Triptolide regulates T cell-mediated immunity via induction of CD11c dendritic cell differentiation

Triptolide(TPT) isolated from one of the Chinese herbs, Tripterygium wilfordii Hook. F. (TWHF), are known to have a variety of immunomodulatory activities. This study was performed to investigate the effect of TPT on the differentiation of splenic DCs and its influence on T cell-mediated immunity regarding to DC subsets CD11c^lowI-a/e^lowCD45RB⁺(CD11c^low DCs) and CD11c^highI-a/e^highCD45RB^- (CD11c^high DCs) in male C57BL/6 mice spleens in vitro. The percentage of CD11c^low DCs was significantly increased after treatment with TPT compared to their counterparts (CD11c^high DCs). It was found that unlike the gradually decreasing interleukin (IL)-12 secretion of CD11c^high DCs induced by TPT, CD11c^low DCs showed a obvious dose-dependent response between the increasing of IL-10 production and TPT stimulation. After treatment with anti-IL-12R or anti-IL-10 monoclonal antibody in CD4⁺ T cells + CD11c^high DCs or CD11c^low DCs mixed lymphocyte reaction, the induction of these DCs on T cells was inhibited dramatically. These data demonstrated that TPT might induce the differentiation of splenic DCs to CD11c^low DCs followed by shifting of Th1 to Th2 with enhancement of T lymphocyte immune function in vitro.     

Lactococcus lactis subsp. cremoris FC triggers IFN-γ production from NK and T cells via IL-12 and IL-18

Lactic acid bacteria (LAB) benefit health as probiotics in a strain-dependent way. In this study, we investigated the immunomodulatory effects of Lactococcus lactis subsp. cremoris FC (LcFC) on dendritic cells (DCs), natural killer (NK) cells and T cells. LcFC induced the production of cytokines such as IL-10, IL-12, IL-6 and TNF-α from murine bone marrow DCs (BMDCs) via MyD88-dependent pathway. In comparison with the type strain L. lactis subsp. cremoris ATCC 19257, LcFC induced particularly high production of IL-12 while induction of IL-6 was moderate. Consequently, LcFC triggered IFN-γ production in splenic NK, CD8⁺, and CD4⁺ cells. Most prominent effect of LcFC on IFN-γ production was observed in NK cells, followed by CD8⁺ cells, which was completely inhibited by combination of neutralizing anti-IL-12 and anti-IL-18 mAbs. Moreover, oral administration of LcFC enhanced the production of IFN-γ and IL-10 from splenocytes of treated mice. These findings suggest that this LAB strain is an efficient activator of protective cellular immunity via stimulation of myeloid cells including DCs.     

Anti-PD-L1 antibody enhances curative effect of cryoablation via antibody-dependent cell-mediated cytotoxicity mediating PD-L1highCD11b+ cells elimination in hepatocellular carcinoma

Cryoablation (CRA) and microwave ablation (MWA) are two main local treatments for hepatocellular carcinoma (HCC). However, which one is more curative and suitable for combining with immunotherapy is still controversial. Herein, CRA induced higher tumoral PD-L1 expression and more T cells infiltration, but less PD-L1^highCD11b⁺ myeloid cells infiltration than MWA in HCC. Furthermore, CRA had better curative effect than MWA for anti-PD-L1 combination therapy in mouse models. Mechanistically, anti-PD-L1 antibody facilitated infiltration of CD8⁺ T cells by enhancing the secretion of CXCL9 from cDC1 cells after CRA therapy. On the other hand, anti-PD-L1 antibody promoted the infiltration of NK cells to eliminate PD-L1^highCD11b⁺ myeloid cells by antibody-dependent cell-mediated cytotoxicity (ADCC) effect after CRA therapy. Both aspects relieved the immunosuppressive microenvironment after CRA therapy. Notably, the wild-type PD-L1 Avelumab (Bavencio), compared to the mutant PD-L1 atezolizumab (Tecentriq), was better at inducing the ADCC effect to target PD-L1^highCD11b⁺ myeloid cells. Collectively, our study uncovered the novel insights that CRA showed superior curative effect than MWA in combining with anti-PD-L1 antibody by strengthening CTL/NK cell immune responses, which provided a strong rationale for combining CRA and PD-L1 blockade in the clinical treatment for HCC.     

Systemic TNF-α blockade attenuates anxiety and depressive-like behaviors in db/db mice through downregulation of inflammatory signaling in peripheral immune cells

Research studies have indicated that the comorbidity burden of mood disorders and obesity is reasonably high. Insulin signaling has been shown to modulate multiple physiological functions in the brain, indicating its association with neuropsychiatric diseases, including mood disorders. Leptin is a hormone responsible for regulating body weight and insulin homeostasis. Previous studies on db/db mice (a mouse model that carries a spontaneous genetic mutation in leptin receptor Lepr^db) have shown that they exhibit inflammation as well as neurobehavioral traits associated with mood. Therefore, targeting inflammatory pathways such as TNF-α may be an effective strategy in the treatment of obesity-linked mood disorders. The objective of this study was to investigate the effect of long-term administration of etanercept (a TNF-α blocker) on anxiety and depressive-like behaviors in db/db mice. This was performed using light/dark box, forced swim, and open field tests with lean littermate wild type (WT) mice serving as a control group. Using flow cytometry in peripheral blood, we further examined the molecular effects of etanercept on NF-κB p65, TNF-α, IL-17A, and TLR-4 expressing CD4+, CD8+, and CD14+ cells in the peripheral blood. Our data show that peripheral administration of etanercept decreased these cells in db/db mice. Furthermore, our results indicated that peripheral administration of etanercept reduced anxiety and depressive-like behaviors. Therefore, targeting TNF-α signaling might be an effective strategy for modulating obesity-associated depression and anxiety.     

Reversing the polarization of tumor-associated macrophages inhibits tumor metastasis

ObjectiveThe M2 phenotype is dominant in tumor associated macrophages (TAM), and plays a key role in promoting tumor growth, invasion and metastasis. Converting TAM polarization from M2 to M1 may contribute to eliciting anti-tumor-specific immune responses and inhibiting tumor metastasis. In this study, the effect of reversing the polarization of TAM on tumor metastasis was investigated.MethodsPeritoneal macrophages were obtained from BABL/c mice, and M2 polarization was induced by IL-4. In an in vivo experiment, BABL/c mice were transplanted with 4 T1 tumor cells. In vitro and in vivo experimental studies, M2 macrophage polarization was reversed with CpG-DNA or CpG-DNA combined with anti-IL-10R Ab. CD68, MHCII and FRβ molecular expression in macrophages were examined with immunofluorescence staining. The mRNA expression of IL-2, IL-6, IL-13, VEGF and MMP-9 were detected with RT-PCR. VEGF and MMP-9 protein expression of tumors in situ was measured by western blot assay. Lung-metastasis of the tumor was observed and assessed by micro-CT.ResultsCpG-DNA and CpG-DNA combined with anti-IL-10R Ab could promote MHCII, IL-2, IL-6 and IL-13 molecular expression, and suppress the expression of FRβ, MMP-9 and VEGF, in both freshly isolated peritoneal macrophages and M2 macrophages. In the CpG-DNA combined with anti-IL-10R Ab injecting group, the percentage of CD68⁺ MHCII⁺ cells were significantly higher than that of CD68⁺ FRβ⁺ cells (P < 0.05). This was distinct from the result of the control group, which CD68⁺ FRβ⁺ was higher than CD68⁺ MHCII⁺ cells (P < 0.01). Furthermore, VEGF-A and MMP-9 level in primary tumor tissues in the experimental group was significantly lower (P < 0.01), compared to the control group. Moreover, the number of detectable lung-metastasis foci was significantly lower in the experimental group than in the control group (P < 0.05).ConclusionReversing the polarization of TAM from M2 to M1 phenotype can inhibit tumor metastasis.     

Tissue factor contributes to neutrophil CD11b expression in alpha-naphthylisothiocyanate-treated mice

Cholestatic liver injury induced by alpha-naphthylisothiocyanate (ANIT) is provoked by injury to intrahepatic bile ducts and the progression of hepatic necrosis requires the procoagulant protein tissue factor (TF) and extrahepatic cells including neutrophils. Recent studies have shown that myeloid cell TF contributes to neutrophil activation. We tested the hypothesis that myeloid cell TF contributes to neutrophil activation in ANIT-treated mice. TF activity in liver homogenates increased significantly in TF^flox/flox mice treated with ANIT, but not in TF^flox/flox/LysMCre mice (TF^ΔMyeloid mice), which have reduced TF expression in monocytes/macrophages and neutrophils. Myeloid cell-specific TF deficiency did not alter expression of the chemokines KC or MIP-2 but reduced hepatic neutrophil accumulation in ANIT-treated mice at 48 h as indicated by tissue myeloperoxidase (MPO) activity. Myeloid cell TF deficiency significantly reduced CD11b expression by blood neutrophils in ANIT-treated mice, and this was associated with reduced plasma MPO protein levels, an index of neutrophil degranulation. However, myeloid cell-specific TF deficiency had no effect on ANIT-induced coagulation cascade activation. The increase in serum ALT and ALP activities in ANIT-treated mice was reduced by myeloid cell TF deficiency (p < 0.05), but the myeloid cell TF deficiency did not reduce hepatic necrosis at 48 h, as determined by histopathology and morphometry. The results suggest that myeloid cell TF contributes to neutrophil CD11b expression during cholestasis by a coagulation-independent pathway. However, the resultant reduction in neutrophil accumulation/activation is insufficient to substantially reduce ANIT hepatotoxicity, suggesting that myeloid cell TF is only one of many factors modulating hepatic necrosis during cholestasis.     

Naoxintong accelerates diabetic wound healing by attenuating inflammatory response

ContextNaoxintong (NXT), a prescribed traditional Chinese medicine, widely used in cerebrovascular and cardiovascular diseases, could be effective in diabetic wounds.ObjectiveThis study evaluates the wound healing activity of NXT by employing an excisional wound splinting model.Materials and methodsNXT was dissolved in saline and given daily by gavage. Wounds were induced at the dorsum of non-diabetic (db/+) and diabetic (db/db) mice and treated with saline or 700 mg/kg/d NXT for 16 days. Wound closure was measured every four days. Extracellular matrix (ECM) remodelling, collagen deposition, leukocyte infiltration and expression of Col-3, CK14, CXCL1, CXCL2, MPO, Ly6G, CD68, CCR7, CD206, p-JAK1, p-STAT3 and p-STAT6 was analysed.ResultsNXT significantly accelerated rate of wound closure increased from 70% to 84%, accompanied by up-regulation of collagen deposition and ECM at days 16 post-injury. Moreover, NXT alleviated neutrophil infiltration, accompanied by down-regulation of CXCL1 and CXCL2 mRNA expression. In addition, NXT markedly augmented neutrophil efferocytosis. In diabetic wounds, the levels of M1 marker gene (CCR7) increased, while M2 marker gene (CD206) decreased, demonstrating a pro-inflammatory shift. Application of NXT increased M2 macrophage phenotype in db/db mice. Mechanistically, NXT treatment increased expression level of p-STAT3 and p-STAT6 at days 3 post-injury, indicating NXT mediated macrophages towards M2 phenotype and alleviated inflammation in diabetic wounds by activation of STAT3 and STAT6.ConclusionsOur study provides evidence that NXT accelerates diabetic wound healing by attenuating inflammatory response, which provides an important basis for use of NXT in the treatment of chronic diabetic wound healing.     

Inhibition of inflammasome activation improves the impaired pattern of healing in genetically diabetic mice

Background and Purpose

Type 2 diabetes impairs the healing process because of an exaggerated and persistent inflammatory response, and an altered expression pattern of angiogenic molecules. We investigated the effects of inflammasome blockade in diabetes-related wound-healings defects, in genetically diabetic mice.

Experimental Approach

An incisional skin wound model was produced on the back of female diabetic C57BL/KsJ-m +/+ Lept^db mice (db⁺/db⁺) and their normal littermates (db⁺/m⁺). Animals were treated daily with two inflammasome blocking agents, BAY 11-7082 (20 mg·kg⁻¹ i.p.), or Brilliant Blue G (BBG, 45.5 mg·kg⁻¹ i.p.), or vehicle. Mice were killed on 3, 6 and 12 days after skin injury to measure expression of the NOD-like receptor NLRP3, caspase-1, VEGF, the inflammasome adapter protein apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) and the chemokine CXCL12. Wound levels of IL-1β and IL-18 were also measured, along with histological assessments of wound tissue and the time to complete wound closure.

Key Results

During healing, the diabetic mice exhibited increased activation of NLRP3, caspase-1, ASC, IL-1β and IL-18. They also showed a reduced expression of VEGF and CXCL12.Treatment with BAY 11-7082 or BBG, to block activation of the inflammasome, decreased the levels of pro-inflammatory molecules. Histological evaluation indicated that inflammasome blockade improved the impaired healing pattern, at day 12 in diabetic mice, along with a decreased time to complete skin healing.

Conclusions and Implications

These data strongly suggest that activation of the NLRP3 inflammasome is one of the key contributors to the delayed healing of wounds in diabetic mice.     

Interferon gamma induced by resveratrol analog,HS-1793, reverses the properties of tumor associated macrophages

Macrophages are capable of both inhibiting and promoting the growth and spread of cancers, depending on their activation state. Tumor-associated macrophages (TAM) are a kind of alternatively activated M2 macrophage, which may contribute to tumor progression. Following our previous study to evaluate the anti-tumor effect of a synthetic resveratrol analog HS-1793, the current study demonstrated that HS-1793 treatment significantly increased IFN-γ secreting cells in splenocytes and decreased CD206 + macrophage infiltration compared to CD68 + cells in the tumor site with a higher expression of IFN-γ. As these results suggested that IFN-γ increased locally at the tumor sites could modulate the status of TAM, we designed an in vitro model to study macrophage morphology and functions in relation to the tumor microenvironment. Human monocytic cell line THP-1 cells stimulated with phorbol-12-myristate-13-acetate (PMA) differentiated to macrophages with M2-like phenotypes. TAM-like properties of CD206^high, CD204^high, IL-10^high, TGF-β^high, IL-6^low, IL-12^low, VEGF^high, and MMP-9^high and promotion of tumor cell invasion were more pronounced in M-2-polarized THP-1 macrophages generated by differentiating THP-1 cells with PMA and subsequently polarizing them with Th2 cytokines (IL-4/IL-13). Upon IFN-γ exposure, THP-1-derived TAM changed their phenotypes to the M-1-like morphology and intracellular granular pattern with an expression of an increased level of proinflammatory and immunostimulatory cytokines and a reduced level of immunosuppressive and tumor progressive mediators. These results explain the underlying mechanism of the anti-tumor activity of HS-1793. The elevated level of IFN-γ production after HS-1793 treatment evoked reprogramming of M-2 phenotype TAM, which efficiently countered the immunosuppressive and tumor progressive influences of TAM.     

Bothrops moojeni venom and BmooLAAO-I downmodulate CXCL8/IL-8 and CCL2/MCP-1 production and oxidative burst response,and upregulate CD11b expression in human neutrophils

Bothrops snake venoms contain biologically active components, including L-amino acid oxidases (LAAO) that induce significant leukocyte accumulation at inflammatory sites characterized by early neutrophil infiltration. As it remains unclear how snake venoms modulate neutrophil activation and chemokine production, here we examined whether Bothrops moojeni crude venom (BmV) and its LAAO (BmooLAAO-I) affect expression of the surface activation markers CD11b and CD66b, production of the chemokines CCL2/MCP-1, CCL5/RANTES, CXCL8/IL-8, CXCL9/MIG, and CXCL-10/IP-10, and activation of oxidative burst in human neutrophils. Cell viability, expression of activation markers, and chemokine production were assessed by flow cytometry, while the oxidative burst response was measured by chemiluminescence. BmV at 50 and 75 µg/mL reduced CXCL8/IL-8 (p < 0.001 and p < 0.01, respectively) and CCL2/MCP-1 production (p < 0.05), while BmooLAAO-I at the same concentrations reduced only CCL2/MCP-1 production (p < 0.01). These effects were accompanied by CD11b upregulation (p < 0.05 for 50 and 75 µg/mL BmV; p < 0.01 for 50 and 75 µg/mL BmooLAAO-I) and CD66b downregulation (p < 0.05 for 50 and 75 µg/mL BmV). Both BmV and BmooLAAO-I at concentrations ranging from 0.625 to 5 µg/mL suppressed the oxidative burst of neutrophils stimulated with phorbol 12-myristate 13-acetate, while BmooLAAO-I at 2.5 and 5 µg/mL also suppressed the neutrophil response stimulated with opsonized zymosan. Considering that neutrophils participate in the pathogenesis of autoimmune and inflammatory diseases, the findings reported herein indicate that BmV and BmooLAAO-I are potential immunomodulating agents.     

Anti-interleukin-6 therapy for Crohn's disease

Proinflammatory cytokines have been demonstrated to play a crucial role in the pathogenesis and physiopathology of various chronic inflammatory conditions including Crohn's disease (CD). Among these cytokines, interleukin-6 (IL-6) must be especially important because increased serum concentrations of acute phase proteins, reduced level of serum albumin, and remarkable thrombocytosis are all well-explained by the increased level of IL-6. Moreover, IL-6 is capable of stimulating even IL-6 receptor (IL-6R) negative cells such as vascular endothelial cells when complexed to soluble form of IL-6R (sIL-6R), and serum level of IL-6 as well as sIL-6R has been demonstrated to increase during inflammation. To investigate the therapeutic potential of IL-6 signaling blockade for CD, anti-IL-6R monoclonal antibody (mAb) was introduced to various murine models of colitis. Anti-IL-6R mAb successfully prevented wasting disease and the development of macroscopic and histological lesions. It suppressed the accumulation of ICAM-1 positive and Mac-1 positive cells in the lamina propria (LP) and the expression of ICAM-1 and VCAM-1 by vascular endothelial cells. Expansion of colonic and splenic CD4(+) T cells was reduced as well as the colonic expression of tumor necrosis factor alpha (TNF-alpha), IL-1beta, and interferon gamma (IFN-gamma) mRNA without affecting the production of transforming growth factor beta (TGF-beta), IL-10, and IL-4 mRNA. The treatment also suppressed established colitis by inducing LP T cell apoptosis. These results strongly suggest that specific targeting of IL-6/sIL-6R pathway will be a promising new approach for the treatment of CD, and the clinical trial of humanized anti-IL-6R mAb is now under way.     

Ursolic acid ameliorates autoimmune arthritis via suppression of Th17 and B cell differentiation

Aim:

Ursolic acid (UA) is a pentacyclic triterpenoid found in most plant species, which has been shown anti-inflammatory and anti-oxidative activities. In this study, we examined the effects of UA on collagen-induced arthritis (CIA) in mice, and to identify the mechanisms underlying the effects.

Methods:

CIA was induced in mice. Two weeks later, the mice were treated with UA (150 mg/kg, ip, 3 times per week) for 4 weeks. The expression of cytokines and oxidative stress markers in joint tissues was measured with immunohistochemistry. The numbers of CD4⁺IL-17⁺, CD4⁺CD25⁺Foxp3⁺ and pSTAT3 cells in spleens were determined using confocal immunostaining or flowcytometric analyses. Serum antibody levels and B cell-associated marker mRNAs were analyzed with ELISAs and qRT-PCR, respectively. CD4⁺ T cells and CD19⁺ B cells were purified from mice spleens for in vitro studies.

Results:

UA treatment significantly reduced the incidence and severity of CIA-induced arthritis, accompanied by decreased expression of proinflammatory cytokines (TNF-α, IL-1β, IL-6, IL-21 and IL-17) and oxidative stress markers (nitrotyrosine and iNOS) in arthritic joints. In CIA mice, UA treatment significantly decreased the number of Th17 cells, while increased the number of Treg cells in the spleens, which was consistent with decreased expression of pSTAT3, along with IL-17 and RORγt in the splenocytes. In addition, UA treatment significantly reduced the serum CII-specific IgG levels in CIA mice. The inhibitory effects of UA on Th17 cells were confirmed in an in vitro model of Th17 differentiation. Furthermore, UA dose-dependently suppressed the expression of B cell-associated markers Bcl-6, Blimp1 and AID mRNAs in purified CD19⁺ B cells pretreated with IL-21 or LPS in vitro.

Conclusion:

UA treatment significantly ameliorates CIA in mice via suppression of Th17 and differentiation. By targeting pathogenic Th17 cells and autoantibody production, UA may be useful for the treatment of autoimmune arthritis and other Th17-related diseases.     

The role of osteopontin in d-galactosamine-induced liver injury in genetically obese mice

Various epidemiological studies have shown that obesity increases the risk of liver disease, but the precise mechanisms through which this occurs are poorly understood. In the present study, we hypothesized that osteopontin (OPN), an extracellular matrix and proinflammatory cytokine, has an important role in making obese mice more susceptible to inflammatory liver injury. After exposure of genetically obese ob/ob and db/db mice to a single dose of d-galactosamine (GalN), the plasma liver enzyme levels, histology and expression levels of cytokines and OPN were evaluated. The ob/ob and db/db mice, which were more sensitive to GalN-induced inflammatory liver injury compared with wild-type mice, had significantly higher plasma and hepatic OPN expression levels. Increased OPN expression was mainly found in hepatocytes and inflammatory cells and was correlated with markedly up-regulated interleukin (IL)-12 and IL-18 levels. Furthermore, pretreatment with a neutralizing OPN (nOPN) antibody attenuated the GalN-induced inflammatory liver injury in ob/ob and db/db mice, which was accompanied by significantly reduced macrophages recruitment and IL-12 and IL-18 productions. Taken together, these results suggest that up-regulated OPN expression is a contributing factor to increased susceptibility of genetically obese mice to GalN-induced liver injury by promoting inflammation and modulating immune response.     

IL-35 interferes with splenic T cells in a clinical and experimental model of acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a life-threatening critical care syndrome with uncontrolled inflammation that is a central issue. Its main characteristic is inflammatory mediators and cytokines as well as agglutinating chemokines that injure target cells. Interleukin (IL)-35 is a newly identified IL-12 cytokine family member with structural similarities to other IL-12, IL-23, and IL-27 cytokines but unique immunological functions. How IL-35 functions in ARDS is unclear. The purpose of our study was to determine what role IL-35 played in the development of ARDS. Here we found serum IL-35 concentrations were significantly elevated in patients with ARDS relative to healthy people. Moreover, we established a mouse model of lipopolysaccharide- and cecal ligation and puncture-induced ARDS treated with neutralizing antibodies (anti-IL-35 Ebi3 or anti-IL-35 P35); the results showed that lung injury occurred more often than in untreated models and the inflammatory cytokines CXCL-1, tumor necrosis factor alpha, IL-6, and IL-17A increased significantly after neutralizing antibody treatment in bronchoalveolar lavage fluid and serum. Therefore IL-35 can protect against the development of ARDS. Even more interesting in our study was that we discovered IL-35 expression differed between lung and spleen across different ARDS models, which further demonstrated that the spleen likely has an important role in extrapulmonary ARDS model only, improving the ratio of CD4⁺/CD4⁺CD25⁺Foxp3⁺(Tregs). Meanwhile in our clinical work, we also found that the concentration of IL-35 and the ratio of CD4⁺/Treg in the serum are higher and the mortality is lower than those with the spleen deficiency in patients with extrapulmonary ARDS. Therefore, IL-35 is protective in ARDS by promoting the ratio of splenic CD4⁺/Tregs in extrapulmonary ARDS, and as such, may be a therapeutic target.     

Mycophenolic acid derivative 118 improves outcome of skin grafts by suppressing IL-17 production

Aim:

To investigate the effects and underlying mechanisms of 118, a novel derivative of mycophenolic acid, in a murine allogeneic skin graft model.

Methods:

Skin grafts were conducted by grafting BALB/c donor tail skin into C57BL/6 skin beds (allograft) or by grafting female C57BL/6 donor tail skin into female C57BL/6 skin beds (syngraft). The mice were treated with the derivative 118 (40 mg·kg⁻¹·d⁻¹, po) for 13 d (3 d before and 10 d after transplantation). Skin grafts, splenocytes and graft-infiltrated lymphocytes were isolated and examined ex vivo. The effects of the derivative 118 on naive CD4⁺ T cell differentiation were examined in vitro.

Results:

Treatment with the derivative 118 dramatically increased the survival rate of murine allogeneic skin grafts. Flow cytometric analysis and H&E staining showed that the derivative significantly decreased inflammatory cell infiltration into the grafts. The levels of the chemokines CXCL1, CXCL2, CCL7, and CCL2 were reduced in the derivative 118-treated grafts. Additionally, the derivative 118 significantly suppressed the IL-17 levels in the grafts but did not affect the differentiation of systemic helper T cells in the murine allogeneic skin graft model. Furthermore, IL-23p19 expression was suppressed in the grafts from the derivative 118-treated group, which might be due to decreases in TLR4 and MyD88 expression. Finally, the derivative 118 did not exert direct influences on helper T cell differentiation in vitro.

Conclusion:

Treatment with the mycophenolic acid derivative 118 improves murine allogeneic skin grafts by decreasing IL-23 expression and suppressing local IL-17 secretion in the grafts, rather than directly inhibiting Th17 differentiation.     

PD-1 regulates CXCR5+ CD4 T cell-mediated proinflammatory functions in non-small cell lung cancer patients

PD-1 inhibitors have been used to revive exhausted T cell responses in non-small cell lung cancer (NSCLC) and other malignancies. CXCR5⁺ T follicular helper (Tfh) cells are characterized by constitutive high PD-1 expression and have been associated with the formation of tertiary lymphoid structures and implicated in antitumor immunity. In this study, we investigated the effect of PD-1 and PD-1 inhibition on CXCR5⁺ CD4 T cells. Data showed that CXCR5⁺ CD4 T cells in both healthy subjects and NSCLC patients presented markedly higher PD-1 expression than CXCR5⁻ CD4 T cells. Both CXCR5⁻ and CXCR5⁺ CD4 T cells from NSCLC patients presented higher PD-1 expression than their counterparts in healthy subjects. PD-1⁺ CXCR5⁺ CD4 T cells were functional, could express IL-21, IL-10, and CXCL13 upon stimulation, demonstrated auxiliary effects toward CD8 T cell-mediated IFN-γ production and proliferation, and promoted IgM and IgG production. However, the potency of PD-1⁺ CXCR5⁺ CD4 T cells was lower than the potency of PD-1⁻ CXCR5⁺ CD4 T cells. PD-1 blocking could significantly enhance the effector functions of PD-1⁺ CXCR5⁺ CD4 T cells. Overall, this study demonstrated that PD-1⁺ CXCR5⁺ CD4 T cells could promote CD8 T cell and B cell inflammation and could be modulated by PD-1 inhibition.     

Dexamethasone inhibits in vivo tumor growth by the alteration of bone marrow CD11b+ myeloid cells

Inflammation is closely associated with tumor growth, which is mediated by the activation of bone marrow-derived CD11b⁺ cells. Here, we investigated whether anti-inflammatory dexamethasone (Dex), a synthetic glucocorticoid (GC), could regulate tumor growth and CD11b⁺ myeloid bone marrow cells (BMCs) in lymphocyte (R1), monocyte (R2) and granulocyte (R3) regions of FSC-SSC dot plot. The growth of B16F10 mouse melanoma tumor was inhibited in Dex-injected group. Lung metastasis was decreased and the lifespan was elongated in Dex-injected mice with tumor resection. Intravenous injection of B16F10 cells increased the percentage of CD11b⁺ myeloid BMCs in R1 and R2 regions from 3 h to 72 h. In contrast, little changes in the percentage of CD11b⁺ myeloid BMCs were detected in R3 region. Among CD11b⁺ myeloid BMCs, the percentage of CD11b⁺Gr-1⁺ cells was increased in R1, R2 and R3 regions. Absolute number of CD11b⁺ and CD11b⁺Gr-1⁺ cells was enhanced in R1 region from 3 h to 72 h. B16F10 tumor growth was significantly increased by intravenous injection of CD11b⁺ BMCs. Tumor-bearing mice showed an increase in the percentage of CD11b⁺ myeloid BMCs in R2 region and CD11b⁺Gr-1⁺ cells in R2 and R3 regions, which are reduced by intravenous injection with Dex. Absolute number of CD11b⁺Gr-1⁺ cells was enhanced in R2 and R3 regions. Tumor growth was significantly inhibited by intravenous injection of BMCs collected from Dex-treated tumor-bearing mice. Taken together, data demonstrate that tumor regression by Dex was resulted from the alteration of CD11b⁺ myeloid BMCs and their inhibitory function to tumor growth. It suggests that CD11b⁺ myeloid BMCs could regulate antitumor efficacy of GCs such as Dex.     

Anti-inflammatory effects of DA-9601, an extract of Artemisia asiatica,on aceclofenac-induced acute enteritis

DA-9601 is an extract obtained from Artemisia asiatica, which has been reported to have anti-inflammatory effects on gastrointestinal lesions; however, its possible anti-inflammatory effects on the small intestine have not been studied yet. Therefore, in this study, we investigated the protective effects of DA-9601 against the ACF-induced small intestinal inflammation. Inflammation of the small intestine was confirmed by histological studies and the changes in the CD4⁺ T cell fraction induced by the inflammation-related cytokines, and the inflammatory reactions were analyzed. Multifocal discrete small necrotic ulcers with intervening normal mucosa were frequently observed after treatment with ACF. The expression of IL-6, IL-17, and TNF-α genes was increased in the ACF group; however, it was found to have been significantly decreased in the DA-9601 treated group. In addition, DA-9601 significantly decreased the levels of proinflammatory mediators such as IL-1β, GM-CSF, IFN-γ, and TNF-α; the anti-inflammatory cytokine IL-10, on the other hand, was observed to have increased. It is known that inflammatory mediators related to T cell imbalance and dysfunction continuously activate the inflammatory response, causing chronic tissue damage. The fractions of IFN-γ⁺ Th1 cells, IL-4⁺ Th2 cells, IL-9⁺ Th9 cells, IL-17⁺ Th17 cells, and Foxp3⁺ Treg cells were significantly decreased upon DA-9601 treatment. These data suggest that the inflammatory response induced by ACF is reduced by DA-9601 via lowering of the expression of genes encoding the inflammatory cytokines and the concentration of inflammatory mediators. Furthermore, DA-9601 inhibited the acute inflammatory response mediated by T cells, resulting in an improvement in ACF-induced enteritis.     

The shiitake mushroom-derived immuno-stimulant lentinan protects against murine malaria blood-stage infection by evoking adaptive immune-responses

Lentinan, a (1-3)-beta glucan from Lentinus edodes, is an effective immunostimulatory drug. We tested the effects of lentinan during blood-stage infection by Plasmodium yoelii 17XL (P.y17XL). Pre-treatment of mice with lentinan significantly decreased the parasitemia and increased their survival after infection. Enhanced IL-12, IFN-γ and NO production induced by lentinan in spleen cells of infected mice revealed that the Th1 immune response was stimulated against malaria infection. In vitro and in vivo, lentinan can result in enhanced expression of MHC II, CD80/CD86, and Toll-like receptors (TLR2/TLR4), and increased production of IL-12 in spleen dendritic cells (DCs) co-cultured with parasitized red blood cells (pRBCs). Moreover, both the number of CD4⁺CD25⁺ regulatory T cells (Tregs) and the levels of IL-10 secreted by Tregs were reduced by pre-treatment with lentinan in the spleen of malaria-infected mice. Meanwhile, apoptosis of CD4⁺ T cell in spleens of mice pretreated with lentinan was significantly reduced. In summary, lentinan can induce protective Th1 immune responses to control the proliferation of malaria parasites during the blood-stage of P.y17XL infection by stimulating maturation of DCs to inhibit negative regulation of the Th1 immune response by Tregs. Taken together, our findings suggest that lentinan has prophylactic potential for the treatment of malaria.