5 It is involved in regulating a range of functions including pha

5 It is involved in regulating a range of functions including phagocytosis, cell adhesion and migration.6–8 CD47 was also found to be a receptor for the extracellular matrix protein thrombospondin,6 and to function as the ligand for signal regulatory protein α (SIRPα/CD172a).7,9 CD172a

is a cell surface immunoglobulin superfamily member expressed by most myeloid cells, but also by non-haematopoietic cells such as vascular endothelial cells selleck compound and smooth muscle cells.10,11 The cytoplasmic tail of CD172a contains immunoreceptor tyrosine-based inhibitory motifs that, upon phosphorylation, are able to recruit the tyrosine phosphatases SHP-1 or SHP-2. These phosphatases in turn modulate phagocytosis, cell migration and cellular responses to growth factors and other soluble signalling molecules.12 Not only interaction between CD47 and CD172a, but also integrin-mediated cell adhesion,10,11 leads to phosphorylation of the CD172a immunoreceptor tyrosine-based inhibitory motifs and regulation of these cellular functions. Blood monocytes, macrophages, granulocytes and Palbociclib cell line CD11b+ (CD4+) DC express CD172a.13,14 The expression of both CD47 and CD172a has recently been shown to be required for the homeostasis of CD11b+ DC in lymphoid organs,15 and also to regulate migration of this DC subset from skin to the draining

lymph nodes (LN).13,14,16 In intestinal tissues, CD172a–CD47 interactions are also required for the regulation of eosinophil degranulation and homeostasis.17 CD47 is crucial for cellular recruitment to sites of intestinal inflammation, as mice lacking CD47 (CD47−/−) fail to recruit CD172a+ CD11c+ cells to the gut and are therefore protected from trinitrobenzenesulphonic acid-induced colitis.18 Moreover, CD47 has been demonstrated to negatively regulate inducible Foxp3+ T regulatory cells expressing CD103, resulting in increased proliferation and accumulation of the T regulatory cells with age in CD47−/− mice.19 However, the role of CD47 in both the induction of immune responses following oral immunization with adjuvants and the maintenance of oral tolerance has not been investigated. In this study we use CD47−/− mice to

explore the role of CD47 and gut-associated lymphoid tissue (GALT) -resident CD172a+ antigen-presenting cells in the induction of oral tolerance and PAK5 following immunization with the adjuvant CT. We observe that CD47−/− mice exhibit reduced total cell numbers selectively in the GALT. In addition, we show that the frequency of CD11b+ CD172a+ DC is reduced by 50% in the small intestine and draining mesenteric lymph nodes (MLN) but not in the Peyer’s patches (PP). Although MLN are required for oral tolerance induction, CD47−/− mice maintain this capacity despite their diminished cell numbers. In contrast, production of antigen-specific intestinal IgA following oral immunization is significantly reduced in CD47−/− mice, although normal antigen-specific systemic IgG and total IgA levels are maintained.

We find no predilection or predisposition towards an accompanying

We find no predilection or predisposition towards an accompanying TDP-43 pathology in patients with FTLD-tau, irrespective of presence or absence of MAPT mutation, or that genetic changes associated Napabucasin mw with FTLD-TDP predispose towards excessive tauopathy. Where the two processes coexist, this is limited and probably causatively independent of each other. “
cases of primary hydrocephalus. Hyh mice, which exhibit either severe or compensated long-lasting forms of hydrocephalus, were examined and compared with wild-type mice. TGFβ1, TNFα and TNFαR1 mRNA levels were quantified using real-time PCR. TNFα and TNFαR1 were immunolocalized in the brain tissues of hyh mice and four hydrocephalic human

foetuses relative to astroglial and microglial reactions. The TGFβ1 mRNA levels were not significantly different between hyh mice exhibiting severe or compensated hydrocephalus and normal mice. In contrast, severely hydrocephalic mice exhibited four- and two-fold increases in the mean

levels of TNFα and TNFαR1, respectively, compared with normal mice. In the hyh mouse, TNFα and TNFαR1 immunoreactivity was preferentially detected in astrocytes that form a particular periventricular reaction characteristic of hydrocephalus. However, these proteins were rarely detected in microglia, which did not appear to be activated. TNFα immunoreactivity was also detected in the glial reaction in the small Angiogenesis inhibitor group of human foetuses exhibiting hydrocephalus that were examined. In the hyh mouse model of congenital hydrocephalus, TNFα and TNFαR1 appear to be associated with the severity of the disease, probably mediating the astrocyte reaction, neurodegenerative processes and ischaemia. “
“Frontotemporal lobar degeneration (FTLD) is classified mainly into FTLD-tau and FTLD-TDP according to the protein present PAK6 within inclusion bodies. While such a classification implies only a single type of protein should be present, recent studies have demonstrated dual tau and TDP-43 proteinopathy can occur, particularly in inherited FTLD. We therefore investigated 33 patients with

FTLD-tau (including 9 with MAPT mutation) for TDP-43 pathological changes, and 45 patients with FTLD-TDP (including 12 with hexanucleotide expansion in C9ORF72 and 12 with GRN mutation), and 23 patients with motor neurone disease (3 with hexanucleotide expansion in C9ORF72), for tauopathy. TDP-43 pathological changes, of the kind seen in many elderly individuals with Alzheimer’s disease, were seen in only two FTLD-tau cases – a 70-year-old male with exon 10 + 13 mutation in MAPT, and a 73-year-old female with corticobasal degeneration. Such changes were considered to be secondary and probably reflective of advanced age. Conversely, there was generally only scant tau pathology, usually only within hippocampus and/or entorhinal cortex, in most patients with FTLD-TDP or MND.

Finally, we examined the biological effects of JAK inhibition usi

Finally, we examined the biological effects of JAK inhibition using OA synovial fibroblasts. As shown in Fig. 5, phospho-JAK-2 staining was observed in monocyte-like cells and phospho-JAK-3 was observed in infiltrating mononuclear

cells into rheumatoid synovial tissues. Whereas phospho-JAK-2 Ipatasertib staining was barely detected in synovial tissues isolated from OA patients. When synovial fibroblasts isolated from OA synovial tissues were stimulated with OSM, phosphorylation of JAK-1/-2/-, as well as STAT-1/-3/-5, was observed. CP-690,550 or INCB028050 pretreatment efficiently blocked OSM-induced JAK-1/-2/-3 and downstream STAT-1/-3/-5 phosphorylation (Fig. 6). Several JAK inhibitors are currently in development for therapy of RA [23]. JAK-3 expression is restricted to immune cells, and selective JAK-3 inhibition thus represents a potential new strategy for immunosuppression [10]. The clinical efficacy of CP-690,550 for treating RA suggests

that targeting JAK-3 is useful for suppressing autoimmune, as well as inflammatory diseases [7]. The inhibition of JAK-3 signalling in lymphocytes has been the main EGFR phosphorylation focus of research [24], and little is known about the effects of JAK inhibitors on the innate immune system. In addition to myeloid cells, such as lymphocytes and monocytes, rheumatoid synovial fibroblasts have also been shown to express phospho-JAK-3 PIK3C2G in vivo. OSM, an IL-6-type proinflammatory cytokine, is a multi-functional cytokine affecting the growth and differentiation of numerous cell types [25]. It is produced by activated T lymphocytes and monocytes, and can induce the expression of various proinflammatory molecules [26]. It is present in the synovial fluid of RA patients and has been implicated in rheumatoid synovitis [27]. OSM had been shown to activate JAK and STAT pathways in primary human rheumatoid synoviocyte systems [18]. However, the mechanisms resulting in JAK activation and the downstream signalling events whereby active STATs may lead to rheumatoid

inflammatory processes are still unclear. Because OSM is likely to play a role in rheumatoid inflammation, we used this cytokine to analyse the mechanisms by which cytokine signalling contributes to inflammatory cascades, and to establish the feasibility of using JAK inhibitors to control inflammation. Previous reports suggested a role for CP-690,550-mediated T cell signalling blockade [28]. It is also possible that inhibition of non-lymphoid cells, such as synovial cells, may contribute to the efficacy of JAK inhibitors. Using a primary rheumatoid synovial fibroblast culture system, we investigated the effects of specific JAK inhibition on proinflammatory signalling.

Here there

Here there find more will need to be ‘reverse translation’, because immune parameters are analysed rarely on peripheral blood and correlated with successful prevention (or lack thereof) of diabetes on an individual basis in murine studies. Surprisingly, two recent trials (Andromeda’s heat shock protein peptide

p277 and Bayhill’s proinsulin expressing DNA vaccine BHT3021; Table 4) reported positive outcomes, even in the more stringent recent-onset diabetes setting, by preserving C-peptide at certain dosing regimens. These observations exceeded expectations based on animal studies, where both strategies were only effective in preventing diabetes but not in reversing hyperglycaemia.

It will be important to explore whether, in either trial, immunological selleckchem outcomes were associated with better preservation of C-peptide and thus could perhaps pave the way in future for using such immunological end-points in staging as entry criteria, or to optimize dosing in larger trials, prior to embarking on the more arduous, expensive and time-consuming prevention trials. Recent, seminal lessons from studies on pancreatic tissue of type 1 diabetic donors provide compelling proof of the autoimmune nature of type 1 diabetes; in particular, the demonstration of β cell autoantigen-specific CD8 T cells in destructive insulitic

lesions has highlighted a link that had not emerged in 2007. Interleukin-2 receptor The persistence of β cells and insulin production as well as inflammatory insulitic lesions many years after clinical manifestations of hyperglycaemia are also arresting, providing an apparent disconnect between β cell mass and function. These studies also emphasize differences in immunopathology between men and mice; provide evidence of pathological and aetiological heterogeneity [43-49]; and provide potential new biomarkers and therapeutic targets centred on CD8 T cell biology [50-53] that were not envisaged at the time of our last review(Fig. 3). Importantly, the ‘biomarker concept’ that has become a critical piece of new drug development in the pharma industry has also begun to feature strongly in current thinking about type 1 diabetes therapies [5]; the term was not even used in the previous paper [1]. There is probably more new insight to be gained from studying the diabetic pancreas in settings such as nPOD. For example, the observation that the remaining β cell mass at clinical manifestation of disease may be substantial (as much as 50%, rather than 10–20% cited in most textbooks) disproves a common assumption that the disease process has always reached an end-stage at this point.

27 The reduced plasma volume may be explained by the capillary le

27 The reduced plasma volume may be explained by the capillary leak syndrome and volume redistribution into the extracellular space, as there is no reduction in extracellular fluid volume.28 Therefore, the elevation in blood pressure may be more closely related to endothelial dysfunction and later, vasoconstriction rather than any direct effect of the RAAS.11 Alternative locally vasoactive compounds such as endothelin, nitric oxide inhibition, oxidative stress or cytokines have been implicated as vasoconstrictors in preeclampsia but www.selleckchem.com/products/Y-27632.html are not proven.29 The use

of antioxidants in humans has not been shown to treat or prevent preeclampsia.30 Interest in the endothelial cell integrity provided by angiogenic factor vascular VEGF (vascular endothelial growth factor) in pregnancy and its potential role in preeclampsia are not new.31,32 There was a resurgence in interest in angiogenic molecules after the elegant demonstration of a mechanistic role for the soluble VEGF receptor, soluble fms-like tyrosine kinase-1 (sFLT-1)33 in preeclampsia. The infusion of sFLT-1 in pregnant rodents induced

find more hypertension and proteinuria in pregnancy. The pathological feature of renal biopsies in this model is endothelial disruption similar to that seen in human preeclampsia. The same renal lesion, however, was seen in non-pregnant animals, thus providing evidence of direct renal toxic effect of sFLT-1. The specificity of this pathological mechanism in pregnancy rests with the placenta as the likely site of production. Zhao et al. have demonstrated a net increase in sFLT-1 binding in human renal tissue in preeclampsia.34 We and others have shown that the likely source of the sFLT-1 is acute placental ischaemia35,36 and that the effect of ischaemia and sFLT-1 on the renal capillary loops mimic those seen in human de novo disease (Fig. 1). The clinical importance of the increased sFLT-1 in humans

was demonstrated subsequently Bacterial neuraminidase in a longitudinal retrospective study. It was found that the maternal circulating sFLT-1 was significantly increased in women who were to develop preeclampsia later in the pregnancy. The elevation in sFLT-1 was noted about 5–6 weeks prior to the onset of clinically apparent disease.37 The correlation of high sFLT and low binding proteins VEGF and its co-agonist placental growth factor (PlGF) confirm the binding activity of the sFLT-1. The relative reduction in free VEGF (resultant from the increased sFLT-1) has a potentially important role in mediating the renal involvement in preeclampsia as outlined above. Other recently identified toxins in preeclampsia such as soluble endoglin38 do not appear to be a direct glomerular cell toxins,39 at least in animal studies where its effect is most potent in the presence of sFLT-1.

While the factors that cause preeclampsia are unclear, placental

While the factors that cause preeclampsia are unclear, placental ischemia, which can be initiated as a result of insufficient trophoblastic invasion of uterine spiral

arteries, as well as impaired placental blood flow, is central to the disorder [83, 89, 97, 156]. As a result of underperfusion in the latter half of gestation, the placenta releases many factors which contribute to the multifaceted maternal syndrome, including endothelial dysfunction (reviewed in [50]). Angiogenic growth factors play a central role in normal fetal and placental vascular development. VEGF is an important endothelial-cell-specific growth factor expressed in numerous tissues including the placenta [12, 24]. It promotes angiogenesis by binding to two receptor tyrosine kinases, VEGF receptor 1 and VEGF receptor 2 (reviewed in [44]). It is also an important permeability factor due to its ability to induce vascular leakage [26, 27]. VEGF expression is induced PXD101 price by various growth factors [39, 106, 109], inflammatory cytokines [25, 61, 112], and hypoxia [128]. In early pregnancy, vascular development and permeability in the endometrium, placenta, and embryo are modulated by VEGF [19, 36, 137]. Furthermore, VEGF has been found in the serum of pregnant women throughout gestation and is believed to play a role in modification of the maternal systemic vasculature by inducing the production of the vasodilators

NO and prostacyclin (PGI2) second by endothelial cells [43, LDE225 58, 152, 151]. PIGF is an angiogenic factor within the VEGF family which interacts with VEGF receptor 1 and Nrp-1 (reviewed in [140]). It functions independently or as a heterodimer with VEGF and is strongly expressed in the placenta, where it is an important facilitator of angiogenesis [18, 24]. Like VEGF, PlGF is a powerful vasodilator and may be involved in the reduction of peripheral vascular resistance during pregnancy [99]. The concentration of circulating PlGF is significantly

lower in women with preeclamptic pregnancies compared to those with normal pregnancies [87, 119]. In preeclampsia, antiangiogenic factors including sFlt-1 and sEng impede the activity of proangiogenic factors and promote vascular dysfunction. sFlt-1 is a splice variant of VEGF receptor 1, produced by the placenta, which binds VEGF and PlGF, thereby inhibiting interaction with their receptors (reviewed in [94]). While serum sFlt-1 levels increase during the last two months of normal pregnancy, this increase occurs earlier and is significantly greater in women with preeclampsia [66, 73, 88]. The increase in circulating sFlt-1 is associated with a decrease in free VEGF and PlGF, resulting in inhibition of vasodilator activity and endothelial dysfunction [84]. In rats, sFlt-1 is capable of blocking VEGF and PlGF-mediated relaxation of renal vessels in vitro, and administration in vivo contributes to hypertension, proteinuria, and glomerular endotheliosis [84].

coli nor by EPEC TLR5 localization is still controversial becaus

coli nor by EPEC. TLR5 localization is still controversial because the findings and interpretations are inconsistent [41, 42], and techniques used to detect TLR5 on the surface membrane have been unsatisfactory. Here, we showed TLR5 re-localization by use of permeabilized versus non-permeabilized cells, and antibodies enabling us to detect TLR5 inside and outside of the cells. Besides analyzing TLR5 polarity, it was important

to define if TLR5 was properly exposed at the cell surface because TLRs are not restricted to the plasma membrane, but also found in endosomal/lysosomal see more compartments [43]. Furthermore, EPEC is an extracellular pathogen that disrupts epithelial polarity [17]. According to our results, in non-stimulated HT-29 cells and cells

interacting with non-pathogenic E. coli, TLR5 is mainly intracellular. Interestingly, EPEC infection modifies TLR5 distribution and increases its presence on the cell surface. EPEC flagellum, translocation of effectors and intimate adherence are required to shift TLR5 distribution, although more research is necessary to assert the role of intimin in the recruitment of TLR5 to the cell surface, because of discrepancies in our results from FACS and confocal microscopy studies. However, quantitatively, the FACS experiment takes into account the whole cell population and not only random cells. Therefore, this result could be considered as more reliable. Regardless of their molecular homology, TLRs have different expression and functional patterns [43]. Unlike TLR5, TLR4 ABC294640 clinical trial distribution in HT-29 cells was found to be located primarily at the surface, and EPEC infection did not alter TLR4 distribution. This Oxymatrine result indicates that EPEC-induced TLR5 redistribution is specific for this flagellin receptor. Redistribution of host components during EPEC infection has been described for cytoskeletal proteins and other cell factors [44–46], and now we report for the first time

on re-localization of a pathogen recognition receptor during EPEC infection. Changes in TLR5 distribution have important implications, because TLR5 recruitment enables efficient recognition of extracellular flagellin. The requirement of EPEC virulence to activate TLR5 re-localization could be involved in the physiological tolerance to non-pathogenic bacteria and vigorous response to infection that epithelial cells possess. Flagellin recognition by TLR5 activates ERK1/2 and NF-κB pathways [43]. ERK1/2 phosphorylation during E2348/69 infection was previously reported [28]. Here, we showed that two different EPEC strains (E2348/69 and E22) equally activate ERK1/2 phosphorylation in infected cells. We found that EPEC have opposite modulators of ERK1/2 phosphorylation: flagellin enhances ERK1/2 activation, whereas intimin down-regulates it. FliC role on ERK1/2 activation has previously been shown [25], but the effect of EPEC intimate adherence in phosphorylation was not clear.

Polymorphisms in the genes encoding various cytokines have been a

Polymorphisms in the genes encoding various cytokines have been associated with tuberculosis susceptibility. Household contacts (HHC) are at increased risk of developing the disease. In this study, we examined the association of IL-1β and IL-10 Trichostatin A cytokine gene polymorphisms with risk of developing tuberculosis in TB patients, their HHC and healthy controls (HC) using JavaStat and SPSS. Multifactor dimensionality reduction (MDR) analyses were performed to explore the potential gene–gene interactions. The genotype and allele frequencies of IL-1β +3954C/T polymorphism did not vary significantly

between TB patients and HC. GG (P < 0.005, OR = 0.219 and 95% CI = 0.059–0.735) and GA (P < 0.0001, OR = 2.938 and 95% CI = 1.526–5.696) genotypes of IL-10-1082 G/A polymorphism were found to be significantly associated with patients versus HC. HHC with CC (P < 0.03, OR = 1.833 and 95% CI = 1.1–3.35) genotype in IL-1β and GA (P < 0.0001, OR = 4.612 and 95% CI = 2.225–9.702) genotype in IL-10 were at increased risk of developing tuberculosis. MDR tests revealed high-risk genotypes in IL-1β and IL-10 based on the association model.

Our results demonstrate that the polymorphisms of IL-1β and IL-10 genes may be valuable markers to predict the risk for the development of TB in household contacts. Tuberculosis, primarily caused by Mycobacterium tuberculosis (M.tb), is one of the PLX4032 in vivo leading causes of morbidity and mortality worldwide despite the existence of National and International control programmes [1, 2]. Recent data from the World Health Hydroxychloroquine clinical trial Organization show that about 8.5–9.2 million new cases arise annually, and eventually 1.2–1.5 million deaths occur every year [3]. It is estimated that one-third of the world’s population is infected with M.tb, while 10% of those infected develop clinical disease [4]. This suggests that besides Mycobacteria itself, the host genetic factors may determine the differences in host

susceptibility to tuberculosis (TB) [5]. Several reports from different countries have shown that household contacts of tuberculosis are at much higher risk of infection that range from 30–80% depending on the intensity of tuberculosis disease transmission [6-9]. Identification of these high-risk individuals in recently exposed or infected individuals is of great importance for reducing the disease burden in the community [10]. Although environmental factors are important determinants of progression to disease, there is a genetic component underlying susceptibility to TB, the basis of which may vary in different populations [11]. Manifestation of clinical TB depends on balance between T helper 1 (Th1) cytokines associated with resistance to infection and Th2 cytokines with progressive disease [12]. Influence of cytokine response may be due to their polymorphisms leading to modification of host immunological response in the pathogenesis of TB [13, 14].

The role of siglec-H as an endocytic receptor has been characteri

The role of siglec-H as an endocytic receptor has been characterized by Zhang et al.,31 who targeted pDCs using anti-siglec-H IgG coupled to ovalbumin. Siglec-H-dependent uptake led to cross-presentation of ovalbumin antigens to CD8+ T cells via MHC class I molecules on pDCs, resulting in antigen-specific CD8+ T-cell expansion.31 Mouse CD33 differs from Selumetinib cell line human CD33 because it also encodes a charged transmembrane containing a lysine residue. To date, it has not been shown whether this feature enables murine CD33 to associate with adaptor molecules such

as DAP12. However, a preliminary analysis of CD33-deficient mice revealed no clear-cut differences in regulation of inflammatory responses.34 Negative regulatory functions of different CD33rSiglecs have been observed in studies of cell expansion, cytokine production, Cilomilast molecular weight cellular activation and induction of apoptosis

(reviewed in ref. 1). It is likely, although not directly demonstrated in most cases, that the cytoplasmic ITIM and ITIM-like motif are important in these functions via recruitment of downstream targets such as SHP-1 and SHP-2 tyrosine phosphatases as well as other SH2-domain-containing effector molecules.1,35 Below we summarize recent data supporting a role of CD33rSiglecs in the regulation of inflammatory and immune responses. Using over-expression in mouse RAW and human THP-1 macrophage-like cell lines, siglec-9 expression was shown to suppress the Toll-like receptor (TLR) -dependent production of pro-inflammatory cytokines, tumour necrosis factor-α (TNF-α)

and IL-6, in macrophages following lipopolysaccharide (LPS) or peptidoglycan stimulation.35 In contrast, production of the anti-inflammatory cytokine IL-10 from was enhanced. These effects were abolished when the critical tyrosine residues in ITIM and ITIM-like motifs of siglec-9 were mutated.35 These observations are consistent with earlier studies of human monocytes in which siRNA-mediated knockdown of CD33 led to spontaneous secretion of pro-inflammatory cytokines36 and collectively they indicate that ITIM-bearing CD33rSiglecs may restrain the pro-inflammatory functions of macrophages. Cross-talk between CD33rSiglecs and TLR signalling pathways was also demonstrated for siglec-H.32,33 Following cross-linking of siglec-H expressed in pDCs with antibodies, type-I interferon production in response to TLR-9 ligation with CpG was strongly inhibited. This paradoxical inhibition of cytokine production via DAP12-coupled ‘activating’ receptors has been observed with several pDC-expressed receptors and may be the result of a signalling pathway in pDCs shared with B cells that suppresses type 1 interferon production.37 Siglec-E is a typical inhibitory murine siglec expressed on myeloid cells.38,39 Boyd et al.40 have recently demonstrated a TLR- and MyD88-dependent up-regulation of siglec-E on murine bone-marrow-derived macrophages.

It includes the previously mentioned pIgR, as well as a receptor

It includes the previously mentioned pIgR, as well as a receptor which can re-internalize IgA–antigen complexes from the gut lumen [94]. This second receptor is also expressed by M cells. Antigens complexed with IgA are addressed to DCs from PP, inducing the production of TGF-β and IL-10 [95]. There is growing evidence

that the biological process of immune tolerance to food and microbial antigens is not confined solely to lymphocytes; conversely, ZD1839 purchase all the cells in the human intestine play a role in shaping the attitude of the organism towards molecules present in the gut content. Our review emphasizes the participation of enterocytes in this orchestra of mechanisms which preserve the equilibrium

between activation and tolerance in the gut mucosa. The ultimate goal of this equilibrium is to decide more clearly when and against which it is necessary to fight back in order to preserve our BKM120 integrity as an organism. In this context, enterocytes constitute more than a physical barrier against foreign substances from the gut; they are capable of reacting intelligently to the heavy antigenic load of the gastrointestinal tract. Through their diverse array of receptors, anti-microbial peptides and regulatory cytokines, enterocytes are true immune-competent cells. The fineness of the immune mechanisms displayed by enterocytes, in conjunction with the complex design of the local lymphoid tissue, is yet to be elucidated. A better understanding of ‘who and how’ is responsible for developing oral tolerance will ultimately offer us the tools for manoeuvering in a wide range of clinical situations. This work was funded by the Romanian National Council of Scientific Research – CNCS (PD_477). The authors have no conflicts of interest to declare. “
“Little is known of how Toll-like receptor (TLR) ligands are processed after recognition by TLRs. This study was therefore designed to investigate how the TLR2 ligand FSL-1 is processed in macrophages after recognition Dichloromethane dehalogenase by TLR2. FSL-1 was internalized into the murine

macrophage cell line, RAW264.7. Both chlorpromazine and methyl-β-cyclodextrin, which inhibit clathrin-dependent endocytosis, reduced FSL-1 uptake by RAW264.7 cells in a dose-dependent manner but nystatin, which inhibits caveolae- and lipid raft-dependent endocytosis, did not. FSL-1 was co-localized with clathrin but not with TLR2 in the cytosol of RAW264.7 cells. These results suggest that internalization of FSL-1 is clathrin dependent. In addition, FSL-1 was internalized by peritoneal macrophages from TLR2-deficient mice. FSL-1 was internalized by human embryonic kidney 293 cells transfected with CD14 or CD36 but not by the non-transfected cells. Also, knockdown of CD14 or CD36 in the transfectants reduced FSL-1 uptake.