We find that LKB1 is required for several key metabolic processes in T-cell progenitors. For example, LKB1 controls expression of CD98, a key subunit of the L-system aa transporter and is also required for the pre-TCR to induce and sustain the regulated phosphorylation of the ribosomal S6 subunit, a key regulator of protein synthesis. In the absence of LKB1 TCR-β-selected thymocytes MAPK Inhibitor Library failed to proliferate and did not survive. LBK1 was also required for survival and proliferation of peripheral T cells. These data thus reveal a conserved and essential role for LKB1 in the proliferative responses

of both thymocytes and mature T cells. “
“The mechanisms underlying Japanese encephalitis virus (JEV) pathogenesis need to be thoroughly explored to delineate therapeutic approaches. It is believed that JEV manipulates the innate and adaptive compartments of the host’s immune system to evade Selleckchem GS 1101 immune response and cross the blood–brain barrier. The present study was thus designed to investigate the functional modulation of DCs after exposure to JEV and to assess the consequences on CD4+ T-lymphocyte functions. Human monocyte-derived DCs were either infected with 1 MOI of live virus, UV-inactivated

virus, or were mock-infected. Replication-competent JEV induced a significant increase in the expression of maturation markers 48 h postinfection, along with that of programmed cell death 1 ligand 1 (PD-L1; also called B7-H1 and CD274). JEV-infected DCs expanded the Treg cells in allogenic mixed lymphocyte reactions. The expansion of Treg cells by JEV-infected DCs was

significantly reduced upon blocking PD-L1 using an antagonist. In addition, JEV-infected DCs significantly altered the proliferation and reduced the polarization of Th cells toward the Th1-cell phenotype. The results, for the first time, Amine dehydrogenase suggest that JEV evades the host’s immune system by modulating the crosstalk between DCs and T lymphocytes via the PD-L1 axis. “
“In this study, we elucidated the role of tumor necrosis factor (TNF)-α in the host defense to pulmonary infection with Streptococcus pneumoniae and defined the cellular source of this cytokine at an early stage of infection. Administration of anti-TNF-α monoclonal antibody (mAb) resulted in the reduced accumulation of neutrophils in bronchoalveolar lavage fluids (BALFs) and severe exacerbation of this infection. In a flow cytometric analysis, the intracellular expression of TNF-α was detected in Gr-1bright+ and Gr-1dull+ cells during the time intervals postinfection, and F4/80+ cells expressed intracellular TNF-α before Gr-1dull+ cells appeared. The Gr-1bright+ and Gr-1dull+ cells sorted from BALF cells at 24 h were identified as neutrophils and macrophage-like cells, respectively, and the Gr-1dull+ cells expressing CD11c, partially CD11b and a marginal level of F4/80 secreted TNF-α in in vitro cultures.

77 The presence of the HLA-Bw4 epitope on an HLA-B allele delivers a stronger inhibitory signal resulting in better protection against NK cell-mediated Kinase Inhibitor Library cytolysis than if present on an HLA-A allele.79 However, this varies with the allele79 and with which amino acid is present at position 80 of the HLA-Bw4 epitope80 and with the KIR3DL1 allele.67 The expansive polymorphism of the KIR gene complex has been described. Whether this allows individuals to respond differently to specific viral infections remains to be determined,

but it is possible that the diversity is the result of natural selection by pathogens. The different population frequency distribution from these studies indicates that KIR genes and alleles have been through rapid diversification and may have been under selection because of functional significance. Indeed, there is little conservation of KIR genes between species and only three KIR genes (KIR2DL4, KIR2DS4, KIR2DL5) KPT-330 molecular weight have been preserved through hominid evolution.81 The diversification is thought to be more rapid for KIR genes than HLA, as HLA genes in humans and chimpanzees are more similar in sequence than their KIR counterparts.7,82 Even the CD94-NKG2 receptors are much more similar in chimpanzees and humans than KIR. Knowing

the many associations of the MHC class I molecules in disease, this diversity of KIR has been sought in many diseases. However, it is imperative that knowledge from functional studies be acquired to ascertain the immunological Farnesyltransferase relevance of the statistical associations found between KIR and several diseases. None. “
“Leukotriene C4 is an important mediator in the development of inflammatory reactions and ischaemia. Previous studies have shown that leukotriene C4 is

able to modulate the function of dendritic cells (DCs) and induce their chemotaxis from skin to lymph node. In this study, we decided to evaluate the modulation exerted by leukotriene C4 on DCs, depending on their status of activation. We showed for the first time that leukotriene C4 stimulates endocytosis both in immature and lipopolysaccharide (LPS) -activated DCs. Moreover, it suppressed the interleukin-12p70 (IL-12p70) release, but induces the secretion of IL-23 by DCs activated with LPS and promotes the expansion of T helper type 17 (Th17) lymphocytes. Furthermore, blocking the release of IL-23 reduced the percentages of CD4+ T cells producing IL-17 in a mixed lymphocyte reaction. Ours results suggest that leukotriene C4 interferes with the complete maturation of inflammatory DCs in terms of phenotype and antigen uptake, while favouring the release of IL-23, the main cytokine involved in the maintenance of the Th17 profile. Dendritic cells (DCs) are highly specialized antigen-presenting cells with a unique capability to activate naive T lymphocytes and initiate the adaptive immune response, as well as induce peripheral tolerance.

Rabbit monoclonal Ab against GAPDH was obtained from Cell Signaling Technology Selleckchem Autophagy inhibitor (Danvers, MA). Western blotting of lung homogenates was performed as described previously [[46, 47]]. RNA was extracted from lung homogenates and cells with Trizol (Invitrogen Life Technologies, Carlsbad, CA) according to the manufacturer’s instructions. Reverse transcription was performed using 1.5 μg of RNA and cDNA was amplified using gene-specific primers [[48, 49]]. The results were normalized with GAPDH. MPO assay was performed as described previously (15). Samples were homogenized in 50 mM hexadecyltrimethylammonium bromide

(HTAB) and assayed as previously described [[45, 50]]. H2DCF dye (Molecular Probes) does not normally Opaganib mw fluoresce under resting conditions, but emits green fluorescence upon reaction with superoxide inside cells. Cells were treated as above and equal amounts of dye added [[16]]. This assay measures color change of MTT upon reduction by enzymes to assess the viability of cells. After infection of MLE-12 cells with K. pneumoniae, MTT dye was added at a final concentration of 1 μg/mL as described previously [[47]]. We used LipofectAmine2000 to transfect cells at 60% confluency and achieved high efficiency in transfection [[22, 51]]. The yellow fluorescent protein (YFP)-Cav-1, YFP-Cav-1Δ51-169 dominant negative (DN) plasmids were generated as described previously [[18]].

MLE-12 cells were infected with K. pneumoniae at MOI 10:1 for 1 h and the free bacteria were removed by washing three times with PBS. The surface bacteria were killed by incubation with 100 μg/mL polymyxin B for 1 h and intracellular bacteria were enumerated to determine CFU. Transfection with cav1 DN plasmid did not affect survival of MLE-12 cells prior to incubation with K. pneumoniae. WP1066 (a novel STAT5 inhibitor from Sigma) was dissolved in 1% DMSO solution and used at a final concentration of 2 μM in culture medium. No adverse effect of the vehicle control was observed in the assays. The differences

in outcomes between cav1 KO and WT control animals after K. pneumoniae infection were calculated by Kaplan–Meier survival curve comparisons, and the Enzalutamide price p values were derived from a log-rank test. Most experiments were performed three times in triplicate. Comparison of experimental groups with controls was done with one-way ANOVA (Tukey’s post-hoc) [[16, 52]]. This project was supported by NIH ES014690, Flight Attendant Medical Research Institute (FAMRI, 103007), and American Heart Association Scientist Development Grant (MW); and by NIH 5R01HL092905-04 and 3R01HL092905-02S1 (HG). We thank S. Rolling of UND imaging core for help with confocal imaging. The authors declare that they have no competing financial interests. Disclaimer: Supplementary materials have been peer-reviewed but not copyedited.

These rescued effects by RAS blockers were inhibited by A-779 which Caspase inhibitor is MAS antagonist. IS-mediated AKI mice exhibited a lower serum Ang 1-7 and renal ACE2 protein expression, higher creatinine, increased renal NOX4, TGF-beta and alpha-SMA protein expression compared to administration with Aliskiren or Losartan groups (Figure 2 and 3). Furthermore, the rescued effect of RAS blockers was less marked in combination groups compared with Aliskiren or Losartan only groups. Conclusion: Individual RAS blocker including Aliskiren or Losartan could enhance ACE2/Ang1-7/MAS axis by up-regulating ACE2 protein expression, thereby inhibiting oxidative stress, inflammation and EMT in

the kidney after IS-mediated AKI. Dual RAS blockade treatment yields no additional effect in renal

protection but may impair the ACE2/Ang1-7/MAS signaling on the duration of IS-mediated AKI. YADAV BRIJESH1, PRASAD NARAYAN2, RAI MOHIT KUMAR3, AGARWAL VIKAS4, JAISWAL AKHILESH5 1Department of Nephrology, SGPGIMS; CT99021 cost 2Department of Nephrology, SGPGIMS; 3Department of Immunology, SGPGIMS; 4Department of Immunology, SGPGIMS; 5Department of Nephrology, SGPGIMS Introduction: Successful graft outcome over a long period depend on early function of the graft. Delayed graft function (DGF) due to acute tubular necrosis. DGF prevalence is 5–10% in live and 3–40% in cadaveric related renal transplant. DGF was defined as requirement of dialysis within first week of transplant. Thus the need of early reliable, sensitive and specific markers to predict the early graft function is of utmost requirement. Objective: To determine expression of KIM-1 in urine and serum of patients of live related renal transplant recipient. To determine sensitivity, specificity and cutoff values of KIM-1 to predict graft dysfunction. Methodology: Sixty live related renal transplant recipient patient were prospectively enrolled. Four were excluded due to early biopsy proven acute Thymidylate synthase ABMR/ATCMR. Post transplant urine sample

was collected at 0, 6, 12, 18, 24, 48 hrs and blood sample at 48 hrs. ELISA: KIM-1 was analyzed by ELISA (R&D System) and creatinine clearance was determined by Cockcroft-Gault (CG) formula. Results: Out of the fifty six patients, (50 male, DGF v/s IGF; mean age (38. ± 12.9 v/s 39.68 ± 11 years), BMI (22.93 ± 2.81 v/s 19.74 ± 2.85 kg/m2) andEGFR (40.35 ± 14.43 v/s 65.39 ± 16.9 ml/min/1.73 m2), nine had delayed and forty seven had immediate graft function respectively. Mean uKIM-1 level in DGF v/s IGF was at, 0 hr (53.66 ± 37. 47 v/s 17.47 ± 48.12, P = 0.036), 6 hrs (194.11 ± 53.34 v/s 143.24 ± 50.72, P = <0.001), 12 hr (426.1 ± 115.07 v/s 194. 24 ± 66.42, P = <0.001), 18 hr (520.2 ± 120.09 v/s 252.05 ± 76.33, P = <0.001), 24 hr (674.77 ± 197.54 v/s 316.66 ± 89.23, P < 0.001), 48 hrs (652.66 ± 207.45 v/s 336.21 ± 123.5 P < 0.001), and in serum sKIM-1 (613.44 ± 213.70 v/s 280.97 ± 107.12, P < 0.001) pg/ml respectively.

A total of 157 peptides were

found to bind to one of the 12 HLA molecules with a measured KD ≤ 500 nm, which is the normally accepted threshold36–38 for being a potential antigenic epitope. The numbers of binding peptides for the individual supertypes are: HLA-A1 (11 peptides), HLA-A2 (15 peptides), HLA-A3 (four peptides), HLA-A24 (14 peptides), HLA-A26 (15 peptides), HLA-B7 (18 peptides), HLA-B8 (seven peptides), HLA-B27 (eight peptides), HLA-B39 (17 peptides), HLA-B44 (20 peptides), HLA-B58 (14 peptides) and HLA-B62 (14 peptides). Consistent with previous classifications, the binding affinity (KD) of the 157 binding peptides can be divided into groups of high-affinity binders (n = 83; KD ≤ 50 nm) and intermediate-affinity binders Selleck Alvelestat (n = 74; 50 nm < KD ≤ 500 nm). The 157 HLA-I binding peptides were tested for their ability to stimulate T cells from a cohort of healthy PPD+ Danish subjects aged 35–65 years. The peptides were evaluated for their ability to stimulate IFN-γ production

in an ELISPOT assay by PBMC from those HLA-matched donors who reacted most strongly with PPD. Since many donors’ PBMC failed to respond after 2 days of peptide exposure, the https://www.selleckchem.com/products/AG-014699.html sensitivity of the procedure was increased by exposing PBMC for 10 days to peptides before performing the ELISPOT assays. Positive reactivity towards peptides was confirmed at least twice in the same donor as well as in other HLA supertype matched donors. According to this criterion eight peptides (5%)

belonging to five different supertypes (A1, A26, B7, B44 and B62) were found to be antigenic. An overview of peptide-reactive donors, their HLA class I type, and their reactivity according to ELISPOT data is shown in Table 1. The number of reactive donors and the actual ELISPOT data are shown in Table 2. Each Cyclooxygenase (COX) of the eight antigenic peptides was also tested in 10 donors with low PPD reactivity. Only four of these donors showed reactivity against one or more of the eight antigenic peptides, an observation, which strongly underscores the M. tuberculosis specificity of the responses observed in the present study. We have previously demonstrated that variola virus-derived 9mer peptides with high HLA-I binding affinity (KD ≤ 5 nm) are able to induce CD4+ T-cell responses from PBMC of vaccinated donors.39 Likewise, we showed that influenza A virus-derived 9mer peptides with binding affinities for HLA-I allele are capable of stimulating strong CD4+ T-cell responses.28 To ascertain whether, or not, CD4+ T cells are involved in the anti-M. tuberculosis responses documented above, a pan-specific anti-HLA-II blocking antibody IVA12 as well as anti-DP, -DQ and -DR blocking antibodies were added into ELISPOT microcultures (see Materials and methods section). Similarly, cultures were exposed to the pan-specific anti-HLA class I antibody W6/32. As shown in Fig.

[91, 92] This C20:2 induced shorter duration of type I NKT cells in the anergic state promotes the more rapid induction of tolerogenic DCs in an IL-10-dependent manner, gives rise to reduced type I NKT cell

death, and enables C20:2-stimulated type I NKT cells to elicit enhanced protection from type 1 diabetes. These findings suggest that C20:2 may be more effective for disease intervention than αGalCer for protection from type 1 diabetes. It is anticipated Selleck 5-Fluoracil that further support for this possibility could be obtained by more informative in vivo imaging studies of the dynamics and kinetics of interaction between type I NKT cells and DCs in pancreatic lymph nodes of NOD mice treated in vivo with either αGalCer or C20:2. In addition, 2P imaging in vivo of differentially activated and anergic NKT cells will further elucidate how a short versus long duration of NKT cell anergy can regulate poor versus strong protection from type 1 diabetes. In a second model, 2P imaging may offer more insight into whether C24:0 sulphatide activates type II NKT cells to enter into and exit from anergy more rapidly than C16:0 sulphatide activation and thereby yield less type II NKT cell death and increased Opaganib protection from T1D.[89] Finally, a third model is based on the report that activation of sulphatide-reactive type II NKT cells and DCs elicits the IL-12- and macrophage inflammatory protein

2-dependent recruitment of type I NKT cells into the liver.[62] The latter recruited type I NKT cells are anergic and prevent concanavalin A (Con A) -induced hepatitis by specifically blocking effector pathways, including the cytokine burst and neutrophil recruitment following Con A injection. Hepatic DCs from IL-12+/+ but not from IL-12−/− mice can adoptively transfer type I NKT cell anergy into recipient mice. Hence, IL-12 secretion by DCs enables them to induce anergy in type I NKT cells. These data describe a novel mechanism by which type II NKT cell–DC interactions in the liver can cross-regulate the activity of type I NKT cells. Further in vivo imaging analyses may help

to demonstrate whether this type of immune cross-regulation applies to human NKT cell subsets. If this is DCLK1 the case, such studies may facilitate immune intervention in inflammatory and autommmune diseases in humans. The ability to detect intracellular signalling that occurs during T-cell–DC contacts by 2P imaging in vivo has dramatically improved our understanding of cellular communication during immune responses.[51, 54] While a brief contact of T cells with antigen-bearing DCs induces T cells to pause momentarily and then continue their migration, these T-cell–DC interactions also induce Ca2+ signalling in T cells that promptly reduces T-cell motility. The Ca2+ signals may synergize with other signalling pathways to stimulate T-cell gene expression, cytokine secretion and proliferation.

The platelet counts

were drastically reduced in WT, IFNAR1−/−, or IFN-γR1−/− mice on day 9 and 7 after either sporozoite or blood-stage PbA infection, respectively (Fig. 2C and D). They remained low for the next 3–4 weeks in ECM-resistant mice, confirming that thrombocytopenia www.selleckchem.com/products/MG132.html is not an indicator of platelet sequestration in brain microvessels in this model, but may rather reflect decreased production or increased activation of platelets [25]. WT mice showed a clear reduction in the number of circulating white blood cells (Fig. 2E and F), largely attributed to a decrease in the number of lymphocytes (Fig. 2G and H) on day 9 or 7 after either sporozoite or blood-stage buy EPZ-6438 PbA infection, respectively. In contrast, in IFN-γR1−/− mice lymphocyte counts were increased on day 9 or 7 postinfection, and white blood cell and lymphocyte counts

further augmented to reach circa 100 × 103 cells/μL 3 weeks postinfection (Fig. 2E–H). IFNAR1−/− mice had white blood cell and lymphocyte counts similar to naive mice on day 9 after sporozoite PbA infection although they were as reduced as in infected WT mice on day 7 of blood-stage PbA infection (Fig. 2E–H). Thereafter, white blood cell and lymphocyte counts increased dramatically in the surviving IFNAR1−/− mice, similar to what was seen in IFN-γR1−/− mice, further augmenting to reach ca 100 × 103 cells/μL two to three weeks postinfection (Fig. 2E–H). Therefore, the partial or full resistance of IFNAR1−/− or IFN-γR1−/− mice to ECM development, respectively, was not associated with reduced thrombocytopenia, but with reduced lymphopenia Y-27632 2HCl and even leukocytosis. Since ECM sensibility and hematological alterations appeared largely independent of the PbA stage used for infection, the neuropathology of IFN pathway-deficient mice was further characterized by MRI and MRA in blood-stage PbA-infected mice. These noninvasive tools are used

in human patients for neurological disease investigation during CM [26-30]. In murine ECM, MRI/MRA allow a semiquantitative analysis of swelling/edema, focal ischemia, brain morphological changes, and microvascular pathology due to small vessel obstruction by erythrocytes and leukocytes and endothelial cell damage [30-33]. WT mice and mice deficient in type I and type II IFN pathways were examined at day 7 after blood-stage PbA infection, when sensitive mice are developing acute ECM. Typical MRI and MRA brain images are shown in Figure 3A and B, respectively. While WT mice presented distinct signs of ischemic brain damage, with brain stem swelling and cerebellum compression, and vascular blood flow perturbations after PbA infection, IFN-γR1−/− mice displayed normal MRI parameters without any sign of microvascular obstruction and IFNAR1−/− mice had an intermediate phenotype.

57 The more pronounced down-regulation of CD20 in activated rhesus B cells may have implications in experimental settings or evaluation of treatment strategies that use antibodies to CD20 for selective depletion of B cells. The type of adjuvant to be chosen for a certain vaccine depends on the nature of the antigen and the type of immune response required for optimal protection. CpG has been used successfully in clinical trials as an adjuvant to

the Engerix-B hepatitis B virus vaccine and an influenza vaccine.21–23 In addition, CpG successfully increased the response to therapeutic vaccination in HIV-infected patients58 and is therefore of interest as an adjuvant for H 89 immune-suppressed individuals.10 The use of ligands targeting TLR7/8 Rucaparib in vivo may be promising for situations where mDCs and pDCs as well as B cells would be advantageous to directly activate to enhance immune responses including cross-presentation and/or antibody production. Both TLR7/8-L and CpG C have been shown,

when administered to rhesus macaques together with an HIV Gag protein, to significantly increase Gag-specific T helper type 1 (Th1) and antibody responses.19,20 The adjuvant effect of several TLR-ligands has been shown to be type I IFN dependent. For example complete Freund’s adjuvant and IC31, adjuvants that both include signalling via TLR9, lost their adjuvant effect in mice lacking the IFN-α/β receptor.59,60 Also Poly I:C, when used with a protein-based vaccine in a mouse model, required systemic type I IFN production

for its adjuvant activity. Of note, IFN-α production to Poly I:C was TLR-independent and mediated to a large extent by non-haematopoietic stromal cells.61 medroxyprogesterone Therefore, for future adjuvant development, the contribution of both haematopoietic and non-haematopoietic cells needs to be considered in terms of type I IFN production. Although direct IFN signalling on DCs was shown to be central to induce adjuvant effects,60,61 in certain circumstances, adjuvant effects mediated by type I IFN require direct signalling on B cells and T cells.9 Different pathogens may require different types of immune responses to cause protection and so the adjuvant may be chosen accordingly to shape the desired responses.62 The currently most used adjuvant is alum, which functions mainly by induction of humoral responses. Several new vaccines in development are also likely to require effective Th1 immunity to induce protection. Ligation of TLR3, TLR4, TLR7/8 and TLR9 generally elicits Th1 cell responses.62 Therefore, the respective TLR-ligands are promising for use in adjuvant formulations. Considering the potent enhancing effect of IFN-α in our B-cell cultures upon stimulation with TLR7/8-ligand, a combination of TLR7/8-ligand with Poly I:C, which induces systemic IFN-α levels, may be promising.

Background: Rhodococcus equi rarely produced human infection. Most Rhodococcus equi infections this website have been associated with profound impairment of cell-mediated immunity, as seen in patients with AIDS, lymphoproliferative malignancies, and organ transplant recipients on immunosuppressive therapy. Fusarium can cause both superficial infection e.g. keratitis and onychomycosis and invasive infection. However it is an uncommon cause for a fungal PD peritonitis. Methods: This is a case report. Results: A 34-year old ex-mechanic presented with peritoneal dialysis peritonitis secondary

to Rhodococcus equi which was treated with intra-peritoneal Vancomycin, oral ciprofloxacin and concomitant oral nilstat without removal of his Tenchkoff catheter. The patient had declined consent for catheter removal despite slow improvement. His second episode occurred three months later where he had a polymicrobial peritonitis with Fusarium oxysporum and Microbacterium/Cellumonas group. A literature review of previously reported cases of Fusarium peritonitis revealed that this organism usually follows a bacterial infection, relatively antimicrobial resistant and usually requires Tenchkoff catheter DNA Damage inhibitor removal.

All these characteristics were present in our patient. However, to the best of our knowledge, back to back infection with these two unusual organisms has not been described before. Conclusions: This case illustrates the risk of PD peritonitis from unusual infections

in the tropical Top-End of Northern Australia and the risk associated with their acquisition. 286 MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS (MPGN) IN WALDENSTROM’S MACROGLOBULINEMIA J LING EH, S YEW, D CHALLIS, W JOHNSON Royal Hobart Hospital, Hobart, Tasmania, Australia Background: Membranoproliferative L-gulonolactone oxidase glomerulonephritis (MPGN) is an uncommon cause of glomerulonephritis (reported incidence 0.14–0.93/100,000). The etiology of immune-complex mediated MPGN includes infection, monoclonal gammopathy and autoimmune disease. MPGN associated with monoclonal gammopathy resulting in immunoglobulin deposition is uncommon, especially in Waldenstrom’s macroglobulinemia (WM). We submit a case of an unexpected diagnosis of MPGN in a patient with WM presenting with acute renal failure. Case Report: A 73-year old man with known WM presented with anuric acute renal failure following an elective laparoscopic cholecystectomy. On admission his creatinine was 878 Umol/L with significant hemoproteinuria noted. His serum creatinine pre-cholecystectomy was 138 Umol/L from 79 Umol/L 4 months before. Other investigations showed low C3,C4 levels, cold agglutinins with no evidence of hemolysis and a stable immunoglobulin M (IgM) level on protein electrophoresis. He was hemodialysed and treated for presumed rapidly progressive crescentic glomerulitis with plasma exchange and pulsed intravenous methylprednisolone while awaiting formal biopsy results.

Recent phylogenetic

reconstructions support the hypothesis that the ancestral mammalian placenta was in fact discoid, hemochorial with labyrinthine interdigitation.33 This is opposed to the previously held view that this type of placenta is very highly evolved and that the ancestral placenta was more limited in its invasiveness and contact with maternal tissue. Furthermore, this phylogenetic evidence indicates that placental structures have evolved independently in different species. Thus, it would be of great interest to investigate placental IDO expression in species with different placentation, and it is a target within our laboratory to study IDO in the normal sheep placenta and pregnant uterine tissue. However,

given our current knowledge of immune control of C. abortus and the importance of IFN-γ-inducible IDO, if the ovine placenta is found to constitutively express learn more IDO, it is paradoxical for the pathogenesis of OEA. Even with the current unknowns regarding IDO expression in the ovine placenta, we know that C. abortus infects and multiplies in both human and mouse placenta and causes abortion in these hosts where placental IDO has been described.34 Exactly how C. abortus is able to access tryptophan, multiply and cause disease in an organ that is theoretically hostile to its growth is unknown. It has been noted that the foetus needs to derive tryptophan from its mother, and hence although IDO expression has been linked to immune tolerance, there are physiological questions regarding its expression this website and its role in preventing abortion.35 It is possible that the specialized nutrient Sclareol transport and sequestration mechanisms of trophoblast cells hold the key to answer both of these questions. The TH1/TH2 paradigm

first applied to mammalian pregnancy in 1993 by Thomas Wegmann36 who postulated that pregnancy is a TH2-dominated phenomenon. This was moving forward from Medawar’s original hypothesis of maternal immune suppression and led to a new paradigm, namely that a dominating maternal TH1-type response (typified by IFN-γ production) is incompatible with successful pregnancy.37 This paradigm itself has been revised more recently with the conclusion that while certain elements remain valid, it is over-simplified in light of new knowledge on innate immunity and T-cell subsets.38,39 Nevertheless, the concept that maternal IFN-γ production is down-regulated during normal pregnancy could help explain the pathogenesis of OEA. Persistence of C. abortus can be induced by IFN-γ, and the placentitis that leads to OEA only occurs from mid-gestation onwards, hence it has been postulated that a reduction in maternal IFN-γ production could permit recrudescence of a persistent, sub-clinical C. abortus infection in pregnant sheep and result in OEA.