Myeloid cells were most commonly confined to massive diffuse pockets around worm migratory tracts (Figure 1a) and to necro-ulcerative areas, the latter especially in neoplastic cases (Figure 1b). Most cases had massive diffuse areas that could not be counted. To a lesser extent, myeloid cells were diffusely scattered throughout the nodules (Table 4). T cells occurred diffusely (Figure 1c) or in a focal/multifocal (Figure 1d)

distribution pattern, predominantly at the periphery of the nodule (Table 5). The number of foci in the most active ×20 field ranged GDC-0449 from 0 to 18. B cells followed the same distribution within the nodule as T cells (Table 6), but there were fewer of them (Table 7), and they were more confined to focal/multifocal areas (Figure 1e). FoxP3+ cells were detected in 30% of nodules (32% of neoplastic cases and 28% of the non-neoplastic cases), especially in T cell foci, but they were not observed in the normal oesophagus. In most of the S. lupi cases where FoxP3+ cells were detected, the number of cells was very low and was not significantly different from

the normal oesophagus, where no FoxP3+ cells were detected (Table 8). However, three cases (one non-neoplastic and two neoplastic) contained a high power field with more than 10 FoxP3+ cells (up INK-128 to 47 cells/0·0625 mm2 in a selected high power field; Figure 1f). High numbers of FoxP3+ cells were observed in the lymph nodes (Table 9, Figure 1g), but no difference was observed between the bronchial and popliteal nodes and between the neoplastic draining however (86·44 ± 34·39, mean ± SD/0·0625 mm2) and non-neoplastic draining nodes (85·95 ± 54·55). These FoxP3+ cells were confined to CD3+ areas (Figure 1h). The current study revealed that the predominant inflammatory cells

in S. lupi oesophageal nodules are of myeloid lineage. These cells were identified by a MAC387 antibody, which does not enable differentiation between the different types of myeloid cells. However, based on the histological appearance, the vast majority of myeloid cells were neutrophils. These neutrophils formed pockets of pus around the worm, or they were confined to necro-ulcerative areas in the neoplastic nodules. Alternatively, neutrophils occurred diffusely throughout the nodules. The lymphocytic infiltrates had a prominent focal/multifocal distribution pattern (compared to the myeloid cells), and they were usually peripherally located within nodules. However, in the majority of cases, lymphocytes occurred in a mixed pattern, namely focal/multifocal and diffuse. The relative proportions of leucocytes within S. lupi nodules were different to our initial observations in H&E-stained sections (5). This finding shows the importance of further identification and quantification of cells using immunohistochemistry. There are two possible explanations for the observed difference.

“
“Alzheimer’s disease and the transmissible spongiform encephalopathies or prion diseases accumulate misfolded and aggregated forms of neuronal cell membrane proteins. Distinctive membrane lesions caused by the accumulation 5-Fluoracil order of disease-associated prion protein (PrPd) are found in prion disease but morphological changes of membranes are not associated with Aβ in Alzheimer’s disease. Membrane changes occur in all prion diseases where PrPd is attached to cell membranes by a glycosyl-phosphoinositol

(GPI) anchor but are absent from transgenic mice expressing anchorless PrPd. Here we investigate whether GPI membrane attached Aβ may also cause prion-like membrane lesions. We used immunogold electron microscopy to determine the localization and pathology of Aβ accumulation in groups of transgenic mice expressing anchored or unanchored forms of Aβ or mutated human Alzheimer’s precursor protein. GPI attached Aβ did not replicate the membrane lesions of PrPd. However, as with PrPd in prion disease, Aβ peptides derived from each transgenic

mouse line initially accumulated on morphologically normal neurite membranes, elicited rapid glial recognition and neurite Aβ was transferred to attenuated microglial and astrocytic processes. GPI attachment of misfolded membrane proteins is insufficient to cause prion-like membrane lesions. Prion disease and murine Aβ amyloidosis both accumulate misfolded monomeric or oligomeric membrane proteins that are recognised by glial processes and acquire such misfolded proteins prior to their accumulation in the Opaganib purchase extracellular space. In contrast to prion disease where glial cells efficiently endocytose PrPd to endo-lysosomes, activated microglial cells in murine Aβ amyloidosis are not as efficient phagocytes. “
“The hope that cell

transplantation therapies will provide an ideal treatment option for neurodegenerative diseases has been considerably revived with the remarkable advancements in genetic engineering towards active cell fate determination DCLK1 in vitro. However, for disorders such as Huntington’s disease (HD), the challenges that we face are still enormous. This autosomal dominant genetic disorder leads, in part, to massive neuronal loss and severe brain atrophy which, despite the cell type used, cannot be easily repaired. And before large clinical trials are even considered, we must take a critical look at the outcomes of the pilot studies already available, not only from a clinical perspective but also by a careful assessment of what we can learn from the autopsies of HD patients who have undergone transplantation. In this review, we summarize and discuss the seven transplantation pilot trials that were initiated worldwide in HD patients more than a decade ago, with a particular emphasis on the post-mortem analyses of nine unique cases.

A further limitation to the LCM is that genes expressed in both, FDC and B cells, such as Cd21 cannot be identified by this approach and are therefore missing from GDC-0068 in vitro the set of genes defined as FDC expressed. The gene expression profile showed that FDC express various extracellular matrix proteins (Fig. 3), known to control the availability of cytokines, chemokines and growth factors 29–31. Indeed, by expressing collagens and fibronectin essential for assembling conduits, FDC may help to regulate the transport of low-molecular-weight proteins 32. The pericellular

localization of biglycan (Fig 4A) is in line with the notion that biglycan functions as an extracellular regulator of cytokines and growth factors 29, 30. Beyond this, FDC may contribute to the mobility of B cells in the GC. Thus, two-photon microscopy has Olaparib shown that fibroblastic reticular cells guide the migration of T cell through the T-cell zone 33 and FDC may regulate B-cell motility in a similar way 34, 35. As shown for adhesion molecules such as Vcam-1

and Madcam-1, upregulation of the extracellular proteins Periostin and Coch may also ensure a tight association of B cells with FDC during the GC reaction (Fig. 2B) 2, 36, 37. A more global function of regulating lymphocyte migration within the immune compartments involves sphingosine-1-phosphate (S1P) 38. However, expression of S1P-generating sphingosin-lipases was not detected in FDC networks (no “present” calls) nor in any other compartment of the spleen 39. Instead, our analyses showed that stromal cells in the B-cell follicle express Enpp2 an ectoenzyme that hydrolyzes both lysophosphatidylcholine and sphingosinphosphorylcholine (Fig. 2A) 40. It is most likely that FDC control S1P-mediated egress of lymphocytes from the spleen. Altogether, these findings emphasize that antigen presentation by FDC is only one of the many functions in B-cell

development. Defining a new set of genes specifically expressed in FDC allows us to determine different developmental stages of stromal cell differentiation. In the absence MRIP of LTα, only weak expression of CXCL13 defines the area where B cells localize (Fig. 4H and Table 1). In CXCR5-deficient mice, LTα is expressed but in the absence of the LTα/CXCL13 feedback-loop the level of LTα is not sufficient for normal development of follicular structures and differentiation of reticular cells into mature FDC 26, 27. Nonetheless, the CXCL13+ stromal cells upregulate the FDC genes BP3, Enpp2 and Bgn (Fig. 4C and G, Table 1). In the SCID mouse, although lymphocytes are missing, the stromal cell compartment does segregate into a BP3hi Bgnhi and a BP3lo Bgnlo area (Fig. 4B). Indeed, with the exception of Serpina1, all of the analyzed FDC genes are expressed also in BP3hi stromal cells, although in most cases at a lower expression level (Fig. 3 and Table 1).

Following intranasal Vadimezan mw infection with C. pneumoniae, iNKT cells accumulate in the lungs during the early phase (day 3 post infection) and express intracellular IFNγ (24, 25). CD8α+ DCs from Jα18 deficient mice show lower CD40 expression and intracellular IL-12 compared to wild type mice, which results in decreased IFNγ production by CD4+ and CD8+ T cells (26). IL-12 production by CD8α+ DCs is dependent on IFNγ and CD40-CD40L interaction (26). These findings suggest that iNKT cells enhance the Th1 response by stimulating DCs via IFNγ and co-stimulatory molecules during certain microbial infections (Fig. 3). Natural killer T cells expressing an invariant T cell antigen receptor also participate in the response

to viruses. Jα18 deficient mice and CD1d deficient mice are highly susceptible to influenza A virus, showing high virus titers and

high mortality (27). In iNKT cell deficient mice, MDSCs expand and IAV specific CD8 T cells are suppressed (27). Adoptively transferring iNKT cells into Jα18 deficient mice, but not into CD1d deficient mice, restores IAV specific CD8 T cells and increases the survival rate by diminishing the suppressive function of MDSCs (27). In addition, in vitro experiments have shown that CD1d and CD40-CD40L interaction inhibit MDSC function (27). These data show that iNKT cells play an important role in the development of an effective IAV specific immune response by directly inhibiting the suppressive function of MDSCs (Fig. 4). MDSCs are present in the peripheral blood of IAV infected patients. Crenolanib ic50 However,

suppression of the human T cell response by MDSCs from IAV infected patients is reduced by iNKT cell activation (27). These results indicate that iNKT cells may play a role in the response old to certain microbial pathogens in humans. Natural killer T cells expressing an invariant T cell antigen receptor have been shown to participate in the pathogenesis of infection induced inflammation in a mouse model of chronic inflammatory lung disease that resembles asthma and COPD. Mice infected with Sendai virus exhibit chronic airway disease that manifests as mucous cell metaplasia and airway hyper-reactivity (28). IL-13 production by macrophages is necessary in this response. The interaction of iNKT cell TCRs with CD1d on macrophages and IL-13 derived from iNKT cells is necessary to activate macrophages to produce IL-13 (28). Importantly, lung tissue from patients with severe COPD exhibits mucous cell metaplasia and an increased number of IL-13+ CD68+ macrophages compared to non-COPD controls (28). Moreover, Vα24iNKT cells are increased in COPD subjects (28). This study suggests that iNKT cells are involved in chronic inflammation in certain viral infections. Natural killer T cells expressing an invariant T cell antigen receptor participate in the response to various microbial pathogens.

major-vaccinated mice. IL-6 treatment also resulted in a decrease of IFN-γ expressing CD4+CD25lo/med T cells (effector Th1 cells in our system 16) (Fig. 2B). As before, IL-6 neutralization also significantly increased the number of CD25hi IL-10+ T cells (Treg in our system 11, 16) (Supporting Information Fig. 1). These data demonstrate that vaccine-induced IL-6 modulates the development of Th17 cells in the Lm/CpG-vaccinated mice. They also suggest that Th17 cells are required for the recruitment or development of Th1 responses. To determine whether Th17 cells have a role in early parasite killing in Lm/CpG-vaccinated animals, we treated mice with anti IL-17 and/or anti IFN-γ neutralizing antibodies (or isotype

control), and examined the frequency of IL-17, IFN-γ-producing cells, and Treg during the GDC-0068 order “silent” phase (wk 2). Antibody treatment decreased the frequency of CD4+ T cells in Lm/CpG-vaccinated animals, but did not significantly affect the frequency of CD4+ T cells in the dermis of L. major-vaccinated animals at wk 2 (Supporting Information Fig. 2); in this case, it is possible that the low frequency of Th1 and Th17 cells in the ears of the latter mice did not allow detecting any differences cause by treatment. As expected, parasite burden was high at wk 2 in L. major-vaccinated animals (>1.5×105 parasites per ear, Fig. 3A), and significantly reduced (fivefold) in

mice vaccinated with Lm/CpG. Neutralization of either anti IL-17 and/or anti IFN-γ did not produce an increase in parasite killing in the L. major-vaccinated group. This was expectable because the number of cytokine positive cells in these mice is very low at wk 2. In contrast, Selleck Olaparib neutralization of IL-17 increased parasite burden in the ears of Lm/CpG-vaccinated mice by tenfold. Similarly, neutralization of IFN-γ or IL-17 plus IFN-γ increased parasite numbers by fivefold, suggesting that both IL-17 and IFN-γ are required for the control of parasite expansion after Lm/CpG vaccination. Differences among antibody-treated groups were not statistically significant. Parasite growth was associated

with an expansion in the number of Treg. Figure 3B shows that the absolute number of Treg significantly increased following antibody MRIP treatments in the Lm/CpG-vaccinated group. The increased frequency of Treg may have also contributed to the expansion in parasite numbers. No additive effect was found when the two cytokines were neutralized at the same time, suggesting that the production of the cytokines may be sequential. We immunized IL-17-receptor-deficient mice (IL-17R−/−) and WT C57BL/6 with the live vaccines. As expected, WT mice vaccinated with Lm/CpG did not develop leishmaniasis, and L. major-vaccinated mice did (Fig. 4A). Disease pathology was slightly accelerated in L. major-vaccinated IL-17R−/− mice. Most importantly, IL-17R−/− mice immunized with Lm/CpG developed large lesions, further indicating that IL-17 is involved in protection.

The observed lower percentage

of CD4+CD25high FoxP3+ regulatory T cells in CAPRI cultures compared to CD3-activated PBMC (Fig. 6) could augment the cytolytic activity of CAPRI cells. Whereas CD3 stimulation of T lymphocytes favours pathways leading to IL-10-producing cells expressing CD25highFoxP3+CD4+ [43], the activation pathway via the αβ TCR [44] may favour the amplification of CD4+ T cells not expressing FoxP3. Furthermore, activation of dendritic cells during the CAPRI procedure may enhance their ability to abrogate the regulatory activities of CD25highFoxP3+CD4+ cells [45]. Our results demonstrate the importance of monocytes and CD4+ T cells for immune responses against cancer. In the CAPRI procedure, tumour-immunogenic

peptides need not Galunisertib ic50 be identified and can be presented by (at least) six HLA class I and six HLA class II molecules. Tumour-immunogenic peptide design should ideally fit HLA class I and HLA class II molecules. Alternatively, tumour-immunogenic peptides could be isolated from activated monocytes of learn more patients with cancer showing a benign course [59]. The first controlled study with CD3-activated PBMC showed a small but significant increase in the survival rate of patients with hepatocellular carcinoma [60]. The results were interpreted as evidence for the amplification of cancer-specific T memory cells and not effector maturation [61]. This interpretation is compatible with our in vitro results showing marginal lysis of cancer cells by CD3-activated PBMC. Preclinical evidence of the CAPRI cell concept was obtained by establishing breast cancer tumours in twelve female nude mice. In this breast cancer model, the size of the tumour increased in the control group but was significantly decreased by CAPRI cells (P = 7.56 × 10−6, Table 2). A significant increase in survival time was also observed for CAPRI

cell-treated mice (P = 5.06 × 10−4, Fig. 6A). In human patients, circumstantial clinical evidence of the CAPRI cell concept was provided in an adjuvant treatment attempt for breast cancer patients with metastasis (T1-4N0-2M1, G2-3, N = 42) Ibrutinib mw by comparing their survival times with those of breast cancer patients (T1-4N0-2M1, G2-3, N = 428) from the Munich Tumor Center (Fig. 6B). The survival curves of female patients with breast cancer and metastases collected in the Munich Tumor Center are nearly identical with those published in text books like Harrison’s ‘Principles of Internal Medicine’ (7th edition) [62] or Conn’s ‘Current Therapy’ (2010) [63]. Both patient groups received standard combinations of chemotherapy and radiation. The average survival time of patients with adjuvant CAPRI cell treatment was 55.19 ± 1.68 months; patients receiving only standard therapy survived an average of 28.60 ± 0.95 months (Fig. 6B, P = 1.36 × 10−14).

Nuclear factor-erythroid 2-related factor 2 (Nrf2) is one selleck chemicals llc of the most important cellular defense mechanisms against oxidative stress. NAD(P)H quinine oxidoreductase (NQO1), was the well-studied Nrf2 target genes that are up-regulated through the antioxidant response element regulatory element in response to oxidative stress. The aims of the research was investigated

the effects of Zn deficiency on diabetes-induced renal oxidative damage, inflammation and fibrosis, and the relation with Nrf2 and NQO1. Methods: Type 1 diabetes was induced in FVB mice with multiple low doses of streptozotocin. Once hyperglycemia was established, diabetic and age matched control mice were treated with and without Zn chelator, N, N, N′, N′-tetrakis (2-pyridylemethyl) ethylenediamine (TPEN) at 5 mg/kg daily for 4 months. Renal oxidative damage, inflammation

and fibrosis mice were examined by histopathological observation, Naphthol AS-D Chloroacetate esterase assay, immunofluorescent staining, and Western blotting assay. Human renal tubular HK 11 cells were treated by TPEN and Zn, the expression of Nrf2 and NQO1 were examined by immunofluorescent and Western bloting assay. Results: Chronic treatment with TPEN significantly INCB024360 research buy next decreased renal Zn levels in both diabetic and control mice. Compared to group with diabetes or TPEN alone, Diabetes/TPEN group showed a significant decrease in Nrf2 expression along with significant increases of renal oxidative damage (protein nitration and lipid oxidation), renal inflammation [infiltrated inflammatory cells and expression of plasminogen activator inhibitor-1(PAI-1) ], and renal fibrosis [PAS staining and expression of profibrotic mediator connective tissue growth factor (CTGF)]. Mechanistic study with human renal tubular HK 11 cells showed that TPEN removal of intracellular Zn decreased

Nrf2 and NQO1 expression, which could be significantly attenuated by Zn supplementation. Conclusion: These results indicated that Zn deficiency significantly enhanced diabetes-induced renal oxidative damage, inflammation and structural remodeling through downregulation of Nrf2 expression and function. CHOI SOO Y1, LIM SUN W2, YOO EUN J1, SANADA SATORU3, LEE HWAN H1, KWON MI J1, LEE-KWON WHASEON1, KWON HYUG M1,3 1UNIST; 2Catholic University of Korea; 3University of Maryland Introduction: We reported previously that, in patients with ∼30 years of type 1 diabetes, proteinuria was associated with ∼50% higher activity of the TonEBP transcription factor in monocytes (1).

© 2012 Wiley Periodicals, Inc. Microsurgery, 2013. “
“The lower third of the leg poses a surgical challenge in patients with complex injuries requiring reconstruction of soft tissue defects. The posterior tibial island fasciocutaneous flap is recognized as a suitable option for coverage of these defects, and provides a versatile solution for a complex problem. A retrospective audit was conducted at our institution from 1996 to 2008 including all patients who underwent this procedure. Patient’s demographics, clinical features, outcome, and complications were noted. The study population was 24 patients Gefitinib mw (23 males, one female) with age

ranging from 11 to 60 years. Mechanism of injury was road traffic accident in 20 patients

and firearm injury in 4. The defect was located in the lower half of the leg in all cases. Tibial fracture was present in 15 patients, treated by external fixation in 13 and internal fixation in two patients. Fasciocutaneous flap from the medial aspect of leg was raised based on a perforator of the posterior tibial artery and rotated distally. Average length of the flaps was 12.3 cm. Patients were followed for an average of 11 months (minimum 3 months). Clinical outcome was graded as good in 19 patients, fair in four patients, and poor in one patient. Posterior tibial selleck chemicals island flap appears to be a safe and reliable option for coverage of complex wounds in lower third of the leg. © 2012 Wiley Periodicals, Inc. Microsurgery, 2012. “
“The aim of this report was to present our experience on the use of different flaps for soft tissue reconstruction of the foot and ankle. From 2007 to

2012, the soft tissue defects of traumatic injuries of the foot and ankle were reconstructed using 14 different flaps in 226 cases (162 male and 64 female). There were 62 pedicled flaps and 164 free flaps used in reconstruction. The pedicled flaps included sural flap, saphenous flap, dorsal pedal neurocutaneous flap, pedicled peroneal artery perforator flap, pedicled tibial artery perforator flap, and medial plantar flap. The free flaps were latissimus musculocutaneous flap, anterolateral next thigh musculocutaneous flap, groin flap, lateral arm flap, anterolateral thigh perforator flap, peroneal artery perforator flap, thoracdorsal artery perforator flap, medial arm perforator flap. The sensory nerve coaptation was not performed for all of flaps. One hundred and ninety-four cases were combined with open fractures. One hundred and sixty-two cases had tendon. Among 164 free flaps, 8 flaps were completely lost, in which the defects were managed by the secondary procedures. Among the 57 flaps for plantar foot coverage (25 pedicled flaps and 32 free flaps), ulcers were developed in 5 pedicled flaps and 6 free flaps after weight bearing, and infection was found in 14 flaps. The donor site complications were seen in 3 cases with the free anterolateral thigh perforator flap transfer.

Lysates were precleared by addition of Autophagy Compound Library IgG antibody (1 μg) and re-suspended Protein A/G-agarose (10 μL). IP with the appropriate antibody (2 μg per sample) was overnight at 4°C. Antibody–protein complexes were pelleted after addition of Protein A/G-agarose (35 μL). Samples were boiled in reducing sample buffer and immunoprecipitates subjected to SDS-PAGE and Western blot analysis. The PathDetect CHOP trans-reporting system (Stratgene, La Jolla, CA, USA) was used,

according to the manufacturer’s recommendations, to measure activation of the p38 MAPK pathway. Briefly, HEK 293-TLR4 (1.8×105 cells/well) were seeded into 96-well plates and grown for 24 h. Cells were then transfected, using Lipofectamine 2000, with the GAL4-CHOP-regulated firefly luciferase reporter plasmid pFR-Luc (60 ng), the trans-activator plasmid pFA-CHOP (activation domain of CHOP check details fused with the yeast Gal4 DNA binding domain) (1 ng), constitutively expressed Renilla-luciferase reporter construct (pGL3-Renilla, 20 ng) and with or without Pellino3S or viral Pellino expression constructs. Luciferase activities

were analysed as described above. HEK 293T cells (1.6×105/well) were seeded into 4-well Lab-Tek chamber slides (Nunc A/S, DK-4000, Denmark) and grown for 24 h. Cells were then transfected, using Lipofectamine, with MAPKAP kinase 2-Ds Red (400 ng) in the presence or absence of Pellino3- or viral Pellino-GFP (400 ng). Cells were fixed in 4% paraformaldehyde for 15 min, washed three times with PBS and mounted with Slowfade antifade reagent [DAPI containing medium (1.5 μg/mL)] (Molecular Probes, USA). Confocal images were captured using the ×63 objective (oil immersion) on the UV Zeiss 510 Meta

System laser-scanning microscope equipped with the appropriate filter sets and analysed using the LSM 5 browser imaging software. The myc-tagged form of the viral Pellino gene was sub-cloned into the lentiviral vector pLV-CMV-GFP. Lentiviral particles encoding vPellino were generated by transfecting HEK293T cells with HSP90 a viral packaging plasmid pPTK (900 ng), a viral envelope plasmid pMDG (100 ng) and pLV-CMV-GFP encoding vPellino (1 μg) or an empty pLV-CMV-GFP vector using Lipofectamine 2000. In total, 24 h post-transfection, the medium was replaced with DMEM supplemented with 30% v/v fetal bovine serum. A total of 24, 48 and 72 h later, medium containing virus was harvested and stored at −20°C with DMEM, supplemented with 30% FBS, added to cells after each harvesting. The pooled virus stocks were titred. THP-1 cells were plated at 2×105 cells/mL in 96-well suspension plates (100 μL/well), supplemented with hexadimethrine bromide (8 μg/mL). On the day of seeding, cells were transduced with lentivirus. The media was removed 24 post-infection and replaced with fresh RPMI medium. The medium was replaced for further 2 days before cells were used in experiments.

Excess p53-binding nucleotide, which does not contain a GAS sequence, did not compete-out the binding of STAT1. check details Therefore, our data suggest that constitutive STAT1 binding to the GILT promoter occurs at GAS sites. In addition, we tested whether mutations that affect the activity of the GILT promoter can influence in vitro binding to the GAS sites in the GILT promoter. The results shown

in Fig. 2b indicate that mutant K544A/E545A (Mut 3) binds to the GILT promoter but mutant V426D/T427D (Mut 1) does not bind GAS sequences in GILT promoter, as expected. However, repeated DAPA did not detect binding of E428A/E429 (Mut 2), although this mutant behaved like STAT1α in the luciferase assay. This may be a result of either the limit of detection of DAPA or because this mutant exerts its

effect on the GILT promoter indirectly. To determine whether mutant STAT1 interacts with the specific sequences in the GILT promoter, regardless of the phosphorylation, WT, Stat1−/−, Stat1β-Y701 and Stat1α-S727 MEFs were treated with IFN-γ and the lysates were incubated with biotinylated BAY 57-1293 cell line oligonucleotides of Stat1 Probe 1 and Probe 2 (Fig. 4a). Our data indicate that, regardless of phosphorylation of Y701 and S727, STAT1 is able to bind target sequences in the GILT promoter. However, to confirm that what is seen here is specific binding, lysates from Stat1−/− cells transfected Fenbendazole transiently with Stat1α, Stat1β-Y701 and Stat1α-S727 were incubated with biotinylated oligonucleotides

of Stat1 Probe 1 and Probe 2 (Fig. 4b). The reactions were competed-out with a 50-fold excess of unlabelled probe corresponding to either Stat1 consensus or p53 sequences. Our data indicate that WT and Stat1 mutants can bind specifically to the sequences in the GILT promoter. Similar results were achieved with the Stat1 probe 1 (data not shown). During an early immune response the expression of various immune molecules is induced. GILT is constitutively expressed in professional APCs and is also inducible in vitro in APCs by inflammatory cytokines such as IFN-γ, tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Stat1 has been shown to regulate the IFN-γ-stimulated induction of GILT.12 However, we found that GILT is also constitutively expressed at detectable levels in other cell types not involved in antigen processing, such as mouse T cells and skin fibroblasts.9,10 Therefore, GILT is produced at basal levels without any extracellular stimuli. We were interested to determine whether Stat1 plays any role in the constitutive expression of GILT. We expected that the absence of Stat1 in Stat1−/− cells would reduce the expression of GILT. Surprisingly, the Stat1−/− mouse fibroblast cell line (MEF) showed increased levels of GILT protein, suggesting that STAT1 may exert a negative regulation on the constitutive expression of GILT.