived or not requiring mechanical ventilation, whereas it was sustained at high levels throughout the disease course in either deceased cases or who developed respiratory failure. The ratio of IL-6/lymphocytes was positively correlated with the risk of mortality, while IL-10/lymphocytes ratio could predict respiratory failure in ICU. IL-6/IL-10 profiling revealed that deceased patients have different magnitudes of both IL-6 and IL-10 cytokine release. Notably, excessive levels of IL-6 concomitant with high levels of IL-10 were more common in diseased COVID-19 patients. Taking into account the IL-6/IL-10 profiling may help clinicians to identify the right time of anti-inflammation treatment and select patients who will respond to anti-cytokine therapies and maintain an adequate inflammatory response for SARS-CoV-2 clearance.

N-Oleoyl dopamine induces IL-10 via central nervous system TRPV1 and improves endotoxemia and sepsis outcomes

BackgroundThe transient receptor potential vanilloid 1 (TRPV1) participates in thermosensation and inflammatory pain, but its immunomodulatory mechanisms remain enigmatic. N-Oleoyl dopamine (OLDA), an endovanilloid and endocannabinoid, is a TRPV1 agonist that is produced in the central nervous system and the peripheral nervous system. We studied the anti-inflammatory effects and TRPV1-dependent mechanisms of OLDA in models of inflammation and sepsis.MethodsMice were challenged intratracheally or intravenously with LPS, or intratracheally with S. aureus to induce pneumonia and sepsis, and then were treated intravenously with OLDA. Endpoints included plasma cytokines, leukocyte activation marker expression, mouse sepsis scores, lung histopathology, and bacterial counts. The role of TRPV1 in the effects of OLDA was determined using Trpv1−/− mice, and mice with TRPV1 knockdown pan-neuronally, in peripheral nervous system neurons, or in myeloid cells. Circulating monocytes/macrophages were depleted using clodronate to determine their role in the anti-inflammatory effects of OLDA in endotoxemic mice. Levels of exogenous OLDA, and of endovanilloids and endocannabinoids, at baseline and in endotoxemic mice, were determined by LC–MS/MS.ResultsOLDA administration caused an early anti-inflammatory response in endotoxemic and septic mice with high serum levels of IL-10 and decreased levels of pro-inflammatory cytokines. OLDA also reduced lung injury and improved mouse sepsis scores. Blood and lung bacterial counts were comparable between OLDA- and carrier-treated mice with S. aureus pneumonia. OLDA’s effects were reversed in mice with pan-neuronal TRPV1 knockdown, but not with TRPV1 knockdown in peripheral nervous system neurons or myeloid cells. Depletion of monocytes/macrophages reversed the IL-10 upregulation by OLDA in endotoxemic mice. Brain and blood levels of endovanilloids and endocannabinoids were increased in endotoxemic mice.ConclusionsOLDA has strong anti-inflammatory actions in mice with endotoxemia or S. aureus pneumonia. Prior studies focused on the role of peripheral nervous system TRPV1 in modulating inflammation and pneumonia. Our results suggest that TRPV1-expressing central nervous system neurons also regulate inflammatory responses to endotoxemia and infection. Our study reveals a neuro-immune reflex that during acute inflammation is engaged proximally by OLDA acting on neuronal TRPV1, and through a multicellular network that requires circulating monocytes/macrophages, leads to the systemic production of IL-10.

Influence of progestin use on the IL-10 level in peritoneal endometriosis

Purpose: How can progestin influence the anti-inflammatory cytokine IL-10 level in the peritoneum with endometriosis? Methods: A cross-sectional study with a laboratory analysis carried out in tertiary hospitals in southern Brazil with clinical-demographic data compilation and sample collection of peritoneal lavage and a peritoneum biopsy from 40 patients — 22 with endometriosis (11 with progestin and 11 without it) and 18 in the control group — was conducted. For the sample analysis, the ELISA was performed, and a comparison of the average IL-10 concentrations by ANOVA followed by Bonferroni was carried out. Results: There was a higher concentration of IL-10 among patients with endometriosis compared to the control group (p ≤ 0.05), and statistical significance was observed with a reduction of IL-10 in the peritoneal lavage of patients with endometriosis in the use of progestin (8.1 ± 7.4 pg/ml) compared to those with endometriosis without using progestin (17.9 ± 10.5 pg/ml). Considering the disease stage, a higher level of IL-10 (p ≤ 0.05) was observed both in the initial stages (12.1 ± 10.5 pg/ml) and in advanced stages (15.4 ± 9.7 pg/ml) compared to the control (1.7 ± 1.8 pg/ml), which was significantly higher for advanced endometriosis.

The Antimicrobial Effects of Bacterial Cellulose Produced by Komagataeibacter intermedius in Promoting Wound Healing in Diabetic Mice.

As a conventional medical dressing, medical gauze does not adequately protect complex and hard-to-heal diabetic wounds and is likely to permit bacterial entry and infections. Therefore, it is necessary to develop novel dressings to promote wound healing in diabetic patients. Komagataeibacter intermedius was used to produce unmodified bacterial cellulose, which is rarely applied directly to diabetic wounds. The produced cellulose was evaluated for wound recovery rate, level of inflammation, epidermal histopathology, and antimicrobial activities in treated wounds. Diabetic mices’ wounds treated with bacterial cellulose healed 1.63 times faster than those treated with gauze; the values for the skin indicators in bacterial cellulose treated wounds were more significant than those treated with gauze. Bacterial cellulose was more effective than gauze in promoting tissue proliferation with more complete epidermal layers and the formation of compact collagen in the histological examination. Moreover, wounds treated with bacterial cellulose alone had less water and glucose content than those treated with gauze; this led to an increase of 6.82 times in antimicrobial protection, lower levels of TNF-α and IL-6 (39.6% and 83.2%), and higher levels of IL-10 (2.07 times) than in mice wounds treated with gauze. The results show that bacterial cellulose produced using K. intermedius beneficially affects diabetic wound healing and creates a hygienic microenvironment by preventing inflammation. We suggest that bacterial cellulose can replace medical gauze as a wound dressing for diabetic patients.

Silibinin downregulates the expression of the Th1 and Th17 profiles by modulation of STATs and transcription factors in pregnant women with preeclampsia

Preeclampsia (PE) is a multifactorial disease that is characterized by inflammation. Some of the factors responsible for this inflammation are the cells of the innate and adaptive immune systems and their interactions. The use of natural products, such as silibinin (SB), can contribute to the control of this inflammation and gestational success. The present study evaluated whether the flavonoid SB has an in vitro immunomodulatory effect on the signal transducers and transcription activators (STATs) signaling pathway and transcription factors of CD4+ T cell subsets obtained from preeclamptic and normotensive (NT) pregnant women. Peripheral blood mononuclear cells (PBMCs) from 18 preeclamptic and 18 NT pregnant women were cultured with and without SB to analyze the expression of STATs and transcription factors by flow cytometry, and cytokines were measured in the culture supernatant by ELISA. The results showed that treating cells with SB decreased STAT1/ STAT4/T-bet and STAT3/RORγt, which characteristic of Th1 and Th17 inflammatory profiles, as well as increased STAT6/GATA-3 and STAT5/FoxP3 of anti-inflammatory and regulatory profiles, respectively. In addition, PBMCs from preeclamptic women treated with SB released lower concentrations of inflammatory cytokines and higher levels of IL-10 and TGF-β. Therefore, SB plays an immunomodulatory role on CD4+ T cell subsets in PE, leading to the downregulation of inflammatory profiles and upregulation of anti-inflammatory and regulatory profiles. More studies are necessary to better understand the modulation of CD4+ T cell subsets by the JAK/STAT and NF-κB pathways in this gestational pathology.

Responses of injured nerve in CD137L knockout mice following sciatic nerve crush-induced neuropathic pain

Abstract Previously, we showed that CD137L, a costimulatory molecule is involved in the development of neuropathic pain following sciatic nerve crush (SNC). CD137L knockout (KO) mice displayed reduced SNC-induced pain-like behaviors and faster recovery following SNC. To determine the responses at the nerve crush site, we further examined the phenotypic and inflammatory changes of injured sciatic nerve in both CD137L KO mice and wild type (WT) C57BL/6 mice. Both CD137L KO and WT mice underwent either SNC or sham surgery. Sample collection occurred at days 0 (naïve), 3, 7, 14, 28, and 56 post-surgery. First, the femur-level segment of sciatic nerve containing the injury site was analyzed via whole mount immunohistochemistry. At the baseline, CD137L KO mice showed higher staining intensity for IB4 (non-peptidergic c-fibers) compared to WT mice. In WT mice but not CD137L KO mice, SNC significantly increased staining intensity for CGRP (all times; peptidergic c-fibers) and IB4 (Days 3 and 28). These increases were not observed in the corresponding CD137L KO mice. Second, selected inflammatory markers were measured via real time qRT-PCR. At baseline, CD137L KO mice expressed significantly lower levels of TNFα, yet higher levels of IL-10. SNC induced higher levels of elevation of IL-6, CCL3, CCL4, and Arg-1 (all peaked at day 3) in CD137L KO mice compared to WT mice. WT but not CD137L KO mice, showed significant up-regulation of CCL5 (throughout the time course) and CXCL1 (peaked at day 14). Therefore, we propose that CD137L-mediated local inflammatory responses may contribute to SNC induced pain-like behaviors in part by affecting the phenotype of injured nerve. Supported by NIH/NINDS R01NS098426 (Cao), COBRE Histology and Imaging Core funded by NIH/NIGMS P20GM103643 (Meng), and the Kahn Family Foundation through the Carmen Pettapiece Student Research Fellowship (Souza Di Nucci).

Splenic B1 B Cells Acquire a Proliferative and Anti-Inflamatory Profile During Pregnancy in Mice.

B cells are a heterogeneous cell population with differential ontogeny, anatomical location, and functions. B1 B cells are a distinct subpopulation characterized by their unique capacity of self-renewal, the production of large quantities of IL-10, and the ability to secrete protective, anti-inflammatory natural antibodies (NAbs), presumably upon down-regulation of CD1d expression. Although natural antibodies are thought to be protective, due to their polyreactivity, their participation in certain autoimmune diseases has been suggested. In the context of pregnancy, the role of B1 B cells has been discussed controversially. While in human pregnancies B1 B cells and natural/polyreactive antibodies they produce are involved in the development of preeclampsia, in mice they promote healthy gestation and fetal protection. In this work, we aimed to functionally characterize the splenic B1 B cell population during pregnancy in mice. Functional enrichment analysis using only up-regulated transcripts from a transcriptomic profile performed on total splenic B cells from pregnant compared to non-pregnant mice showed augmented cell cycle and DNA replication pathways. Proliferation studies by flow cytometry showed augmented Ki-67 proliferation marker expression and percentages of B1 B cells. Furthermore, B1 B cells produced higher levels of IL-10 and lower levels of TNF-α leading to an increased IL-10/TNF-α ratio and showing an immunoregulatory phenotype. Finally, we observed lower expression of CD1d on B1 B cells, suggesting a higher capacity to produce NAbs in the context of pregnancy. In summary, our results showed not only an expanded and proliferative splenic B1 B cell population during pregnancy but also the acquisition of immunomodulatory capacities suggesting its critical role in the intricate process of pregnancy tolerance.

Ten-eleven translocation-2 inactivation restrains IL-10-producing regulatory B cells to enable antitumor immunity in hepatocellular carcinoma.

IL-10-producing regulatory B cells (IL-10 + B cells), a dominant regulatory B cell (Breg) subset, foster tumor progression. However, the mechanisms underlying their generation in HCC are poorly understood. Ten-eleven translocation-2 (TET2), a predominant epigenetic regulatory enzyme in B cells, regulates gene expression by catalyzing demethylation of 5-methylcytosine into 5-hydroxymethyl cytosine (5hmC). In this study, we investigated the role of TET2 in IL-10 + B cell generation in HCC and its prospects for clinical application. TET2 activation in B cells triggered by oxidative stress from the HCC microenvironment promoted IL-10 expression, whereas adoptive transfer of Tet2 -deficient B cells suppressed HCC progression. The aryl hydrocarbon receptor is required for TET2 to hydroxylate Il10 . In addition, high levels of IL-10, TET2, and 5hmc in B cells indicate poor prognosis in patients with HCC. Moreover, we determined TET2 activity using 5hmc in B cells to evaluate the efficacy of anti-programmed death 1 (anti-PD-1) therapy. Notably, TET2 inhibition in B cells facilitates antitumor immunity to improve anti-PD-1 therapy for HCC. Our findings propose a TET2-dependent epigenetic intervention targeting IL-10 + B cell generation during HCC progression and identify the inhibition of TET2 activity as a promising combination therapy with immune checkpoint inhibitors for HCC.

Stress-induced pro- and anti-inflammatory cytokine concentrations in female PTSD and depressive patients

Alterations of the hypothalamus pituitary-axis on one hand and heightened rates of somatic diseases and mortality on the other hand are consistently found for PTSD and MDD patients. A possible link between these factors might be the immune system, in particular pro- and anti-inflammatory cytokines. A ‘low-grade inflammation’ in PTSD and MDD patients was found, whereas the influence of acute stress and the role of anti-inflammatory cytokines was rarely examined. In this study, 17 female PTSD patients participated in the Trier social stress test while serum cytokine levels (IL-6, IL-10) were assessed. Cytokine levels of PTSD patients were compared with levels of female depressive patients (n = 18) and female healthy controls (n = 18). Group differences were assessed using a 3 (group) x 8 (time: −15, −1, +1, +10, +20, +30, +45, +60 min) ANCOVA for repeated measures with baseline values as covariates. There was no group difference regarding IL-6 levels (p = 0.920) but PTSD patients showed significantly higher levels of IL-10 compared with depressive patients (p < 0.001, d = 0.16) and healthy controls (p = 0.001, d = 0.38). Under acute stress, PTSD patients did not show the widely found elevated IL-6 levels but showed an increase of anti-inflammatory IL-10. Therefore, acute stress seems to promote an imbalance of pro- and anti-inflammatory cytokine levels in PTSD and might indicate a hyperreactive immune response. This should be considered in future studies to further understand the role of the immune system as a link between stress response and somatic diseases.

The Secretome of Preconditioned Mesenchymal Stem Cells Drives Polarization and Reprogramming of M2a Macrophages toward an IL-10-Producing Phenotype.

The preconditioning of mesenchymal stem cells (MSCs) has been recognized as an attractive tool to improve their regenerative and immunomodulatory capacities based on their paracrine effects. In this study, we examined the potential of an MSC-conditioned medium (MSC-CM) to alter the phenotype of murine macrophages and to drive reprogramming toward an anti-inflammatory, M2-like state in vitro. We further explored the impact of MSC cytokine preconditioning on the immunosuppressive properties of the MSC secretome. The MSC-CM suppressed the expression of proinflammatory genes in murine M1 macrophages, but only the CM from preconditioned MSCs (preMSC-CM) downregulated their expression during M1 polarization. Remarkably, only the preMSC-CM significantly increased the expression of M2a-, M2b- and M2c-specific genes and proteins during M2a polarization. Further, macrophages were found to secrete high levels of anti-inflammatory IL-10. Similarly, M2a macrophages cultured in the presence of the preMSC-CM displayed an enhanced expression of M2b/M2c-specific markers, suggesting that the secretome of preMSC promotes the repolarization of M2a-like macrophages to M2b/M2c subtypes. The preMSC-CM was found to be enriched in molecules involved in M2 polarization. Additionally, a unique downregulation of extracellular matrix components was observed. Altogether, the preMSC-CM may provide an attractive strategy to dampen inflammation by suppressing the expression of proinflammatory mediators and promoting the polarization and phenotype switch of M2a cells to IL-10-secreting M2b/M2c-like macrophages.

Mesenchymal stromal cell delivery as a potential therapeutic strategy against COVID-19: Promising evidence from in vitro results.

BACKGROUNDSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) pandemic, which was initiated in December 2019. COVID-19 is characterized by a low mortality rate (< 6%); however, this percentage is higher in elderly people and patients with underlying disorders. COVID-19 is characterized by mild to severe outcomes. Currently, several therapeutic strategies are evaluated, such as the use of anti-viral drugs, prophylactic treatment, monoclonal antibodies, and vaccination. Advanced cellular therapies are also investigated, thus representing an additional therapeutic tool for clinicians. Mesenchymal stromal cells (MSCs), which are known for their immunoregulatory properties, may halt the induced cytokine release syndrome mediated by SARS-CoV-2, and can be considered as a potential stem cell therapy.AIMTo evaluate the immunoregulatory properties of MSCs, upon stimulation with COVID-19 patient serum. METHODSMSCs derived from the human Wharton’s Jelly (WJ) tissue and bone marrow (BM) were isolated, cryopreserved, expanded, and defined according to the criteria outlined by the International Society for Cellular Therapies. Then, WJ and BM-MSCs were stimulated with a culture medium containing 15% COVID-19 patient serum, 1% penicillin-streptomycin, and 1% L-glutamine for 48 h. The quantification of interleukin (IL)-1 receptor a (Ra), IL-6, IL-10, IL-13, transforming growth factor (TGF)-β1, vascular endothelial growth factor (VEGF)-a, fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), and indoleamine-2,3-dioxygenase (IDO) was performed using commercial ELISA kits. The expression of HLA-G1, G5, and G7 was evaluated in unstimulated and stimulated WJ and BM-MSCs. Finally, the interactions between MSCs and patients’ macrophages were established using co-culture experiments.RESULTSThawed WJ and BM-MSCs exhibited a spindle-shaped morphology, successfully differentiated to “osteocytes”, “adipocytes”, and “chondrocytes”, and in flow cytometric analysis were characterized by positivity for CD73, CD90, and CD105 (> 95%) and negativity for CD34, CD45, and HLA-DR (< 2%). Moreover, stimulated WJ and BM-MSCs were characterized by increased cytoplasmic granulation, in comparison to unstimulated cells. The HLA-G isoforms (G1, G5, and G7) were successfully expressed by the unstimulated and stimulated WJ-MSCs. On the other hand, only weak expression of HLA-G1 was identified in BM-MSCs. Stimulated MSCs secreted high levels of IL-1Ra, IL-6, IL-10, IL-13, TGF-β1, FGF, VEGF, PDGF, and IDO in comparison to unstimulated cells (P < 0.05) after 12 and 24 h. Finally, macrophages derived from COVID-19 patients successfully adapted the M2 phenotype after co-culturing with stimulated WJ and BM-MSCs.CONCLUSIONWJ and BM-MSCs successfully produced high levels of immunoregulatory agents, which may efficiently modulate the over-activated immune responses of critically ill COVID-19 patients.