42 resultados para Leucine-rich immune molecule 1
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Tight homeostatic control of brain amino acids (AA) depends on transport by solute carrier family proteins expressed by the blood-brain barrier (BBB) microvascular endothelial cells (BMEC). To characterize the mouse BMEC transcriptome and probe culture-induced changes, microarray analyses of platelet endothelial cell adhesion molecule-1-positive (PECAM1(+)) endothelial cells (ppMBMECs) were compared with primary MBMECs (pMBMEC) cultured in the presence or absence of glial cells and with b.End5 endothelioma cell line. Selected cell marker and AA transporter mRNA levels were further verified by reverse transcription real-time PCR. Regardless of glial coculture, expression of a large subset of genes was strongly altered by a brief culture step. This is consistent with the known dependence of BMECs on in vivo interactions to maintain physiologic functions, for example, tight barrier formation, and their consequent dedifferentiation in culture. Seven (4F2hc, Lat1, Taut, Snat3, Snat5, Xpct, and Cat1) of nine AA transporter mRNAs highly expressed in freshly isolated ppMBMECs were strongly downregulated for all cultures and two (Snat2 and Eaat3) were variably regulated. In contrast, five AA transporter mRNAs with low expression in ppMBMECs, including y(+)Lat2, xCT, and Snat1, were upregulated by culture. We hypothesized that the AA transporters highly expressed in ppMBMECs and downregulated in culture have a major in vivo function for BBB transendothelial transport.
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Activated T cells use very late antigen-4/α4β1 integrin for capture, rolling on, and firm adhesion to endothelial cells, and use leukocyte function-associated antigen-1/αLβ2 integrin for subsequent crawling and extravasation. Inhibition of α4β1 is sufficient to prevent extravasation of activated T cells and is successfully used to combat autoimmune diseases, such as multiple sclerosis. Here we show that effector T cells lacking the integrin activator Kindlin-3 extravasate and induce experimental autoimmune encephalomyelitis in mice immunized with autoantigen. In sharp contrast, adoptively transferred autoreactive T cells from Kindlin-3-deficient mice fail to extravasate into the naïve CNS. Mechanistically, autoreactive Kindlin-3-null T cells extravasate when the CNS is inflamed and the brain microvasculature expresses high levels of integrin ligands. Flow chamber assays under physiological shear conditions confirmed that Kindlin-3-null effector T cells adhere to high concentrations of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1, albeit less efficiently than WT T cells. Although these arrested T cells polarize and start crawling, only few remain firmly adherent over time. Our data demonstrate that the requirement of Kindlin-3 for effector T cells to induce α4β1 and αLβ2 integrin ligand binding and stabilization of integrin-ligand bonds is critical when integrin ligand levels are low, but of less importance when integrin ligand levels are high.
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he abundance and distribution of isotopes throughout the Solar System can be used to constrain the number and type of nucleosynthetic events that contributed material to the early nebula. Barium is particularly well suited to quantifying the degree of isotope heterogeneity in the Solar System because it comprises seven stable isotopes that were synthesized by three different nucleosynthetic processes (s-, r-, and p-processes), all of which contributed material to the Solar System. There is also potential contribution to 135Ba from short-lived radioisotope 135Cs, conclusive evidence for which is yet to be reported. Four Allende (CV3) Ca,Al-rich inclusions (CAI 1, CAI 2, CAI 4, CAI 5) and one Allende dark inclusion (DI) were analyzed for Ba isotope variability. Two CAIs (CAI 2 and CAI 5) display 135Ba excesses that are not accompanied by 137Ba anomalies. Calcium–aluminum-rich inclusion 1 displays a 135Ba excess that is possibly coupled with a 137Ba excess, and the remaining refractory inclusions (CAI 2 and DI) have terrestrial Ba isotope compositions. These Ba isotope data are presented in conjunction with published whole rock Ba isotope data from individual Allende CAIs. The enrichment in 135Ba and absence of coupled 137Ba excesses in CAI 2 and CAI 5 is interpreted to indicate that the anomalies are not purely nucleosynthetic in origin but also contain contributions (16–48 ppm) from the decay of short-lived 135Cs. The majority of Allende CAIs studied to date may also have similar contributions from 135Cs on the basis of higher than expected 135Ba excesses if the Ba isotope anomalies were purely nucleosynthetic in origin. The 135Ba anomalies appear not to be coupled with superchondritic Cs/Ba, which may imply that the contribution to 135Ba did not occur via in situ decay of live 135Cs. However, it is feasible that the CAIs had a superchondritic Cs/Ba during decay of 135Cs, but Cs was subsequently removed from the system during aqueous alteration on the parent body. An alternative scenario is the potential existence of a transient high-temperature reservoir having superchondritic Cs/Ba in the early Solar System while 135Cs was extant, which enabled a radiogenic 135Ba signature to develop in some early condensates. The nucleosynthetic source of 135Cs can be determined by reconciling the predicted astrophysical 135Cs abundance with its measured abundance in meteorites. Further, the currently accepted initial 135Cs/133Cs of the Solar System, [135Cs/133Cs]0, may be underestimated because the spread of Cs/Ba among samples is small and the range of excess 135Ba is limited thus leading to inaccuracies when estimating [135Cs/133Cs]0. If the initial meteoritic abundance of 135Cs was indeed higher than is currently thought, the most probable stellar source of short-lived radioisotopes was a nearby core-collapse supernova and/or the Wolf–Rayet wind driven by its progenitor.
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BACKGROUND Vascular Ehlers-Danlos syndrome (VEDS) causes reduced life expectancy because of arterial dissections/rupture and hollow organ rupture. Although the causative gene, COL3A1, was identified >20 years ago, there has been limited progress in understanding the disease mechanisms or identifying treatments. METHODS AND RESULTS We studied inflammatory and transforming growth factor-β (TGF-β) signaling biomarkers in plasma and from dermal fibroblasts from patients with VEDS. Analyses were done in terms of clinical disease severity, genotype-phenotype correlations, and body composition and fat deposition alterations. VEDS subjects had increased circulating TGF-β1, TGF-β2, monocyte chemotactic protein-1, C-reactive protein, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and leptin and decreased interleukin-8 versus controls. VEDS dermal fibroblasts secreted more TGF-β2, whereas downstream canonical/noncanonical TGF-β signaling was not different. Patients with COL3A1 exon skipping mutations had higher plasma intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, and VEDS probands had abnormally high plasma C-reactive protein versus affected patients identified through family members before any disease manifestations. Patients with VEDS had higher mean platelet volumes, suggesting increased platelet turnover because of ongoing vascular damage, as well as increased regional truncal adiposity. CONCLUSIONS These findings suggest that VEDS is a systemic disease with a major inflammatory component. C-reactive protein is linked to disease state and may be a disease activity marker. No changes in downstream TGF-β signaling and increased platelet turnover suggest that chronic vascular damage may partially explain increased plasma TGF-β1. Finally, we found a novel role for dysregulated TGF-β2, as well as adipocyte dysfunction, as demonstrated through reduced interleukin-8 and elevated leptin in VEDS.
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BACKGROUND Distinct populations of neutrophils have been identified based on the expression of intercellular adhesion molecule 1 (ICAM1, CD54) and chemokine receptor 1 (CXCR1, interleukin 8 receptor α). AIM We analyzed the expression of vascular endothelial growth factor receptor 1 (VEGFR1), a physiological negative regulator of angiogenesis, on distinct populations of neutrophils from the blood of patients before and after adjuvant chemotherapy for breast cancer. MATERIALS AND METHODS Neutrophil populations were distinguished as reverse transmigrated (ICAM1(high)/CXCR1(low)), naïve (ICAM1(low)/CXCR1(high)), or tissue-resident neutrophils (ICAM1(low)/CXCR1(low)), and their VEGFR1 expression quantified. RESULTS Reverse transmigrated ICAM1(high)/CXCR1(low) neutrophilic granulocytes decreased significantly after chemotherapy and these were also the cells with highest mean fluorescence intensity for VEGFR1. CONCLUSION Chemotherapy mainly reduces the number of reverse transmigrated long-lived ICAM1(high)/CXCR1(low) VEGFR1-expressing neutrophils. The decrease of antiangiogenic VEGFR1 may have a potential impact on tumour angiogenesis in patients undergoing adjuvant chemotherapy.
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A compact and planar donor–acceptor molecule 1 comprising tetrathiafulvalene (TTF) and benzothiadiazole (BTD) units has been synthesised and experimentally characterised by structural, optical, and electrochemical methods. Solution-processed and thermally evaporated thin films of 1 have also been explored as active materials in organic field-effect transistors (OFETs). For these devices, hole field-effect mobilities of μFE=(1.3±0.5)×10−3 and (2.7±0.4)×10−3 cm2 V s−1 were determined for the solution-processed and thermally evaporated thin films, respectively. An intense intramolecular charge-transfer (ICT) transition at around 495 nm dominates the optical absorption spectrum of the neutral dyad, which also shows a weak emission from its ICT state. The iodine-induced oxidation of 1 leads to a partially oxidised crystalline charge-transfer (CT) salt {(1)2I3}, and eventually also to a fully oxidised compound {1I3}⋅1/2I2. Single crystals of the former CT compound, exhibiting a highly symmetrical crystal structure, reveal a fairly good room temperature electrical conductivity of the order of 2 S cm−1. The one-dimensional spin system bears compactly bonded BTD acceptors (spatial localisation of the LUMO) along its ridge.
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Salmonella enterica subspecies 1 serovar Typhimurium is a principal cause of human enterocolitis. For unknown reasons, in mice serovar Typhimurium does not provoke intestinal inflammation but rather targets the gut-associated lymphatic tissues and causes a systemic typhoid-like infection. The lack of a suitable murine model has limited the analysis of the pathogenetic mechanisms of intestinal salmonellosis. We describe here how streptomycin-pretreated mice provide a mouse model for serovar Typhimurium colitis. Serovar Typhimurium colitis in streptomycin-pretreated mice resembles many aspects of the human infection, including epithelial ulceration, edema, induction of intercellular adhesion molecule 1, and massive infiltration of PMN/CD18(+) cells. This pathology is strongly dependent on protein translocation via the serovar Typhimurium SPI1 type III secretion system. Using a lymphotoxin beta-receptor knockout mouse strain that lacks all lymph nodes and organized gut-associated lymphatic tissues, we demonstrate that Peyer's patches and mesenteric lymph nodes are dispensable for the initiation of murine serovar Typhimurium colitis. Our results demonstrate that streptomycin-pretreated mice offer a unique infection model that allows for the first time to use mutants of both the pathogen and the host to study the molecular mechanisms of enteric salmonellosis.
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BACKGROUND Everolimus reduces the progression of cardiac allograft vasculopathy (CAV) in de novo heart transplant (HTx) recipients, but the influence on established CAV is unknown. METHODS In this Nordic Certican Trial in Heart and lung Transplantation substudy, 111 maintenance HTx recipients (time post-HTx 5.8 ± 4.3 years) randomized to everolimus+reduced calcineurin inhibitor (CNI) or standard CNI had matching (intravascular ultrasound) examinations at baseline and 12 months allowing accurate assessment of CAV progression. RESULTS No significant difference in CAV progression was evident between the treatment groups (P = 0.30). When considering patients receiving concomitant azathioprine (AZA) therapy (n = 39), CAV progression was attenuated with everolimus versus standard CNI (Δmaximal intimal thickness 0.00 ± 0.04 and 0.04 ± 0.04 mm, Δpercent atheroma volume 0.2% ± 3.0% and 2.6% ± 2.5%, and Δtotal atheroma volume 0.25 ± 14.1 and 19.8 ± 20.4 mm(3), respectively [P < 0.05]). When considering patients receiving mycophenolate mofetil (MMF), accelerated CAV progression occurred with everolimus versus standard CNI (Δmaximal intimal thickness 0.06 ± 0.12 vs. 0.02 ± 0.06 mm and Δpercent atheroma volume 4.0% ± 6.3% vs. 1.4% ± 3.1%, respectively; P < 0.05). The levels of C-reactive protein and vascular cell adhesion molecule-1 declined significantly with AZA+everolimus, whereas MMF+everolimus patients demonstrated a significant increase in levels of C-reactive protein, vascular cell adhesion molecule-1, and von Willebrand factor. CONCLUSIONS Conversion to everolimus and reduced CNI does not influence CAV progression among maintenance HTx recipients. However, background immunosuppressive therapy is important as AZA+everolimus patients demonstrated attenuated CAV progression and a decline in inflammatory markers, whereas the opposite pattern was seen with everolimus+MMF. The different effect of everolimus when combined with AZA versus MMF could potentially reflect hitherto unknown interactions.
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INTRODUCTION Clinical treatment of spinal metastasis is gaining in complexity while the underlying biology remains unknown. Insufficient biological understanding is due to a lack of suitable experimental animal models. Intercellular adhesion molecule-1 (ICAM1) has been implicated in metastasis formation. Its role in spinal metastasis remains unclear. It was the aim to generate a reliable spinal metastasis model in mice and to investigate metastasis formation under ICAM1 depletion. MATERIAL AND METHODS B16 melanoma cells were infected with a lentivirus containing firefly luciferase (B16-luc). Stable cell clones (B16-luc) were injected retrogradely into the distal aortic arch. Spinal metastasis formation was monitored using in vivo bioluminescence imaging/MRI. Neurological deficits were monitored daily. In vivo selected, metastasized tumor cells were isolated (mB16-luc) and reinjected intraarterially. mB16-luc cells were injected intraarterially in ICAM1 KO mice. Metastasis distribution was analyzed using organ-specific fluorescence analysis. RESULTS Intraarterial injection of B16-luc and metastatic mB16-luc reliably induced spinal metastasis formation with neurological deficits (B16-luc:26.5, mB16-luc:21 days, p<0.05). In vivo selection increased the metastatic aggressiveness and led to a bone specific homing phenotype. Thus, mB16-luc cells demonstrated higher number (B16-luc: 1.2±0.447, mB16-luc:3.2±1.643) and increased total metastasis volume (B16-luc:2.87±2.453 mm3, mB16-luc:11.19±3.898 mm3, p<0.05) in the spine. ICAM1 depletion leads to a significantly reduced number of spinal metastasis (mB16-luc:1.2±0.84) with improved neurological outcome (29 days). General metastatic burden was significantly reduced under ICAM1 depletion (control: 3.47×10(7)±1.66×10(7); ICAM-1-/-: 5.20×10(4)±4.44×10(4), p<0.05 vs. control) CONCLUSION Applying a reliable animal model for spinal metastasis, ICAM1 depletion reduces spinal metastasis formation due to an organ-unspecific reduction of metastasis development.
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Sphingosine-1-phosphate (S1P) has been implicated in angiogenesis, inflammation, cancerogenesis, neurological excitability and immune regulation and is synthesized by two different sphingosine kinases (SphK). It was suggested that mice lacking the gene for SphK1 exhibit no obvious phenotype, because SphK2 compensates for its absence. However, recent investigations revealed that under challenge SphK1 contributed to pro-inflammatory processes favoring Th2 and Th17 rather than Th1-type reactions. To investigate the immune modulatory role of SphK1 as opposed to SphK2 specifically for the Th1 propagating IL-12p70 we compared WT and SphK1(-/-) splenocytes and Flt3-ligand differentiated BMCs of WT and SphK1(-/-), representing dendritic cells as major producers of IL-12p70, incubated with LPS. We determined the impact on IL-12p70 in comparison to other inflammatory cytokines, and on DC and macrophage surface marker expression, SphK mRNA, protein expression and enzymatic activity in splenocytes. Our data demonstrated that SphK1 deficiency enhanced LPS-induced IL-12p70 production although SphK2 was present. To further characterize SphK1-dependent IL-12p70 regulation we exogenously applied S1P, SEW2871 and the new potent S1P1 agonist CYM5442. Both S1P and S1P1-specific analogs fully compensated the increase of IL-12p70 production in SphK1-deficient splenocytes. The use of pertussis toxin, to block G(i)-coupled signaling downstream of S1P1, again increased IL-12p70 and neglected the compensation achieved by addition of S1P and S1P1 agonists pointing on the importance of this specific S1P-receptor. Given that, in parallel to a prominent IL-12p35 increase following LPS stimulation, LPS also enhanced SphK expression and total SphK activity, we concluded that SphK1-derived S1P acting via S1P1 is a major mechanism of this negative IL-12p70 feedback loop, which did not affect other cytokines. Moreover, our data showed that SphK2 activity failed to compensate for SphK1 deficiency. These findings clearly point to a divergent and cytokine-specific impact of immune cell SphK1 and SphK2 in chronic inflammation and cancer.
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Inhibiting the α4 subunit of the integrin heterodimers α4β1 and α4β7 with the mab natalizumab is an effective treatment of multiple sclerosis (MS). Which of the two α4 heterodimers is involved in disease pathogenesis has, however, remained controversial. Whereas the development of experimental autoimmune encephalomyelitis (EAE), an animal model of MS, is ameliorated in β7-integrin-deficient C57BL/6 mice, neutralizing antibodies against the β7-integrin subunit or the α4β7-integrin heterodimer fail to interfere with EAE pathogenesis in the SJL mouse. To facilitate α4β7-integrin-mediated immune-cell trafficking across the blood-brain barrier (BBB), we established transgenic C57BL/6 mice with endothelial cell-specific, inducible expression of the α4β7-integrin ligand mucosal addressin cell adhesion molecule (MAdCAM)-1 using the tetracycline (TET)-OFF system. Although TET-regulated MAdCAM-1 induced α4β7-integrin mediated interaction of α4β7(+) /α4β1(-) T cells with the BBB in vitro and in vivo, it failed to influence EAE pathogenesis in C57BL/6 mice. TET-regulated MAdCAM-1 on the BBB neither changed the localization of central nervous system (CNS) perivascular inflammatory cuffs nor did it enhance the percentage of α4β7-integrin(+) inflammatory cells within the CNS during EAE. In conclusion, our study demonstrates that ectopic expression of MAdCAM-1 at the BBB does not increase α4β7-integrin-mediated immune cell trafficking into the CNS during MOG(aa35-55)-induced EAE.
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Chronic lung infections by Pseudomonas aeruginosa strains are a major cause of morbidity and mortality in cystic fibrosis (CF) patients. Although there is no clear evidence for a primary defect in the immune system of CF patients, the host is generally unable to clear P. aeruginosa from the airways. PTX3 is a soluble pattern recognition receptor that plays nonredundant roles in the innate immune response to fungi, bacteria, and viruses. In particular, PTX3 deficiency is associated with increased susceptibility to P. aeruginosa lung infection. To address the potential therapeutic effect of PTX3 in P. aeruginosa lung infection, we established persistent and progressive infections in mice with the RP73 clinical strain RP73 isolated from a CF patient and treated them with recombinant human PTX3. The results indicated that PTX3 has a potential therapeutic effect in P. aeruginosa chronic lung infection by reducing lung colonization, proinflammatory cytokine levels (CXCL1, CXCL2, CCL2, and IL-1β), and leukocyte recruitment in the airways. In models of acute infections and in in vitro assays, the prophagocytic effect of PTX3 was maintained in C1q-deficient mice and was lost in C3- and Fc common γ-chain-deficient mice, suggesting that facilitated recognition and phagocytosis of pathogens through the interplay between complement and FcγRs are involved in the therapeutic effect mediated by PTX3. These data suggested that PTX3 is a potential therapeutic tool in chronic P. aeruginosa lung infections, such as those seen in CF patients.
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The major route of transmission of Neospora caninum in cattle is transplacentally from an infected cow to its progeny. Therefore, a vaccine should be able to prevent both the horizontal transmission from contaminated food or water and the vertical transmission. We have previously shown that a chimeric vaccine composed of predicted immunogenic epitopes of NcMIC3, NcMIC1 and NcROP2 (recNcMIC3-1-R) significantly reduced the cerebral infection in BALB/c mice. In this study, mice were first vaccinated, then mated and pregnant mice were challenged with 2×10(6)N. caninum tachyzoites at day 7-9 of pregnancy. Partial protection was only observed in the mice vaccinated with a tachyzoite crude protein extract but no protection against vertical transmission or cerebral infection in the dams was observed in the group vaccinated with recNcMIC3-1-R. Serological and cytokine analysis showed an overall lower cytokine level in sera associated with a dominant IL-4 expression and high IgG1 titers. Thus, the Th2-type immune response observed in the pregnant mice was not protective against experimental neosporosis, in contrary to the mixed Th1-/Th2-type immune response observed in the non-pregnant mouse model. These results demonstrate that the immunomodulation that occurs during pregnancy was not favorable for the protection against N. caninum infection conferred by vaccination with recNcMIC3-1-R.
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Drug-induced hypersensitivity reactions have been explained by the hapten concept, according to which a small chemical compound is too small to be recognized by the immune system. Only after covalently binding to an endogenous protein the immune system reacts to this so called hapten-carrier complex, as the larger molecule (protein) is modified, and thus immunogenic for B and T cells. Consequently, a B and T cell immune response might develop to the drug with very heterogeneous clinical manifestations. In recent years, however, evidence has become stronger that not all drugs need to bind covalently to the MHC-peptide complex in order to trigger an immune response. Rather, some drugs may bind directly and reversibly to immune receptors like the major histocompatibility complex (MHC) or the T cell receptor (TCR), thereby stimulating the cells similar to a pharmacological activation of other receptors. This concept has been termed pharmacological interaction with immune receptors the (p-i) concept. While the exact mechanism is still a matter of debate, non-covalent drug presentation clearly leads to the activation of drug-specific T cells as documented for various drugs (lidocaine, sulfamethoxazole (SMX), lamotrigine, carbamazepine, p-phenylendiamine, etc.). In some patients with drug hypersensitivity, such a response may occur within hours even upon the first exposure to the drug. Thus, the reaction to the drug may not be due to a classical, primary response, but rather be mediated by stimulating existing, pre-activated, peptide-specific T cells that are cross specific for the drug. In this way, certain drugs may circumvent the checkpoints for immune activation imposed by the classical antigen processing and presentation mechanisms, which may help to explain the peculiar nature of many drug hypersensitivity reactions.
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Blockade of cytokines, particularly of tumour necrosis factor alpha (TNF-alpha), in immuno-inflammatory diseases, has led to the greatest advances in medicine of recent years. We did a thorough review of the literature with a focus on inflammation models in rodents on modified gene expression or bioactivity for IL-1, IL-6, and TNF-alpha, and we summarized the results of randomized controlled clinical trials in human disease. What we have learned herewith is that important information can be achieved by the use of animal models in complex, immune-mediated diseases. However, a clear ranking for putative therapeutic targets appears difficult to obtain from an experimental approach alone. This is primarily due to the fact that none of the disease models has proven to cover more than one crucial pathogenetic aspect of the complex cascade of events leading to characteristic clinical disease signs and symptoms. This supports the notion that the addressed human immune-mediated diseases are polygenic and the summation of genetic, perhaps epigenetic, and environmental factors. Nevertheless, it has become apparent, so far, that TNF-alpha is of crucial importance in the development of antigen-dependent and antigen-independent models of inflammation, and that these results correlate well with clinical success. With some delay, clinical trials in conditions having some relationship with rheumatoid arthritis (RA) indicate new opportunities for blocking IL-1 or IL-6 therapeutically. It appears, therefore, that a translational approach with critical, mutual reflection of simultaneously performed experiments and clinical trials is important for rapid identification of new targets and development of novel treatment options in complex, immune-mediated, inflammatory diseases.