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 Osimertinib 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 PKC inhibitor 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, Resveratrol 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.

The same procedure

is repeated for the rest sutures as well as at the posterior vessel wall (Figs. 1F and 1G). We performed this technique in 30 venous and 15 arterial anastomoses during free tissue transfer. In 15 free flaps, both the arterial and venous anastomoses were performed with the described method, meanwhile in other 15 free flaps, the arterial anastomoses were performed with the conventional method ITF2357 price and the venous anastomosis with the “continuous-interrupted” technique. In both of the groups, no complications were noted performing this technique as all the flaps survived well. Furthermore, the same surgeon in anterolateral thigh flap (ALT) flaps performed 20 venous anastomoses, 10 with the conventional technique, and 10 with the proposed method in order

to compare the time difference between the two methods in vessels with the same size. Statistically significant less time was required (P < 0.05) for the venous anastomosis with the “continuous-interrupted” method. The described method for microvascular anastomosis has several advantages. First of all, the application of the sutures can be very precise as the loosely running suture leaves spaces between the vessels, allowing the lumen to be visible without extensive manipulation of the vessel. This is very useful especially when the last suture of the anterior and posterior wall is applied, which with the conventional method there is limited space between the two edges of vessels. Similarly, during the anastomosis, the posterior vessel wall is always visible, avoiding inadvertent two-wall sewing. Additionally, Selleckchem Raf inhibitor even though the suture is applied continuously, finally

tied as the interrupted fashion, hence there is no risk of stenosis at the anastomotic site. Finally, the anastomosis is performed faster than the conventional method, as the surgeon saves time applying the sutures with a running manner. Stamatis Sapountzis, M.D.* “
“The most suitable free flap alternative in upper extremity reconstruction has adequate and quality of tissue with consistent vascular pedicle. Free flap must provide convenient tissue texture to reconstruct aesthetic and functional units of upper extremity. Furthermore, minimal donor site morbidity is preferred features Thiamet G in free flap election. In our efforts to obtain the best possible outcome for patients, we chose, as a first priority, the free superficial circumflex inferior artery (SCIA)/superficial inferior epigastric artery (SIEA) flap over other free flap options for the soft-tissue reconstruction of upper extremities. The authors retrospectively report the results of 20 free SCIA/SIEA flaps for upper extremity reconstruction during the past 3 years. Nineteen of 20 flaps were successful (95%): three required emergent postoperative reexploration of the anastomosis and one failed.

[4] Although the details of how this switch occurs in T cells remain unclear, the mTOR pathway is strongly implicated, because its activation up-regulates the surface expression of the glucose transporter, Glut1, probably as a result of T-cell

PFT�� receptor and CD28 signalling through phosphatidylinositide 3-kinase (PI3K) and protein kinase B (PKB also known as AKT).[5] AKT signalling via mTOR also leads to higher expression of amino acid and other nutrient transporters, such as the transferrin receptor.[6] The mTOR pathway acts in all cells to coordinate many other aspects of cell growth and metabolism, including the response to hypoxia and the biogenesis and oxidative capacity of mitochondria.[7] mTOR forms two structurally distinct

complexes (TORC1 and TORC2).[8] The core components of TORC1, which is thought to represent the main nutrient-sensing complex, are the serine/threonine kinase PF-6463922 datasheet mTOR itself, the scaffolding protein Raptor, the positive accessory proteins FKB12, Deptor and mLST8, plus a regulatory subunit PRAS40, which is a target of AKT downstream of PI3K signalling.[9] The immunosuppressive drug rapamycin (which gave mTOR its name as the mammalian target of rapamycin) actually binds to FKB12 and disrupts the formation and function of the TORC1 complex.[10] A critical activator of the TORC1 complex

is the ras homologue expressed in brain (Rheb), which is localized within the cell in a Rab7+ lysosomal compartment. Rheb is in turn controlled by the tuberous sclerosis (TSC) 1/2 complex, which acts downstream of many different signalling pathways, including AMP-activated protein kinase, PI3K and AKT.[11] AMP kinase can act as a sensor of increasing Glutamate dehydrogenase AMP/ATP ratios during hypoxia, while PI3K provides signals from growth factor receptors and co-stimulatory molecules such as CD28 and programmed death-1 during T-cell receptor activation. The interaction between TORC1 and Rheb is entirely dependent on the sensing of sufficient amino acids, and although the molecular sensor has yet to be identified in mammals, downstream signalling requires the four ras-related GTP binding (or RAG GTPase: RRAG) proteins (A–D) together with the ragulator complex,[12, 13] so that a lack of available amino acids acts as a potent inhibitor of TORC1 activity. Conversely, activation of TORC1 drives protein synthesis via phosphorylation of S6K1, which in turn phosphorylates the ribosomal protein S6, which is required for the initiation of translation. At the same time, 4E-BP1, an inhibitor of protein translation, is also deactivated by mTOR-mediated phosphorylation. Much less is known about how the TORC2 complex is regulated: in the short term (i.e.

However, DU did not affect urodynamic parameters and LUTS after RP. Conclusion: Although RP improves urodynamic parameters, it does not significantly affect LUTS. Urinary continence gradually improves and is satisfactory within 1 year after RP. The status of preoperative detrusor contractility did not affect urodynamic parameters or LUTS MK-1775 in vivo after RP. “
“Objectives: To study the effects of metabolic syndrome on prostate α-adrenergic contractile function using fructose-fed rats (FR). Methods: Age-matched male Wistar rats were divided into two groups: group I, normal control rats; and group II, 9-week FR. Animal body weight, blood pressure and serum metabolic parameters were monitored.

The prostate was removed 9 weeks after induction of metabolic syndrome in the FR. The contractile responses of prostatic strips to phenylephrine (10−7 to 10−6 M) and KCl (50 mM) were tested. Prostate α1-adrenoceptor (α1-AR) protein expression was studied by Western blotting analysis with a polyclonal antiserum. Results: At week 9, the FR showed significant increases in body weight, blood pressure, Saracatinib supplier plasma glucose, insulin and triglyceride levels. The FR prostate weight was significantly higher than that of

the controls (610.5 ± 13.2 vs 422.3 ± 7.7 mg, P < 0.05 for n = 8). FR prostate contractile responses to phenylephrine and KCl were both significantly increased. Interestingly, prostate α1-AR protein expression level was lower in the FR. Liothyronine Sodium However, after in vitro 10−6 M phenylephrine stimulation, FR prostate α1-AR protein expression was significantly increased. Conclusion: Metabolic syndrome in FR significantly increases

prostate contractile responses to KCl and α-adrenergic stimulation. Paradoxically, FR prostate α1-AR protein expression is decreased, but significantly enhanced after in vitro phenylephrine stimulation. “
“No clinical characteristic picture and impact of symptoms on quality of life (QOL) of interstitial cystitis (IC) patients in Taiwan had been reported. This paper is intended to provide preliminary descriptive results of IC research in Taiwan. A total of 319 patients, based on National Institute of Arthritis, Diabetes, Digestive and Kidney Diseases (NIDDK) criteria, were enrolled in the study from February 2004 through March 2006. Evaluation data included baseline demographic information, patient and family medical history, dietary effects, pregnancy data, sexual relationships with symptoms, and impact of symptoms on quality of life. The main responsibility of the hospitals discussed was patient care and data collection. Taichung Hospital presents the results. The Interstitial Cystitis Database (ICDB) patients were predominantly female, that is, 86% of the total, with an average enrollment age of 46. The analysis of various symptoms indicates the following distribution: (i) 94% frequency; (ii) 80% pain; (iii) 53% nocturia; (iv) 43% urgency; and (v) 10% associated incontinence.

aeruginosa PA14 transposon insertion mutants, Mah et al. (2003) identified a mutant that had decreased tobramycin susceptibility when grown in biofilms, but was otherwise indistinguishable from the wild-type strain (i.e. no differences in tobramycin susceptibility when

grown planktonically). The mutation was mapped to PA1163 (ndvB), coding for a periplasmic glucosyltransferase required for the synthesis of cyclic-β-(1,3)-glucans. VX-809 research buy Through a series of elegant experiments, the authors were able to demonstrate that the cyclic glucans synthesized by ndvB can sequester various antibiotics (including tobramycin, gentamycin and ciprofloxacin) and as such interfere with the movement of the antibiotics through the periplasmic space. Semi-quantitative PCR confirmed that ndvB is preferentially expressed in sessile cells. In addition, further screening of this Tn5 insertion mutant bank resulted in the identification of a novel efflux pump (PA1874–PA1877) that was more highly expressed in biofilm cells than in planktonic cells and contributed to the increased resistance

of sessile populations to tobramycin, gentamycin and ciprofloxacin (Zhang & Mah, 2008) (Table 2). In P. aeruginosa biofilms treated with 1 μg mL−1 of the β-lactam antibiotic imipenem (a concentration below the MIC), 336 genes were induced or repressed at least twofold (Bagge et al., 2004). Not surprisingly, ampC (encoding a chromosomal β-lactamase) showed the strongest differential expression (150-fold on day 3). Several genes involved in alginate Tamoxifen mouse biosynthesis (including the algD to algA cluster and the algU-mucABC gene cluster) were also upregulated, while in younger biofilms treated with a subinhibitory concentration of imipenem, downregulation of motility-associated genes (flgC to flgI cluster,

pilA, pilB, pilM to pilQ) was observed. The upregulation of alginate-related genes was associated with a drastic (up to 20-fold) increase in alginate production. Imipenem treatment also resulted in significant differences in biofilm structure, with treated biofilms containing more biomass per area and being thicker, but having a smoother surface, leading to a lower surface-to-volume ratio. The overexpression of ampC and genes Anidulafungin (LY303366) involved in alginate biosynthesis probably allows the more efficient neutralization of imipenem: the AmpC β-lactamase is secreted in membrane vesicles and the accumulation of this enzyme in the matrix allows the rapid hydrolysis of β-lactams as they penetrate the matrix. Exposure of P. aeruginosa PAO1 biofilms to sub-MIC levels of azithromycin (2 μg mL−1) for 4 days resulted in the differential expression (≥5-fold difference) of 274 genes compared with untreated control biofilms (Gillis et al., 2005). Several of the upregulated genes encode resistance-nodulation-cell division (RND) efflux pumps, including mexC (94.8 ×), oprJ (19.3 ×), nfxB (14.5 ×), mexD (12.7 ×) and oprN (6.7 ×).

SCIG offers many patients a viable, convenient alternative to IVIG. A logical step forward from the successful use of SCIG in replacement therapy is the use of SCIG in the setting of immunomodulation. Multi-focal motor neuropathy (MMN) is known to be responsive to IVIG therapy. MMN is a serious autoimmune neuropathy characterized by segmental demyelination, conduction block and asymmetric weakness, with relatively preserved muscle bulk. MMN is associated with anti-GM1 antibodies in 50–80% of cases.

Three recent studies of SCIG in patients find more with MMN who were switched from IVIG show that SCIG was as efficacious as IVIG, as measured by combined dynamometric [28] and the Medical Research Council (MRC) muscle strength Fostamatinib mw scores [29]. In a more recent study, patients were switched gradually over 3 weeks from IVIG to SCIG [30]. The majority of patients maintained MRC muscle strength score over the 6-month study. In all three studies, the majority of patients elected to continue SCIG administration at the end

of the study (Table 2). One patient who experienced muscle strength deterioration also continued to use this form of administration [29]. Thus, SCIG showed good efficacy, was preferred by patients with MMN and its use in immunomodulation should be investigated further. SCIG may also be effective in dermatological autoimmune disorders as demonstrated in IVIG-responsive epidermolysis bullosa acquisita (EBA). A case report Sinomenine study of a patient with EBA who was switched to SCIG (0·9 g/kg/month) showed improved clinical outcome [31]. Successful treatment of MMN and EBA suggests that SCIG use can be explored in many other conditions where IVIG is effective. A recent retrospective study offers insight into new ways to improve convenience in SCIG administration. Infusion with a syringe and butterfly needle (rapid push) was compared with the usual pump administration. The rapid push method involves more frequent subcutaneous administration of smaller doses compared

to weekly SCIG. Of 104 patients with PI who had either no previous IgG therapy or had been on IVIG, 74 patients used rapid push administration and 29 used a pump to infuse a 16% SCIG IgG formulation. Patients using rapid push underwent an average of 3·1 infusions per week, and those using pump an average of 2·9 infusions per week. Rapid push was found to be an efficacious alternative, as no difference in mean serum IgG levels was observed between the two different administration methods [32]. Additionally, serum IgG levels achieved with either route of SCIG infusion were higher than those achieved with the previous IVIG therapy, due probably to the frequent administration of smaller doses and the slow transition of IgG into the vascular space. Rapid push infusion thus offers a suitable alternative, for example, when a pump is not available or when high infusion volumes per injection site are not tolerated.

The first is clonal deletion. Although it can be very effective, when actually studied in the periphery it seems to take a very long time to eliminate the autoreactive population [5]. In cases where

the antigen is chronic, this presents a problem since the animal continues to suffer a risk of autoimmunity while the cells are being “slowly deleted.” Therefore, two other processes are thought to operate to keep the cells in check — a functional inactivation, originally termed anergy and the action of Treg cells [6, 7]. However, a clear separation between the three processes in vivo and an understanding of the principles that selleck compound library lead to the choice of any one or a combination of them is still lacking. We have previously reported that adoptively transferring antigen specific T cells to mice expressing their target antigen resulted in the induction of anergy and “slow deletion”, but not of Treg cells [5]. Typically, these studies involved the infusion of 1–3 million TCR transgenic T cells to CDK inhibitor congenic hosts. About 10% of the injected cells effectively incorporate into the secondary lymphoid organs. Nevertheless, work from several labs (using acute immunization, not chronic or self-antigens)

subsequently suggested that at such high frequencies, the T-cell responses were severely constrained by interference between the transferred T cells themselves [8-14]. This phenomenon, termed clonal competition, affects the robustness of the initial T-cell response, the subsequent survival of the activated T cells (memory) and even the extent of differentiation into different subsets [13, 15]. We therefore wondered if such a “precursor frequency effect” could also influence the behavior of self-reactive T cells. Interestingly, we find that chronic antigen stimulation elicits a precursor frequency independent response pattern, compared to an acute challenge. In the latter case the expansion phase and to a much lesser extent, the

onset of contraction was influenced by how many T cells participated in the original response. However, the self-reactive T cells were only minimally affected by precursor frequency during the initial expansion phase. 4-Aminobutyrate aminotransferase Furthermore, in the later phase, recipients seeded with about a 100 self-reactive T cells showed no evidence of clonal deletion for over 4 months. But, even at lower frequency, the self-reactive T cells entered an anergic state marked by reduced recall cytokine production and no conversion to Foxp3 positivity. These data suggest that in the normal repertoire, T cells reactive to chronic self-antigens that escape thymic deletion can respond and persist in the periphery, albeit in an anergic state. The impact of initial precursor frequency on the magnitude of the subsequent T-cell response was modeled using an adoptive transfer strategy wherein log dilutions of congenically marked naïve T cells were injected intravenously into recipient mice and challenged in vivo.

The donors recognized four peptides of the 23 20-mer peptides in DENV-1, five peptides of the 35 20-mer peptides of DENV-2, five peptides of the 35 peptides of the DENV-3 and five peptides of the 28 20-mer peptides of DENV-4 (Table 2). All dengue immune donors responded to the peptides of at least two DENV serotypes. Two donors responded to peptides of all four DENV serotypes. The number of healthy donors responding to at least two peptides of the four DENV serotypes in the cultured ELISPOT assays is shown in Table 3. Eight of 20 (40%) of the individuals responded

to at least two peptides of DENV-4 and responses to at least two peptides of other serotypes ranged from 30 to 50% (Table 3). The frequency Selleckchem HSP inhibitor of cultured ELISPOT responses to each of these peptides is shown in Fig. 1. These peptides had <15% homology between the four DENV serotypes except for 30% homology for four peptides (DENV-1 peptide with DENV-1 pep-11, DENV-2 pep-33, DENV-4 pep-12, DENV-2 pep-11, DENV-3 pep-11. DENV-2 peptide 17 with DENV-3 pep-21, DENV-3 pep-11 with DENV-4 pep-19). Of the 19 conserved and non-cross-reactive regions identified from the four DENV serotypes, two peptides were from the envelope region,

one peptide from the DENV-2 was from the NS1 region, six peptides were from the NS2A region, two peptides from the NS2B region, one peptide of SAR245409 clinical trial DENV-1 was from the NS3 region, four peptides were from the NS4A region and three peptides were from the NS5 region (Table 2). Of the six peptides identified which were from the NS2A Quinapyramine region, one peptide each was from DENV-2 and DENV-3, two peptides from DENV-4 and two of the peptides were from DENV-1. Three of six of these peptides were from the region represented by amino acids (aa) 99–133, and two of six peptides were from the region represented by

aa 184–216. One peptide from DENV-4 was from the aa 135–148. Variants of all the peptides are shown in supplementary Table S1 and are based on NCBI Virus Variation website data. In the current study we have used the most common sequence, which accounted for >90% of the detected variation in the majority of cases. The three peptides, from aa 99 to 133, were again found to be highly conserved. Of these three peptides, peptide 28 of DENV-3 (RENLLLGVGLAMATTLQLPE), which was the most frequently recognized peptide among all donors (nine of 20), had two changes in the amino acids in only two sequences. In these two variants, threonine in position 14 is replaced by alanine and arginine in position 17 was replaced by methionine. Peptide 10 of DENV-4 (AMTTTLSIPHDLMELIDGIS) had the amino acid leucine in position 6 replaced by isoleucine in some sequences. Although we also used this sequence in our peptide matrix, we did not detect any responses to the sequence with the altered amino acid.

The amount of HRP taken up by DCs was determined as the difference

between HRP activities in disrupted and non-disrupted cells. The HRP activity in non-disrupted DCs was always < 15% compared with disrupted cells. Total RNA was extracted from lung (positive control for CysLT1 receptor), gut tissues (positive control for CysLT2 receptor) and mouse immature and LPS-treated DCs, using Trizol reagent (Gibco-Life Technologies). The reverse Selleck Obeticholic Acid transcription reaction contained 3 μg total RNA and was performed using the Moloney-murine leukaemia virus reverse transcriptase enzyme (Promega). The primers were provided by Invitrogen: forward primers for the CysLTR1 and CysLTR2: CAA CGA ACT ATC CAC CTT CAC C and CCA AGG TCA CAA GAG GGT GT, respectively. Reverse primers for the CysLTR1 and CysLTR2: AGC CTT CTC CTA AAG TTT CC AC and GAG TTG ACA GAG GCG AGG AC, respectively. A GeneAmp PCR system (Perkin-Elmer/Applied Biosystems, Foster City, CA) was used. The PCR products were separated on a 1·5% agarose gel, stained with ethidium RO4929097 mw bromide, and visualized by a UV transilluminator. Murine DCs were suspended in complete medium (2 × 106/500 μl) were prewarmed for 30 min at 37°. The DCs were treated without or with

1 μg/ml LPS for 20 min at 37°. Then cells were washed and treated with or without 0·01 μm LTC4 for 5 min at 37°. The reaction was stopped by adding cold PBS, the mixture was centrifuged and pellets were resuspended at 3 × 106 cells/ml in Western sample buffer (100 mm Tris–HCl pH 6·8; 4% SDS, 0·2% Bromophenol-Blue, 20% glycerol, 200 mm dithiothreitol) and frozen at – 80°. Before the analysis, lysates were thawed, heated for 3 min to 96° and finally homogenized with a sonicator

3-mercaptopyruvate sulfurtransferase and 5 × 104 cells (10 μl extract) per lane were separated onto 10% SDS–PAGE followed by electroblotting. The membranes were blocked in PBS + 5% milk powder for 2 hr, and then incubated with the following primary antibodies in blocking buffer + 0·1% Tween-20 overnight at 4°: anti-phospho-ERK1/2 (Thr202/Tyr204, 1 : 1000; Cell Signaling Technology, Boston, MA), anti-phospho-p38K (1 : 1000; Cell Signaling). After washing, secondary antibodies were applied in blocking buffer for 2 hr at room temperature: anti-rabbit or anti-mouse-HRP mAb (1 : 3000; Cell Signaling). Membranes were washed and specific bands were developed by enhanced chemiluminescence (Amersham Biosciences, Uppsala, Sweden). Membranes were stripped and reproved with a rabbit mAb against murine β-actin (Cell Signaling Technology).

Treatment with hCDR1 down-regulated the expression of the latter molecule.51 Our present results, as well as previous data, indicate that treatment with hCDR1 affects a number of cell types and pathways. Figure 8 summarizes schematically our updated knowledge on the effects of treatment of SLE-affected mice with hCDR1 on T and B cells. As illustrated in the Fig. 8, the expression of CD74/CD44 complex in B cells of the treated mice is down-regulated along with down-regulation of the ligand of this complex, MIF, which results in suppressed expression of survival molecules, (e.g. Bcl-xL). Previous studies suggested

that suppression of NF-κB signalling mediated the latter,17,19 in agreement with our findings following down-regulation of HM781-36B purchase BAFF in the hCDR1-treated mice.16 In addition to the inhibitory effect of hCDR1 on the state of activation of B cells,8 the resultant enhancement of B-cell apoptosis may lead to the reduced production of dsDNA specific autoantibodies. In the T-cell compartment, however, hCDR1 induced CD4 and CD8 regulatory T cells,6,7 up-regulated the expression of Bcl-xL, and led to decreased rates of T-cell apoptosis and inhibition of T-cell activation.8,9 As a result, the production of pathogenic cytokines was significantly down-regulated. The reduced production of autoantibodies and pathogenic cytokines

is associated https://www.selleckchem.com/products/carfilzomib-pr-171.html with clinical amelioration of SLE manifestations. In conclusion, the present work has shown the involvement of the CD74/MIF pathway in the development of pathogenic B cells and in SLE-afflicted target organs. Moreover, treatment with the tolerogenic peptide, hCDR1, ameliorates disease manifestations, at least in part, by affecting this pathway. The authors have no financial conflicts of interest. “
“Antigen-presenting cell-associated four-domain MHC class II (MHC-II) molecules play a central role in activating

autoreactive CD4+ T cells involved in multiple sclerosis (MS) and type 1 diabetes (T1D). In contrast, two-domain MHC-II structures with the same Demeclocycline covalently attached self-peptide (recombinant T-cell receptor ligands (RTLs)) can regulate pathogenic CD4+ T cells and reverse clinical signs of experimental autoimmune diseases. RTL1000, which is composed of the β1α1 domains of human leukocyte antigen (HLA)-DR2 linked to the encephalitogenic human myelin oligodendrocyte glycoprotein (MOG)-35-55 peptide, was recently shown to be safe and well tolerated in a phase I clinical trial in MS. To evaluate the opposing biological effects of four- versus two-domain MHC-II structures, we screened phage Fab antibodies (Abs) for the neutralizing activity of RTL1000. Five different TCR-like Abs were identified that could distinguish between the two- versus four-domain MHC–peptide complexes while the cognate TCR was unable to make such a distinction.