33 to 36 (sequences 33–47 to 36–50), peptides no. 48 to 58 (sequences 48–62 to 58–72), peptides no. 117 to 123 (sequences 117–131 to 123–137), peptides no. 151 to 166 Midostaurin cost (sequences 151–165 to 166–180), and peptides no. 261 to 263 (sequences 288–302 to 292–306). Conversely, some epitopes were specific for a particular HLA subtype, such as the determinant encompassing peptides no. 1 to 9 (sequences 1–15 to 9–23), which was specific for DR*0101 (Fig. 1). We additionally used the TEPITOPE program to predict the nonamer core sequences

binding to HLA DR*0101 and *0401 as well as to DR*0404 molecules. TEPITOPE identified 31 core epitopes; of these, 19 are listed in the column 2 of Table 1 because they were also binding in our assay. The 12 additional core sequences, predicted as poor binders by TEPITOPE, are listed in Supporting Information. The detailed analysis of hnRNP-A2 peptides binding to RA-associated molecules described above showed that these epitopes were too numerous to be tested with human https://www.selleckchem.com/products/epz-6438.html cells. Thus, T-cell epitope candidates were selected stepwise as follows: (i) When multiple overlapping nonameric peptide frames were found and/or predicted to interact with

RA-associated HLA molecules, the peptide length was determined to include all possible peptide frames within the sequence. Using these parameters, we selected and synthesized a set of 16 peptide sequences of 17–23 amino-acid length (see Table 1). These peptides were further tested in binding assays

to determine their relative Edoxaban affinity to HLA molecules compared to influenza hemagglutinin control peptides. The results obtained showed that hnRNP-A2 peptides are relatively poor binders compared to the control peptides (Supporting Information Fig. 1). The best binders were peptides 289–306 for DR*0401, 177–193 and 152–170 for DR*0404, and 3–19 for DR*0101, respectively (Table 1 and Supporting Information Fig. 1). There were some discrepancies between the binding assays and the binding prediction given by the TEPITOPE program: for example, peptide 120–133 was predicted to bind well to DR*0404 but appeared to be an extremely weak binder, at the limit of sensitivity of our assay (Table 1). If one postulates that a determinant intrinsically linked to RA pathogenesis should be presented by most RA-associated HLA molecules, i.e. by DR*0101, 0401 and 0404, peptides binding to these three molecules would represent the best candidates. The four peptides 10–26, 50–70, 120–133, and 152–170 were found to fulfill this criterium, although 10–26 bound weakly to DR*0101, 120–133 weakly to DR*0404, and 152–170 weakly to DR*0401. Therefore, these epitopes, followed by peptides 3–19, 177–193, and 289–306, were considered best candidates to detect hnRNP-A2 specific T cells in patients with RA. To verify that peptides binding to DR*0401 in vitro are also immunogenic, DR*0401-Tg mice were immunized subcutaneously with individual hnRNP-A2 peptides (Fig. 2).

9 It has been suggested that targeting IL-13

alone or in combination with IL-4 may be more Angiogenesis inhibitor useful in combating asthma.139 Also, a mutated IL-4 that targets IL-4Rα, thereby blocking the effects of IL-4 and IL-13, is also being developed.140 Other strategies that target IL-5 and tumour necrosis factor-α have been proposed, but the benefits of using biological modifiers need to be weighed against the risks of unwanted effects before they can be put into clinical use. The type-2 microenvironment has been re-structured over the past 5 years with the born-again basophil providing early IL-4 and with the capacity to process and present antigen to Th cells. At 90 degrees to this interaction is the discovery of innate-like cells with the

capacity to secrete large amounts of IL-5, IL-13 and IL-9, triggering type-2 responses, presumably before the clonal expansion of antigen-restricted Th2 cells. Finally, the observation that Th2 cells can develop into Th1,5 Th176 or ‘Th9’3 cells with the appropriate environmental cues suggest a great degree of plasticity within the Th cell populations. However, while these newer discoveries fill in the gaps of the type 2 environment and have tended to down-grade the Th2 cell into a co-star role, there is still a great deal we do not know about Th2 cells. If antigen this website specificity and memory Th responses are required for improved vaccine efficacy, either directly or via antibody production, and if allergen-reactive T cells are responsible for atopic disorders, then investigating how these newer discoveries impact Th2 cell development and their effector function in this context remains an important area of

research. We gratefully thank the MRC and Lady TATA foundation for supporting MSW and ISO. We also thank Nicholas Mathioudakis and Stephanie Czieso for helpful discussions. “
“A dilemma in cancer immunology is that, although patients often develop active antitumor immune responses, the tumor still outgrows. It has become clear that under the pressure of the host’s immune system, PIK3C2G cancer cells have adapted elaborate tactics to reduce their immunogenicity (also known as immunoselection) and/or to actively suppress immune cells and promote immune tolerance (also known as immunosubversion). In this issue of the European Journal of Immunology, Dolen and Esendagli [Eur. J. Immunol. 2013. 43: 747–757] show that acute myeloid leukemia (AML) cells develop an adaptive immune phenotype switching mechanism: In response to attack by activated T cells, the leukemia cells quickly downregulate the T-cell costimulatory ligand B7-H2 and reciprocally upregulate the coinhibitory ligands B7-H1 and B7-DC in order to shut down T-cell activation via the PD-1 pathway.

This transient deficiency in IFN-I benefits the host as it does not lower resistance to common secondary bacterial infections (Fig. 1). In support of this hypothesis, IFN-I exhaustion is most likely to be evolutionarily as it

appears to be a consequence of all primary viral infections. We and others have shown this to be the case for adenoviruses, alphaviruses, orthomyxoviruses, murine cytomegalovirus and lymphocytic choriomeningitis virus [16, 21]. From an evolutionary perspective, there must have been a strong selective advantage to transiently exhaust IFN-I responses after primary viral infections selleck kinase inhibitor to occur. Thus, it is reasonable to speculate the evolutionary advantage of negative feedback regulation to suppress virus-induced immune responses that are detrimental against secondary bacterial infections. It has been shown previously, exploring influenza virus/S. pneumoniae co-infection models, that secondary challenges, with either virus or bacteria, at the peak or during the IFN-I response, are highly lethal and the increased lethality is attributable to IFN-I [34-36]. It would be interesting

to find out whether the outcome of such co-infection experiments would differ if mice undergoing a primary virus infection were challenged with bacterial pathogens at the time of IFN-I exhaustion, 5–9 days post-infection. Thus, to provide evidence for the above-outlined hypothesis, all that find more would be required is to establish correlates of strength of IFN-I response and exhaustion with severity of secondary bacterial challenges. A time course of bacterial infections after primary virus infection and/or poly I:C treatment would provide an answer to this question. Poly I:C, a synthetic analogue of double-stranded RNA, mimics RNA viral infections, but would eliminate potential unrelated viral-induced pathologies affecting secondary bacterial pathologies. It has been shown that poly I:C-treated mice mount IFN-I responses that render the host transiently more susceptible to bacterial infections [41, 46]. Evaluation of the severity of bacterial growth, morbidity and mortality should establish whether IFN-I exhaustion ameliorates secondary bacterial pathology.

Poly I:C-treated experimental groups will eliminate potential unknown viral-induced complications. It is somewhat surprising that the by now widely known phenomenon, that of an Terminal deoxynucleotidyl transferase IFN-I refractory period after a viral infection, has as yet not been investigated as to its consequences for the host’s susceptibility to bacterial infections, given its potential clinical implications. The known detrimental consequences of the refractory period to secondary viral infections, namely heightened susceptibility, are somewhat hard to understand in evolutionary terms unless there exists an overriding host–benefit rationale. This may well turn out to be protection from potentially lethal bacterial infection, which can be controlled in the absence of IFN-I.

High-risk haematological malignancies included acute leukaemias, chronic myelocytic leukaemia with blastic transformation, myelodysplastic syndromes that required intensive chemotherapy and high-grade non-Hodgkin’s lymphomas. Patients who gave informed consent were included in the study starting from the day they were admitted to the wards and followed up until death, discharge or withdrawal of consent, whichever occurred earlier. Death or discharge within 10 days of hospitalisation, less than

10 days of neutropenia or major difficulty in obtaining blood samples were the exclusion criteria. Demographic characteristics, selleck underlying diseases and risk factors for invasive fungal infections (IFI), such as administration of chemotherapy, corticosteroids, antimicrobials, total parenteral nutrition within 30 days and stem-cell transplantation within 1 year, were noted. Patients were followed up by daily visits for vital signs, existing or newly developing signs and symptoms, clinical and laboratory findings. Colony stimulating factors, chemotherapeutic and antimicrobial agents administered were recorded during each visit. Culture growths and the results of the imaging studies were also noted. The HM781-36B study protocol required that blood be drawn twice a week during the follow-up of the patients,

however because of the problems in venous access and reluctance of the patients, regular sampling could not be performed all the time. Blood samples were then transported to the laboratory and preserved at −70 °C until all the specimens were analysed by the ELISA method at the end of the study period. All patients with haematological malignancies who developed fever were consulted with the infectious diseases team as a routine part of patient care at our centre. GM levels were tested subsequently; therefore the primary physician and the infectious Non-specific serine/threonine protein kinase diseases consultant were not aware of the results during patient care. No antifungal prophylaxis was used in this cohort of patients. Patients were treated with amphotericin B formulations

during inpatient periods and discharged on oral itraconazole when indicated for IA. Invasive fungal infections were defined according to the European Organization for Research and Treatment of Cancer – Mycoses Study Group (EORTC-MSG) consensus case definitions.27 As this study aimed to evaluate the accuracy of GM in diagnosis, GM positivity was not used as a microbiological criterion for classifying IA. Galactomannan levels were studied by sandwich ELISA commercial kit (Platelia®Aspergillus; Bio-Rad Laboratories) in accordance with the manufacturer’s instructions. Results are checked with positive and negative controls. The GM index was expressed as the ratio of the optical density of the sample relative to the optical density of the threshold control.

Furthermore, LCMV infection in vivo or LCMV-infected DCs in vitro rendered, via TLR2, CD4+CD25+ Tregs capable of diminishing T1D. We identify novel mechanisms by which TLR2 promotes immunoregulation and controls autoimmune diabetes in naïve or infected hosts. This work should help understand T1D etiology and develop novel immune-based therapeutic

interventions. Type 1 diabetes (T1D) is a genetic disease resulting in the destruction of insulin-producing β cells by autoreactive T cells in the pancreatic islets of Langerhans Selleckchem Atezolizumab 1. The importance of additional environmental factors such as infections in the development of this disease has long been reported, but to date whether and how these might trigger or prevent T1D is not understood 2. It has been proposed that the inflammatory events induced upon anti-infectious immunity enable enhanced presentation of β-cell antigens to autoreactive T cells. Pro-inflammatory Selleckchem BI-6727 cytokines cause the up-regulation of class I MHC molecules on β cells, and may thereby “unmask” them for recognition by CD8+ T cells 3. In addition, concomitant damage to β cells and activation of APCs by the infection may promote the presentation of β-cell antigens to CD8+ T cells. This has notably been demonstrated in NOD mice using Coxsackievirus B4 4, or in RIP-LCMV mice, which transgenically

express lymphocytic choriomeningitis virus (LCMV) antigens on their β cells and develop autoimmune diabetes following LCMV infection 5–7. Inflammatory signals not only promote DC and T-cell activation but might also directly cause β-cell destruction 8–10, therefore strongly contributing to T1D development. On the other hand, studies in humans and mice suggest that infections and inflammation might play a protective role in T1D; notably, disease can be prevented in

NOD mice by infection with a number of viruses 2. Antiviral immunity may increase resistance to diabetogenic infections or “distract” the immune system from their detrimental effect 11. In addition, Buspirone HCl as we reported recently 12, viral infections may shape the immune system such that diabetogenic T cells are impaired or kept under control by immunoregulatory mechanisms. We found that viral infection triggered the expansion of invigorated CD4+CD25+ Tregs that produced TGF-β and protected from autoimmune diabetes by synergizing with programmed death-ligand 1 (PD-L1). These findings indicated a beneficial role of virally induced inflammation in T1D. A number of studies in mice have underscored the capacity of pro-inflammatory agents to prevent rather than induce T1D when intervening in the absence of β-cell damage and autoantigen 13. TLRs are usually referred to as “danger-sensing” molecules that play a central part in triggering inflammation and immunity in response to infection 14.

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 learn more “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, LBH589 research buy 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 Progesterone 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.

Then sera from immunized mice were diluted before added into the wells and incubated for 2 h at 37 °C. Plates were then washed with washing buffer (PBS-0.05% Tween 20) three times for 3 min each and goat anti-mouse IgG was added into the wells and incubated for 1 h at 37 °C. After washing as above, TMB (3, 3′,5,5′-tetramethylbenzidine dihydrochloride) substrate

(Sigma) was added and color intensity was determined spectrophotometrically at OD 450 nm. Statistical analysis was performed by Gehan-Breslow-Wilcoxon Test using Graphpad Prism 5. P≤ 0.05 was regarded as significant. 19 proteins associated with S. aureus invasion or pathogenesis were dotted onto NC membranes and reacted with sera from mice recovered from infection with different S. aureus strains. The sera from https://www.selleckchem.com/products/apo866-fk866.html mice infected with S. aureus 1884 reacted with proteins FnBA, SasA, SasF and SPA (S. aureus proteins A) (Fig. 1A). The sera from mice infected with S. aureus 546 reacted with proteins

CNA, FnBA, SasA, SasF, and SPA(Fig. 1B). The sera from mice infected with S. aureus USA300 reacted with proteins ClfA, IsdA, SasA and SPA (Fig. 1C). We found different S. aureus strains induced different antibody responses. The proteins SasA and SPA reacted with all of the sera. Protein SPA is a mitogen that interacts with many immunoglobulins by binding to the Fc region. The results showed that SasA was expressed on all of the above strains and could induce strong antibody response during S. aureus infection. selleck screening library To detect whether the antibody response induced by SasA is protective, part of the protein was expressed. The SasA protein is composed of 2272 amino acids. The secondary structure of SasA protein was analyzed by DNAstar software and fragment (48aa-333aa, named fSasA) was selected to be amplified from the genomic DNA of S. aureus USA300 by PCR using primers SasAF and SasAR. Recombinant plasmid pET-fSasA was constructed, sequencing verified, and transformed into E. coli BL21 for protein expression. After induction with 1 mM IPTG at 37 °C for 4 h, the total soluble proteins of bacteria were analyzed by SDS-PAGE. It showed

that fSasA was expressed at a level of up to 10% of whole cell protein (Fig. 2A). After 2-step purification, fSasA protein of high purity was obtained (Fig. 2B). Western blot with antibody against 6x His tag showed that LY294002 the protein size was correct (Fig 2C). The purified protein can be used as antigen for animal immunization. SasA is a surface protein of S. aureus. The fSasA was absorbed well by aluminium hydroxide gel in physiological saline. After second immunization, BALB/c mice generated strong IgG response against fSasA protein. The response was further elevated after third immunization (Fig. 3). To test the role of immunity induced by fSasA against S. aureus infection, BALB/c mice were challenged with 3 × 109 S. aureus USA300, collected at early exponential phase, 7 days after the third immunization with fSasA.

3) (P < 0·05). MDR1 and MRP inhibitors induced a marked decrease in mDCs [half maximal inhibitory concentration (IC50): P-glycoprotein inhibition using valspodar (PSC833 5 μM, CAS 115104-28-4 (MK571) 50 μM and probenecid 2·5 μM] Selleck PLX4720 and an increase in iDCs. Thus, after hypoxia, PSC inhibited mDCS to 31·4% (P < 0·05), MK571 to 40% (P < 0·05) and PBN to 45·6% (P < 0·05). The effect of ABC blockers on DC maturation after LPS showed similar results: PSC833

reduced mDCS to 48·8% (P < 0·05), MK571 to 51·6% (P < 0·05) and PBN to 50·6% (P < 0·05). All mean values were analysed for 10 experiments. To rule out a toxic effect of inhibitors on DC viability, cell apoptosis was analysed by annexin V/7-ADD assay. A comparable percentage of viable cells was observed after hypoxia exposure with or without ABC inhibitors exposure (H: 86·1%, H + PSC: 84·25%, H + MK: 85·29% and H + PBN: 83·7%). We found no statistical Lumacaftor changes between hypoxia DC and non-stimulus. Hypoxic conditions induced a twofold

DC maturation compared to control non-stimulated DCs (P < 0·05), analysed as intensity of different maturation markers (CD40, CD83, HLADR and CD54). This confirmed the results validated in a previous study [8]. ABC inhibitors showed a clear decrease in both plamacytoid-like and conventional DC phenotype maturation, depending on the stimuli (Table 1). When iDCs were stimulated by LPS the mean fluorescence intensity (MFI) of CD80, CD86, HLA-DR and CD54 maturation markers increased MFI threefold with respect to control, and there was a twofold increase of MFI with respect to hypoxia stimulus (Table 1). Interestingly, CD83 and CD40 were similarly up-regulated under both stimuli, and CD86 was down-regulated under hypoxia-achieving control values, suggesting a plasmocytoid-like phenotype pattern with respect to LPS-DC. Despite these differences in the maturation response of DCs after the two stimuli, the up-regulation of maturation markers was abrogated strongly when ABC inhibitors were added at a similar intensity (Table 1). All results are representative of six experiments. Figure 4 is a representative histogram of the most relevant changes in DC maturation markers

Vitamin B12 after hypoxia or LPS. HIF-1α expression in control cells was 37·5 ± 5·2%, when DCs stimulated by hypoxia were increased significantly with respect to control (67·6 ± 3·7). Interestingly, when ABC inhibitors were added to hypoxic-DC, HIF-1α results were similar to hypoxia-DCs (H + PSC833 57·5 ± 4·4 and H + MK571 62·3 ± 5·1) (Fig. 5). To address the functional impact of ABC transporter inhibition on DCs, we next assessed the effects of these cells on lymphocyte proliferation in the MLR, evaluated by CFSE staining. Hypoxia- and LPS-matured DCs were capable of inducing a significantly (P < 0·05) higher lymphocyte proliferation than non-stimulated iDCs. Functional studies showed a higher T cell proliferation after LPS than after hypoxia stimulus (53·9% with LPS versus 28·5% with hypoxia).

Glucocorticoids treatment was administerd

to eighty two patients (90.1%) and the initial dose of prednisolone (PSL) was 0.7 ± 0.3 mg/kg/day. Cyclophosphamide (CY) was prescribed to 17 patients (18.7%). During the period of 55 ± 52 months after the onset of RRT, 18 vasculitis relapses occurred in 12 patients corresponding to an incidence rate of 0.048 episodes per person-year (95% CI: 0.029–0.076). Organ systems affected by relapses included lungs Adriamycin (n = 10), ears (n = 2), and eyes (n = 1). The duration from the onset of RRT to relapse was 49 ± 44 months and maximal duration was 156 months. At the relapse, 5 patients were not receiving immunosuppressive therapy and PSL (7.7 ± 3.4 mg/day) was prescribed for the remaining patients. Survival rates for 1, 3 and 5 years after RRT were 82.3%, 75.4% and 65.3%, respectively. The causes of deaths were infection (59.5%), cardiovascular event (24.3%), gastrointestinal bleeding (8.1%), malignancy (5.4%) and interstitial pneumonia (2.7%).

By Cox’s multivariate analysis, patient year (HR1.09, 95%CI:1.05–1.13) and pulmonary involvement (HR 3.95, 95%CI 1.77–8.83) were significant positive risks and the use of CY (HR 0.10, 95%CI 0.014–0.78) was a significant negative risk for mortality. Conclusion: Relapse could occur even after a long see more period from the onset of RRT. Infection was the most frequent cause of death and pulmonary involvement was related with mortality. It is important to clarify the optimal duration of maintenance therapy after RRT. PRATT RAYMOND D, LIN VIVIAN, GUSS CARRIE, GUPTA AJAY Rockwell Medical Introduction: Triferic (Ferric Pyrophosphate Citrate) is a novel iron salt that is soluble in dialysate and crosses the dialyzer membrane. Triferic, delivered via hemodialysate donates iron rapidly and directly to apo-transferrin, bypassing the reticuloendothelial system. Methods: In two, single blind, randomized placebo controlled clinical (CRUISE) Ribonuclease T1 trials, iron replete HD patients received either dialysate containing Triferic at 2 μM (110 μg iron/L, combined N = 299) or placebo (standard

dialysate, combined N = 300) for up to 48 weeks. Once randomized, no changes in ESA dose or administration of IV or oral iron were allowed. During the randomized treatment period, patients meeting pre-defined anemia management criteria (ESA dose change or IV iron administration for the development of iron deficiency) completed the study and were transitioned into an open label extension. Results: Dialytic transfer of Triferic with each HD was reliable and not significantly affected by dialyzer membrane type or reuse. A greater number of placebo subjects (57%) than Triferic subjects (46%) met pre-defined criteria for a change in anemia management and transitioned into the open-label study. IV iron was required by more subjects with placebo (12%) than Triferic (2%).

In case the p values were smaller than 0.05, differences were considered to be statistically significant. All data were obtained from at least two independent experiments using at least two independent individuals. The authors are grateful to Dr. Junji Takeda and Dr. Jun-ichi Miyazaki for providing Cre-expressing mice. The authors also thank Dr. Toshio Imai, Dr. Chikako Nishigori, and Dr. Yoichi Kurebayashi for helpful discussions, and Dr. Mingzhen Li, Dr. Yunfeng Bai, Dr. Shuzo Ikuta, Ms. Keiko Sumimoto, and Mr. Kazuhiro Takegawa for suggestions. This work was supported by Grants-in-Aid

to T. K. (1701406, 20390080, Global COE Program A08) and to H. E. (20790229, 22790290) from the Ministry selleck inhibitor of Education, Culture, Sports, Science and Technology of Japan, a Grant for the Program for Promotion of Fundamental Studies of Health Sciences 06-3 from the National Institute of Biomedical Innovation to T. K., a grant from Kanae Foundation for the Promotion of Medical Science to H. E., and a buy Adriamycin Grant-in-Aid for Japan Society for the Promotion

of Science Fellows 19-55411 to N. T. Conflict of interest: The authors declare no financial or commercial conflict of interest. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. “
“Cytotoxic T lymphocyte antigen-4 (CTLA-4) is a major negative regulatory molecule for T-cell activation with a complex biology and function. CTLA-4 is known to regulate homeostatic lymphoproliferation as well as tolerance induction and has been proposed to be an important effector molecule by which Treg cells suppress immunity. The immunoregulatory properties of CTLA-4 are primarily mediated by competition with the costimulator

CD28 for ligand binding but also by delivering negative signals to T cells through its cytoplasmic tail. In this study, we addressed the effect of directly mutating the amino acid residue, Tyrosine 201 (Tyr201), of the intracellular domain of CTLA-4 in situ and its implications in T-cell function in the context of autoimmunity. Therefore, a novel CTLA-4 knock-in mouse (Y201V KI) was generated, in which Tyr201 was replaced by a valine Temsirolimus in vitro that could not be phosphorylated. Mice expressing the CTLA-4 mutant molecule were generally healthy and did not show signs of disruption of T-cell homeostasis under steady-state conditions seen in CTLA-4 deficient mice. However, T cells isolated from Y201V KI mice expressed higher levels of CTLA-4 on the cell surface and displayed a Th2-biased phenotype following TCR stimulation. Furthermore, Y201V KI mice developed exacerbated disease as compared to wild-type upon antigen-specific T-cell activation in an in vivo model of EAE. Importantly, the Y201V mutation resulted in impaired suppressive activity of Treg cells while T effector function remained intact.