Gallen, Switzerland). BALB/c and BALB/c Thy1.1 mice were obtained from Charles River (Germany) and CD4-deficient BALB/c mice were obtained from Jackson Laboratories (USA). Mice deficient for the IFNGR [45], IL-6 [46], and IL-17A [47] mice were backcrossed on the BALB/c background for at least ten times.

Splenic CD4+ effector Th cells were obtained from 3-deazaneplanocin A peptide-immunized mice at the peak of disease on day 21 post immunization [48] and restimulated in vitro for 2 days with 10 μg/mL myhca614–629 peptide and 50 U/mL IL-2. BW 5147 lymphoma cells (kindly provided by Dr. Annette Oxenius, ETH Zürich) were fused to antigen-stimulated splenocytes using polyethylene glycol 1500 (PEG 1500; Roche) following the manufacturer’s instructions. Following the substitution of hypoxanthin-aminopterin-thymidine (HAT; Gibco) selection medium, antigen specificity was assessed by ELISPOT assay [48], and positive clones were monoclonolized by limiting dilution. RNA isolation from myhca614–629-specific hybridoma cells was performed using TRIzol (Invitrogen) following the manufacturer’s instructions. cDNA synthesis was performed using Super Script II Reverse Transcriptase (Invitrogen) and oligo (dT) primers. The TCR V Cetuximab purchase genes were analyzed by flow cytometry and RT-PCR using previously published primer pairs [49]]. The DNA sequence of the myhca614–629-specific TCR was analyzed by PCR sequencing

and sequence alignment using the ImMunoGeneTics information system database (http://www.imgt.org). The TCR variable regions

(Vα-2J42; Vβ-8D-1J2–4) were cloned into TCR cassette vectors [50] using the following PCR primers: α-chain: 5′-ATTACCCGGGGCTTCAGTCTAGGAAGAATGGACACG-3′; 5′-ATTAGCGGCCGCCTTTAACACTTACTTGATTTAACAGAG-3′; β-chain: 5′-ATTACTCGAGCCTGCCTTAGTTCTGAGATGGGC-3′; 5′-ATTACCGCGGCTATACCCCAGCTTACCTAGCACCG-3′. Linearized constructs were injected at an equimolar ratio into fertilized oocytes of the CB6F1xBALB/c background and founder lines were backcrossed to BALB/c. TCR-M mice were kept heterozygous and ioxilan nontransgenic littermates were used as controls. For histological analysis, hearts were fixed in 4% formaldehyde (formafix) for at least 12 h and embedded in paraffin. Histopathological changes were evaluated following hematoxilin/eosin and Elastica van Giesson (EVG) staining. Myocarditis severity was evaluated using a semiquantitative scoring system: 0, no inflammation; 1, <100 inflammatory cells involved, small inflammatory lesions; 2, >100 inflammatory cells involved, larger inflammatory lesions; 3, >10% of the heart section involved in inflammation; 4, >30% of the heart section involved in inflammation; 5, >30% of the heart section involved in inflammation with extensive fibrosis and dilation of ventricle. Images from heart sections were acquired using a Leica DMRA microscope and processed using Adobe Photoshop (Adobe Systems). In vivo neutralization of IL-17A was done with the anti-mouse IL-17A monoclonal antibody BZN035 (IgG2a).

Here we show for the first time, using two experimental approaches, that abundant IL-10 is spontaneously produced by Treg cells in tumors subcutaneously injected in mice. Of note, IL-10 was not detectable

anymore after FACS-sorting and culture of Treg cells (data not shown), an observation suggesting that IL-10 induction may be a transient and reversible feature of tumor-infiltrating Treg cells, closely dependent on microenvironmental cues at the tumor site. IL-10 is a crucial cytokine for immune suppression in tumors. Tumor-associated macrophages constitutively express IL-10 34, thus maintaining an impaired immune status. We and others 35, 36 have reported that IL-10 receptor blockade, when combined with TLR agonists and/or other immunostimulatory

agents, rescue the functional Tanespimycin mouse paralysis of tumor-infiltrating DCs and macrophages toward an efficient cancer therapy. However, macrophages are not the sole IL-10 source in tumors. Studies in human cancer have shown that Treg cells recruited at tumor sites produce abundant IL-10 37, 38, which may work as the main mediator of Treg-cell functional suppression 37. Conversely, in a murine tumor model, others have shown that CD25+-cell depletion and IL-10 receptor blockade exert distinct, though partially overlapping, effects in suppressing DC activation and anti-tumor CD8+ response 13. Even if a Foxp3-directed, rather than CD25-directed, mTOR inhibitor Treg-cell depletion may provide more reliable results about

the functional redundancy of Treg cells and IL-10, it is likely that Treg cells are not the only source of IL-10 at the tumor site 13 and that sole IL-10 receptor blockade cannot recapitulate the efficient anti-tumor activity of combination Resveratrol therapies 35, 36, of the sole OX40 triggering 3, 21 or of Foxp3-targeted Treg-cell depletion, when combined to vaccination 39 or even as single treatment 40. A link between OX40 stimulation and IL-10 production has been already highlighted in human Tr1 cells 6. OX40L exposure not only prevented the generation of IL-10-producing Tr1 cells from both naïve and memory T cells under different differentiating stimuli, but also repressed IL-10 production and suppressive functions of pre-established Tr1 cells 6. Completely distant regulatory pathways may operate in thymus-derived and tumor-expanded murine Treg cells, expressing Foxp3, as in our system, compared with in vitro generated human Tr1 cells, likely not expressing Foxp3 41. However, OX40 signal may influence conserved pathways regulating IL-10 secretion in divergent lineages. For instance, OX40 engagement inhibits IL-10 production along Th2 differentiation 42 and during anti-viral immune responses 43. Moreover, we show here that OX40 signal may regulate IL-10 secretion through the modulation of IRF1, a Th1-related transcription factor 44. We found IRF1 expressed in tumor-infiltrating but not peripheral Treg cells producing or not IL-10, respectively.

Populations III and IV were further sorted into CD4SP and CD8SP subsets. qRT-PCR using cDNA from each sorted subset showed that Egr2 was upregulated between populations I and II, at the point when selection occurs, and that its expression

declined thereafter (Fig. 1B, left panel). When we performed the analogous sort, but using thymocytes purified from β2m−/− (centre panel) and MHC class II−/− (right panel) mice to exclusively generate CD4SP and CD8SP cells, respectively, a similar expression pattern was observed irrespective of genotype, suggesting selleck that upregulation is dependent on selection, but is not lineage-specific. In primary DP cells, Egr2 is upregulated by the MAPK and calcineurin pathways following TCR ligation 15, 22, but the kinetics of its induction, and the interplay between these two pathways, has not been fully mTOR inhibitor explored. To address this issue, we cultured naïve MHC-null thymocytes directly ex vivo with PMA and ionomycin, with or without inhibitors of Erk or calcineurin signaling. As shown in Fig. 1C, maximal induction of Egr2 mRNA was achieved after 30 min of PMA/ionomycin stimulation. This rapid induction was inhibited by FK506 or cyclosporin A, inhibitors of calcium and hence calcineurin signaling, and was completely abrogated by

the inclusion of PD98059 or U0126 to inhibit Erk signaling. To further dissect Egr2′s induction by the MAPK pathway, we looked at Egr2 expression in mice deficient in the MAPK-activated transcription factor Sap-1 (Elk4), which is required for normal positive selection 23. Pre-selection TCR-βloCD69− and TCR signaled TCR-βloCD69+ thymocytes were sorted from Sap-1−/− mice and littermate controls, and Egr2 mRNA levels were measured by qRT-PCR. In both populations, there was a significant (p<0.02) reduction in the levels Olopatadine of Egr2, compared with WT (Fig. 1D). Therefore, Egr2 is rapidly

upregulated by Erk and calcineurin signaling in primary thymocytes, and, like Egr1 23, its induction by Erk is dependent upon Sap-1. The timing and regulation of Egr2 expression are consistent with its having a role in positive selection. To study the role of Egr2 in thymocyte development, Tg mice overexpressing Egr2 were constructed. Mice carrying a Cre-inducible Egr2 Tg construct were bred to mice transgenic for CD4Cre recombinase 27, so that the effects of Egr2 overexpression specifically from the DP stage of development onwards could be examined. A schematic of the construct and verification that Egr2 is overexpressed in DP and SP cells, but not in the earlier DN stage, in the line presented in this paper, are shown in Supporting information Fig. 1A and B.

The results from those studies mentioned above drew a consistent conclusion that PHB could protect the cells or tissue from reactive oxygen species (ROS) induced injury. There were some observations reported that the PHB might be observed in renal tissue and these studies found that PHB might play a protective role in kidney against renal disease. Guo et al.18 observed that PHB protein was positively expressed at normal renal tissues, strongly downregulated in renal biopsy specimens from patients, and negatively correlated with the degrees of tubulointerstitial lesions, and they also conducted a study in rat kidney fibroblasts cell line and found that the overexpression of PHB suppressed the renal interstitial

fibroblasts proliferation and cell phenotypic change induced by TGF-βl. Ribociclib supplier Wu et al.45 performed a study in rats with renal tubular atrophy and interstitial fibrosis induced by aristolochic acid and found that the expression of PHB protein

Selleck SAHA HDAC was downregulated in renal tissue of rats. Quan et al.46 observed that the expression of prohibitin-2 (homologue of PHB147) was downregulated in RTEC stimulated by elevated uric acid, which might promote trans-differentiation of RTEC, and they also noted that prohibitin-2 was associated with RTEC apoptosis due to uric acid. Those reports consistently agreed that PHB was a protective factor, and Quan et al.46 found that prohibitin-2 was associated with RTEC apoptosis in vitro. It was similar to our result in vivo. However, there was not any investigation

performed in vivo to report that there was an association between PHB expression and the expression of Caspase-3 or the cell apoptosis in renal interstitium of RIF rats. This study was performed to explore this association in RIF rats induced by UUO. Results from our study showed that protein expression of Caspase-3, TGF-βl, Col-IV or FN, indexes of RIF and cell apoptosis were more markedly increased in the GU group than those in SHO group, especially at 28 days. We also found that the impaired RTEC was the main contributor for RIF progression in the UUO Tacrolimus (FK506) model. It could draw a conclusion that the RIF model induced by UUO in our study was successful. However, the pathological mechanism of RIF was not elucidated. In this study, we found that PHB was mainly located in RTEC and PHB expression was negatively correlated with protein expression of Caspase-3, TGF-βl, Col-IV or FN, index of RIF or cell apoptosis index. The PHB expression in the normal control group was more marked when compared with that in the GU group. In conclusion, PHB suppressed the development of RIF and alleviated the protein expression of Caspase-3, TGF-βl, Col-IV or FN, and weakened the indexes of cell apoptosis and RIF. As those mentioned above, PHB was associated with the expression of Caspase-3/apoptotic cell in renal interstitium of UUO rats.

Most available data is not from an Australian or New Zealand source. The effects on quality of life of different management

pathways on patients, carers and staff still need to be addressed. “
“SATURDAY 23 AUGUST 2014  Meeting Room 213 0830–0915 ABO Incompatible Transplantation Kate Wyburn 0915–1000 TSA HDAC mouse Donor Specific Antibodies – What, When, How John Kanellis 1000–1030 Morning tea 1030–1115 Nutrition, Inflammation, Heart Health and Outcomes in PD Patients Angela Wang 1115–1145 Haemodialysis at Home John Agar 1145–1215 CRB Prevention Kevan Polkinghorne 1215–1315 Lunch (not provided) 1315–1400 Cardiorenal Syndrome Henry Krum 1345–1430 Diabetic Nephropathy Mark Cooper 1430–1500 Afternoon tea 1500–1530 Nephrolithiasis Sorafenib nmr and the Nephrologist Bruce Cooper 1530–1615 Cancers of the Kidney – Medical Perspective Ian Davis 1615–1645 Cancers of the Kidney – Urological Perspective Lih-Ming Wong SUNDAY 24 AUGUST 2014  Meeting Room 105 0830–0900 Renal Aspects of Dysproteinaemias Paul Coughlin 0900–0945

Primary or Secondary Membranous Nephropathy? Diagnosis and Consequences R Stahl 0945–01015 IgA Nephropathy Muh Geot Wong 1015–1045 Morning Tea 1045–1115 Immunisation in CKD Amelia Le Page 1115–1145 FSGS and Minimal Change Disease Steve Alexander 1145–1215 Recurrent GN in Transplantation Steve Chadban 1215–1315 Lunch (provided for RACP Advanced Trainees meeting) 1315–1345 Lupus Nephritis Richard Kitching 1345–1415 Alport’s Disease – Update on Genetics Judy Savige 1415–1445 SSR128129E ANCA Vasculitis Steve Holdsworth 1445–1515 Afternoon Tea 1515–1600 The Ups and Downs of Sodium Balance Robert Unwin 1600–1645 Acid Base

Disorders David Harris “
“2014 ANZSN SOCIETY SPONSORS Platinum Sponsors Amgen Australia Pty Ltd Fresenius Medical Care Australia Roche Products Pty Ltd Gold Sponsors Baxter Healthcare Pty Ltd/Gambro Pty Ltd Novartis Pharmaceuticals Australia Pty Ltd Shire Australia Pty Ltd Silver Sponsor Sanofi Australia and New Zealand Bronze Sponsor Servier Laboratories Australia Pty Ltd “
“Available guidelines fall into 2 categories – medication guides and service provision guides Few guidelines exist for the management of patients choosing to not have dialysis apart from those covering end of life (EOL) management and general ones for the management of chronic kidney disease. Most guidelines are only based on low level evidence, relying on expert opinion or current practice. This limits their usage when advising on matters such as trials of dialysis and caution should be applied when discussing these matters. More data is needed before firmer recommendations can be made. Units in Australia and New Zealand should consider maintaining registers of ‘at risk’ patients to allow greater input into symptom management and end-of-life support “
“By establishing Kidney Diseases: Improving Global Outcome (KDIGO), nephrology has taken an important step towards developing global clinical practice guidelines (CPG).

With a sub-set of splenic Treg cells displaying a CXCR5+ CCR7− phenotype, the possibility exists that iTreg cells are attracted to splenic GCs in the mouse, as shown by studies examining human and mouse tissue.44,45,60,61 Mice were therefore challenged with SRBC and spleens

were harvested at day 8, the height of the response. Snap-frozen tissues were thin sectioned and stained, as shown in Fig. 7. In the upper panel, the section was stained with PNA and anti-CD4 mAb to highlight GCs (green) and T-cell zones (red). Serial sections were stained with anti-IgD mAb and anti-Foxp3 mAb (middle panel) selleck inhibitor to denote the follicular mantle (green) as well as individual Treg cells (blue), and with anti-IgD mAb and control rat IgG2a (lower panel) to control for background staining. As expected, a population of Foxp3+ staining cells was found to reside within the T-cell zone. Figure 7 further shows the presence of Foxp3+ cells (designated with arrows) within the GC (PNA+ IgD− area outlined in white). These observations are consistent with a sub-set of splenic CD4+ Foxp3+ cells exhibiting a CXCR5 CCR7− phenotype, and suggest

the possibility that Treg cells may effect their suppressive activity directly within the GC. The Treg-cell MI-503 population induced to control responses to novel antigens is thought to arise from naive CD4+ Foxp3− Progesterone T cells in the periphery. A number of key signals and cytokines have been shown to be essential for the generation of iTreg cells both in vitro and in vivo.14,15 Of the various signals, TGF-β has been repeatedly

demonstrated to be critical for the induction and maintenance of Foxp3+ iTreg cells.63–65 In addition, a recent report suggested that IL-10 also has a central role in maintaining Foxp3 and the associated suppressive activity in Treg cells.66 Towards this end, a large number of studies have utilized anti-TGF-β67–72 or anti-IL-10R70–74 blocking mAbs over extended periods to impede the induction and activity of Treg cells in vivo. We therefore took a similar approach and examined the effect of anti-TGF-β mAb or anti-IL-10R mAb on SRBC-induced GC responses. In the first set of experiments, mice were injected i.p. with 100 μg anti-TGF-β (1D11) mAb or control mouse IgG every 2 days starting at day 0 and continued until the mice were killed. The SRBC were given i.p. on day 0. The results are shown in Fig. 8, and illustrate an excess in the percentage and total number of IgM− switched GC B cells (Fig. 8b). This imbalance was evident already at day 8 and became progressive as the response matured. Although control of the switched GC sub-set was impaired in anti-TGF-β-treated mice, the overall size of the B220+ PNAhi population was not significantly different from that in control-treated animals (Fig.

The evolution of these activating receptors may have been driven in part by pathogen exploitation of inhibitory siglecs, thereby providing the host with additional pathways by which to combat these pathogens. Inhibitory siglecs seem to play important and varied roles in the regulation of host immune responses. For example, several CD33rSiglecs have been implicated in the negative regulation of Toll-like receptor signalling during innate responses; siglec-G functions as a negative regulator of B1-cell expansion and appears to suppress inflammatory responses to host-derived ‘danger-associated

molecular patterns’. Recent work has also shown that engagement of BAY 57-1293 neutrophil-expressed siglec-9 by certain strains of sialylated Group B streptococci can suppress killing responses, thereby providing experimental support for pathogen exploitation of host CD33rSiglecs. Sialic-acid-binding immunoglobulin-like lectins, siglecs, form a family of cell surface receptors expressed on immune cells that mostly mediate inhibitory signalling1–3

(Fig. 1, Table 1). Like other important inhibitory immune receptor families such as killer-cell immunoglobulin-like receptor4,5 and leucocyte immunoglobulin-like receptor,6 siglecs are transmembrane molecules that contain inhibitory signalling motifs named immunoreceptor tyrosine-based inhibitory motifs (ITIMs)7,8 in their cytoplasmic tails and immunoglobulin superfamily domains in their extracellular check details portions. Compared with other immunoglobulin superfamily proteins, a unique feature of siglecs is that their specific ligands are sialylated carbohydrates, unlike most other immune receptors that bind to protein determinants. Interest in siglecs has grown over recent years as it has become increasingly clear that these receptors play a wide range of roles in the immune system. Following the sequencing of the human genome,9 known siglecs have expanded from the well-characterized conserved Non-specific serine/threonine protein kinase members: sialoadhesin,10 CD22,11–16 CD3317 and myelin-associated glycoprotein,18 to the rapidly evolving large CD33-related siglec (CD33rSiglec) subfamily (Fig. 1,

Table 1)19 and novel potentially activating members of the siglec family.20–22 This review focuses on new ideas about the evolution of the CD33rSiglecs and discusses the functional roles that CD33rSiglecs play in the host as well as their interactions with pathogens. Sialic acids are ubiquitously found on the surface of mammalian cells.1,2 CD33rSiglecs form a large cluster on chromosome 19 in humans and this cluster is well conserved in all mammals.2,23 Following a study of different species including primates, rodents, dog, cow, marsupials, amphibians and fish, Cao et al.23 proposed that the CD33rSiglecs cluster in mammals was the product of a major inverse duplication of a smaller sub-cluster that arose early in mammalian evolution 180 million years ago (Fig. 2).

Our finding may provide a more feasible Fulvestrant purchase strategy for deceased-donor renal transplantation. The greatest barrier in allotransplantation is the anti-alloimmune rejection. Dendritic

cells (DC) have been proposed as the first initiator of allograft rejection. DC are the most potent professional antigen-presenting cells and play crucial roles in innate and adopted immune responses. Studies indicated that the maturation states of DC are related with their ability to induce immune response or tolerance [1–3]. The mature DC with high levels of cell surface class II major histocompatibility complex (MHC-II) and costimulatory molecules including CD80 (B7-1), CD86 (B7-2), and CD40 induce immune response, while immature DC characterized by low expression of both MHC class II and costimulatory molecules are capable of inducing tolerance [1–4]. Mechanisms of immature DC-inducing tolerance include T-cell anergy, immune deviation, promotion of activated T-cell apoptosis,

and formation of regulatory T cells [3–5]. Tolerogenic immature DC can be generated in several different ways, including conditioning the cells with immunological or pharmacological reagents [4–6] genetic engineering with different genes [7–11]. It was reported that the nuclear factor-kappa B plays a critical role in dendritic cell maturation and tolerance induction [12–14]. Further study indicated that IKK2 plays essential role in DC antigen presentation [15]. AZD5363 datasheet Treatment of murine bone marrow-derived DC with double-stranded oligodeoxyribonucleotides (ODN), which contains binding sites for NF-κB, generated DC with a significantly reduced CD80 and

CD86 expression when compared with untreated cells. ODN-treated DC exhibited an impaired allostimulatory capacity in vitro and prolonged heart allograft survival when infused in MHC-mismatched mice [14]. Blocking IKK2 in human monocyte-derived DC by adenoviral transfection with a kinase-defective dominant negative Ponatinib cost form of IKK2 (IKK2dn) generated DC with impaired allostimulatory capacity, which failed to increase MHC-II antigens and costimulatory molecules in response to CD40 engagement [15]. Using adenoviral vector encoding for IKK2dn to block NF-κB of rat bone marrow-derived DC results in blocking DC maturation, and IKK2-blocked donor DC treatment prolonged kidney allograft survival in rat by inducing regulatory T-cell generation [7]. Those results indicated that NF-κB inhibition is capable of blocking DC maturation and inducing allogenic tolerance, while those studies are transferring donor’s DC into recipients.

“
“Axin, a negative regulator of the Wnt signaling pathway, plays a critical role in various cellular events including cell proliferation and cell death. Axin-regulated cell death affects multiple processes, including viral replication. For example, axin expression suppresses herpes simplex virus (HSV)-induced necrotic cell death and enhances viral replication. Based on these observations, this study investigated the involvement of autophagy in Ribociclib regulation of HSV replication and found axin expression inhibits autophagy-mediated suppression of viral replication in L929 cells. HSV infection induced autophagy

in a time- and viral dose-dependent manner in control L929 cells (L-EV), whereas virus-induced autophagy was delayed in axin-expressing L929 cells (L-axin). Subsequent analysis showed that induction of autophagy by rapamycin reduced HSV replication, and that inhibiting autophagy by 3-methyladenine (3MA) and beclin-1 knockdown facilitated

viral replication in L-EV cells. In addition, preventing autophagy with 3MA suppressed virus-induced cytotoxicity SAHA HDAC in vivo in L-EV cells. In contrast, HSV replication in L-axin cells was resistant to changes in autophagy. These results suggest that axin expression may render L929 cells resistant to HSV-infection induced autophagy, leading to enhanced viral replication. “
“NK cells are rapid IFN-γ responders to Plasmodium falciparum-infected erythrocytes (PfRBC) in vitro and are involved in controlling early parasitaemia in murine models, yet little is known about their contribution to immune responses following malaria infection in humans. Here, we studied the dynamics of and requirements for in vitro NK responses to PfRBC in malaria-naïve volunteers undergoing a single experimental malaria infection under highly

controlled circumstances, and in naturally exposed individuals. NK-specific IFN-γ responses to PfRBC following exposure resembled an immunological recall pattern and were tightly correlated with T-cell responses. However, although Tacrolimus (FK506) PBMC depleted of CD56+ cells retained 20–55% of their total IFN-γ response to PfRBC, depletion of CD3+ cells completely abrogated the ability of remaining PBMC, including NK cells, to produce IFN-γ. Although NK responses to PfRBC were partially dependent on endogenous IL-2 signaling and could be augmented by exogenous IL-2 in whole PBMC populations, this factor alone was insufficient to rescue NK responses in the absence of T cells. Thus, NK cells make a significant contribution to total IFN-γ production in response to PfRBC as a consequence of their dependency on (memory) T-cell help, with likely positive implications for malaria vaccine development. NK cells are lymphocytes belonging to the innate immune system whose hallmark is their potent activity against altered self-cells, such as tumor cells and virus-infected cells 1, but are also capable of responding against extracellular protozoan pathogens 2, 3, including Plasmodia.

In vivo studies complemented with tissue-specific genetic ablation of either the receptor or key metabolic enzymes are required to gain further insight. A new wrinkle is added to these complex roles in this issue of the European Journal of Immunology by Lee et al. [25], who use RA pretreatment to assess the contribution

of retinoid signaling to immune-driven liver damage using two in vivo models of hepatitis. One model uses concanavalin A (Con A) to induce rapid T-cell, granulocyte, and Kupffer cell infiltration in the liver, leading to hepatocyte death and eventually the Gefitinib cost death of the animal [26]. This model is believed to depend on NKT-cell selleck chemical activity; NKT cells in this model produce large amounts of cytokines, such as IFN-γ, IL-4, and TNF-α, leading to hepatocyte damage [27, 28]. While animals injected with Con A all died after 6 h, mice pretreated with RA all survived for at least 24 h [24]. This remarkable difference is accompanied by reduced levels of IFN-γ and IL-4, but no change in TNF-α levels [24]. Using a pharmacological inhibitor of RA synthesis (Disulfiram), the authors also showed that the reduction of endogenous RA production could aggravate Con A-induced hepatitis. By excluding the participation of other cell types,

such as Kupffer cells and Treg cells, and also by excluding changes in the activation cAMP of NKT cells per se, they pinpointed the changes in cytokine production as the cause of the in vivo phenotype. Remarkably, in the other model of NKT cell driven hepatitis, RA pretreatment was ineffective. In this model, αGalCer, the ligand of CD1d, was administered to induce hepatic tissue damage [29]. However, this model depends on FasL

and TNF-α rather than IFN-γ, and while the RA-induced changes in cytokines were similar to those induced in the Con A model (i.e. reduced levels of IFN-γ and IL-4, but no change in TNF-α levels), this did not translate into a marked phenotype in α-GalCer-induced liver injury as these cytokines are not the phenotype drivers. As far as the mechanisms behind these finding are concerned, the authors propose that RA downregulates IFN-γ and IL-4 production by a MAPK-dependent mechanism, while the NFAT-dependent TNF-α induction would be unaltered, hence explaining the differential effect on cytokine production (Fig. 1). These new data are important as they strongly implicate RA and, critically, its endogenous production, in the control of NKT-cell cytokine production and, by doing so, provide new pharmacological targets for controlling hepatic inflammation in vivo. These findings also provide support for the concept that lipid signaling, metabolism, and diet are important in the immune regulation of T-cell subpopulations.