Regulatory B cells correlate with HIV disease progression

A rare subset of IL‐10‐producing B cells, named Breg, was recently identified in mice and humans. Currently, there are no unified cell surface markers to identify Breg, and the relationship between the frequency of Breg and HIV disease progression in chronic HIV infection is unclear. In the present study, we determined whether the cell surface markers of Breg reported for other diseases are suitable for identifying Breg in HIV‐infected patients. In addition, we examined the relationship between Breg and HIV disease progression. We found that Breg frequency correlated positively with viral load and negatively with CD4 count in chronic HIV infection. Following antiretroviral treatment, the CD4 count increased and the frequency of Breg decreased stepwise. There was no difference in IL‐10 expression of CD1d^hi or CD1d^lo cells isolated from HIV‐infected patients. Therefore, CD1d may not be a marker of Breg in HIV‐infected patients.     

Critical role of inflammatory mast cell in fibrosis: Potential therapeutic effect of IL‐37

Background

Fibrosis involves the activation of inflammatory cells, leading to a decrease in physiological function of the affected organ or tissue.

Aims

To update and synthesize relevant information concerning fibrosis into a new hypothesis to explain the pathogenesis of fibrosis and propose potential novel therapeutic approaches.

Materials and Methods

Literature was reviewed and relevant information is discussed in the context of the pathogenesis of fibrosis.

Results

A number of cytokines and their mRNA are involved in the circulatory system and in organs of patients with fibrotic tissues. The profibrotic cytokines are generated by several activated immune cells, including fibroblasts and mast cells (MCs), which are important for tissue inflammatory responses to different types of injury. MC‐derived TNF, IL‐1, and IL‐33 contribute crucially to the initiation of a cascade of the host defence mechanism(s), leading to the fibrosis process. Inhibition of TNF and inflammatory cytokines may slow the progression of fibrosis and improve the pathological status of the affected subject. IL‐37 is generated by various types of immune cells and is an IL‐1 family member protein. IL‐37 is not a receptor antagonist; it binds IL‐18 receptor alpha (IL‐18Rα) and delivers the inhibitory signal by using TIR8. It has been shown that IL‐37 can be protective in inflammation and injury, and inhibits both innate and adaptive immunity.

Discussion

IL‐37 may be useful for suppression of inflammatory diseases induced by inhibiting MyD88‐dependent TLR signalling. In addition, IL‐37 downregulates NF‐κB induced by TLR2 or TLR4 through a mechanism dependent on IL‐18Rα.

Conclusion

This review summarizes current knowledge on the role of MC in inflammation and tissue/organ fibrosis, with a focus on the therapeutic potential of IL‐37‐targeting cytokines.

     

Syngeneic fibroblasts transfected with a plasmid encoding interleukin-4 as non-viral vectors for anti-inflammatory gene therapy in collagen-induced arthritis

Background

No effective long‐term treatment is available for rheumatoid arthritis. Recent advances in gene therapy and cell therapy have demonstrated efficiency in collagen‐induced arthritis (CIA). Interleukin‐4 (IL‐4) is already known to be efficient in CIA in systemic injection or administered by gene therapy. This study was designed to evaluate the effect of a non‐viral gene therapy of CIA, involving injection of syngeneic fibroblasts transfected with a plasmid encoding for IL‐4.

Methods

Immortalised fibroblasts from DBA/1 mice (DBA/1/0 cells) were transfected with a plasmid expressing IL‐4 cDNA (DBA/1/IL‐4 cells). Xenogeneic fibroblasts from Chinese hamster ovary (CHO) transfected with a plasmid expressing IL‐4 cDNA (CHO/IL‐4) were studied also. The cells were engrafted in mice developing CIA by subcutaneous injection of 3 × 10⁶ DBA/1/0 or DBA/1/IL‐4 or CHO/IL‐4 cells.

Results

Injection of DBA/1/IL‐4 cells, on days 10 and 25 after immunisation, was associated with a significant and lasting improvement in the clinical and histological evidence of joint inflammation and destruction as compared with DBA/1/0 and CHO/IL‐4 cells. DBA/1/IL‐4 cell treatment decreased also the production of IgG2a antibody to CII and the proliferation of CIIB‐specific nodal T cells. Later treatments (engraftments on days 23 and 35 after immunisation) exerted also an anti‐inflammatory effect, as evaluated on clinical and histological signs of CIA.

Conclusions

Taken together, these findings indicate that systemic administration of syngeneic cells transfected with an anti‐inflammatory cytokine gene, namely IL‐4, with a non‐viral method is effective in CIA and may attenuate the cytokine imbalance seen in this disease. Copyright © 2002 John Wiley & Sons, Ltd.

     

Regulatory B and T cells in infections

The role of T and B lymphocytes, as antigen-specific effector immune cells playing an essential role in host defense against pathogens, is well recognized. Over the last decade, these lymphocytes have however also emerged as key regulatory components of the immune system, able to prevent various immunopathologies due to excessive inflammatory responses. These regulatory T (Treg) and B (Breg) cells, endowed with anti-inflammatory properties, operate via both antigen-specific and non-specific mechanisms and mainly develop during chronic infections. Here, we discuss the role of Treg and Breg lymphocytes in various infectious diseases, in experimental murine models and in human.     

Attenuated accumulation of regulatory T cells and reduced production of interleukin 10 lead to the exacerbation of tissue injury in a mouse model of acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a pathological condition that involves diffuse lung injury and severe hypoxemia caused by pulmonary and systemic diseases. We have established a mouse model of severe ARDS, developed by intratracheal injection of α‐galactosylceramide (α‐GalCer), an activator of natural killer T (NKT) cells, followed by LPS. In the present study, we used this model to investigate the regulatory mechanism in the early inflammatory response during acute lung injury. In α‐GalCer/LPS‐treated mice, the number of CD4⁺CD25⁺Foxp3⁺ regulatory T (Treg) cells and the expression of a Treg cell‐tropic chemokine, secondary lymphoid‐tissue chemokine (SLC), in the lungs was significantly lower than in mice treated with LPS alone. Giving recombinant (r)SLC increased the number of Treg cells in α‐GalCer/LPS‐treated mice. Treatment with anti‐IFN‐γ mAb enhanced the expression of SLC and the accumulation of Treg cells in the lungs of α‐GalCer/LPS‐treated mice, whereas giving recombinant (r)IFN‐γ reduced the number of Treg cells in mice treated with LPS alone. IL‐10 production was significantly lower in α‐GalCer/LPS‐treated mice than in mice treated with LPS alone. Giving rIL‐10 prolonged survival and attenuated lung injury as a result of reduced production of inflammatory cytokines (such as IL‐1β, IL‐6, TNF‐α, and IFN‐γ) and chemokines (including MCP‐1, RANTES, IP‐10, Mig, MIP‐2, and KC) in α‐GalCer/LPS‐treated mice. Treatment with anti‐IFN‐γ mAb enhanced IL‐10 production in α‐GalCer/LPS‐treated mice. These results suggest that the attenuated accumulation of Treg cells may be involved in the development of severe ARDS through a reduction in the synthesis of IL‐10.

     

Association of immune system gene polymorphisms with quantitative traits pathogenetically important for chronic virus hepatitis

The IL4 C(?590)T, IL4RA Ile50Val, and TNF G(?308)A polymorphisms were tested for association with quantitative traits important for chronic virus hepatitis, including the levels of IL4, IL10, IL12, TNF-α, fibronectin, collagenase, the proteinase inhibitor, macroglobulin, and free and protein-bound (PBO) oxyproline. Allele A of the TNF G(?308)A polymorphism was associated with a lower TNF-α production by mononuclear cells, a higher production of IL4 and IL12, and a lower PBO level. The genotype CT of the IL4 C(?590)T polymorphism was associated with a high PBO level.     

Autocrine stimulation of IL-10 is critical to the enrichment of IL-10-producing CD40hiCD5+ regulatory B cells in vitro and in vivo

IL-10-producing B (Breg) cells regulate various immune responses. However, their phenotype remains unclear. CD40 expression was significantly increased in B cells by LPS, and the Breg cells were also enriched in CD40^hiCD5⁺ B cells. Furthermore, CD40 expression on Breg cells was increased by IL-10, CD40 ligand, and B cell-activating factor, suggesting that CD40^hi is a common phenotype of Breg cells. LPS-induced CD40 expression was largely suppressed by an anti-IL-10 receptor antibody and in IL-10^−/−CD5⁺CD19⁺ B cells. The autocrine effect of IL-10 on the CD40 expression was largely suppressed by an inhibitor of JAK/STAT3. In vivo, the LPS treatment increased the population of CD40^hiCD5⁺ Breg cells in mice. However, the population of CD40^hiCD5⁺ B cells was minimal in IL-10^−/− mice by LPS. Altogether, our findings show that Breg cells are largely enriched in CD40^hiCD5⁺ B cells and the autocrine effect of IL-10 is critical to the formation of CD40^hiCD5⁺ Breg cells. [BMB Reports 2015; 48(1): 54-59]     

Polybrene and interleukin-4: two opposing factors for retroviral transduction of bone-marrow-derived dendritic cells

Background

Gene transfer using retroviral transduction offers the advantage of long‐term transgene expression in developing strategies that use dendritic cells (DCs) for immunotherapy. The goal of this study was to infect DCs in an immature state in order to take advantage of their proliferating and tolerogenic potential.

Methods

Immature DCs were generated from murine bone marrow (BM) using either GM‐CSF alone or GM‐CSF plus IL‐4. The cells were transduced directly with retroviral supernatants or by co‐culture with the GP + E‐86 retroviral packaging cell line in the presence of two different cationic polymers: polybrene and protamine sulfate. Phenotypic and functional characterization of the transduced cells were then performed.

Results

Our results show a low efficiency of retroviral infection of DCs in the presence of polybrene. This cationic polymer was found to be directly cytotoxic to murine DCs and thus favored the growth of contaminating macrophages. This effect was not observed using protamine sulfate. Furthermore, stimulation by IL‐4 early in the culture increased DC differentiation, proliferation and transduction. However, we found that DCs generated in GM‐CSF plus IL‐4 presented a more mature phenotype with an enhanced allogeneic stimulating activity. Finally, we showed that DCs themselves down‐regulated transgene expression in the co‐cultured packaging cell line in a promoter‐dependent manner.

Conclusions

We have defined optimal conditions to generate and transduce murine BM‐derived DCs. This included: the use of protamine sulfate during exposure to retroviral infectious supernatant and the addition of IL‐4 at an early stage of the culture. Nevertheless, this cytokine also induced DC maturation. These findings have potential implications in experimental gene therapy. Copyright © 2002 John Wiley & Sons, Ltd.

     

Clinical significance of weak interleukin‐35 expression in patients with psoriasis

CD4+T cells and their related cytokines play an important role in the pathogenesis of psoriasis, a chronic, recurrent, inflammatory skin disease. The role of IL‐35, an immunosuppressive cytokine involved in many autoimmune diseases, in the pathogenesis of psoriasis is unclear. In this study IL‐35 expression and its clinical significance in patients with psoriasis were evaluated. Protein and mRNA levels of specified markers were measured by ELISA and qRT‐PCR, respectively. It was found that plasma IL‐35 concentrations were lower in patients with psoriasis than in healthy individuals (Z = ?6.525, P < 0.0001). mRNA titers of Ebi3 and p35 were lower in peripheral blood mononuclear cells from patients with psoriasis than in those from healthy individuals (Z = ?5.078, P < 0.0001; Z = ?2.609, P = 0.009, respectively). The areas under the receiver‐operating characteristic (ROC) curves for IL‐35, Ebi3 and p35 in patients with psoriasis versus controls were 0.86, 0.78 and 0.64, respectively. Pearson correlation analysis showed that, in patients with psoriasis, plasma IL‐35 expression correlated negatively with concentrations of INF‐γ, tumor necrosis factor‐alpha, IL‐23, ?17, and ?22, and the Psoriasis Activity and Severity Index and positively with concentrations of transforming growth factor beta and IL‐10 . In summary, IL‐35 may mediate pathogenesis of psoriasis by influencing expression of Th1/Th17/T_reg‐related cytokines and may therefore be a putative target for monitoring or treating psoriasis.

     

The contrasting roles of Th17 immunity in human health and disease

The human immune system is a tightly regulated network that protects the host from disease. An important aspect of this is the balance between pro‐inflammatory Th17 cells and anti‐inflammatory T regulatory (Treg) cells in maintaining immune homeostasis. Foxp3+ Treg are critical for sustaining immune tolerance through IL‐10 and transforming growth factor‐β while related orphan receptor‐γt+ Th17 cells promote immunopathology and auto‐inflammatory diseases through the actions of IL‐17A, IL‐21 and IL‐22. Therefore, imbalance between Treg and Th17 cells can result in serious pathology in many organs and tissues. Recently, certain IL‐17‐producing cells have been found to be protective against infectious disease, particularly in relation to extracellular bacteria such Streptococcus pneumoniae; a number of other novel IL‐17‐secreting cell populations have also been reported to protect against a variety of other pathogens. In this mini‐review, the dual roles of Treg and Th17 cells are discussed in the context of autoimmunity and infections, highlighting recent advances in the field. Development of novel strategies specifically designed to target these critical immune response pathways will become increasingly important in maintenance of human health.     

B cell subsets and dysfunction of regulatory B cells in IgG4-related diseases and primary Sj?gren’s syndrome: the similarities and differences

Introduction

IgG4-related disease (IgG4-RD) is a multisystem-involved autoimmune disease. Abnormally activated and differentiated B cells may play important roles. Regulatory B cells (Breg) are newly defined B cell subgroups with immunosuppressive functions. In this study, we investigated the differences of B cell subsets, the expressions of co-stimulatory molecules on B cells, and the function of Breg cells in patients with IgG4-RD, primary Sjögren’s syndrome (pSS) as well as in healthy controls (HC).

Methods

Newly diagnosed IgG4-RD patients (n = 48) were enrolled, 38 untreated pSS patients and 30 healthy volunteers were recruited as disease and healthy controls. To analyze B cell subsets and B cell activity, PBMCs were surface stained and detected by flow cytometry. The function of Breg cells was tested by coculturing isolated CD19 + CD24^hiCD38^hi Breg cells with purified CD4 + CD25- T cells. Serum cytokines were measured by ELISA and cytometric bead array. Relationship between clinical data and laboratory findings were analyzed as well.

Results

Compared with pSS patients and HC, IgG4-RD patients had a lower frequency of peripheral Breg cells. Interestingly, CD19 + CD24-CD38^hi B cell subsets were significantly higher in peripheral B cells from IgG4-RD patients than in pSS patients and HC, which correlated with serum IgG4 levels. The expression of BAFF-R and CD40 on B cells was significantly lower in IgG4-RD patients compared with those in pSS patients and HC. Unlike HC, Breg cells from pSS patients lacked suppressive functions.

Conclusions

B cells in patients with IgG4-RD and pSS display a variety of abnormalities, including disturbed B cell subpopulations, abnormal expression of key signaling molecules, co-stimulatory molecules, and inflammatory cytokines. In addition, a significantly increased B cell subset, CD19 + CD24-CD38^hi B cells, may play an important role in the pathogenesis of IgG4-RD.     

Entinostat,a histone deacetylase inhibitor,increases the population of IL-10+ regulatory B cells to suppress contact hypersensitivity

IL-10⁺ regulatory B (Breg) cells play a vital role in regulating the immune responses in experimental autoimmune encephalomyelitis, colitis, and contact hypersensitivity (CHS). Several sti-mulants such as lipopolysaccharide (LPS), CD40 ligand, and IL-21 spur the activation and maturation of IL-10⁺ Breg cells, while the epigenetic mechanism for the IL-10 expression remains largely unknown. It is well accepted that the histone acetylation/deacetylation is an important mechanism that regulates the expression of IL-10. We found that entinostat, an HDAC inhibitor, stimulated the induction of IL-10⁺ Breg cells by LPS in vitro and the formation of IL-10⁺ Breg cells to suppress CHS in vivo. We further demonstrated that entinostat inhibited HDAC1 from binding to the proximal region of the IL-10 expression promoter in splenic B cells, followed by an increase in the binding of NF-κB p65, eventually enhancing the expression of IL-10 in Breg cells.     

Interleukin‐17‐induced expression of monocyte chemoattractant protein‐1 in cardiac myocytes requires nuclear factor κB through the phosphorylation of p65

IL‐17 plays a key role in a variety of autoimmune diseases. MCP‐1 is involved in the infiltration of mononuclear cells of myocardium in VMC. However, the relationship between IL‐17 and MCP‐1 in myocardial injury remains unclear. In this study, expression of MCP‐1 mRNA and protein in cardiac myocytes was detected with qRT‐PCR and ELISA, respectively. It was found that IL‐17A induced MCP‐1 expression in a dose‐ and time‐dependent manner in cardiac myocytes, which could be blocked by IL‐17A and IL‐17RA neutralizing antibodies. NF‐κB p65 and p‐p65 protein expression in cardiac myocytes was studied with western blotting. Rates of p‐p65 in whole lysates and in nuclear lysates all increased in the first 15 min. Meanwhile, the amount of NF‐κB p65 in whole lysates did not change, but the amount of NF‐κB p65 in nuclear lysates increased in the first 15 min. Then the optimal sequence and concentration of NF‐κB p65 siRNAs was selected. After transfection of 10 nM siRNA‐2 of NF‐κB p65 into cardiac myocytes before stimulation by IL‐17A, expression of MCP‐1 mRNA and protein obviously decreased. In conclusion, expression of MCP‐1 induced by IL‐17 requires NF‐κB through the phosphorylation of p65 in cardiac myocytes, which is meaningful to study the onset of chronic viral myocarditis and will provide a new target for the treatment of viral myocarditis.

     

EDIII‐DENV3 nanospheres drive immature dendritic cells into a mature phenotype in an in vitro model

Domain III of E protein of dengue virus (DENV) is a target for vaccine development. Unfortunately, this protein based platform has low general immunogenicity. To circumvent this problem, the use of an adjuvant‐nanoparticle delivery system to facilitate immunogenicity of soluble DENV‐EDIII protein was investigated. One of the key features of this delivery system is its ability to simultaneously deliver antigens and exert adjuvanticity on specialized immune cells. In this study, N‐trimethyl chitosan (TMC) nanoparticles (NPs) were generated to be used as adjuvant and carrier for soluble E‐domain III of dengue virus serotype 3 (sEDIII‐D3). Using ionotropic gelation, purified sEDIII‐D3 was encapsulated into TMC NPs to form EDIII‐D3 TMC NPs. After optimization, EDIII‐D3 TMC particles exhibited a loading efficiency of 81% and a loading capacity of 41%. The immunogenicity of EDIII‐D3 TMC NPs was tested using monocyte‐derived dendritic cells (MoDCs). It was found that EDIII‐D3 TMC NPs were well taken up by MoDCs. In addition, EDIII‐D3 TMC NP treated MoDCs significantly upregulated maturation markers (CD80, CD83, CD86 and HLA‐DR) and induced secretion of various cytokines and chemokines (IFN‐α, IL‐1β, IL‐6, IL‐2, IL‐12p70, IFN‐γ, IL‐4, IL‐10, IL‐8, MCP‐1, macrophage inflammatory protein‐1β, granulocyte‐colony stimulating factor, granulocyte–macrophage colony‐stimulating factor and IL‐7). These results indicate that EDIII‐D3 TMC NPs are potent immunogens, at least in vitro , with the ability to induce maturation of DCs and highlight the potential use of TMC NPs for enhancing immunogenicity of a non‐replicating dengue vaccine.

     

Interleukin 35 Regulatory B Cells

B lymphocytes play a central role in host immunity. They orchestrate humoral immune responses that modulate activities of other immune cells and produce neutralizing antibodies that confer lasting immunity to infectious diseases including smallpox, measles and poliomyelitis. In addition to these traditional functions is the recent recognition that B cells also play critical role in maintaining peripheral tolerance and suppressing the development or severity of autoimmune diseases. Their immune suppressive function is attributed to relatively rare populations of regulatory B cells (Bregs) that produce anti-inflammatory cytokines including interleukin 10 (IL-10), IL-35 and transforming growth factor-β. The IL-35-producing B cell (i35-Breg) is the newest Breg subset described. i35-Bregs suppress central nervous system autoimmune diseases by inducing infectious tolerance whereby conventional B cells acquire regulatory functions that suppress pathogenic Th17 responses. In this review, we discuss immunobiology of i35-Breg cell, i35-Breg therapies for autoimmune diseases and potential therapeutic strategies for depleting i35-Bregs that suppress immune responses against pathogens and tumor cells.     

Variants of the IL‐10 gene associate with muscle strength in elderly from rural Africa: a candidate gene study

Recently, it has been shown that the capacity of the innate immune system to produce cytokines relates to skeletal muscle mass and strength in older persons. The interleukin‐10 (IL‐10) gene regulates the production capacities of IL‐10 and tumour necrosis factor‐α (TNF‐α). In rural Ghana, IL‐10 gene variants associated with different production capacities of IL‐10 and TNF‐α are enriched compared with Caucasian populations. In this setting, we explored the association between these gene variants and muscle strength. Among 554 Ghanaians aged 50 years and older, we determined 20 single nucleotide polymorphisms in the IL‐10 gene, production capacities of IL‐10 and TNF‐α in whole blood upon stimulation with lipopolysaccharide (LPS) and handgrip strength as a proxy for skeletal muscle strength. We distinguished pro‐inflammatory haplotypes associated with low IL‐10 production capacity and anti‐inflammatory haplotypes with high IL‐10 production capacity. We found that distinct haplotypes of the IL‐10 gene associated with handgrip strength. A pro‐inflammatory haplotype with a population frequency of 43.2% was associated with higher handgrip strength (P = 0.015). An anti‐inflammatory haplotype with a population frequency of 7.9% was associated with lower handgrip strength (P = 0.006). In conclusion, variants of the IL‐10 gene contributing to a pro‐inflammatory cytokine response associate with higher muscle strength, whereas those with anti‐inflammatory response associate with lower muscle strength. Future research needs to elucidate whether these effects of variation in the IL‐10 gene are exerted directly through its role in the repair of muscle tissue or indirectly through its role in the defence against infectious diseases.     

Immunomodulation by mesenchymal stem cells:Interplay between mesenchymal stem cells and regulatory lymphocytes

Mesenchymal stem cells(MSCs) possess immunomodulatory properties, which confer enormous potential for clinical application. Considerable evidence revealed their efficacy on various animal models of autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus and uveitis. MSCs elicit their immunomodulatory effects by inhibiting lymphocyte activation and proliferation, forbidding the secretion of proinflammatory cytokines, limiting the function of antigen presenting cells, and inducing regulatory T(Treg) and B(Breg) cells. The induction of Treg and Breg cells is of particular interest since Treg and Breg cells have significant roles in maintaining immune tolerance. Several mechanisms have been proposed regarding to the MSCs-mediated induction of Treg and Breg cells. Accordingly, MSCs induce regulatory lymphocytes through secretion of multiple pleiotropic cytokines, cell-to-cell contact with target cells and modulation of antigen-presenting cells. Here, we summarized how MSCs induce Treg and Breg cells to provoke immunosuppression.     

Activation of the NLRP3 inflammasome in microglia: the role of ceramide

Inflammation within the CNS is a major component of many neurodegenerative diseases. A characteristic feature is the generation of microglia‐derived factors that play an essential role in the immune response. IL‐1β is a pro‐inflammatory cytokine released by activated microglia, able to exacerbate injury at elevated levels. In the presence of caspase‐1, pro‐IL‐1β is cleaved to the mature cytokine following NOD‐like receptor pyrin domain containing 3 (NLRP3) inflammasome activation. Growing evidence suggests that ceramide plays a critical role in NLRP3 inflammasome assembly, however, the relationship between ceramide and inflammasome activation in microglia remains unknown. Here, we investigated potential mechanistic links between ceramide as a modulator of NLRP3 inflammasome assembly and the resulting secretion of IL‐1β using small bioactive enzyme stimulators and inhibitors of ceramide signaling in wild‐type and apoptosis‐associated speck‐like protein containing a CARD knockout (ASC^?/?) primary microglia. To induce the expression of inflammasome components, microglia were primed prior to experiments. Treatment with sodium palmitate (PA) induced de novo ceramide synthesis via modulation of its synthesizing protein serine palmitoyl transferase resulting in increased IL‐1β secretion in microglia. Exposure of microglia to the serine palmitoyl transferase‐inhibitor l ‐cycloserine significantly prevented PA‐induced IL‐1β secretion. Application of the ceramide analogue C2 and the sphingosine‐1‐phosphate‐receptor agonist Fingolimod (FTY720) up‐regulated levels of IL‐1β and cleaved caspase‐1 in wild‐type microglia, whereas ASC^?/? microglia were unaffected. HPA‐12 inhibition of ceramide transport did not affect inflammasome activation. Taken together, our findings reveal a critical role for ceramide as a positive modulator of NLRP3 inflammasome assembly and the resulting release of IL‐1β.

     

Large numbers of interleukins‐22‐ and ‐17A‐producing T helper cells in cholangiocarcinoma related to liver fluke infection

Cholangiocarcinoma (CCA) associated with liver fluke infection involves inflammatory and immune processes; however, whether these involve the proinflammatory cytokine IL‐17A and proliferative cytokine IL‐22 remains unclear. Here, numbers of IL‐22‐ and IL‐17A‐producing Th cells and cytokine concentrations in 30 patients with CCA and long‐term liver fluke infection, 40 patients with liver‐fluke infection but not CCA, and 16 healthy controls were compared. Analyses were performed using immunohistochemistry, flow cytometry, ELISA and RT‐PCR. Immunohistochemical staining showed weaker expression of IL‐22 and IL‐17A in patients with CCA with than in those without liver fluke infection (P < 0.01). Flow cytometry revealed significantly greater median proportions of IL‐22‐producing T helper cells in patients with CCA (2.2%) than in those without it (0.69%) or controls (0.4%, P < 0.001). Similar results were obtained for IL‐17A‐producing T helper cells. ELISA revealed plasma concentrations of IL‐22 were 1.3‐fold higher in patients with CCA than in those without it and 4.6‐fold higher than in controls (P < 0.001). Plasma concentrations of IL‐17A were 2.5‐fold higher in patients with CCA than in those without it, and 21‐fold higher than in controls (P < 0.001). Amounts of IL‐22 and IL‐17A mRNAs in blood were significantly higher in patients with CCA than in the other two groups. Proportions of CD4⁺CD45RO⁺ T cells producing IL‐22 correlated with proportions producing IL‐17A (r = 0.759; P < 0.001), and plasma concentrations of IL‐22 correlated with those of IL‐17A (r = 0.726; P < 0.001). These results suggest that both IL‐17A and IL‐22 affect development of CCA related to liver fluke infection.