Regulation of adaptive immunity; the role of interleukin-10

Increased Interleukin-10 Expression by the Inhibition of Ca2+-Activated K+ Channel KCa3.1 in CD4+CD25+ Regulatory T Cells in the Recovery Phase in an Inflammatory Bowel Disease Mouse Model

Inflammatory bowel diseases (IBD) are chronic inflammatory diseases of the gastrointestinal tract arising from abnormal responses of the innate and adaptative immune systems. Interleukin (IL)-10-producing CD4⁺CD25⁺ regulatory T (T_reg) cells play a protective role in the recovery phase of IBD. In the present study, the effects of the administration of the selective Ca²⁺-activated K⁺ channel K_Ca3.1 inhibitor TRAM-34 on disease activities were examined in chemically induced IBD model mice. IBD disease severity, as assessed by diarrhea, visible fecal blood, inflammation, and crypt damage in the colon, was significantly lower in mice administered 1 mg/kg TRAM-34 than in vehicle-administered mice. Quantitative real-time polymerase chain reaction examinations showed that IL-10 expression levels in the recovery phase were markedly increased by the inhibition of K_Ca3.1 in mesenteric lymph node (mLN) T_reg cells of IBD model mice compared with vehicle-administered mice. Among several positive and negative transcriptional regulators (TRs) for IL-10, three positive TRs-E4BP4, KLF4, and Blimp1-were upregulated by the inhibition of K_Ca3.1 in the mLN T_reg cells of IBD model mice. In mouse peripheral CD4⁺CD25⁺ T_reg cells induced by lectin stimulation, IL-10 expression and secretion were enhanced by the treatment with TRAM-34, together with the upregulation of E4BP4, KLF4, and Blimp1. Collectively, the present results demonstrated that the pharmacological inhibition of K_Ca3.1 decreased IBD symptoms in the IBD model by increasing IL-10 production in peripheral T_reg cells and that IL-10^high T_reg cells produced by the treatment with K_Ca3.1 inhibitor may contribute to efficient T_reg therapy for chronic inflammatory disorders, including IBD. SIGNIFICANCE STATEMENT: Pharmacological inhibition of Ca²⁺-activated K⁺ channel K_Ca3.1 increased IL-10 expression in peripheral T_reg cells, together with the upregulation of the transcriptional regulators of IL-10: Krüppel-like factor 4, E4 promoter-binding protein 4, and/or B lymphocyte-induced maturation protein 1. The manipulation of IL-10^high-producing T_reg cells by the pharmacological inhibition of K_Ca3.1 may be beneficial in the treatment of chronic inflammatory diseases such as inflammatory bowel disease.

Antigen- and Epitope-Delivering Nanoparticles Targeting Liver Induce Comparable Immunotolerance in Allergic Airway Disease and Anaphylaxis as Nanoparticle-Delivering Pharmaceuticals

The targeting of natural tolerogenic liver sinusoidal endothelial cells (LSEC) by nanoparticles (NPs), decorated with a stabilin receptor ligand, is capable of generating regulatory T-cells (Tregs), which can suppress antigen-specific immune responses, including to ovalbumin (OVA), a possible food allergen. In this regard, we have previously demonstrated that OVA-encapsulating poly(lactic-co-glycolic acid) (PLGA) nanoparticles eliminate allergic airway inflammation in OVA-sensitized mice, prophylactically and therapeutically. A competing approach is a nanocarrier platform that incorporates pharmaceutical agents interfering in mTOR (rapamycin) or NF-κB (curcumin) pathways, with the ability to induce a tolerogenic state in nontargeted antigen-presenting cells system-wide. First, we compared OVA-encapsulating, LSEC-targeting tolerogenic nanoparticles (TNPs) with nontargeted NPs incorporating curcumin and rapamycin (Rapa) in a murine eosinophilic airway inflammation model, which is Treg-sensitive. This demonstrated roughly similar tolerogenic effects on allergic airway inflammation by stabilin-targeting NP^OVAversus nontargeted NPs delivering OVA plus Rapa. Reduction in eosinophilic inflammation and TH2-mediated immune responses in the lung was accompanied by increased Foxp3⁺ Treg recruitment and TGF-β production in both platforms. As OVA incorporates IgE-binding as well as non-IgE-binding epitopes, the next experiment explored the possibility of obtaining immune tolerance by non-anaphylactic T-cell epitopes. This was accomplished by incorporating OVA^323-339 and OVA^257-264 epitopes in liver-targeting NPs to assess the prophylactic and therapeutic impact on allergic inflammation in transgenic OT-II mice. Importantly, we demonstrated that the major histocompatibility complex (MHC)-II binding (former) but not the MHC-I binding (latter) epitope interfered in allergic airway inflammation, improving TNP^OVA efficacy. The epitope-specific effect was transduced by TGF-β-producing Tregs. In the final phase of experimentation, we used an OVA-induced anaphylaxis model to demonstrate that targeted delivery of OVA and its MHC-II epitope could significantly suppress the anaphylaxis symptom score, mast cell release, and the late-phase inflammatory response. In summary, these results demonstrate comparable efficacy of LSEC-targeting versus pharmaceutical PLGA nanoparticles, as well as the ability of T-cell epitopes to achieve response outcomes similar to those of the intact allergens.

Interaction Between Dendritic Cells and Candida krusei β-Glucan Partially Depends on Dectin-1 and It Promotes High IL-10 Production by T Cells

Host-Candida interaction has been broadly studied during Candida albicans infection, with a progressive shift in focus toward non-albicans Candida species. C. krusei is an emerging multidrug resistant pathogen causing rising morbidity and mortality worldwide. Therefore, understanding the interplay between the host immune system and C. krusei is critically important. Candia cell wall β-glucans play significant roles in the induction of host protective immune responses. However, it remains unclear how C. krusei β-glucan impacts dendritic cell (DC) responses. In this study, we investigated DC maturation and function in response to β-glucans isolated from the cell walls of C. albicans, C. tropicalis, and C. krusei. These three distinct Candida β-glucans had differential effects on expression of the DC marker, CD11c, and on DC maturation. Furthermore, bone-marrow derived DCs (BMDCs) showed enhanced cytokine responses characterized by substantial interleukin (IL)-10 production following C. krusei β-glucan stimulation. BMDCs stimulated with C. krusei β-glucan augmented IL-10 production by T cells in tandem with increased IL-10 production by BMDCs. Inhibition of dectin-1 ligation demonstrated that the interactions between dectin-1 on DCs and cell wall β-glucans varied depending on the Candida species. The effects of C. krusei β-glucan were partially dependent on dectin-1, and this dependence, in part, led to distinct DC responses. Our study provides new insights into immune regulation by C. krusei cell wall components. These data may be of use in the development of new clinical approaches for treatment of patients with C. krusei infection.

Environmental signals rather than layered ontogeny imprint the function of type 2 conventional dendritic cells in young and adult mice

Conventional dendritic cells (cDC) are key activators of naive T cells, and can be targeted in adults to induce adaptive immunity, but in early life are considered under-developed or functionally immature. Here we show that, in early life, when the immune system develops, cDC2 exhibit a dual hematopoietic origin and, like other myeloid and lymphoid cells, develop in waves. Developmentally distinct cDC2 in early life, despite being distinguishable by fate mapping, are transcriptionally and functionally similar. cDC2 in early and adult life, however, are exposed to distinct cytokine environments that shape their transcriptional profile and alter their ability to sense pathogens, secrete cytokines and polarize T cells. We further show that cDC2 in early life, despite being distinct from cDC2 in adult life, are functionally competent and can induce T cell responses. Our results thus highlight the potential of harnessing cDC2 for boosting immunity in early life.

Production of biologically active human interleukin-10 by Bifidobacterium bifidum BGN4

BACKGROUND

Bifidobacterium spp. are representative probiotics that play an important role in the health of their hosts. Among various Bifidobacterium spp., B. bifidum BGN4 exhibits relatively high cell adhesion to colonic cells and has been reported to have various in vivo and in vitro bio functionalities (e.g., anti-allergic effect, anti-cancer effect, and modulatory effects on immune cells). Interleukin-10 (IL-10) has emerged as a major suppressor of immune response in macrophages and other antigen presenting cells and plays an essential role in the regulation and resolution of inflammation. In this study, recombinant B. bifidum BGN4 [pBESIL10] was developed to deliver human IL-10 effectively to the intestines.

RESULTS

The vector pBESIL10 was constructed by cloning the human IL-10 gene under a gap promoter and signal peptide from Bifidobacterium spp. into the E. coli-Bifidobacterium shuttle vector pBES2. The secreted human IL-10 from B. bifidum BGN4 [pBESIL10] was analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), Western Blotting, and enzyme-linked immunosorbent assay (ELISA). More than 1,473 ± 300 ng/mL (n = 4) of human IL-10 was obtained in the cell free culture supernatant of B. bifidum BGN4 [pBESIL10]. This productivity is significantly higher than other previously reported human IL-10 level from food grade bacteria. In vitro functional evaluation of the cell free culture supernatant of B. bifidum BGN4 [pBESIL10] revealed significantly inhibited interleukin-6 (IL-6) production in lipopolysaccharide (LPS)-induced Raw 264.7 cells (n = 6, p < 0.0001) and interleukin-8 (IL-8) production in LPS-induced HT-29 cells (n = 6, p < 0.01) or TNFα-induced HT-29 cells (n = 6, p < 0.001).

CONCLUSION

B. bifidum BGN4 [pBESIL10] efficiently produces and secretes significant amounts of biologically active human IL-10. The human IL-10 production level in this study is the highest of all human IL-10 production reported to date. Further research should be pursued to evaluate B. bifidum BGN4 [pBESIL10] producing IL-10 as a treatment for various inflammation-related diseases, including inflammatory bowel disease, rheumatoid arthritis, allergic asthma, and cancer immunotherapy.

High HDL-Cholesterol Paradox: SCARB1-LAG3-HDL Axis

Purpose of the Review

To evaluate recent studies related to the paradox of high HDL-C with mortality and atherosclerotic cardiovascular disease (ASCVD) risk.

Recent Findings

Two observational studies (Cardiovascular Health in Ambulatory Care Research Team [CANHEART] and Copenhagen City Heart Study and the Copenhagen General Population Study [Copenhagen Heart Studies]) of adults without pre-existing ASCVD have shown a significant U-shaped association of HDL-C with all-cause and cause-specific mortality. Both studies showed that low HDL-C levels consistently increased hazard risk (HR) for all-cause and cause-specific mortality. In the CANHEART study, high HDL-C levels, HDL-C > 90 mg/dL, were associated with increased HR for non-CVD/non-cancer mortality. In the Copenhagen Heart Studies, women with HDL-C ≥ 135 mg/dL showed increased HR for all-cause and CVD mortality, while men with HDL-C > 97 mg/dL showed increased HR for all-cause and CVD mortality. Genetic association studies failed to show that genetic etiologies of high HDL-C significantly reduced risk for myocardial infarction (MI), while hepatocyte nuclear factor-4 (HNF4A) was significantly associated with high HDL-C and increased MI risk. Candidate gene studies have identified scavenger receptor B class I (SCARB1) and lymphocyte activation gene-3 (LAG3) as genes significantly associated with high HDL-C and increased MI risk.

Summary

Low HDL-C remains as a significant factor for increased disease risk while high HDL-C levels are not associated with cardioprotection. Clinical CVD risk calculators need revision.

Suppressive Effects of a Truncated Inhibitor K562 Protein-Derived Peptide on Two Proinflammatory Cytokines, IL-17 and TNF-α

Inhibitor K562 (IK) protein was first isolated from the culture medium of K562 cells, a leukemia cell line, and is an inhibitory regulator of interferon-γ-induced major histocompatibility complex class II expression. Recently, exogenous truncated IK (tIK) protein showed potential as a therapeutic agent for inflammation-related diseases. In this study, we designed a novel putative anti-inflammatory peptide derived from tIK protein based on homology modeling of the human interleukin-10 (hIL-10) structure, and investigated whether the peptide exerted inhibitory effects against proinflammatory cytokines such as IL-17 and tumor necrosis factor-α (TNF-α). The peptide contains key residues involved in binding hIL-10 to the IL-10 receptor, and exerted strong inhibitory effects on IL- 17 (43.8%) and TNF-α (50.7%). In addition, we used circular dichroism spectroscopy to confirm that the peptide is usually present in a random coil configuration in aqueous solution. In terms of toxicity, the peptide was found to be biologically safe. The mechanisms by which the short peptide derived from human tIK protein exerts inhibitory effects against IL-17 and TNF-α should be explored further. We also evaluated the feasibility of using this novel peptide in skincare products.

Modulation of immune responses by bile acid receptor agonists in myasthenia gravis

Bile acids bind to multiple receptors, including Takeda G protein-coupled receptor 5 (TGR5) and farnesoid-X-receptors alpha (FXRα). We compared the response of PBMCs to the activation of these receptors in healthy controls and myasthenic patients. We found that TGR5 is a more potent negative regulator of T cell cytokine response than FXRα in both groups. In contrast, TGR5 and FXRα agonists elicit distinct B cell responses in myasthenia compared to controls, specifically on the frequency of IL-6⁺ B cells and regulatory B cells, as well as IL-10 secretion from PBMCs. We propose that TGR5 is a potential therapeutic target in myasthenia.

A biomathematical model of immune response and barrier function in mice with pneumococcal lung infection

Pneumonia is one of the leading causes of death worldwide. The course of the disease is often highly dynamic with unforeseen critical deterioration within hours in a relevant proportion of patients. Besides antibiotic treatment, novel adjunctive therapies are under development. Their additive value needs to be explored in preclinical and clinical studies and corresponding therapy schedules require optimization prior to introduction into clinical practice. Biomathematical modeling of the underlying disease and therapy processes might be a useful aid to support these processes. We here propose a biomathematical model of murine immune response during infection with Streptococcus pneumoniae aiming at predicting the outcome of different treatment schedules. The model consists of a number of non-linear ordinary differential equations describing the dynamics and interactions of the pulmonal pneumococcal population and relevant cells of the innate immune response, namely alveolar- and inflammatory macrophages and neutrophils. The cytokines IL-6 and IL-10 and the chemokines CCL2, CXCL1 and CXCL5 are considered as major mediators of the immune response. We also model the invasion of peripheral blood monocytes, their differentiation into macrophages and bacterial penetration through the epithelial barrier causing blood stream infections. We impose therapy effects on this system by modelling antibiotic therapy and treatment with the novel C5a-inactivator NOX-D19. All equations are derived by translating known biological mechanisms into equations and assuming appropriate response kinetics. Unknown model parameters were determined by fitting the predictions of the model to time series data derived from mice experiments with close-meshed time series of state parameters. Parameter fittings resulted in a good agreement of model and data for the experimental scenarios. The model can be used to predict the performance of alternative schedules of combined antibiotic and NOX-D19 treatment. We conclude that we established a comprehensive biomathematical model of pneumococcal lung infection, immune response and barrier function in mice allowing simulations of new treatment schedules. We aim to validate the model on the basis of further experimental data. We also plan the inclusion of further novel therapy principles and the translation of the model to the human situation in the near future.

Regulatory T cells mediated immunomodulation during asthma: a therapeutic standpoint

Asthma is an inflammatory disease of the lung airway network, which is initiated and perpetuated by allergen-specific CD4⁺ T cells, IgE antibodies, and a massive release of Th2 cytokines. The most common clinical manifestations of asthma progression include airway inflammation, pathological airway tissue and microvascular remodeling, which leads to airway hyperresponsiveness (AHR), and reversible airway obstruction. In addition to inflammatory cells, a tiny population of Regulatory T cells (Tregs) control immune homeostasis, suppress allergic responses, and participate in the resolution of inflammation-associated tissue injuries. Preclinical and clinical studies have demonstrated a tremendous therapeutic potential of Tregs in allergic airway disease, which plays a crucial role in immunosuppression, and rejuvenation of inflamed airways. These findings supported to harness the immunotherapeutic potential of Tregs to suppress airway inflammation and airway microvascular reestablishment during the progression of the asthma disease. This review addresses the therapeutic impact of Tregs and how Treg mediated immunomodulation plays a vital role in subduing the development of airway inflammation, and associated airway remodeling during the onset of disease.

High-affinity antigen association to cationic liposomes via coiled coil-forming peptides induces a strong antigen-specific CD4+ T-cell response

Liposomes are widely investigated as vaccine delivery systems, but antigen loading efficiency can be low. Moreover, adsorbed antigen may rapidly desorb under physiological conditions. Encapsulation of antigens overcomes the latter problem but results in significant antigen loss during preparation and purification of the liposomes. Here, we propose an alternative attachment method, based on a complementary heterodimeric coiled coil peptide pair pepK and pepE. PepK was conjugated to cholesterol (yielding CPK) and pepE was covalently linked to model antigen OVA323 (yielding pepE-OVA323). CPK was incorporated in the lipid bilayer of cationic liposomes (180 nm in size). Antigen was associated more efficiently to functionalized liposomes (Kd 166 nM) than to cationic liposomes (Kd not detectable). In vivo co-localization of antigen and liposomes was strongly increased upon CPK-functionalization (35% -> 80%). CPK-functionalized liposomes induced 5-fold stronger CD4⁺ T-cell proliferation than non-functionalized liposomes in vitro. Both formulations were able to induce strong CD4⁺ T-cell expansion in mice, but more IFN-y and IL-10 production was observed after immunization with functionalized liposomes. In conclusion, antigen association via coiled coil peptide pair increased co-localization of antigen and liposomes, increased CD4⁺ T-cell proliferation in vitro and induced a stronger CD4⁺ T-cell response in vivo.

Lymphocyte Immunosuppression and Dysfunction Contributing to Persistent Inflammation, Immunosuppression, and Catabolism Syndrome (PICS)

ABSTRACT

Persistent Inflammation, Immune Suppression, and Catabolism Syndrome (PICS) is a disease state affecting patients who have a prolonged recovery after the acute phase of a large inflammatory insult. Trauma and sepsis are two pathologies after which such an insult evolves. In this review, we will focus on the key clinical determinants of PICS: Immunosuppression and cellular dysfunction. Currently, relevant immunosuppressive functions have been attributed to both innate and adaptive immune cells. However, there are significant gaps in our knowledge, as for trauma and sepsis the immunosuppressive functions of these cells have mostly been described in acute phase of inflammation so far, and their clinical relevance for the development of prolonged immunosuppression is mostly unknown. It is suggested that the initial immune imbalance determines the development of PCIS. Additionally, it remains unclear what distinguishes the onset of immune dysfunction in trauma and sepsis and how this drives immunosuppression in these cells. In this review, we will discuss how regulatory T cells (Tregs), innate lymphoid cells, natural killer T cells (NKT cells), TCR-a CD4- CD8- double-negative T cells (DN T cells), and B cells can contribute to the development of post-traumatic and septic immunosuppression. Altogether, we seek to fill a gap in the understanding of the contribution of lymphocyte immunosuppression and dysfunction to the development of chronic immune disbalance. Further, we will provide an overview of promising diagnostic and therapeutic interventions, whose potential to overcome the detrimental immunosuppression after trauma and sepsis is currently being tested.

Sp3 Transcription Factor Cooperates with the Kaposi's Sarcoma-Associated Herpesvirus ORF50 Protein To Synergistically Activate Specific Viral and Cellular Gene Promoters

The Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded open reading frame 50 (ORF50) protein is the key transactivator responsible for the latent-to-lytic switch. Here, we investigated the transcriptional activation of the ORF56 gene (encoding a primase protein) by ORF50 and successfully identified an ORF50-responsive element located in the promoter region between positions -97 and -44 (designated 56p-RE). This 56p-RE element contains a noncanonical RBP-Jκ-binding sequence and a nonconsensus Sp1/Sp3-binding sequence. Electrophoretic mobility shift assays revealed that RBP-Jκ, Sp3, and ORF50 could form stable complexes on the 56p-RE element. Importantly, transient-reporter analysis showed that Sp3, but not RBP-Jκ or Sp1, acts in synergy with ORF50 to activate the 56p-RE-containing reporter construct, and the synergy mainly depends on the Sp1/Sp3-binding region of the 56p-RE element. Sequence similarity searches revealed that the promoters for ORF21 (thymidine kinase), ORF60 (ribonucleotide reductase, small subunit), and cellular interleukin-10 (IL-10) contain a sequence motif similar to the Sp1/Sp3-binding region of the 56p-RE element, and we found that these promoters could also be synergistically activated by ORF50 and Sp3 via the conserved motifs. Noteworthily, the conversion of the Sp1/Sp3-binding sequence of the 56p-RE element into a consensus high-affinity Sp-binding sequence completely lost the synergistic response to ORF50 and Sp3. Moreover, transcriptional synergy could not be detected through other ORF50-responsive elements from the viral PAN, K12, ORF57, and K6 promoters. Collectively, the results of our study demonstrate that ORF50 and Sp3 can act in synergy on the transcription of specific gene promoters, and we find a novel conserved cis-acting motif in these promoters essential for transcriptional synergy.IMPORTANCE Despite the critical role of ORF50 in the KSHV latent-to-lytic switch, the molecular mechanism by which ORF50 activates its downstream target genes, especially those that encode the viral DNA replication enzymes, is not yet fully understood. Here, we find that ORF50 can cooperate with Sp3 to synergistically activate promoters of the viral ORF56 (primase), ORF21 (thymidine kinase), and ORF60 (ribonucleotide reductase) genes via similar Sp1/Sp3-binding motifs. Additionally, the same synergistic effect can be seen on the promoter of the cellular IL-10 gene. Overall, our data reveal an important role for Sp3 in ORF50-mediated transactivation, and we propose a new subclass of ORF50-responsive elements in viral and cellular promoters.

The hepatic microenvironment and regulatory T cells

The human liver is regarded as a lymphoid organ that contributes to both local and systemic immune response. Intrahepatic immune cells including regulatory T cells (Tregs) reside in the hepatic microenvironment which is enriched with proinflammatory cytokines, chemokines and metabolites. In addition, the hepatic microenvironment has the unique ability to establish and maintain immune tolerance despite the continuous influx of the gut derived microbial products via the portal vein. Regulatory T cells play a crucial role in maintaining the hepatic tolerogenic state; however, the phenotypic stability, function and survival of Tregs in the inflamed liver microenvironment is still poorly understood. Despite this, Tregs immunotherapy remains as an appealing therapeutic option in autoimmune and immune mediated liver diseases. In order to advance cell therapy, it is important for us to further our understanding of the hepatic microenvironment, with the aim of developing ways to modify the hostile, inflamed environment to one which is more favourable. By doing so, T cell stability and function would be enhanced, resulting in improved clinical outcomes.

DIFFERENCES OF INTERLEUKIN-18 AND INTERLEUKIN-10 LEVELS IN RIFAMPICIN RESISTANT AND RIFAMPICIN SENSITIVE PULMONARY TUBERCULOSIS PATIENTS IN DR. SOETOMO HOSPITAL SURABAYA

Rifampicin is an anti-tuberculosis drug which has an efficient antimicrobial effect and the basis of a short-term treatment regimen for tuberculosis (TB) patients. Rifampicin plays an important role against the growth and slow metabolism of Bacilli M. tuberculosis. Resistance to rifampicin causes the duration of tuberculosis treatment to be longer. Interleukin-18 (IL-18) is a pro-inflammatory cytokine which plays a role in controlling the growth of M. tuberculosis through its ability to induce IFN-γ, while Interleukin-10 (IL-10) is an anti-inflammatory cytokine which plays a role in limiting tissue damage due to the inflammatory process and maintain tissue homeostasis. IL-18 and IL-10 has an important role in explaining the different degrees of inflammation in rifampicin resistant (RR) and rifampicin sensitive (RS) pulmonary tuberculosis patients. The purpose of this study is to determine different levels of IL-18 and IL-10 in new TB patients with RR and RS. This study was a retrospective cohort study with a cross-sectional design carried out from August-November 2018 in the TB-DOTS/MDR clinic at Dr. Soetomo Hospital, Surabaya. 50 research subjects were examined and grouped into two groups, namely pulmonary TB with RR (n = 25) and pulmonary TB with RS (n = 25) based on GeneXpert examination and anti-tuberculosis drug therapy ≤ 1 month. IL-18 and IL-10 were measured using the ELISA Method. Differences in IL-18 and IL-10 levels between groups were analyzed using the Mann-Whitney test. The mean level of IL-18 (pg/ml) in RR and RS pulmonary TB patients were 1273.53±749.86 and 787.96 ±589.28 respectively. The mean level of IL-10 (pg/ml) in RR and RS pulmonary TB patients were 125.25±118.32 and 128.81±135.77 repectively. The mean level of IL-18 in RR and RS pulmonary TB patients were found to have a significant difference, while the mean level of IL-10 did not have a significant difference. Keywords: Interleukin-18, Interleukin-10, Tuberculosis, Rifampicin Resistant, Rifampicin Sensitive

Transitional immature regulatory B cells and regulatory cytokines can discriminate chronic antibody-mediated rejection from stable graft function

BACKGROUND

The balance between inflammatory and anti-inflammatory responses of the immune system has been demonstrated to determine the fate of transplanted allografts. Here we analyzed CD19⁺CD24^hiCD38^hi immature transitional regulatory B (TRB) cells, as well as the gene and protein levels of interleukin (IL)-10 and transforming growth factor (TGF)-β in the three separate groups, include of stable transplanted subjects, chronic antibody-mediated rejection (cAMR) patients, and healthy individuals.

METHOD

Peripheral blood mononuclear cells (PBMCs) from stable subjects (n = 36), cAMR patients (n = 36) and healthy controls (n = 18) were isolated. Flowcytometry was performed for CD19, CD24, and CD38 surface markers. ELISA and quantitative real-time PCR were performed for IL-10 and TGF-β cytokines.

RESULT

The percentages of immature TRB cells were significantly decrease in cAMR patients (0.98%) versus stable recipients (2.81%) and healthy subjects (4.03%) (P = 0.001 and P < 0.001, respectively). Total lymphocytes, circulating B cells, memory and mature subsets of B cells did not show any significant difference between the groups. TGF-β mRNA was 3-fold upregulated in the cAMR group compared to stable patients (P < 0.001.), but without significant alteration at the protein level. Also, long-term survival renal transplant recipients had a higher protein but not mRNA levels of IL-10 than short-term survival renal transplant recipients.

CONCLUSION

It seems that immature TRB cell subpopulation might be a crucial regulator of immune system response and plays an important role in determining the transplantation outcome. Furthermore, immunosuppressive IL-10 and TGF-β cytokines might act as a double sword and can exhibit either pathogenic or protective effects against allograft.

The role of toll-like receptor 9 (TLR9) in Epstein-Barr virus-associated gastric cancer

Epstein-Barr virus-associated gastric carcinoma (EBVaGC) is the most common malignancy caused by EBV infection. Toll-like receptors (TLRs) as major components of innate immune system are crucial in the development of inflammatory processes and carcinogenesis. The aim of our study was to evaluate tissue and serum level of TLR9 in EBV-positive and EBV-negative gastric cancer patients. The study involved 30 EBV(+) and 30 EBV(-) patients. EBV DNA was detected in fresh frozen tumor tissue. In serum samples TLR9 level, transforming growth factor β (TGFβ), interleukin 10 (IL-10) and antibodies against EBV were detected using ELISA tests. TLR9 level was also measured in homogenate of tumour tissue. TLR9 level was statistically lower in EBV(+) patients both in serum and tissue, with statistically higher level in tissue than in serum. Lower level of TLR9 was accompanied by higher level of Epstein-Barr virus capsid antigen (EBVCA), Epstein-Barr virus nuclear antigen (EBNA) and early antigen (EA). A lower level of TLR9 was detected in patients with poorly differentiated cancer (G3) and greater lymph nodes involvement (N3-N4). Lower level of TLR9 in patients with EA may point to TLR9 role in reactivation of EBV infection.

STAT3/SOCS3 axis contributes to the outcome of salmonid whirling disease

There are differences in disease susceptibility to whirling disease (WD) among strains of rainbow trout. The North American strain Trout Lodge (TL) is highly susceptible, whereas the German Hofer (HO) strain is more resistant. The suppressor of cytokine signaling (SOCS) proteins are key in inhibiting cytokine signaling. Their role in modulating the immune response against whirling disease is not completely clear. This study aimed at investigating the transcriptional response of SOCS1 and SOCS3 genes to Myxobolus cerebralis along with that of several upstream regulators and immune response genes. M. cerebralis induced the expression of SOCS1, the IL-6-dependent SOCS3, the anti-inflammatory cytokine IL-10 and the Treg associated transcription factor FOXP3 in TL fish at multiple time points, which likely caused a restricted STAT1 and STAT3 activity affecting the Th17/Treg17 balance. The expression of SOCS1 and the IL-6-dependent SOCS3 was induced constraining the activation of STAT1 and STAT3 in TL fish, thereby causing Th17/Treg17 imbalance and leaving the fish unable to establish a protective immune response against M. cerebralis or control inflammatory reactions increasing susceptibility to WD. Conversely, in HO fish, the expression of SOCS1 and SOCS3 was restrained, whereas the expression of STAT1 and IL-23-mediated STAT3 was induced potentially enabling more controlled immune responses, accelerating parasite clearance and elevating resistance. The induced expression of STAT1 and IL-23-mediated STAT3 likely maintained a successful Th17/Treg17 balance and enabled fish to promote effective immune responses favouring resistance against WD. The results provide insights into the role of SOCS1 and SOCS3 in regulating the activation and magnitude of host immunity in rainbow trout, which may help us understand the mechanisms that underlie the variation in resistance to WD.

Effect of Aspirin on the Intestinal Response to a Necrotic Enteritis Challenge

The effect of aspirin on intestinal lesions was evaluated in birds undergoing an experimental challenge with Clostridium perfringens as part of a model for inducing subclinical necrotic enteritis (SNE). Broilers were raised on clean wood shavings and randomly assigned to three treatments: Uninfected (U), Infected (I), and Infected + Aspirin (I+A; 0.025% acetylsalicylic acid in drinking water during days 21-25). Birds in the I and I+A groups were gavaged with Eimeria maxima on day 18 and their feed was inoculated with C. perfringens (1 × 10⁹ CFU/bird) during days 23-25. On day 26, birds were euthanatized, intestinal lesions were evaluated, and intestinal tissue was collected for qPCR assessment of genes thought to be involved in the immune response to SNE: IL-1β, IL-10, MMP-2, and MMP-7. Birds in the I+A group had more-severe and numerous lesions compared to the I group. For all genes except MMP-2, expression was upregulated in the I group compared to the U group, but did not differ between the I and I+A groups. These results indicate that aspirin exacerbated the intestinal lesions associated with this disease. Aspirin could play a role in the development of a reliable and consistent model for the induction of necrotic enteritis under experimental settings.

Attenuation of canonical NF-κB signaling maintains function and stability of human Treg

Nuclear factor ‘κ‐light‐chain‐enhancer’ of activated B cells (NF‐κB) signaling is a signaling pathway used by most immune cells to promote immunostimulatory functions. Recent studies have indicated that regulatory T cells (Treg) differentially integrate TCR‐derived signals, thereby maintaining their suppressive features. However, the role of NF‐κB signaling in the activation of human peripheral blood (PB) Treg has not been fully elucidated so far. We show that the activity of the master transcription factor forkhead box protein 3 (FOXP3) attenuates p65 phosphorylation and nuclear translocation of the NF‐κB proteins p50, p65, and c‐Rel following activation in human Treg. Using pharmacological and genetic inhibition of canonical NF‐κB signaling in FOXP3‐transgenic T cells and PB Treg from healthy donors as well as Treg from a patient with a primary NFKB1 haploinsufficiency, we validate that Treg activation and suppressive capacity is independent of NF‐κB signaling. Additionally, repression of residual NF‐κB signaling in Treg further enhances interleukin‐10 (IL‐10) production. Blockade of NF‐κB signaling can be exploited for the generation of in vitro induced Treg (iTreg) with enhanced suppressive capacity and functional stability. In this respect, dual blockade of mammalian target of rapamycin (mTOR) and NF‐κB signaling was accompanied by enhanced expression of the transcription factors FOXP1 and FOXP3 and demethylation of the Treg‐specific demethylated region compared to iTreg generated under mTOR blockade alone. Thus, we provide first insights into the role of NF‐κB signaling in human Treg. These findings could lead to strategies for the selective manipulation of Treg and the generation of improved iTreg for cellular therapy.

Short-term Immunopathological Changes Associated with Pulse Steroids/IVIG/Rituximab Therapy in Late Kidney Allograft Antibody Mediated Rejection

Background

B-cell depletion is a common treatment of antibody-mediated rejection (ABMR). We sought to determine the specific immunopathologic effects of this therapeutic approach in kidney transplantation.

Methods

This was a prospective observational study of kidney transplant recipients diagnosed with late ABMR (>3 months after transplant). Patients received treatment with pulse steroids, IVIG, and rituximab. Donor specific HLA antibodies (DSA), kidney allograft pathology, renal function, immune cell phenotypes, and 47 circulating cytokines were assessed at baseline and at three months.

Results

We enrolled 23 patients in this study between April 2015 and March 2019. The majority of patients were male (74%) and Caucasian (78%) with an average age of 45.6±13.8 years. ABMR was diagnosed at 6.8±5.9 years (4 months-25 years) post-transplant. Treatment was associated with a significant decline in circulating HLA class I DSA (P=0.003) and class II DSA (P=0.002) and peritubular capillaritis (ptc, P=0.04) compared to baseline. Serum creatinine, BUN, eGFR, and proteinuria (UPC) remained stable. Circulating B-cells were depleted to barely detectable levels (P≤0.001), whereas BAFF (P=0.001), APRIL (P<0.001), and IL-10 (P=0.02), levels increased significantly post-treatment. Notably, there was a significant rise in circulating CD4+ (P=0.02) and CD8+ T-cells (P=0.003). We also noted a significant correlation between circulating cytotoxic CD8+ T-cells and BAFF (P=0.05), regulatory T-cells and IL10 (P=0.002), and HLA class I DSA (P=0.005).

Conclusions

Short-term pulse steroids/IVIG/rituximab therapy was associated with inhibition of ABMR (DSA and ptc), stabilization of kidney function, and increased regulatory B-cell and T-cell survival cytokines. Additional studies are needed to understand the implications of B cell-depletion on the crosstalk between T-cells, B-cells, and humoral components that regulate ABMR.

Immunomodulatory and anti-oxidative effect of the direct TRPV1 receptor agonist capsaicin on Schwann cells

Background

Only few studies describe the impact of nutritive factors on chronic inflammatory demyelinating polyneuropathy (CIDP), an inflammatory disease of the peripheral nervous system. The active component of chili pepper, capsaicin, is the direct agonist of the transient receptor potential channel vanilloid subfamily member 1. Its anti-inflammatory effect in the animal model experimental autoimmune neuritis (EAN) has been previously demonstrated.

Methods

In the present study, we describe the anti-inflammatory and anti-oxidative influence of capsaicin on Schwann cells (SCs) in an in vitro setting. Hereby, we analyze the effect of capsaicin on Schwann cells’ gene expression pattern, major histocompatibility complex class II (MHC-II) presentation, and H₂O₂-induced oxidative stress. Furthermore, the effect of capsaicin on myelination was examined in a SC-dorsal root ganglia (DRG) coculture by myelin basic protein staining. Finally, in order to investigate the isolated effect of capsaicin on SCs in EAN pathology, we transplant naïve and capsaicin pre-treated SCs intrathecally in EAN immunized rats and analyzed clinical presentation, electrophysiological parameters, and cytokine expression in the sciatic nerve.

Results

In SC monoculture, incubation with capsaicin significantly reduces interferon gamma-induced MHC-II production as well as toll-like receptor 4 and intercellular adhesion molecule 1 mRNA expression. Calcitonin gene-related peptide mRNA production is significantly upregulated after capsaicin treatment. Capsaicin reduces H₂O₂-induced oxidative stress in SC in a preventive, but not therapeutic setting. In a SC-DRG coculture, capsaicin does not affect myelination rate. After intrathecal transplantation of naïve and capsaicin pre-treated SCs in EAN-immunized rats, naïve, but not capsaicin pre-treated intrathecal SCs, ameliorated EAN pathology in rats.

Conclusions

In conclusion, we were able to demonstrate a direct immunomodulatory and anti-oxidative effect of capsaicin in a SC culture by reduced antigen presentation and expression of an anti-inflammatory profile. Furthermore, capsaicin increases the resistance of SCs against oxidative stress. A primary effect of capsaicin on myelination was not proven. These results are in concordance with previous data showing an anti-inflammatory effect of capsaicin, which might be highly relevant for CIDP patients.

A T cell-myeloid IL-10 axis regulates pathogenic IFN-γ-dependent immunity in a mouse model of type 2-low asthma

BACKGROUND

Although originally defined as a type 2 (T2) immune-mediated condition, non-T2 cytokines, such as IFN-γ and IL-17A, have been implicated in asthma pathogenesis, particularly in patients with severe disease. IL-10 regulates TH cell phenotypes and can dampen T2 immunity to allergens, but its functions in controlling non-T2 cytokine responses in asthmatic patients are unclear.

OBJECTIVE

We sought to determine how IL-10 regulates the balance of TH cell responses to inhaled allergen.

METHODS

Allergic airway disease was induced in wild-type, IL-10 reporter, and conditional IL-10 or IL-10 receptor α (IL-10Rα) knockout mice by means of repeated intranasal administration of house dust mite (HDM). IL-10 and IFN-γ signaling were disrupted by using blocking antibodies.

RESULTS

Repeated HDM inhalation induced a mixed IL-13/IL-17A response and accumulation of IL-10-producing forkhead box P3-negative effector CD4+ T cells in the lungs. Ablation of T cell-derived IL-10 increased the IFN-γ and IL-17A response to HDM, reducing IL-13 levels and airway eosinophilia without affecting IgE levels or airway hyperresponsiveness. The increased IFN-γ response could be recapitulated by IL-10Rα deletion in CD11c+ myeloid cells or local IL-10Rα blockade. Disruption of the T cell-myeloid IL-10 axis resulted in increased pulmonary monocyte-derived dendritic cell numbers and increased IFN-γ-dependent expression of CXCR3 ligands by airway macrophages, which is suggestive of a feedforward loop of TH1 cell recruitment. Augmented IFN-γ responses in the HDM allergic airway disease model were accompanied by increased disruption of airway epithelium, which was reversed by therapeutic blockade of IFN-γ.

CONCLUSIONS

IL-10 from effector T cells signals to CD11c+ myeloid cells to suppress an atypical and pathogenic IFN-γ response to inhaled HDM.

Xanthones, A Promising Anti-Inflammatory Scaffold: Structure, Activity, and Drug Likeness Analysis

Inflammation is the body's self-protective response to multiple stimulus, from external harmful substances to internal danger signals released after trauma or cell dysfunction. Many diseases are considered to be related to inflammation, such as cancer, metabolic disorders, aging, and neurodegenerative diseases. Current therapeutic approaches include mainly non-steroidal anti-inflammatory drugs and glucocorticoids, which are generally of limited effectiveness and severe side-effects. Thus, it is urgent to develop novel effective anti-inflammatory therapeutic agents. Xanthones, a unique scaffold with a 9H-Xanthen-9-one core structure, widely exist in natural sources. Till now, over 250 xanthones were isolated and identified in plants from the families Gentianaceae and Hypericaceae. Many xanthones have been disclosed with anti-inflammatory properties on different models, either in vitro or in vivo. Herein, we provide a comprehensive and up-to-date review of xanthones with anti-inflammatory properties, and analyzed their drug likeness, which might be potential therapeutic agents to fight against inflammation-related diseases.

Pre-evaluation of humoral immune response of Bactrian camels by the quantification of Th2 cytokines using real-time PCR

With the increasing immunological studies on camels due to the advantage of their single-chain antibodies for humanizations, it is demanding to develop an easy-to-handle evaluation method of their humoral immune response before proceeding with immunization of foreign antigens that may be toxic to camels. In this study, we quantitatively determined the expression levels of T-helper 2 (Th2) cytokines in peripheral blood lymphocytes obtained from Bactrian camels by real-time PCR. The recorded kinetic profiles resulting from the immunization of ovalbumin (OVA) indicated that after immunization, Th2 cytokines including interleukin (IL) families such as IL-4, IL-10, and IL-13 in the camels were up-regulated by a factor of 1.78, 3.15, and 1.22, respectively, which was validated by traditional enzyme-linked immunosorbent assay (ELISA) methods. Unlike ELISA which requires specific enzyme-labeled antibodies, this established method based on the minimal amount of blood samples holds an advantage in the preliminary evaluation of camel humoral immune response with desirable precision, which is meaningful for biomedical explorations of camel-derived antibodies.

Human Monocytes/Macrophage Inflammatory Cytokine Changes Following in vivo and in vitro Schistomam manoni Infection

Introduction

Epidemiological and animal studies indicate that helminth infections have positive effects due to their potential to protect against autoimmune diseases. Here, we aim to assess the effect of S. mansoni infection on immune modulation of human monocytes and their potential protection against autoimmune disease development both in vivo and in vitro.

Materials and Methods

Monocytes were isolated from helminth-infected Ethiopians (MHIE), and from Dutch healthy volunteers (MHV). The MHV were stimulated in vitro with S. mansoni soluble egg antigens (SEA) or soluble worm antigens (SWA). In addition, phenotypical changes were studied directly, as well as after culturing for 6 days in the presence of human serum to obtain macrophages. Q-PCR, flow cytometry, multiplex bead immunoassay, and live-cell imaging were employed during analysis.

Results

MHIE showed elevated transcripts of SOCS-1 and TNF-α compared to MHV. Similarly, MHV that were stimulated with SEA demonstrated enhanced levels of SOCS-1, IL-10, and IL-12 mRNA, compared to control MHV. Remarkably, the SEA-treated monocytes showed a much higher motility than control monocytes, a hallmark of a patrolling phenotype. Furthermore, in vitro cultured macrophages that were stimulated by SEA exhibited enhanced mRNA levels of SOCS-1, IL-10, TNF-α, IL-12 and TGF-β, compared to control macrophages.

Conclusion

Macrophages from MHIE as well as SEA-treated MHV show an intermediate activation phenotype with both pro-inflammatory and anti-inflammatory characteristics in vitro. The observed pro-inflammatory properties might reflect a recent response of the cells due to contact with a pathogen, whereas the anti-inflammatory properties might contribute to helminth-induced protection against inflammatory diseases. Large-scale study is recommended to consolidate the findings of the present study.

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Molecular switches for regulating the differentiation of inflammatory and IL-10-producing anti-inflammatory T-helper cells

CD4 T-helper (Th) cells secret a variety of inflammatory cytokines and play critical roles in host defense against invading foreign pathogens. On the other hand, uncontrolled inflammatory responses mediated by Th cells may result in tissue damage and inflammatory disorders including autoimmune and allergic diseases. Thus, the induction of anti-inflammatory cytokine expression becomes an important "brake" to repress and/or terminate aberrant and/or unnecessary immune responses. Interleukin-10 (IL-10) is one of the most important anti-inflammatory cytokines to limit inflammatory Th cells and immunopathology and to maintain tissue homeostasis. Many studies have indicated that Th cells can be a major source of IL-10 under specific conditions both in mouse and human and that extracellular signals and cell intrinsic molecular switches are required to turn on and off Il10 expression in different Th cells. In this review, we will highlight the recent findings that have enhanced our understanding on the mechanisms of IL-10 induction in distinct Th-cell subsets, including Th1, Th2, and Th17 cells, as well as the importance of these IL-10-producing anti-inflammatory Th cells in immunity and inflammation.

Immune Responses after Vascular Photodynamic Therapy with Redaporfin

Photodynamic therapy (PDT) relies on the administration of a photosensitizer (PS) that is activated, after a certain drug-to-light interval (DLI), by the irradiation of the target tumour with light of a specific wavelength absorbed by the PS. Typically, low light doses are insufficient to eradicate solid tumours and high fluence rates have been described as poorly immunogenic. However, previous work with mice bearing CT26 tumours demonstrated that vascular PDT with redaporfin, using a low light dose delivered at a high fluence rate, not only destroys the primary tumour but also reduces the formation of metastasis, thus suggesting anti-tumour immunity. This work characterizes immune responses triggered by redaporfin-PDT in mice bearing CT26 tumours. Our results demonstrate that vascular-PDT leads to a strong neutrophilia (2-24 h), systemic increase of IL-6 (24 h), increased percentage of CD4⁺ and CD8⁺ T cells producing IFN-γ or CD69⁺ (2-24 h) and increased CD4⁺/CD8⁺ T cell ratio (2-24 h). At the tumour bed, T cell tumour infiltration disappeared after PDT but reappeared with a much higher incidence one day later. In addition, it is shown that the therapeutic effect of redaporfin-PDT is highly dependent on neutrophils and CD8⁺ T cells but not on CD4⁺ T cells.

Comparison of TGF-β, IL-10 levels and LMP-1 in gastric and oropharyngeal carcinoma associated with EBV infection

Increasing interest has been focused on the Epstein-Barr Virus (EBV)-associated cancers, including oropharyngeal cancer (OPC) and gastric cancer (GC). Different cytokines, growth factors and proteins take part in oncogenesis. The aim of our study was to generate a comparison of interleukin 10 (IL-10) and transforming growth factor β (TGF-β) levels, as well as latent membrane protein (LMP-1), Epstein-Barr virus capsid antigen (EBVCA), Epstein-Barr virus nuclear antigen (EBNA) and early antigen (EA) frequency in the serum of patients with GC and OPC. The study involved 50 patients with diagnosed GC and 50 patients with OPC. All studied patients were EBV positive. Fresh-frozen tumor tissue fragments were tested using nested PCR assay for EBV DNA detection. Sera from all individuals were investigated using ELISA tests to detect the presence of EBVCA IgG, EBNA IgG, EA IgG, as well as to determine the levels of IL-10 and TGF-β. The obtained results were subjected to statistical analysis. In patients with GC, the levels of TGF-β and IL-10 were significantly higher than in OPC patients. However, the frequency and level of EBVCA, EBNA and EA in patients with OPC and GC were not significantly different. In contrast, TGF-β and IL-10 levels were significantly higher in EBVaGC, as compared to OPC, suggesting their role in gastric carcinogenesis. The differences in frequency of LMP-1 detection in patients with OPC and GC may suggest different mechanism of oncogenesis. Further studies are required to clarify the role of Epstein-Barr virus in cancer development.

Role of CCR7 on dendritic cell‑mediated immune tolerance in the airways of allergy‑induced asthmatic rats

Dendritic cells (DCs) have an important role in initiating and maintaining the immune inflammatory response in allergic asthma, and CC chemokine receptor 7 (CCR7) is directly involved in the pathogenesis of DC- and T cell-mediated allergic asthma. The present study aimed to investigate the effects of CCR7 on DC-mediated immune tolerance in allergic asthma. In the present study, bone marrow-derived DCs were transfected with an adenovirus encoding the rat CCR7 gene or a short hairpin RNA targeting CCR7 (sh-CCR7). Rats injected with DCs overexpressing CCR7 or presenting CCR7 knockdown were examined. After the rats were injected with DCs via the tail vein, bronchoalveolar lavage fluid was collected to assess its cellular composition. The protein expression levels of CCR7 in DCs were determined using immunohistochemistry and western blot analysis. The protein expression levels of interferon-γ (IFN-γ), interleukin-4 (IL-4), IL-10, IL-12, transforming growth factor-β (TGF-β) and immunoglobulin E (IgE) were determined by ELISA. Compared with the control group, the protein expression level of CCR7 was significantly higher in the CCR7 overexpression group and significantly lower in sh-CCR7 group. Similarly, the number of DCs was higher in the CCR7 overexpression group and lower in the sh-CCR7 group. The protein expression levels of IL-10 and TGF-β were significantly lower in the CCR7 overexpression group and higher in the sh-CCR7 group. In addition, the expression levels of IL-4, IL-12, IFN-γ and IgE were higher in the CCR7 overexpression group and lower in the sh-CCR7 group. The present results suggested that the role of cytokines and IgE in immune inflammation and immune tolerance in allergic asthma may be associated with the expression level of CCR7 in DCs, suggesting that CCR7 may serve a role in DC-mediated immune tolerance in allergic asthma.

The effect of regulatory T cells on tolerance to airborne allergens and allergen immunotherapy

Forkhead box P3-positive regulatory T (Treg) cells are essential mediators of tolerance against self-antigens and harmless exogenous antigens. Treg cell deficiencies result in multiple autoimmune and allergic syndromes in neonates. How Treg cells affect conventional allergies against aeroantigens, which are restricted to a few specific proteins released from inhaled particles, remains controversial. The hallmarks of antigen-specific loss of tolerance are allergen-specific T_H2 cells and IgE. However, difficulties in identifying the rare allergen-specific Treg cells have obscured the cellular basis of tolerance to aeroallergens, which is also a major obstacle for the rational design of novel and more efficient allergen-specific immunotherapies. Recent technological progress allowing characterization of allergen-specific effectors and Treg cells with minimal in vitro manipulation revealed their detailed contribution to tolerance. The data identified inhaled particles as immunodominant Treg cell targets in healthy and allergic subjects. Conversely, the supposed immunodominant major allergens being rapidly released from inhaled particles apparently do not actively induce tolerance but are ignored by the immune system. Here, the partially contradictory data on various allergen-specific T-cell types in healthy subjects, allergic patients, and patients undergoing allergen-specific immunotherapy are discussed and integrated into one model, postulating Treg cell-dependent and Treg cell-independent checkpoints of tolerance and allergy development.

Impact of host immunity on HTLV-1 pathogenesis: potential of Tax-targeted immunotherapy against ATL

Human T-cell leukemia virus type-1 (HTLV-1) causes adult T-cell leukemia/lymphoma (ATL), HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), and other inflammatory diseases. There is no disease-specific difference in viral strains, and it is unclear how HTLV-1 causes such different diseases manifesting as lymphoproliferation or inflammation. Although some progress has been made in therapies for these diseases, the prognosis for ATL is still dismal and HAM/TSP remains an intractable disease. So far, two regulatory proteins of HTLV-1, Tax and HBZ, have been well studied and shown to have pleiotropic functions implicated in viral pathogenesis. Tax in particular can strongly activate NFκB, which is constitutively activated in HTLV-1-infected cells and considered to contribute to both oncogenesis and inflammation. However, the expression level of Tax is very low in vivo, leading to confusion in understanding its role in viral pathogenesis. A series of studies using IL-2-dependent HTLV-1-infected cells indicated that IL-10, an anti-inflammatory/immune suppressive cytokine, could induce a proliferative phenotype in HTLV-1-infected cells. In addition, type I interferon (IFN) suppresses HTLV-1 expression in a reversible manner. These findings suggest involvement of host innate immunity in the switch between lymphoproliferative and inflammatory diseases as well as the regulation of HTLV-1 expression. Innate immune responses also affect another important host determinant, Tax-specific cytotoxic T lymphocytes (CTLs), which are impaired in ATL patients, while activated in HAM/TSP patients. Activation of Tax-specific CTLs in ATL patients after hematopoietic stem cell transplantation indicates Tax expression and its fluctuation in vivo. A recently developed anti-ATL therapeutic vaccine, consisting of Tax peptide-pulsed dendritic cells, induced Tax-specific CTL responses in ATL patients and exhibited favorable clinical outcomes, unless Tax-defective ATL clones emerged. These findings support the significance of Tax in HTLV-1 pathogenesis, at least in part, and encourage Tax-targeted immunotherapy in ATL. Host innate and acquired immune responses induce host microenvironments that modify HTLV-1-encoded pathogenesis and establish a complicated network for development of diseases in HTLV-1 infection. Both host and viral factors should be taken into consideration in development of therapeutic and prophylactic strategies in HTLV-1 infection.

The Role of Mesenchymal Stem Cells in Radiation-Induced Lung Fibrosis

Radiation therapy is one of the most important treatment modalities for thoracic tumors. Despite significant advances in radiation techniques, radiation-induced lung injury (RILI) still occurs in up to 30% of patients undergoing thoracic radiotherapy, and therefore remains the main dose-limiting obstacle. RILI is a potentially lethal clinical complication of radiotherapy that has 2 main stages: an acute stage defined as radiation pneumonitis, and a late stage defined as radiation-induced lung fibrosis. Patients who develop lung fibrosis have a reduced quality of life with progressive and irreversible organ malfunction. Currently, the most effective intervention for the treatment of lung fibrosis is lung transplantation, but the lack of available lungs and transplantation-related complications severely limits the success of this procedure. Over the last few decades, advances have been reported in the use of mesenchymal stem cells (MSCs) for lung tissue repair and regeneration. MSCs not only replace damaged lung epithelial cells but also promote tissue repair through the secretion of anti-inflammatory and anti-fibrotic factors. Here, we present an overview of MSC-based therapy for radiation-induced lung fibrosis, focusing in particular on the molecular mechanisms involved and describing the most recent preclinical and clinical studies carried out in the field.

Mesenchymal stromal cell-derived nanovesicles ameliorate bacterial outer membrane vesicle-induced sepsis via IL-10

Background

Sepsis remains a source of high mortality in hospitalized patients despite proper antibiotic approaches. Encouragingly, mesenchymal stromal cells (MSCs) and their produced extracellular vesicles (EVs) have been shown to elicit anti-inflammatory effects in multiple inflammatory conditions including sepsis. However, EVs are generally released from mammalian cells in relatively low amounts, and high-yield isolation of EVs is still challenging due to a complicated procedure. To get over these limitations, vesicles very similar to EVs can be produced by serial extrusions of cells, after which they are called nanovesicles (NVs). We hypothesized that MSC-derived NVs can attenuate the cytokine storm induced by bacterial outer membrane vesicles (OMVs) in mice, and we aimed to elucidate the mechanism involved.

Methods

NVs were produced from MSCs by the breakdown of cells through serial extrusions and were subsequently floated in a density gradient. Morphology and the number of NVs were analyzed by transmission electron microscopy and nanoparticle tracking analysis. Mice were intraperitoneally injected with Escherichia coli-derived OMVs to establish sepsis, and then injected with 2 × 10⁹ NVs. Innate inflammation was assessed in peritoneal fluid and blood through investigation of infiltration of cells and cytokine production. The biodistribution of NVs labeled with Cy7 dye was analyzed using near-infrared imaging.

Results

Electron microscopy showed that NVs have a nanometer-size spherical shape and harbor classical EV marker proteins. In mice, NVs inhibited eye exudates and hypothermia, signs of a systemic cytokine storm, induced by intraperitoneal injection of OMVs. Moreover, NVs significantly suppressed cytokine release into the systemic circulation, as well as neutrophil and monocyte infiltration in the peritoneum. The protective effect of NVs was significantly reduced by prior treatment with anti-interleukin (IL)-10 monoclonal antibody. In biodistribution study, NVs spread to the whole mouse body and localized in the lung, liver, and kidney at 6 h.

Conclusions

Taken together, these data indicate that MSC-derived NVs have beneficial effects in a mouse model of sepsis by upregulating the IL-10 production, suggesting that artificial NVs may be novel EV-mimetics clinically applicable to septic patients.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1352-4) contains supplementary material, which is available to authorized users.

Micro-RNA-96 and interleukin-10 are independent biomarkers for multiple sclerosis activity

BACKGROUND

Micro-RNAs (miRNAs) are evolving as biological markers for multiple sclerosis (MS) both in activity and remission. miR-96 is associated with remission, however, the exact mechanism through which it contributes to the anti-inflammatory pathway is not clear.

OBJECTIVE

To study the expression of miR-96 and IL-10 (anti-inflammatory mediator) in relapsing remitting (RR) MS.

SUBJECTS AND METHODS

A case control study including 32 RRMS patients from Kasr Al-Ainy MS clinic, Cairo University, Egypt, and 26 healthy controls (HC). Assessment of serum IL-10 by ELISA, and miR-96 via real time PCR was done during relapse and remission in patients, and in HC.

RESULTS

IL-10 was higher in RRMS patients during remission and in HC compared with relapse (P ˂ 0.001). miR-96 expression was higher in RRMS patients during remission compared with relapse and HC, and was higher in HC than in relapse (P ˂ 0.001). IL-10 level in remission correlated positively with disease duration (r = 0.41; P = 0.02). Otherwise, no correlation was found between IL-10 and relapse number or EDSS (P>0.05). miR-96 in relapse negatively correlated with EDSS in relapse (r=-0.47; P=0.007), but no correlation was found with disease duration or relapse number, whereas, miR-96 in remission did not correlate with any clinical parameters (P>0.05). No correlation was found between IL-10 and miR-96 either in relapse or remission (P>0.05).

CONCLUSION

IL-10 and miR-96 are associated with MS quiescence, however, the lack of a significant correlation between them implicates that the influence of miR-96 may be exhibited through some pathway other than IL-10.

Wuchereria bancrofti-infected individuals harbor distinct IL-10-producing regulatory B and T cell subsets which are affected by anti-filarial treatment

Despite worldwide mass drug administration, it is estimated that 68 million individuals are still infected with lymphatic filariasis with 19 million hydrocele and 17 million lymphedema reported cases. Despite the staggering number of pathology cases, the majority of LF-infected individuals do not develop clinical symptoms and present a tightly regulated immune system characterized by higher frequencies of regulatory T cells (Treg), suppressed proliferation and Th2 cytokine responses accompanied with increased secretion of IL-10, TGF-β and infection-specific IgG4. Nevertheless, the filarial-induced modulation of the host`s immune system and especially the role of regulatory immune cells like regulatory B (Breg) and Treg during an ongoing LF infection remains unknown. Thus, we analysed Breg and Treg frequencies in peripheral blood from Ghanaian uninfected endemic normals (EN), lymphedema (LE), asymptomatic patent (CFA+MF+) and latent (CFA+MF-) W. bancrofti-infected individuals as well as individuals who were previously infected with W. bancrofti (PI) but had cleared the infection due to the administration of ivermectin (IVM) and albendazole (ALB). In summary, we observed that IL-10-producing CD19⁺CD24^highCD38d^high Breg were specifically increased in patently infected (CFA+MF+) individuals. In addition, CD19⁺CD24^highCD5⁺CD1d^high and CD19⁺CD5⁺CD1d^highIL-10⁺ Breg as well as CD4⁺CD127^-FOXP3⁺ Treg frequencies were significantly increased in both W. bancrofti-infected cohorts (CFA+MF+ and CFA+MF-). Interestingly, the PI cohort presented frequency levels of all studied regulatory immune cell populations comparable with the EN group. In conclusion, the results from this study show that an ongoing W. bancrofti infection induces distinct Breg and Treg populations in peripheral blood from Ghanaian volunteers. Those regulatory immune cell populations might contribute to the regulated state of the host immune system and are probably important for the survival and fertility (microfilaria release) of the helminth.

Regulation of the host`s immune system by filarial nematodes is crucial for the fertility and survival of the nematode. Indeed, the majority of W. bancrofti-infected individuals are characterized by a regulated state including increased regulatory T cells (Treg), IL-10, TGF-β and filarial-specific IgG4 and suppressed Th2 cytokine responses. However, the functional role of Treg populations and regulatory B cells (Breg) during filarial infection remains unknown. Thus, in this study we investigated whether W. bancrofti-infected individuals from Ghana harbored distinct Breg and Treg populations which might be important for filarial-specific immunomodulation. Overall, this study shows that W. bancrofti induces distinct Breg populations, especially in patently (microfilaremic) infected individuals who presented significantly increased frequencies of IL-10-producing CD19<sup>+</sup>CD24<sup>high</sup>CD38d<sup>high</sup> Breg. Furthermore, clearance of the infection, due to anti-filarial treatment, returned these regulatory immune cells to homeostatic levels showing that an ongoing filarial infection is important for the activation of distinct Breg and Treg subsets. Those regulatory immune cell subsets are a part of a complex system which are induced by filarial nematodes to modulate the host`s immune system and maintain long-term survival.

Effects of systemic and neuraxial morphine on the immune system

In the study, we tried to evaluate the effects of morphine injected through the systemic or neuraxial route on immune cell function and cytokine production in healthy women.In total, 29 paired samples of fresh peripheral blood were collected from healthy women who had been administered morphine for anesthetic analgesia through intravenous (IV), epidural, or spinal route postpartum. Their isolated peripheral blood mononuclear cells were mitogen-activated and stained with fluorochrome-conjugated anti-CD4, anti-CD8, anti-interleukin (IL)-2, and anti-interferon (IFN)-γ antibodies for flow cytometry, and the plasma levels of cytokines, including IL-6, IFN-α2, IL-10, IL-8, GM-CSF, and monocyte chemoattractant protein (MCP)-1, were measured through enzyme-linked immunosorbent assay.The results demonstrated that regardless of the administration route, morphine delivery slightly reduced IL-2 expression in CD4 cells after activation, and the same effect was not noted for CD8 cells. Intravenous or epidural morphine tended to reduce IFN-γ expression in CD8 cells. Spinal and IV morphine substantially increased IL-6 production, whereas epidural morphine hindered IL-10 and GM-CSF production. IV morphine injection reduced MCP-1 production in plasma. Compared with spinal morphine, IV or epidural morphine may more effectively inhibit the expression of various cytokines and thus affect immune response.All 3 routes of morphine injection tended to decrease IL-2 production by CD4 cells, whereas IV or epidural morphine injection showed lower IFN-γ production by CD8 cells. However, additional large-scale studies with longer follow-up durations are warranted.

Salivary gland immunization via Wharton's duct activates differential T-cell responses within the salivary gland immune system

Salivary glands are a major component of the mucosal immune system that confer adaptive immunity to mucosal pathogens. As previously demonstrated, immunization of the submandibular gland with tissue culture-derived murine cytomegalovirus (tcMCMV) or replication-deficient adenoviruses expressing individual murine cytomegalovirus (MCMV) genes protected mice against a lethal MCMV challenge. Here, we report that salivary gland inoculation of BALB/cByJ mice with tcMCMV or recombinant adenoviruses differentially activates T helper (Th)1, -2, and -17 cells in the salivary glands vs. the associated lymph nodes. After inoculation with tcMCMV, lymphocytes from the submandibular gland preferentially express the transcription factor T-cell-specific T-box transcription factor (T-bet), which controls the expression of the hallmark Th1 cytokine, IFN-γ. Lymphocytes from the periglandular lymph nodes (PGLNs) express both T-bet and GATA-binding protein 3 (GATA3), which promotes the secretion of IL-4, -5, and -10 from Th2 cells. In contrast, after inoculation with replication-deficient adenoviruses, lymphocytes from the submandibular gland express T-bet, GATA3, and RAR-related orphan receptor γ, thymus-specific isoform (RORγt) (required for differentiation of Th17 cells) and forkhead box P3 (Foxp3) (required for the differentiation of regulatory T cells). Lymphocytes from the PGLNs were not activated. The differential induction of Th responses in the salivary gland vs. the PGLNs after inoculation with attenuated virus vs. a nominal protein antigen supports the use of the salivary as an alternative mucosal route for administering vaccines.-Liu, G., Zhang, F., Wang, R., London, S. D., London, L. Salivary gland immunization via Wharton's duct activates differential T-cell responses within the salivary gland immune system.

Controlling Gut Inflammation by Restoring Anti-Inflammatory Pathways in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is caused by a dysregulated immune response against normal components of the intestinal microflora combined with defective functioning of anti-inflammatory pathways. Currently, all therapies approved for IBD manipulate the immune system by inhibiting pro-inflammatory mechanisms, such as tumor necrosis factor-α, gut-homing α4β7 integrin, interleukin-12/interleukin-23, and Janus kinases. However, some IBD patients are non-responders to these drugs, which are also associated with serious side effects. Thus, it has been hypothesized that therapies aimed at restoring anti-inflammatory signals, by exploiting the tolerogenic potential of cytokines (interleukin-10, transforming growth factor-β, granulocyte macrophage colony-stimulating factor), immune cells (regulatory T cells, tolerogenic dendritic cells), or mesenchymal stem cells, might offer promising results in terms of clinical efficacy with fewer side effects. In this review, we provide new insights into putative novel treatments aimed at restoring anti-inflammatory signaling pathways in IBD.

Induced Pluripotent Stem Cell-Derived T Cells for Cancer Immunotherapy

Adoptive T cell therapy for solid malignancies is limited because obtaining sufficient numbers of less-differentiated tumor-specific T cells is difficult. This roadblock can be theoretically overcome by the use of induced pluripotent stem cells (iPSCs), which self-renew and provide unlimited numbers of autologous less-differentiated T cells. iPSCs can generate less-differentiated antigen-specific T cells that harbor long telomeres and increased proliferative capacity, and exhibit potent antitumor efficacy. Although this strategy holds great promise for adoptive T cell therapy, highly reproducible and robust differentiation protocols are required before the translation of iPSC technology into the clinical setting.

[Ru(bpy)2(NO)SO3](PF6), a Nitric Oxide Donating Ruthenium Complex, Reduces Gout Arthritis in Mice

Monosodium urate crystals (MSU) deposition induces articular inflammation known as gout. This disease is characterized by intense articular inflammation and pain by mechanisms involving the activation of the transcription factor NFκB and inflammasome resulting in the production of cytokines and oxidative stress. Despite evidence that MSU induces iNOS expression, there is no evidence on the effect of nitric oxide (NO) donors in gout. Thus, the present study evaluated the effect of the ruthenium complex donor of NO {[Ru(bpy)₂(NO)SO₃](PF₆)} (complex I) in gout arthritis. Complex I inhibited in a dose-dependent manner MSU-induced hypersensitivity to mechanical stimulation, edema and leukocyte recruitment. These effects were corroborated by a decrease of histological inflammation score and recruitment of Lysm-eGFP⁺ cells. Mechanistically, complex I inhibited MSU-induced mechanical hypersensitivity and joint edema by triggering the cGMP/PKG/ATP-sensitive K (+) channels signaling pathway. Complex I inhibited MSU-induced oxidative stress and pro-inflammatory cytokine production in the knee joint. These data were supported by the observation that complex I inhibited MSU-induced NFκB activation, and IL-1β expression and production. Complex I also inhibited MSU-induced activation of pro-IL-1β processing. Concluding, the present data, to our knowledge, is the first evidence that a NO donating ruthenium complex inhibits MSU-induced articular inflammation and pain. Further, complex I targets the main physiopathological mechanisms of gout arthritis. Therefore, it is envisaged that complex I and other NO donors have therapeutic potential that deserves further investigation.

Association between Neonatal Whole Blood Iron Content and Cytokines, Adipokines, and Other Immune Response Proteins

(1) Background: High iron associates with inflammation and type 1 diabetes (T1D). Iron is essential not only for neonatal development but also for infectious microorganisms. The neonatal immune system is immature, and innate immunity prevails before immunocompetence develops. (2) Methods: In 398 newborns from the Danish Newborn Screening Biobank, we examined if whole blood iron (WB-Iron) content were associated with cytokines, adipokines, C-reactive protein (CRP), and mannose-binding lectin (MBL) in non-infected healthy neonates, and if these associations differed in newborns who later developed T1D (cases) (n = 199). WB-Iron was quantified using laser ablation inductively coupled plasma mass spectrometry on the neonatal dried blood spots. For each analyte, the relative change (RC) in the mean level was modeled by robust log-normal regression. (3) Results: A one unit increase in neonatal WB-Iron was associated with a 38% decrease in mean interleukin (IL)-6 levels (0.62; 95% CI: 0.40–0.95, p = 0.03), and a 37% decrease in mean MBL levels (0.63; 95% CI: 0.41–0.95, p = 0.03), but was not statistically significant after correction for multiple testing. (4) Conclusions: In summary, we found that higher neonatal WB-iron content was inversely associated with IL-6 and MBL, which may increase susceptibility to infections.

Short Communication: Tracking Tregs: Translocation of CD49b/LAG-3+ Type 1 T Regulatory Cells to the Gut-Associated Lymphoid Tissue of HIV+ Patients

The gastrointestinal mucosa [gut-associated lymphoid tissue (GALT)] represents the largest site of chronic immune activation and HIV replication. Important cellular agents in the immunopathogenesis of an HIV infection are, in particular, CD49b/LAG-3⁺ type 1 T regulatory cells (Tr1), which secrete large amounts of IL-10 (interleukin-10), and plasmacytoid dendritic cells, the main producers of IFN-α (interferon-alpha). However, the distribution of CD49b/LAG-3⁺ Tr1 cells along the GALT is unknown.

The Combination Vaccine Adjuvant System Alum/c-di-AMP Results in Quantitative and Qualitative Enhanced Immune Responses Post Immunization

The development of new effective vaccines strongly depends on adjuvants and formulations able to stimulate not only strong humoral responses against a certain pathogen but also effector as well as memory CD4+ and CD8+ T cells (Dubensky et al., 2013). However, the majority of vaccines licensed for human use or currently under clinical investigation fail to stimulate efficient cellular responses. For example, vaccines against hepatitis B virus (HBV), human papillomavirus (HPV), diphtheria, tetanus and influenza are usually administered by intramuscular (i.m.) injection and contain aluminum salts (alum) as adjuvant. Alum has been shown to stimulate Th2 immune cells resulting in increased production of antigen-specific antibodies but to be incapable of stimulating robust Th1 or cytotoxic responses. To overcome such limitations recent research has focused on the development of adjuvant combinations (e.g., MF59, AS03 or AS04) to not only further strengthen antigen-specific immune responses but to also allow their modulation. We have shown previously that bis-(3',5')-cyclic dimeric adenosine monophosphate (c-di-AMP) constitutes a promising adjuvant candidate stimulating both effective Th1/Th2 and cytotoxic immune responses when included in mucosal or parenteral vaccine formulations. In the present work we demonstrate that c-di-AMP can be also combined with other adjuvants like alum resulting in increases in not only humoral responses but more striking also in cellular immune responses. This leads to improved vaccine efficacy against intracellular pathogens.

Microbiotas from Humans with Inflammatory Bowel Disease Alter the Balance of Gut Th17 and RORγt+ Regulatory T Cells and Exacerbate Colitis in Mice

Microbiota are thought to influence the development and progression of inflammatory bowel disease (IBD), but determining generalizable effects of microbiota on IBD etiology requires larger-scale functional analyses. We colonized germ-free mice with intestinal microbiotas from 30 healthy and IBD donors and determined the homeostatic intestinal T cell response to each microbiota. Compared to microbiotas from healthy donors, transfer of IBD microbiotas into germ-free mice increased numbers of intestinal Th17 cells and Th2 cells and decreased numbers of RORγt+ Treg cells. Colonization with IBD microbiotas exacerbated disease in a model where colitis is induced upon transfer of naive T cells into Rag1-/- mice. The proportions of Th17 and RORγt+ Treg cells induced by each microbiota were predictive of human disease status and accounted for disease severity in the Rag1-/- colitis model. Thus, an impact on intestinal Th17 and RORγt+ Treg cell compartments emerges as a unifying feature of IBD microbiotas, suggesting a general mechanism for microbial contribution to IBD pathogenesis.

Regulatory cytokine function in the respiratory tract

The respiratory tract is an important site of immune regulation; required to allow protective immunity against pathogens, while minimizing tissue damage and avoiding aberrant inflammatory responses to inhaled allergens. Several cell types work in concert to control pulmonary immune responses and maintain tolerance in the respiratory tract, including regulatory and effector T cells, airway and interstitial macrophages, dendritic cells and the airway epithelium. The cytokines transforming growth factor β, interleukin (IL-) 10, IL-27, and IL-35 are key coordinators of immune regulation in tissues such as the lung. Here, we discuss the role of these cytokines during respiratory infection and allergic airway disease, highlighting the critical importance of cellular source and immunological context for the effects of these cytokines in vivo.

The Potential for Cancer Immunotherapy in Targeting Surgery-Induced Natural Killer Cell Dysfunction

Natural Killer (NK) cells are granular lymphocytes of the innate immune system that are able to recognize and kill tumor cells without undergoing clonal selection. Discovered over 40 years ago, they have since been recognized to possess both cytotoxic and cytokine-producing effector functions. Following trauma, NK cells are suppressed and their effector functions are impaired. This is especially important for cancer patients undergoing the removal of solid tumors, as surgery has shown to contribute to the development of metastasis and cancer recurrence postoperatively. We have recently shown that NK cells are critical mediators in the formation of metastasis after surgery. While research into the mechanism(s) responsible for NK cell dysfunction is ongoing, knowledge of these mechanisms will pave the way for perioperative therapeutics with the potential to improve cancer outcomes by reversing NK cell dysfunction. This review will discuss mechanisms of suppression in the postoperative environment, including hypercoagulability, suppressive soluble factors, the expansion of suppressive cell populations, and how this affects NK cell biology, including modulation of cell surface receptors, the potential for anergy, and immunosuppressive NK cell functions. This review will also outline potential immunotherapies to reverse postoperative NK dysfunction, with the goal of preventing surgery-induced metastasis.