IL-12p40 Expression Research Articles

A novel susceptibility locus in the IL12B region is associated with the pathophysiology of Takayasu arteritis through IL-12p40 and IL-12p70 production

BackgroundA previous study revealed the association between susceptibility to Takayasu arteritis (TAK) and a single nucleotide polymorphism (SNP) rs6871626 located in IL12B, which encodes interleukin (IL)-12p40, a common component of IL-12p70 and IL-23. We investigated the expression of these cytokines in patients with TAK, stratifying them into those with or without the risk allele at the rs6871626 SNP.MethodsPlasma levels of IL-12p40, IL-12p70, and IL-23 were quantified in 44 patients with TAK and 19 healthy controls (HCs) by enzyme-linked immunosorbent assays. Monocytes were obtained from 20 patients with TAK and 14 HCs, treated with interferon-γ (IFN-γ) and lipopolysaccharide, and then supernatant cytokines were quantified. In addition, the ratio of IFN-γ+ or IL-17A+ cells to CD4+ T cells was measured by flow cytometric analysis of peripheral blood mononuclear cells.ResultsThe levels of plasma IL-12p40, plasma IL-12p70, and supernatant IL-12p70 were significantly higher in patients with TAK than in HCs, whereas there were no significant differences in the levels of plasma IL-23, supernatant IL-23, or supernatant IL-12p40. The levels of plasma IL-12p70, supernatant IL-12p40, and supernatant IL-12p70 were significantly higher in patients with the risk allele than in those without. The ratio of CD4+IFN-γ+ cells was significantly higher in patients with the risk allele, whereas CD4+IL-17A+ cells showed no differences.ConclusionsThe rs6871626 SNP in IL12B may influence the increased expression of IL-12p40 and IL-12p70. These enhanced cytokines might play roles in the pathophysiology of TAK.

CD103+ Dendritic Cell Function Is Altered in the Colons of Patients with Ulcerative Colitis.

Human intestinal innate myeloid cells can be divided into 3 subsets: HLA-DRCD14 cells, HLA-DRCD103 dendritic cells (DCs), and HLA-DRCD14CD103 cells. CD103 DCs generate Treg cells and Th17 cells in the ileum, but their function in the colon remains largely unknown. This study characterized CD103 DCs in the colon and investigated whether these cells are implicated in the pathogenesis of ulcerative colitis (UC). Normal intestinal mucosa was obtained from intact sites of patients with colorectal cancer (n = 24). Noninflamed and inflamed colonic tissues were obtained from surgically resected specimens of patients with UC (n = 13). Among LinCD45HLA-DR intestinal lamina propria cells, CD14 cells and CD103 DCs were sorted and analyzed for microRNA expression of cytokines and toll-like receptors by quantitative real-time polymerase chain reaction. In addition, IL-4/IL-5/IL-13/IL-17/IFN-γ production and Foxp3 expression by naive T cells cultured with CD14 cells and CD103 DCs were analyzed. CD103 DCs in the normal colon showed lower expression of toll-like receptors and proinflammatory cytokines than CD14 cells. Coculture with naive T cells revealed that CD103 DCs generated Treg cells. CD103 DCs from patients with UC did not generate Treg cells, but they induced IFN-γ-, IL-13-, and IL-17-producing CD4 T cells and showed higher expression of IL6 (P < 0.0001), IL23A (P < 0.05), IL12p35 (P < 0.05), and TNF (P < 0.05). In patients with UC, CD103 DCs show the impaired ability to generate Treg cells, but exhibit a colitogenic function inducing Th1/Th2/Th17 responses. These findings show how human CD103 DCs could contribute to the pathogenesis of UC.

Antitumor effect of Batf2 through IL-12 p40 up-regulation in tumor-associated macrophages

The development of effective treatments against cancers is urgently needed, and the accumulation of CD8+ T cells within tumors is especially important for cancer prognosis. Although their mechanisms are still largely unknown, growing evidence has indicated that innate immune cells have important effects on cancer progression through the production of various cytokines. Here, we found that basic leucine zipper transcription factor ATF-like 2 (Batf2) has an antitumor effect. An s.c. inoculated tumor model produced fewer IL-12 p40+ macrophages and activated CD8+ T cells within the tumors of Batf2-/- mice compared with WT mice. In vitro studies also revealed that the IL-12 p40 expression was significantly lower in Batf2-/- macrophages following their stimulation by toll-like receptor ligands, such as R848. Additionally, we found that BATF2 interacts with p50/p65 and promotes IL-12 p40 expression. In conclusion, Batf2 has an antitumor effect through the up-regulation of IL-12 p40 in tumor-associated macrophages, which eventually induces CD8+ T-cell activation and accumulation within the tumor.

Nrf2 suppresses the function of dendritic cells to facilitate the immune escape of glioma cells

Nrf2 is presented in dendritic cells (DCs) and contributes to the maintenance of redox homeostasis. However, the expression pattern and function of Nrf2 in the maturation of DCs in the glioma-infiltrated microenvironment remain unrevealed. Our study aims to investigate the roles of Nrf2 in glioma cell-tamed DCs and their impact on the downstream T cell proliferation and cytotoxicity to glioma cells. It was showed that the inducible maturation of DCs was significantly suppressed after stimulation with tumor-conditioned medium (TCM) prepared from glioma cells (LN-18 and U118MG), as suggested by the decreased CD80, CD86 and IL-12 p70 expression and higher levels of IL-10 than the normal astrocyte medium treated DCs. Moreover, the TCM-exposed DCs had significantly increased expression and transcriptional activity of Nrf2 compared to the negative control. Nrf2 inhibition in DC cells substantially antagonized the inhibitory effects of TCM on the maturation and activation of DC cells, reflected by the elevated maturation markers and IL-12 p70. We further confirmed that Nrf2 inhibition in TCM-exposed DC cells promoted the proliferation of T cells as evaluated by the CFSE-labeled assay and Th1 response shown by the elevated production of IFN-γ. The cytotoxic T lymphocyte assay revealed that Nrf2 genetic suppression in DC cells greatly enhanced the capacity of T cells in the cytotoxicity to glioma cells dependent on the E:T ratio. Collectively, our study demonstrated that Nrf2 inhibition in DCs in glioma-exposed microenvironment could enhance the maturation of DCs and the subsequent activation of T cells and their cytotoxicity on glioma cells.

Mycobacterium tuberculosis PPE44 (Rv2770c) is involved in response to multiple stresses and promotes the macrophage expression of IL-12 p40 and IL-6 via the p38, ERK, and NF-κB signaling axis

Tuberculosis (TB), caused by Mycobacterium tuberculosis, remains a formidable threat to global public health. The successful intracellular persistence of M. tuberculosis significantly contributes to the intractability of tuberculosis. Proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) are mycobacterial exclusive protein families that widely reported to be involved in the bacterial virulence, physiology and interaction with host. Rv2770c (PPE44), a predicted virulence factor, was up-regulated upon the infected guinea pig lungs. To investigate the role of Rv2770c, we heterologously expressed the PPE44 in the nonpathogenic fast-growing M. smegmatis strain. Subcellular location analysis demonstrated that Rv2770c is a cell wall associated protein, suggestive of a potential candidate involved in host-pathogen interaction. The Rv2770c can enhance M. smegmatis survival within macrophages and under stresses such as H2O2, SDS, diamide exposure, and low pH condition. M. smegmatis expressing Rv2770c is more virulent as testified by the increased death of macrophages and the increased expression of interlukin-6 (IL-6) and interlukin-12p40 (IL-12p40). Moreover, Rv2770c altered the secretion of IL-6 and IL-12p40 of macrophages via NF-κB, ERK1/2 and p38 MAPK axis. Taken together, this study implicated that Rv2770c was a virulent factor actively engaged in the interaction with host macrophage.

Molecular, biochemical characterization and assessment of immunogenic potential of cofactor-independent phosphoglycerate mutase against Leishmania donovani: a step towards exploring novel vaccine candidate.

Despite immense efforts, vaccine against visceral leishmaniasis has yet not been developed. Earlier our proteomic study revealed a novel protein, cofactor-independent phoshoglycerate mutase (LdiPGAM), an important enzyme in glucose metabolism, in T helper cells type 1 (Th1) stimulatory region of soluble Leishmania donovani antigen. In this study, LdiPGAM was biochemically and molecularly characterized and evaluated for its immunogenicity and prophylactic efficacy against L. donovani. Immunogenicity of recombinant LdiPGAM (rLdiPGAM) was initially assessed in naïve hamsters immunized with it by analysing mRNA expression of inducible nitric oxide (NO) synthase (iNOS) and other Th1/T helper cells type 2 cytokines, which revealed an upregulation of Th1 cytokines along with iNOS. Immunogenicity of rLdiPGAM was further evaluated in lymphocytes of treated Leishmania-infected hamsters and peripheral blood mononuclear cells of Leishmania patients in clinical remission by various parameters, viz. lymphoproliferation assay and NO production (hamsters and patients) and levels of various cytokines (patients). rLdiPGAM induced remarkable Lymphoproliferative response and NO production in treated Leishmania-infected hamsters as well as in patients and increase in interferon gamma (IFN-γ), interleukin-12 (IL-12p40) responses in Leishmania patients in clinical remission. Vaccination with rLdiPGAM exerted considerable prophylactic efficacy (73%) supported by increase in mRNA expression of iNOS, IFN-γ and IL-12p40 with decrease in transforming growth factor beta and interleukin-10. Above results indicate the importance of rLdiPGAM protein as a potential vaccine candidate against visceral leishmaniasis.

A Lactococcus lactis BFE920 feed vaccine expressing a fusion protein composed of the OmpA and FlgD antigens from Edwardsiella tarda was significantly better at protecting olive flounder (Paralichthys olivaceus) from edwardsiellosis than single antigen vaccines

Edwardsiellosis is a major fish disease that causes a significant economic damage in the aquaculture industry. Here, we assessed vaccine efficacy after feeding oral vaccines to olive flounder (Paralichthys olivaceus), either L. lactis BFE920 expressing Edwardsiella tarda outer membrane protein A (OmpA), flagellar hook protein D (FlgD), or a fusion antigen of the two. Feed vaccination was done twice with a one-week interval. Fish were fed regular feed adsorbed with the vaccines. Feed vaccination was given over the course of one week to maximize the interaction between the feed vaccines and the fish intestine. Flounder fed the vaccine containing the fusion antigen had significantly elevated levels T cell genes (CD4-1, CD4-2, and CD8α), type 1 helper T cell (Th1) subset indicator genes (T-bet and IFN-γ), and antigen-specific antibodies compared to the groups fed the single antigen-expressing vaccines. Furthermore, the superiority of the fusion vaccine was also observed in survival rates when fish were challenged with E. tarda: OmpA-FlgD-expressing vaccine (82.5% survival); FlgD-vaccine (55.0%); OmpA-vaccine (50%); WT L. lactis BFE920 (37.5%); Ctrl (10%). In addition, vaccine-fed fish exhibited increased weight gain (∼20%) and a decreased feed conversion ratio (∼20%) during the four week vaccination period. Flounder fed the FlgD-expressing vaccine, either the single or the fusion form, had significantly increased expression of TLR5M, IL-1β, and IL-12p40, suggesting that the FlgD may be a ligand of olive flounder TLR5M receptor or closely related to the TLR5M pathway. In conclusion, the present study demonstrated that olive flounder fed L. lactis BFE920 expressing a fusion antigen composed of E. tarda OmpA and FlgD showed a strong protective effect against edwardsiellosis indicating this may be developed as an E. tarda feed vaccine.

Di-(2-ethylhexyl) phthalate suppresses IL-12p40 production by GM-CSF-dependent macrophages via the PPARα/TNFAIP3/TRAF6 axis after lipopolysaccharide stimulation.

Activation of peroxisome proliferator-activated receptor α (PPARα) by di-(2-ethylhexyl) phthalate (DEHP) has an anti-inflammatory effect. This study investigated the potential combined influence of PPARα, tumor necrosis factor α-induced protein 3 (TNFAIP3/A20), and tumor necrosis factor receptor-associated factor 6 (TRAF6) on interleukin (IL)-12p40 production by macrophages exposed to DEHP and stimulated with lipopolysaccharide (LPS). LPS upregulated IL-12p40 expression by granulocyte-macrophage colony-stimulating factor-dependent macrophages (on day 9 of culture), whereas adding DEHP to cultures significantly attenuated the response of IL-12p40 to LPS stimulation. PPARα protein was also reduced by DEHP. Interestingly, transfection of macrophages with small interfering RNA (siRNA) duplexes for PPARα, TNFAIP3/A20, or dual oxidase 2 restored the response of IL-12p40 protein to LPS stimulation in the presence of DEHP. siRNAs for various protein kinase Cs (PKCs) (α, β, γ, or δ) also restored IL-12p40 production by macrophages exposed to LPS and DEHP. While LPS upregulated both IL-12p40 and TNFAIP3/A20 production, adding DEHP to cultures dramatically reduced IL-12p40 and TNFAIP3/A20 levels. Silencing of PKCα reduced TNFAIP3/A20 production, whereas PKCγ siRNA (but not PKCβ or δ siRNA) significantly increased TNFAIP3/A20. TRAF6 was also attenuated by macrophages with DEHP. The PPARα/TNFAIP3/TRAF6 axis may have an important role in the mechanism through which DEHP reduces IL-12p40 production by LPS-stimulated macrophages.

Abstract 1614: Intratumoral delivery of a P2A-linked bicistronic IL-12 construct leads to high intratumoral expression and systemic anti-tumor response

Abstract The use of immunomodulatory cytokines has been shown effective in regressing a wide range of tumors. However, systemic delivery of recombinant cytokines can result in serious adverse effects, often life-threatening. DNA transfer via electroporation (EP) is a safe and effective method of delivering cytokines to target tissues. Intratumoral (IT) electroporation of Interleukin 12 (IL-12), a potent immunomodulatory cytokine, is well tolerated with an acceptable safety profile and objective response rates of 34-40% and 33% in Phase II clinical trials in advanced melanoma and Merkel cell carcinoma, respectively. We sought to improve the systemic anti-tumor response of IT pIL-12-EP by improving IL-12p70 expression and electroporation conditions, which were evaluated in vitro and in vivo with a two-tumor syngeneic mouse model of melanoma. As functional IL-12 p70 is a heterodimer, we compared different expression constructs to achieve high levels of IL-12 protein expression. IL-12p70 protein expression from a plasmid that incorporated a picornavirus-derived co-translational cleavage site (P2A) was higher than constructs with an internal ribosomal entry sequence (IRES) or a fusion of the p35 and p40 subunits. In functional in vitro assays, pIL-12(P2A) was superior to pIL-12(IRES) and the fusion protein. Using the murine B16.F10 tumor model, we show that IT EP of pIL-12 (P2A) plasmid regresses the treated lesions in a dose-dependent manner compared to control treatments. Systemic effects of IT-expressed IL-12 was assessed by monitoring generation of an antigen-specific CD8 T cell response and regression of B16.F10 contralateral (untreated) tumors following primary tumor electroporation. IT-pIL12-EP treatment with the P2A-linked construct resulted in a significant increase in antigen-specific CD8 T cells, as well as enhanced contralateral tumor growth inhibition suggesting the induction of strong systemic anti-tumor immune response. * Contributed equally to this work Citation Format: David A. Canton, Christoph Burkart, Shawna A. Shirley, Anandaroop Mukhopadhyay, Richard J. Connolly, Arya Bahrami, Jean S. Campbell, Robert H. Pierce. Intratumoral delivery of a P2A-linked bicistronic IL-12 construct leads to high intratumoral expression and systemic anti-tumor response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1614. doi:10.1158/1538-7445.AM2017-1614

Brucella Omp25 Upregulates miR-155, miR-21-5p, and miR-23b to Inhibit Interleukin-12 Production via Modulation of Programmed Death-1 Signaling in Human Monocyte/Macrophages.

Brucella spp. infection results in compromised Type1 (Th1) cellular immune response. Several reports have described an immunomodulatory function for Brucella major outer membrane protein Omp25. However, the mechanism by which Omp25 modulates macrophage dysfunction has not been defined. Herein, we reported that Omp25-deficient mutant of Brucella suis exhibited an enhanced ability to induce interleukin (IL)-12 whereas ectopic expression of Omp25 protein inhibited TLR agonists-induced IL-12 p70 production through suppression of both IL-12 p40 and p35 subunit expression in THP-1 cells. In addition, Omp25 significantly upregulated miR-155, -23b and -21-5p, as well as the immunomodulator molecule programmed death-1 (PD-1) in monocyte/macrophages. The upregulation of miR-155 and -23b correlated temporally with decreased TAB2 levels, IκB phosphorylation and IL-12 p40 levels by targeting TAB2 and il12B 3′ untranslated region (UTR), respectively, while miR-21-5p increase directly led to the reduction of lipopolysaccharide (LPS)/R848-induced IL-12 p35 protein by targeting il12A 3′UTR. Consistent with this finding, reduction of miR-155 and -23b attenuated the inhibitory effects of Omp25 on LPS/R848-induced IL-12 p40 expression at both transcriptional and posttranscriptional levels, while reduction of miR-21-5p attenuated the inhibitory effects of Omp25 on LPS/R848-induced IL-12 p35 expression at the posttranscriptional level, together significantly enhanced IL-12 p70 production upon LPS/R848 stimulation. We also found that blocking PD-1 signaling decreased the expression of miR-155, -23b and -21-5p induced by Omp25 and enhanced IL-12 production in monocyte/macrophages. Altogether, these data demonstrate that Brucella Omp25 induces miR-155, -23b and -21-5p to negatively regulate IL-12 production at both transcriptional and posttranscriptional levels via regulation of PD-1 signaling, which provides an entirely new mechanism underlying monocyte/macrophages dysfunction during Brucella spp. infection.

Nickel Sulfate Promotes IL-17A Producing CD4+ T Cells by an IL-23-Dependent Mechanism Regulated by TLR4 and Jak-STAT Pathways

Allergic contact dermatitis, caused by nickel, is a delayed-type hypersensitivity reaction, and 14.5% of the general population may be affected in Europe. Among a wide range of cytokines, the IL-12 family has unique structural and immunological characteristics. Whereas IL-12p70 promotes T helper (Th) 1 cell polarization, IL-23 promotes Th17 cell development and both have been isolated from nickel-allergic patients. In this work, we were interested in understanding the mechanism behind nickel-induced Th17 cell development. We showed that nickel induced an early production of IL-23 in human monocyte-derived dendritic cells along with an increase in the expression of il-23p19 and il-12p40 mRNA. However, the production of a significant level of IL-12p70 required an additional signal such as IFN-γ. Moreover, nickel-treated monocyte-derived dendritic cells induced an increase in the percentage of IL-17A+ CD4+ T cells, an effect reduced by IL-23 neutralization. We then investigated the molecular mechanism of IL-23 production. Our results showed that toll-like receptor 4, p38 mitogen-activated protein kinase, and NF-κB were involved in IL-23 production induced by nickel. However, Jak-signal transducer and activator of transcription activation seems to maintain the IL-23/IL-12p70 balance by limiting IL-23 production and promoting Th1 polarization. These results indicate that nickel-induced Th17 cell development is dependent on the production of IL-23 by human monocyte-derived dendritic cells via toll-like receptor 4, p38 mitogen-activated protein kinase, NF-κB, and Jak-signal transducer and activator of transcription pathways.

A nano particle vector comprised of poly lactic-co-glycolic acid and monophosphoryl lipid A and recombinant Mycobacterium avium subsp paratuberculosis peptides stimulate a pro-immune profile in bovine macrophages.

We evaluated the potential of a nanoparticle (NP) delivery system to improve methods of delivery of candidate peptide-based vaccines for Paratuberculosis in cattle. Peptides derived from Mycobacterium avium subsp. paratuberculosis (Map), and the pro-inflammatory monophosphoryl lipid A (MPLA) were incorporated in polymeric NPs based on poly (d,l-lactide-co-glycolide) (PLGA). The PLGA/MPLA NPs carriers were incubated with macrophages to examine their effects on survival and function. PLGA/MPLA NPs, with and without Map antigens, are efficiently phagocytized by macrophages with no evidence of toxicity. PLGA/MPLA NP formulations did not alter the level of expression of MHC I or II molecules. Expression of TNFα and IL12p40 was increased in Map-loaded NPs. T-cell proliferation studies using a model peptide from Anaplasma marginale demonstrated that a CD4 T-cell recall response could be elicited with macrophages pulsed with the peptide encapsulated in the PLGA/MPLA NP. These findings indicate PLGA/MPLA NPs can be used as a vehicle for delivery and testing of candidate peptide-based vaccines. These results will assist on more in depth studies on PLGA NP delivery systems that may lead to the development of a peptide-based vaccine for cattle.

Regulation of immune gene expression by the zinc finger DNA binding protein, CNBP/ZNF9

Abstract An inducible program of inflammatory gene expression is a hallmark of antimicrobial defenses. This response is controlled by a collaboration involving signal-dependent activation of transcription factors, transcriptional co-regulators, and chromatin-modifying factors. Here we have identified a highly conserved Zinc finger DNA binding protein CNBP (also called ZNF9) upregulated in myeloid cells exposed to lipopolysaccharide. CNBP resides primarily in the cytosol and upon TLR4 engagement, CNBP translocate to the nucleus. To investigate the functional consequences of these events, we generated mice lacking CNBP and characterized the role of CNBP in controlling the inducible transcriptional program using a combination of RNA-sequencing and multiplex gene expression analysis (Nanostring). In response to an array of signals such as LPS, CNBP-deficient macrophages were impaired in their ability to induce important immune genes including IL12p40 and IL6 amongst others. CNBP-deficient cells showed normal activation of TBK1 and p65. However, the nuclear translocation of c-Rel that is critical for the inducible expression of IL-12p40 was significantly compromised in cells lacking CNBP. Furthermore, Chromatin Immunoprecipitation experiments revealed that CNBP itself bound the IL12 promoter and c-Rel binding to this promoter was compromised in CNBP-deficient macrophages. Lastly, ectopic expression of wild type CNBP but not a mutant form that could not be phosphorylated together with c-Rel led to synergistic activation of an IL12 promoter driven reporter gene. Collectively, these findings identify CNBP as a novel DNA binding protein that acts as a transcriptional regulator controlling the inflammatory program in macrophages.

CD46 activation on monocyte-derived dendritic cells

Abstract Objective CD46 is an important immune modulatory receptor that influences the expression of certain cytokines in different cell types. This function has been proposed to depend on expression of specific isoforms of CD46. The common isoforms are named BC1, BC2, C1 and C2, and activation of T cells induces a switch towards dominance of BC2 and C2. However, the effect of CD46 activation on the cytokine production in dendritic cells (DCs) has so far been inconclusive and the relative distribution of CD46 isoforms in monocytes and DCs is unknown. Methods Monocytes were isolated from peripheral mononuclear blood cells and differentiated to dendritic cells (moDC). The maturation of moDCs was confirmed by flow cytometry using a panel of maturation markers. Monocytes and moDCs were stimulated with LPS in presence or absence of CD46 activation and the production of various cytokines were analyzed by real-time PCR. The monocytes and moDCs were furthermore analyzed for their expression of different CD46 isoforms by an isoform-specific real-time PCR assay. Results Upregulation of CD40, CD80, and CD83 on the surface of moDCs demonstrated the maturation of monocytes to moDCs. Activation of CD46 in moDCs during LPS stimulation was found to reduce the mRNA expression of IL12p40 and CXCL10 while no effect of CD46 activation on these cytokines was observed in monocytes. Examination of CD46 isoforms revealed a dominant expression of the isoforms BC2/C2 in moDCs upon differentiation from monocytes. Conclusion The results presented here suggest that CD46 activation reduces the pro-inflammatory potential of LPS stimulation in moDCs but not in monocytes. These functional changes are associated with a switch towards dominant expression of BC2/C2 isoforms.

Fetuin-A deficiency protects mice from Experimental Autoimmune Encephalomyelitis (EAE) and correlates with altered innate immune response.

Fetuin-A is a biomarker of disease activity in multiple sclerosis. Our aim was to investigate whether Fetuin-A plays a direct role in the neuroinflammatory response in the mouse EAE model. Peak Fetuin-A expression in the CNS and in peripheral lymphoid tissue correlated with peak EAE disease activity. Fetuin-A-deficient mice showed reduced EAE severity associated with an accumulation of splenic monocyte and dendritic cell populations, increased IL-12p40, ASC1, and IL-1β expression, and an increase in T regulatory cells. The upregulation of Fetuin-A in LPS-stimulated dendritic cells and microglia further supports an intrinsic role of Fetuin-A in regulating innate immune activation during EAE.

CD163-Positive Macrophages Within the Tumor Stroma Are Associated With Lymphangiogenesis and Lymph Node Metastasis in Oral Squamous Cell Carcinoma

Increasing evidence shows that tumor stromal components, particularly tumor-associated macrophages (TAMs), play an important role in the tumor progression of various solid malignant tumor types. However, their roles in oral squamous cell carcinoma (OSCC) have not been fully elucidated. Seventy human tongue OSCC samples were analyzed in the present study. Immunohistochemistry was used to investigate the correlations between the densities of CD68-, CD163-, and CD204-positive TAMs and clinicopathologic parameters. Lymphatic vessel density (LVD) was estimated using the D2-40 antibody. Invitro studies also were conducted to investigate the effect of conditioned medium (CM) derived from OSCC cell lines on cytokine and chemokine expression in RAW264.7 mouse monocytic leukemia cells. Increased densities of CD68-, CD163-, and CD204-positive TAMs were significantly correlated with lymph node metastasis (P=.035, .0082, and .038, respectively). Higher LVD occurred considerably more frequently in patients with nodal metastasis than in those without such metastasis. Moreover, LVD was considerably increased in patients with higher CD163-positive TAM densities. Studies using immunofluorescence showed that vascular endothelial growth factor (VEGF)-C was expressed in 52 of 70 patients with CD163-positive TAMs (74.2%). Moreover, CM derived from OSCC cell lines stimulated the expression of Il-10, Ccl22, Vegf-a, and Vegf-c in RAW264.7cells; however, Il-12p35 expression levels were not changed. CD163-positive TAMs promote lymphangiogenesis through VEGF-C expression, which contributes to regional lymph node metastasis in OSCC.

Kynurenic acid downregulates IL-17/1L-23 axis in vitro.

Exploring the function of interleukin (IL) 17 and related cytokine interactions have been proven useful toward understanding the role of inflammation in autoimmune diseases. Production of the inflammatory cytokine IL-23 by dendritic cells (DC's) has been shown to promote IL-17 expression by Th17 cells. It is well established that Th17 cells play an important role in several autoimmune diseases including psoriasis and alopecia. Our recent investigations have suggested that Kynurenine-rich environment can shift a pro-inflammatory response to an anti-inflammatory response, as is the case in the presence of the enzyme Indoleamine 2,3 dioxygenase (IDO), the rate-limiting enzyme in tryptophan degradation and Kynurenine (Kyn) production. In this study, we sought to explore the potential role of kynurenic acid (KynA), in modulating the expression of IL-23 and IL-17 by DCs and CD4+ cells, respectively. The result of flow cytometry demonstrated that the frequency of IL-23-producing DCs is reduced with 100µg/ml of KynA as compared with that of LPS-stimulated DCs. KynA (100μg/ml) addition to activated T cells significantly decreased the level of IL-17 mRNA and frequency of IL-17+ T cells as compared to that of concanavalin (Con) A-activated T cells. To examine the mechanism of the suppressive role of KynA on IL-23/IL-17 in these cells, cells were treated with 3μM G-protein-coupled receptor35 (GPCR35) inhibitor (CID), for 60min. The result showed that the reduction of both adenylate cyclase (AC) and cyclic adenosine monophosphate (cAMP) by KynA is involved in suppression of LPS-induced IL-23p19 expression. Since GPCR35 is also detected on T cells; therefore, it is concluded that KynA plays an important role in modulating the expression of IL-23 and IL-17 in DCs and Th17 cells through inhibiting GPCR35 and downregulation of both AC and cAMP.

TRIM21 is important in the early phase of inflammation in the imiquimod-induced psoriasis-like skin inflammation mouse model.

Tripartite motif-containing protein 21 (TRIM21) regulates pro-inflammatory cytokines and type I interferons and acts as an autoantigen in certain autoimmune diseases, but TRIM21 has not been investigated in psoriasis. It has been suggested that TRIM21 may have a dual function; in the early phase of inflammation, it may function as a stimulator; but upon immune stimulation, its ubiquitinating mode of action may shift from stabilization to degradation of IRF3 causing inhibition of the immune responses. The imiquimod (IMQ)-induced psoriasis-like mouse model displays features similar to those of human psoriasis. However, chronicity is lacking in this model. We investigated whether the role of TRIM21 in psoriasis was pro-inflammatory or anti-inflammatory. We hypothesized that a shift of the TRIM21-ubiquitinating mode of action may explain the lack of chronicity in the IMQ-induced psoriasis-like mouse model. We showed that TRIM21 expression is increased in lesional psoriatic skin and in the early phase of IMQ-induced inflammation both in vitro and in vivo. Surprisingly, inflammation was significantly less pronounced in TRIM21 knockout mice than in wild-type mice as shown by ear thickness measured at days 8, 9 and 10 after treatment start, by spleen weight as a marker of systemic effect of IMQ at 10days after treatment start and by expression of IL-12p40 at days 3 and 10 after treatment start and IL-17A at day 3 after treatment start. Therefore, induction of TRIM21 expression cannot explain the lack of chronicity in the IMQ-induced psoriasis-like skin inflammation mouse model.

Ginger extract modulates the expression of IL-12 and TGF-β in the central nervous system and serum of mice with experimental autoimmune encephalomyelitis.

The main function of IL-12 is differentiation of naive T cells intoTh1 cells and TGF-β is a powerful immunoregulatory cytokine. The immunomodulatory and anti-inflammatory properties of ginger have also been reported in some studies. The aim of this study was to evaluate the effects of ginger extract on the expression of IL-12 and TGF-β in a model of experimental autoimmune encephalomyelitis (EAE). EAE was induced in C57BL/6 mice by immunization with myelin oligodendroglial glycoprotein emulsified in complete Freund's adjuvant. The mice were administered intra-peritoneally with ginger extracts or PBS, from day +3 to +30. On day 31, mice were scarified and the expression of IL-12 and TGF-β mRNA in the spinal cord were determined by using real time-PCR. The serum levels of cytokines were measured by ELISA. In PBS-treated EAE mice, the expression of IL-12 P35 and IL-12 P40 mRNA in the CNS and the mean serum levels of IL-12 were significantly higher than those of healthy group (p<0.001). In ginger-treated EAE mice, the expression of IL-12 mRNA and its serum levels were significantly lower as compared to PBS-treated EAE mice. No significant difference was observed between PBS-treated EAE mice and healthy group regarding the expression of TGF-β mRNA. In ginger (300 mg/kg)-treated EAE group, the expression of TGF-β mRNA and its serum levels were significantly higher in comparison to PBS-treated EAE mice (p<0.01 and p<0.05, respectively). These results indicated that ginger extract modulates the expression of IL-12 and TGF-β in CNS and serum of EAE mice.

Ionizing Radiation Induces Innate Immune Responses in Macrophages by Generation of Mitochondrial Reactive Oxygen Species.

During radiotherapy for tumors, the innate immune system also responds to ionizing radiation and induces immune modulation. However, little is known about the molecular mechanisms by which radiation modulates innate immune responses. In this study, we observed that radiation triggered the generation of mitochondrial reactive oxygen species (mROS), leading to innate immune responses in murine bone marrow-derived macrophages (BMDM). Radiation-induced mROS was essential for robust induction of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-12p40 mRNA and protein in BMDM. Exposure to radiation also led to rapid activation of the mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-κB pathways in BMDM. Notably, radiation-induced MAPK activation and NF-κB signaling were regulated by mROS in macrophages. Additionally, radiation-induced expression of TNF-α, IL-6 and IL-12p40 was dependent on JNK, p38 and NF-κB activation in BMDM. These data suggest a key role for radiation-induced pro-inflammatory responses and activation of the MAPK and NF-κB pathways through a triggering mechanism involving mROS generation.