The latter proteins not only link transmembrane TJ/AJ proteins an

The latter proteins not only link transmembrane TJ/AJ proteins and the actin cytoskeleton but also take part in intracellular signaling (Gonzalez-Mariscal et al., 2003). TJs are composed of the integral transmembranous proteins, occludin, claudins, and junctional adhesion molecules (JAMs), while vascular endothelium cadherin (Ve-cadherin) is the major transmembrane protein of endothelial AJs. Transmembrane proteins of TJs are

connected to the actin cytoskeleton by TJ-anchoring proteins, zonula occludens proteins ZO-1, ZO-2, and ZO-3 (Fig. 1). Infections are quite common, but why do we BAY 57-1293 cell line only see infections of the CNS in rare occasions? One major factor is the special barrier BBB and its building blocks BMECs. BMECs and normal ECs differ from each other in functional and structural terms. Some of these differences are with respect to cytokine and growth-related molecules, stress-related proteins, metabolic enzymes, and signal transduction proteins (Lu et al., 2007). Several TJ proteins, Doxorubicin cell line including occludin, claudin-1, claudin-3, claudin-5, claudin-12, JAM-A, JAM-B, JAM-C, endothelial cell-selective adhesion molecule, ZO-1, ZO-2, cingulin, 7H6 antigen, and PAR-3, are expressed differentially in BMECs and peripheral vascular ECs (Nagasawa et al., 2006). For example, claudin-1, claudin-4, claudin-5, claudin-7, and

claudin-8 are less abundant in BMECs than in gut ECs; VCAM, ICAM-1, and E-selectin are induced in lower extent than in HUVEC; and the expression of endothelial nitric oxide synthase and ICAM-1 (approximately 30-fold) is lesser than in pulmonary ECs (Panes et al., Reverse transcriptase 1995; Stevens et al., 2001). Occludin and Ve-cadherin are expressed

much higher in BMECs compared to non-neuronal ECs (Hirase et al., 1997; Stevens et al., 2001). Similarly, researchers observed high abundance of Lutheran membrane glycoprotein (Shusta et al., 2002), CD46 complement regulator, and autoantigen Ro52 (Shusta et al., 2002)as well as relatively low expression of P-selectin and tissue factor pathway inhibitor on BMECs (Bajaj et al., 1999; Solovey et al., 2004). It is interesting to note that BMECs express unique cell surface glycoproteins that are not found on other ECs, such as the cerebral cell adhesion molecule, LK48, BBB-specific anion transporter 1, angiogenic factors (vascular endothelial growth factor, follistatin, fibroblast growth factor 1 and 5), and CXC chemokines with Glu-Leu–Arg motifs (epithelial cell-derived neutrophil-activating peptide 78 and growth-regulated oncogene-α) (Grab et al., 2005). BMECs interact dynamically with neighboring cells, astroglia, pericytes, and microglia that contribute to their unique characteristics. Despite the fact that astrocytes envelop more than 99% of the BBB endothelium, they are not directly involved in the physical properties of BBB (Hawkins & Davis, 2005).

It has been

It has been Selleckchem KU-60019 suggested that multifunctional CD4+T cells, able to produce simultaneously IFN-γ, IL-2 and TNF-α, are associated with protective immunity or a beneficial outcome in chronic infectious diseases, such as HIV [25–28] and HCV [29]. We therefore evaluated the quality of Th1 responses

induced by LbAg and LaAg in healed CL patients, based on their ability to secrete these three major Th1-related cytokines at the single-cell level. Using multiparametric flow cytometry, seven distinct populations of cytokine-producing cells can be delineated based on any of the possible combinations of IFN-γ+, IL-2+ and TNF-α+ producers, and the relative frequency of these distinct populations defines the quality of the Th1 response. The percentages of cytokine-producing cells were shown to be higher in the healed CL patient group than in healthy controls, and we were able to observe statistically significant differences between those groups for triple-positive (3+) multifunctional https://www.selleckchem.com/products/MDV3100.html T cells (with both LbAg and LaAg), IFN-γ single-positive cells after LaAg stimulation and for IFN-γ+IL-2+ cells stimulated with LbAg (Fig. 2a). When comparing the quality of the Th1 response elicited by each Leishmania antigen evaluated we could observe that LbAg induces significantly higher percentages of multifunctional CD4+T cells and

IFN-γ+IL-2+ cells than LaAg stimulation in the healed CL patient group (Fig. 2a). The quality of the Th1 response was also evaluated by analysing the contribution of each phenotype in the total Th1 response, and is represented pictorially by pie charts (Fig. 2b). This kind of representation demonstrates clearly that LbAg induced a major proportion of multifunctional CD4+T cells (in red – 28% of the total Th1 response evaluated) and double-positive CD4+T cells MG132 (in blue – comprising 44% of the total Th1 response), while LaAg induced

predominantly single-positive cells (68%). More than half of the single-positive cells induced by LaAg were IFN-γ single-positive. In the control group, the majority of responsive cells were single-positives (>60%), and no major differences were observed concerning LbAg and LaAg stimulation. Having shown that LbAg induced higher cytokine production by CD4+T cells than LaAg in healed CL patients (Fig. 1b), we also investigated the relative cytokine concentrations produced by all distinct Th1 phenotypes induced by LbAg and LaAg, measured as the geometric MFIs. The highest MFI values for all three cytokines were found among triple-positive multifunctional CD4+T cells (both after LbAg and LaAg stimulation) (Fig. 2c) and a progressive decrease in the MFIs for all cytokines was observed as the degree of functionality decreased (3+ to single-positives). MFIs for IFN-γ and IL-2 from multifunctional T cells stimulated with LbAg were significantly higher than those obtained after LaAg stimulus (Fig. 2c).

Finally, the actin-bundling protein LPL induces

the requi

Finally, the actin-bundling protein LPL induces

the required F-actin rigidity for receptor stabilization. Thus, recruitment of LPL to the IS is crucial for sustained LFA-1 cluster formation within the IS. LPL associates with LFA-1 in unstimulated and stimulated T cells. Therefore, LPL may stabilize LFA-1 in its localization in both situations. A similar mechanism was suggested for avidity regulation by F-actin 32. Whether LPL is also https://www.selleckchem.com/products/Decitabine.html involved in the active transport of LFA-1 or whether LFA-1 moves through diffusion to the contact zone is currently unknown. In addition to LPL, Talin is one candidate that associates with LFA-1 1, 33. Whether LPL acts in concert with Talin is not known at present. However, in LPL knock-down T cells the relocalization of Talin in the contact zone was severely disturbed, indicating that Talin acts downstream of LPL. It is tempting to speculate that calmodulin regulates LFA-1 localization in the IS by stabilizing LPL. Interestingly, LPL binds to calmodulin only in the presence of EGTA, whereas calcium

even inhibits this interaction. These results suggested a binding to calcium-free calmodulin (ApoCalmodulin) 27. However, the exact mechanisms of LPL/calmodulin interaction in vivo remains to be determined. Nevertheless, up to now, only very little was known about the 5-Fluoracil in vitro function of calmodulin for T-cell polarization. It was demonstrated that calmodulin regulates the myosin light chain kinase 34, 35. Antagonizing calmodulin led to a reduction in cell spreading and migration on surface coated ICAM-1 34. This finding supports our results demonstrating that calmodulin antagonists reduce the T-cell/APC interface. In addition, our data provide evidence for an unusual function of calmodulin by introducing a direct connection of calmodulin with LFA-1 cluster stabilization during T-cell activation. The TCR/CD3 complex migrated to the IS independent of LPL expression. This Thiamet G difference is likely caused by the fact that CD3 does not bind to LPL and uses distinct linkers to the actin cytoskeleton. Note that the superantigens used to

stimulate PBT represent rather strong stimuli and bind outside the peptide-binding groove. So far, we cannot judge whether TCR/CD3 recruitment to the IS through (weak) agonistic peptide-antigens would be influenced in a different way. Taken together, we introduced new proteins that are important for the sustained – but not initial – accumulation of LFA-1 in the mature IS, i.e. LPL and calmodulin. The combined functions of these two proteins control the size, molecular composition and duration of the T-cell/APC interface, which is fundamental for the activation of T cells. These findings might also be relevant for other actin-dependent functions that require receptor polarization, e.g. cell migration and/or extravasation.

melitensis In this work, we use as a clumping strain a B melite

melitensis. In this work, we use as a clumping strain a B. melitensis 16M strain overexpressing aiiD (an AHL-acylase that destroys the QS signal molecules) called MG210. The characterization of the clumps produced by this strain allowed us to demonstrate the presence of exopolysaccharide(s), DNA and OMVs, three classical components of extracellular matrices. Copanlisib Moreover, here, we provide the first structural information on the complex exopolysaccharide produced by B. melitensis 16M since we found that its molecular weight is about 16 kDa and that it is composed of glucosamine, glucose and mostly mannose. In addition, we found the presence of 2- and/or 6- substituted

mannosyl residues, which provides the first insights into the linkages involved in this polymer. We demonstrate that the MG210 strain displays increased adherence properties both on polystyrene and on HeLa cell surfaces. Taken together, our data reinforce the evidences that B. melitensis could form biofilms in its lifecycle. All the strains

and plasmids used in this study are listed in Table 1. Brucella strains were grown with shaking at 37 °C in 2YT medium (10% yeast extract, 10 g L−1 tryptone, 5 g L−1 NaCl) containing appropriate antibiotics from an initial OD600 nm of 0.05. The Escherichia coli DH10B (Gibco BRL) and S17-1 strains were grown in Luria–Bertani medium with appropriate Lumacaftor datasheet antibiotics. Chloramphanicol and nalidixic acid were used at 20 and 25 μg mL−1, respectively. For exopolysaccharide purifications, Brucella were grown in RPMI 1640 medium supplemented with 10 g L−1 of d-xylose and appropriate antibiotics. DNA manipulations were performed according to standard techniques (Ausubel et al., 1991). Restriction enzymes were purchased from Roche, and primers were purchased from Invitrogen. Derivatives of the replicative plasmids pRH001 and pRH002 17-DMAG (Alvespimycin) HCl (Hallez et al., 2007) harboring aiiDsuis or aiiDmelitensis were constructed using the Gateway technique (Invitrogen). The destination

vectors pRH001 and pRH002 harbor a chloramphenicol resistance (cat) marker and the toxic cassette ccdB. This group of genes is flanked by attR1 and attR2 recombination sites. The wild-type allele corresponding to the total AiiD protein of Brucella suis (amino acids 1–761) was amplified with primers AiiD-B1 (5′-ATGAACGTCGCGAGTGCC-3′) and AiiD-B2 (5′-AAGATGGCTGCATAATC-3′). The wild-type allele corresponding to the total AiiD protein of B. melitensis (amino acids 1–782) was amplified with primers AiiD-B3 (5′-ATGAACGTCGCGAGTGCC-3′) and AiiD-B4 (5′-AAGATGCCTGCATAATCAGG-3′). Brucella melitensis 16M genomic DNA was used as the template for all amplifications. The resulting PCR products (aiiDsuis and aiiDmelitensis, respectively) were cloned into pDONR201 (Invitrogen Life Technologies) by the BP reaction as described previously (Dricot et al., 2004).

[34] The misclassification of ectopy may also explain the discrep

[34] The misclassification of ectopy may also explain the discrepancy of findings across studies due to the lack of standardized criteria in

addition to variations in age and parity of participants. One of the most important methodological limitations selleck products of cross-sectional data is the imprecision of the timing of cervical ectopy in relation to HIV acquisition, which can introduce bias. Hence, studies have often been unable to assess the appearance of the cervix at the time of HIV acquisition.[12, 26] If cervical ectopy facilitates HIV acquisition and transmission, then it is important to identify other factors that influence the development of ectopy. Prior studies have noted an association between hormonal forms of contraception, primarily oral contraceptive pills, and the injectable depot medroxyprogesterone acetate, with increased ectopy[12]; this effect is likely mediated by the influence of estrogen on columnar epithelium.[5, 9, 35] Additionally, C. trachomatis has been shown to preferentially infect columnar cells, and hence, ectopy may increase exposure of susceptible cells to infection.[4]

C. trachomatis increases the susceptibility to acquiring HIV infection in women.[36] The interrelationships between cervical ectopy, hormonal contraception, C. trachomatis, and HIV are important selleck inhibitor to discern in young women, given that cervical ectopy, hormonal contraception use, and C. trachomatis are highly prevalent in this population. Additional mechanisms by which the cervical mucosa can be disrupted include Papanicolaou smears, trauma during sexual intercourse, as well as certain intravaginal practices by women in certain social settings. Because human studies cannot ethically

be designed to demonstrate HIV acquisition with or without find more cervical ectopy, animal studies or ex vivo studies (i.e., explants, tissues samples) may provide the data to arrive at this causal association. Future studies would need to be mindful of additional confounding factors that could affect HIV acquisition, including STIs, ulcerative lesions, phase of menstrual cycle, inflammation, bacterial vaginosis, exudate, and alcohol use (see Table 2). It is difficult to reconcile the divergent results of observational studies assessing the impact of cervical ectopy on the increased risk of HIV acquisition. Ectopy is difficult to measure, and even when present, it is difficult to interpret. A recent review study did not find any evidence for the routine treatment of cervical ectopy.[37] Given that cervical ectopy is a common feature of the immature cervix, this may contribute to the disproportionate risk of HIV infection faced among young sexually active women in resource-limited settings, particularly in the hyperendemic regions of sub-Saharan Africa.

Several studies demonstrated that polarization

Several studies demonstrated that polarization click here of Th17 cells, in addition to Th1 cells, can profoundly accelerate the perpetuation of IBD.[18] On the contrary, switching of a Th1/Th17 profile to the enhancement of Treg cells or inhibition

of Th17 polarization is beneficial for restraining immune response and ameliorating intestinal inflammation.[19-21] The immunophilin ligand sirolimus, a macrolide antibiotic produced by Streptomyces hygroscopicus, exhibits potent immunosuppressive properties and is used therapeutically in countering autoimmunity and preventing allograft rejection.[22, 23] Specific inhibition by sirolimus of the serine/threonine protein kinase mammalian target of rapamycin (mTOR) in T cells blocks co-stimulation and cytokine-induced signalling but allows T-cell receptor-mediated signal transduction.[24] Consequently, sirolimus promotes T-cell anergy and deletion.[25, 26] Unlike other commonly used immunosuppressants, such as cyclosporine A and FK506, sirolimus does not appear to interfere with tolerance induction[27, 28] and permits the in vitro proliferation and suppressive function of Treg cells.[29, 30] Whether sirolimus influences the imbalance between Th17 and Treg cells in the development of IBD, however, has not been fully elucidated. In this study, we investigated the immunomodulatory effect of sirolimus in a 2,4,6-trinitrobenzene

BYL719 supplier sulphonic acid (TNBS) -induced murine colitis model. We also explored the potential mechanisms involved, especially in the balance of Treg and Th17 cells. Male BALB/c mice (8–10 weeks old) were purchased from the Center of Experimental Animals of Guangdong Province, and maintained at an animal facility under pathogen-free conditions. All studies involving mice were approved by the Guangdong Pharmaceutical University Animal Care and Use Committee. Colitis was induced by administration of TNBS in mice at day 0 as described previously.[31] In brief, mice were anaesthetized lightly, and a 3·5-F catheter was inserted intrarectally to 4 cm proximal to the anus. To

induce colitis, 120 μl 2·5 mg TNBS (Sigma-Aldrich, St Louis, MO) in 50% ethanol was injected slowly into the lumen via the catheter. Control PDK4 mice received the same volume of 50% ethanol alone. To study the therapeutic effect of sirolimus, 1·25 mg/kg sirolimus (LC Laboratories, Woburn, MA) was administered intraperitoneally for three consecutive days starting at day 0 after TNBS administration. Animals were monitored daily for appearance of diarrhoea, loss of body weight and survival. The disease activity index was used to assess the grade of colitis based on a previously published scoring system by Reinecke et al.[31] All of the mice were killed at the indicated time after administration of TNBS. Colonic morphology was evaluated as a gross indicator of colitis.

No matter what the aims of the application are, the antibody’s bi

No matter what the aims of the application are, the antibody’s binding characteristics will still be the main features determining

the assay’s reliability. Here, we describe a protocol for determination of antibody-binding epitopes using an antigen-focused, library-based approach where library members are generated by fragmentation of antigen DNA buy Birinapant and presented as cloned peptides on the cell surface of the Gram-positive bacterium Staphylococcus carnosus. The rigid cell structure of this organism allows for multivalent expression and permits rapid library analysis and sorting of antibody-binding cells using flow-sorting devices. Epitopes are determined by DNA sequencing of the sorted cells and alignment back to the antigen sequence. The protocol described here has been shown useful for mapping of both monoclonal and polyclonal binders with varying epitope lengths. Curr. Protoc. Immunol. 90:9.9.1-9.9.17. © 2010 by John Wiley & Sons, Inc. “
“Division of Molecular Virology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden Depletion of Foxp3+CD4+

regulatory T cells (Treg) in adults results in chronic inflammation and autoimmune disease. However, the impact of transient Treg-cell depletion on self-reactive responses is poorly defined. Here, we studied the effect of transient depletion of Treg cells on CD4+ T-cell responses to endogenous self-antigens. BMN 673 Short-term ablation of Treg cells in mice resulted in rapid activation of CD4+ T cells, increased percentage of IFN-γ+ and Th17 cells in lymphoid organs, and development of autoimmune gastritis. To track self-reactive responses, we analyzed the activation of naïve gastric-specific CD4+ T cells. There was a dramatic increase in proliferation and acquisition of effector function of gastric-specific T cells in the stomach draining LNs of Treg-cell-depleted

mice, compared with untreated mice, either during Treg-cell depletion or after Treg-cell reconstitution. Moreover, the hyperproliferation of gastric-specific T cells in the 5-Fluoracil manufacturer Treg-cell-ablated mice was predominantly antigen-dependent. Transient depletion of Treg cells resulted in a shift in the ratio of peripheral:thymic Treg cells in the reemerged Treg-cell population, indicating an altered composition of Treg cells. These findings indicate that transient Treg-cell depletion results in ongoing antigen-driven self-reactive T-cell responses and emphasize the continual requirement for an intact Treg-cell population. “
“IL-2 plays a critical role in the induction and maintenance of FoxP3-expressing regulatory T cells (FoxP3+Tregs). Reduced expression of IL-2 is linked to T-cell-mediated autoimmune diseases such as type 1 diabetes (T1D), in which an imbalance between FoxP3+Tregs and pathogenic T effectors exists.

After incubating at 37°C and 5% CO2 for 48 h, 1 μCi 3H-thymidine

After incubating at 37°C and 5% CO2 for 48 h, 1 μCi 3H-thymidine (Amersham) was added to each well. The cultures were harvested 18 h later and then processed for measurement of incorporated radioactivity in a liquid scintillation counter. The inhibitors of NO, 200 uM L-NMMA; arginase, 40 uM nor-NOHA (NW-hydroxyl-nor-l-arginine) (Calbiochem); or ROS scavenger, 5 mM NAC (N-acetyl l-cystein) (Sigma) were added at the beginning of the culture. One million of SCs or IHLs were incubated in 1%

FBS Vincristine molecular weight 1% BSA in PBS with the relevant Abs. Intracellular cytokine staining [48], nitrotyrosine staining [35], and detection of CD107a (BioLegend) [49] were made as previously described. For iNOS detection, splenocytes were cultured and stimulated with Con A (5 mg/mL) for 48 h. Then, cells were stained with allophycocyanin-anti-CD11b (clone M170) and PE-anti-Gr1, fixed, permeabilized with Cytofix/Cytoperm buffer, and were incubated with rabbit

polyclonal anti-iNOS Ab (BD Bioscience). After washing, samples were examined using BD FACS Canto II flow cytometer (BD Biosciences). The Abs conjugated were allophycocyanin-anti-Ly6G/Ly6C (Gr-1, clone RB6–8C5), PE-anti-Ly6G (clone 1A8), FITC-anti-Ly6C (clone AL-21) (BD Bioscience), allophycocyanin-anti-CD4 (clone GK1.5)(BioLegend), PE-anti-CD8 (clone 53-6.7), PE-anti-IL6 (MP5-20F3), PE-anti-IFNγ (XMG1.2,), buy Saracatinib PE-anti-IL-17A (clone eBio17B7) (eBioscience), and anti-Phospho-Stat3 (Tyr705)(clone D3A7) (Cell Signaling). Oxidation-sensitive dye DCFDA (Molecular Probes/Invitro-gen), was used to measure ROS production [27]. Cytokine levels were determined by ELISA sandwich for detecting TNF-α, IL6, and IFN-γ (eBioscience) in plasma and in culture supernatants from sorted MDSCs cultured in supplemented RPMI 1640 at 24 h. Splenocytes were cultured

with ConA for 48 h, fixed in 4% paraformaldehyde, blocked with PBS-BSA Chloroambucil 1% and labeled with allophycocyanin-anti-CD4, PE-anti-CD8, and Alexa Fluor 488-anti-NT and visualized using FV1000 (Olympus) confocal microscope. Sorted CD11b+Gr1+ were put on a slide by the citospin technique and were stained with DNA-binding fluorochrome Hoechst 33 258 (2 ug/mL) and FITC-anti-phosphoSTAT3. Slides were observed with a NIKON ECLIPE Microscope. Purified MDSCs were washed and lysed (1% Triton X-100, 0.5% sodium deoxicholate, 9% SDS, 1 mM sodium ortovanadate, and 10 g PMSF in PBS). Aliquots of tissue lysates, were separated on a 10% SDS-PAGE and transferred to nitrocellulose membranes. After blocking, they were incubated with rabbit polyclonal Ab anti-p47phox (Santa Cruz) followed by HRP-anti-rabbit Ab (Sigma) and assayed using the ECL chemiluminescent system. Protein loading was visualized by anti-actin Ab (Santa Cruz). Experimental differences over the controls were analyzed with the Student’s t-test and nonparametric test and differences with p-value of <0.

g , van der Fits, Otten, Klip, van Eykern, & Hadders-Algra, 1999;

g., van der Fits, Otten, Klip, van Eykern, & Hadders-Algra, 1999; Hopkins & Rönnqvist, 2002; Rochat & Goubet, 1995; Rochat, Goubet, & Senders, 1999; Shumway-Cook www.selleckchem.com/products/EX-527.html & Woollacott, 2001; Thelen & Spencer, 1998). Infants first begin to develop the motor skills that serve as the foundation for reaching at around 4–5 months of age. These early reaching attempts are characterized by a lack of control in the form of flailing and corrective movements, are often performed with both hands, and are limited to supine or supported

sitting postures because infants cannot yet reach while sitting independently (Corbetta & Snapp-Childs, 2009; von Hofsten, 1991; Thelen et al., 1993; White, Castle, & Held, 1964). New sitters support their weight with their arms, causing them to topple over if they let go to reach for an object (Rochat & Goubet, 1995). In a supine or otherwise supported position, 5-month-olds increase their chances of making contact Panobinostat cell line with an object using a bimanual reach where they approach the object with both hands from either side (Rochat, 1992), but with supplementary postural support to the pelvic girdle and

upper legs or trunk, nonsitters can be induced to carry out more mature reaches, moving just one hand to the object (Hopkins & Rönnqvist, 2002; Marschik et al., 2008). Unimanual reaching increases around 5–6 months of age (Fagard, 1998). Between 6 and 7 months, infants demonstrate two aspects of bimanual role differentiation (e.g., Fagard, Spelke, & von Hofsten, 2009; Kimmerle, Mick, & Michel, 1995). One aspect is related to the characteristics of the target of the reach. For example, infants begin to differentiate between large target objects that require both hands to grasp ID-8 and small ones that they can obtain with one hand. The second aspect of bimanual role differentiation is related to the functional roles of the two hands. Infants’ reaching and their ability to manipulate objects mature as they use their hands in

complementary roles, such as supporting an object with one hand while manipulating it with the other (Bojczyk & Corbetta, 2004; Fagard, 1998, 2000; Karniol, 1989; Kimmerle et al., 1995; Ramsay & Weber, 1986). At 7 months, infants begin to display stabilized, relatively nonvariable reaching patterns, and show signs of modifying their reaching according to the context (Clearfield & Thelen, 2001). Aside from the direct relationship between the motor control required for infants to stabilize their bodies without support and having their arms free to reach (c.f., Bertenthal & von Hofsten, 1998; Spencer, Vereijken, Diedrich, & Thelen, 2000), other work has demonstrated a relationship between reaching behavior and change in posture that demonstrate an interconnectedness of the motor system (c.f., Babik, 2010; Berger, Friedman, & Polis, 2011; Corbetta & Bojczyk, 2002; Goldfield, 1989; Thurman, Corbetta, & Bril, 2012).

A total of 157 peptides were

found to bind to one of the

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 GS-1101 datasheet (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 Maraviroc concentration 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 PD184352 (CI-1040) 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.