In contrast, ot was exclusively transferred by CD4+ cells. Thus, the regenerated environment facilitated by the surviving stromal cells determines whether Treg or B-cell expansion is induced. In summary, OVA feeding of mLNtx and pLNtx animals resulted in a tolerogenic phenotype, characterized by a low DTH response. Although pLNtx animals were unable to induce similar numbers of Tregs compared to mLNtx, pLNtx induced an effect that resulted in a lower DTH response against OVA. However, pLNtx showed B-cell expansion and an Ag-specific Ab production. Thus, a humoral

immune response seems to be induced in pLNtx, whereas mLNtx animals showed immune response suppression by Treg induction. However, induction of tolerance in the periphery by the skin draining pLN (pLN-pt) also showed a low DTH response, and a similar cell subset composition Panobinostat manufacturer was determined in pLNtx and pLN-pt. This tolerance could be transferred by IgG+ cells isolated from selleck compound pLN-pt mice. Otherwise CD4+ cells are exclusively responsible for ot induced by mLN. Thus, stromal cells coming from the periphery regenerate in the mesentery, but they remain in the skin draining-specific environment and act independently of the draining area. In conclusion, stromal cells have a high impact on creating an environment: they have a strong influence on the process of immunological responses

and are important for the balance between tolerance and immunity. Overall, stromal cells of pLN and mLN influence which response to Ag is chosen. Female C57BL/6 and

C57BL/6 plt/plt mice were bred at the central animal laboratory of Hannover Medical School and were used at a weight of 18–25 g. All animal experiments were performed see more in accordance with the institutional guidelines and had been approved by the Niedersächsisches Landesamt für Verbraucherschutz und Lebensmittelsicherheit (No. 33-42502-05/960). As described earlier 16, mLNs and pLNs were isolated from C57BL/6 mice and used as donors for C57BL/6 mice. Under combined anesthesia with ketamine (Gräub AG, Bern, Switzerland) and xylazine 2% (Bayer Health Care, Leverkusen, Germany), the mLN of the small and large intestine of the host were removed and donor mLNtx or axillary and brachial LN (pLNtx) were transplanted into this region. Total RNA was isolated according to the manufacturer’s protocol (Rneasy Kit, Qiagen, Hilden, Germany) and cDNA synthesis was performed with 50 mM oligo primer, 0.1 M DTT, 5× first strand buffer, 10 mM dNTP, 35 U/μL Rnase inhibitor, and 200 U/μL M-MLV reverse transcriptase (all obtained from Invitrogen, Karlsruhe, Germany) in a total volume of 20 μL at 37°C for 50 min. With this cDNA quantitative real-time PCR was performed using the QuantiTect SYBR-Green protocol of Qiagen.

Recent in vitro studies document IL-1α and IL-1β secretions upregulated in the cell culture supernatant of human skin equivalents when stimulated with S. scabiei var. canis whole mites (55). Subsequent studies by the same group show unknown components in whole mite extracts of S. scabiei var. canis downregulate secretion of interleukin-1 receptor antagonist (IL-1ra) and IL-8 and stimulate secretion of IL-6 and vascular endothelial cell growth factor (VEGF)

in cultured normal epidermal keratinocytes (56). In the same study learn more IL-6, IL-8, granulocyte-colony stimulating factor (G-CSF) and VEGF were upregulated in cultured normal human dermal fibroblasts. Of interest, when keratinocytes were cultured in the presence ABT-199 molecular weight of inflammatory cytokines (IL-1α and IL-1β, TNF-α and IL-17), the same S. scabiei var. canis extract was shown to still downregulate levels of IL-8 secretion and also granulocyte/macrophage-colony

stimulating factor secretion from cultured fibroblasts (57). Furthermore, in this latter study levels of the growth-related oncogene alpha (GROalpha), TGF-α and cutaneous T-cell attracting chemokine from keratinocytes and IL-6 and G-CSF from fibroblasts were also downregulated. Another study using stimulated cultured dermal microvascular endothelial cells documents that the var. canis extract inhibits the Decitabine expression of intracellular adhesion molecule-1 and E-selectin and downregulates secretion of IL-1α (58). Furthermore, these observed inhibitory effects were not altered in the presence of histamine and lipid-derived biologic mediators (59). Over all, these findings confirm uncharacterized mite proteins have immunomodulatory properties that favour invasion of the host by the parasite via down regulating or depressing inflammatory processes of resident cells in the skin and possibly influencing a delayed immune reaction. Interestingly, recent reports describe the proteolytic activity

of house dust mite (HDM) cysteine and serine proteases stimulating human keratinocytes and upregulating IL-8 secretion in vitro (60,61). The specific effects of scabies mite cysteine and serine proteases, homologues of the HDM cysteine protease group 1 and 3 allergens, on keratinocytes still remain to be elucidated (62–64). Similarly, the effect on the skin immune system of other reported scabies mite homologues to HDM allergens is also currently unknown. These include a scabies mite mu class and a delta class glutathione S-transferase group 8 allergen implicated as a major allergen in crusted scabies immune response (65,66), localized to the mite gut (9); and an apolipoprotein, homologous to the C terminus of group 14 allergen (67).

We examined the titre of IgG of these six patients. Their serum levels of IgG were not altered markedly (Fig. 3j). Next, we investigated the relationship between the number of PBDCs and duration time of Sicca syndrome in selleck products secondary SS. As shown in Fig. 3d–f, a direct correlation was observed between the number of PBDCs and the time from the onset of Sicca syndrome in secondary SS, as in primary SS. We have demonstrated previously that, in primary SS, a number of mature myeloid DCs as well as numerous IFN-γ-producing T cells are infiltrated in the interstitial areas of labial salivary glands [2]. In this study, we also carried out similar histological

examinations on the labial salivary glands biopsied from secondary SS patients by staining with DC markers CD11c, HLA-DR and fascin. We found infiltration of a number of mononuclear cells (MNCs) around the glandular structures by H&E staining of the labial salivary gland from 16 of 24 secondary SS patients who agreed to undergo biopsy (Fig. 4a, patient 22 in Table 2; Sicca syndrome onset, 2 months). Similar to primary SS [2], many fascin-positive MNCs were detected among numerous PF-01367338 molecular weight fascin-negative MNCs in the areas surrounding the tubular ducts in secondary SS (Fig. 4b). In addition, immunohistochemical double-staining of CD11c and HLA-DR demonstrated that

the CD11c/HLA-DR double-positive cells with DC morphology had infiltrated the MNC area at the same frequency as the fascin-positive cells (Fig. 4c), suggesting that these cells are myeloid DCs. As described above, patients in the early phase of primary SS showed a significant decrease of total PBDCs and myeloid DCs, whereas patients in the chronic phase of primary SS showed a lesser extent of decrease of PBDCs and myeloid DCs (Fig. 3). These findings suggest that the decreased levels of PBDCs and myeloid DCs restore gradually Tacrolimus (FK506) to normal levels during the natural course of the disease. This prompted us to examine how infiltration of mature myeloid DCs in labial salivary glands in primary SS is altered as the clinical course proceeds. Thus, we examined the immunohistochemical staining of labial salivary glands of primary

SS patients who passed through a long period of time after the onset of Sicca syndrome (60 months from the Sicca syndrome onset) and calculated the percentage of fascin-positive cells to the total infiltrating MNCs in salivary glands. Similar to the early phase of primary SS [2], numerous MNCs were detected in the interstitial areas around the tubular ducts in labial salivary glands in the later phase of primary SS (Fig. 4d). However, in contrast to the early phase of primary SS, fascin-positive MNCs were barely detected in the later phase of primary SS (Fig. 4e). We confirmed that the percentage of fascin-positive cells to infiltrated MNCs was decreased statistically in salivary gland sections during the natural course of primary SS (Fig. 5).

However, the generation of effective antiviral or autoreactive adaptive this website immune responses requires blocking of immunosuppression by Tregs. In this study, we show that TLR7 ligands reduce the number of Tregs generated

de novo from naïve murine T cells in vitro and in vivo. In the presence of TLR7-activated splenic DCs, Foxp3 was transiently induced in naïve T cells by TGF-β but was downregulated at later time points. Neutralization experiments revealed that loss of Foxp3 after initial induction was mostly dependent on IL-6 produced in the DC–T-cell cocultures containing TLR7 ligands. Thus, under the influence of TLR7 ligands fewer Tregs were generated and these expressed lower levels of Foxp3 correlating with a reduced capacity to suppress responder T-cell proliferation. Thus, we provide evidence that TLR7

ligands affect Treg-dependent immune regulation and may thereby contribute to the development of autoimmune diseases such as systemic lupus erythematosus. Viral RNA as well as self-RNA present in nuclear autoantigens of patients with autoimmune diseases such as systemic lupus erythematosus (SLE) activate Toll-like receptor (TLR) 7 1–6. Accordingly, TLR7 has been shown to play an important role in antiviral defense 7 as well as autoimmunity, as was shown in several mouse models of SLE 8–13. DCs and B cells which are directly activated by TLR7 ligands support the activation and expansion of effector T and B lymphocytes directed against viral antigens 7 or autoantigens

buy MDV3100 10. In addition, TLR7 activation could be involved in breaking peripheral tolerance mediated by Tregs, which has to be overcome in order to generate protective antiviral immune responses 14 or pathogenic autoreactive immunity. In several murine models of SLE and in patients with active D-malate dehydrogenase SLE, reduced frequencies and suppressive functions of Tregs have been observed 15–18, supporting the concept that defects in the Treg compartment are critical factors in the pathogenesis of this autoimmune disease. We propose that in addition to the direct stimulatory effects on APCs, TLR7 activation by exogenous and endogenous TLR7 ligands impairs Treg generation and function. However, the studies investigating the effect of TLR7 ligands on Treg suppressive function have yielded controversial results 19, 20 and the influence of TLR7 activation on the de novo generation of Tregs from naïve T cells has not been examined. We show that TGF-β induces Foxp3 expression in naïve T cells even in the presence of TLR7 ligand and DCs; however, Foxp3 expression is only transient and is downregulated at later time points. Loss of Foxp3 expression is dependent on soluble factors – mainly IL-6 – produced in DC–T-cell cocultures in response to TLR7 ligands. Upon exposure to TLR7 ligands, reduced numbers of Tregs are generated which additionally express lower levels of Foxp3 and have a reduced capacity to inhibit the proliferation of responder T cells.

Although free-living species display a high propensity for symbioses spanning the spectrum from commensalism to parasitism, there is strong evidence that the major parasitic lineages form a monophyletic group, demonstrating that obligate parasitism arose only once during the course of flatworm evolution (11). This was associated with a major developmental shift involving the separation of ontogenetically distinct

larval and adult stages, with replacement of the larval epidermis by a syncytial tegument. Within this clade, we now recognize four independent lineages: the cestodes (tapeworms), digeneans (flukes) and monopisthocotylean and polyopisthocotylean ‘monogeneans’. Interrelationships of these lineages remain controversial, but have begun to point toward a sister relationship between cestodes and digeneans, see more and paraphyly of the ‘Monogenea’ (11,14,15), in contrast to previous hypotheses (and classifications) that considered ‘monogeneans’ to be both monophyletic and the sister group to tapeworms. The main implications of the molecular-based hypotheses are a common origin of both enteric parasitism and complex life cycles in tapeworms Metabolism inhibitor and flukes despite major differences in their life histories, and that the first neodermatan flatworms were nonenteric and direct-developing, as seen in contemporary monopisthocotylean

and polyopisthocotylean parasites. Only in the last two decades CYTH4 has our understanding of tapeworm interrelationships begun to stabilize, thanks to a more concerted effort on the part of cestodologists (16) and the wide application of molecular phylogenetic techniques (14). Circumscription of even the primary tapeworm lineages has required major revisions to reflect new insights into their affinities, resulting in the proposal of three new tapeworm orders since 2008 (17,18). Interrelationships of the 15 or more natural (i.e. monophyletic) groups of tapeworms

have yet to be resolved satisfactorily, but it is clear that early branching lineages colonized a wide spectrum of cartilaginous and bony fishes before subsequent diversification led to the colonization of homeothermic hosts (e.g. birds, mammals) (19–21). Among the early branching groups, only the Diphyllobothriidea [n.b. formally classified as a family of Pseudophyllidea (18)] radiated into homeotherms, but retained its association with fishes (which became 2nd intermediate hosts) and transmission via aquatic life cycles (22). There was thus a single primary colonization of homeothermic hosts coincident with the adoption of fully terrestrial life cycles that gave rise to the most speciose contemporary group, the Cyclophyllidea. The extent to which tapeworm–host associations were shaped by the unique adaptive immunity of the mammalian host is not clear from an evolutionary perspective.

A low level of serum IgA was detectable in these mice (228·0 ± 33·89, n = 5 for wt, 9·220 ± 4·548, n = 5 for αΔtail+/+) (Fig. 3a, right). In addition, the production of secretory IgA transported into digestive

secretions was very low and was maintained at around 1·7 μg/ml in the jejunum fluid (1·7 ± 0·6 μg/ml, n = 5) instead of 1058 ± 163·1 μg/ml in wt mice (n = 5) (Fig. 3b, right). By contrast IgM levels in digestive secretions were significantly higher in homozygous mutant animals than in the wt controls (2·380 ± 0·7415 μg/ml, for αΔtail+/+ mice and 0·6800 ± 0·2024 μg/ml for wt) (Fig. 3b, left). Serum IgG levels were normal in homozygous mutant animals (Fig. 3a). To determine the dimeric and monomeric forms of IgA, immunoglobulins circulating in serum were separated by non-reducing SDS–PAGE. Monomeric IgA demonstrated single bands at a molecular weight of 150 000  whereas dimeric forms in samples showed buy 5-Fluoracil bands at 360 000 (Fig. 3c, up). To test whether the dimeric IgA assembled correctly

with endogenous mouse J-chain, we performed immunoprecipitation of J-chain from serum, followed by immunodetection using an anti-mouse IgA. In mutant mice, IgA was immunoprecipitated with anti J-chain (Fig. 3c, bottom), and indicated that few circulating IgA can dimerize and bind the J-chain. We evaluated the amount of IgA-producing cells generated in vitro during a short-term culture independent of both antigen stimulation and BCR selleck signalling. Splenocytes were stimulated with LPS and TGF-β for 4 days. Supernatants were then harvested and analysed for IgA content by isotype-specific ELISA. As we expected, IgA secretion

was altered in LPS/TGF-β (33·2 ± 3·9 μg/ml, DCLK1 n = 5, instead of 260·9 ± 83·68 μg/ml, n = 5 for wt) (Fig. 4a). Secretion of IgG2b, IgG3 and IgM was normal, as expected (data not shown). To test class switching in vitro, we used molecular markers for CSR from the μ-chain to the α-chain: α-germline transcripts (Iα-Cα), production of which is a prerequisite for CSR, and Iμ-Cα transcripts that are expressed from the IgH locus after μ-chain to α-chain switching; we quantified those transcripts after 3 days of in vitro stimulation. The results showed that IgA CSR occurred in such conditions (Fig. 4b). Cell cytometry revealed fewer B cells expressing mIgA in Peyer’s patches (Fig. 5a,b). We also evaluated IgA plasma cells in lymphoid tissues. Hence, tissues were analysed by immunofluorescence for the presence of intracellular immunoglobulin, showing that fewer IgA-positive plasma cells were present in the lamina propria of mutant animals than in wt mice (Fig. 6). By contrast, the global amount of plasma cells infiltrating the lamina propria along the intestinal crypts did not appear to be affected in mutant mice when MALT tissues were examined by immunofluorescence with anti-κ-chain antibodies (Fig. 6b). No global difference was observed either when tissues were analysed by immunohistochemistry with anti-CD138 and anti-B220 antibodies (Fig.

How CD23 on B cells modulates active systemic anaphylaxis needs further IDH inhibitor clinical trial studies. A direct effect of CD23 on effector cells or a proposed negative regulatory function of CD23 on B cells could be involved [23, 31]. Because the CD23−/− IgE knock-in mice displayed increased anaphylaxis, we reasoned that they would be better targets to test a potential protective effect of basophil depletion on active anaphylaxis. Therefore, we treated sensitized mice with Ba103 Ab (anti-CD200R3), which depletes basophils, but not mast cells [32] to examine the effect on IgE or IgG1 dominated anaphylaxis.

In WT, heterozygous and homozygous IgEki mice 65, 80, and 85% of basophils (CD49b+-IgE+) in peripheral blood were depleted, respectively (Supporting Information Fig. 2). The depletion of basophils resulted in reduction of body temperature drop in all three genotypes. This effect was most prominent in IgE knock-in mice in the late phase of anaphylaxis, between 60–90 min. At the endpoint after 90 min the body temperature was 3–4°C lower in untreated mice as compared with that of basophil-depleted mice. In line with this observation, the mortality rate dropped to zero in treated mice. However, at the peak of anaphylaxis around 30–40 min past challenge, basophil-depleted IgE knock-in mice also reacted with substantial anaphylaxis,

although they recovered faster than the untreated mice (Fig. 4B and C, panels 3 and 4). Due to genetic differences between BALB/c mice (where the knock-in was made) and C57BL/6 mice (used for backcrosses) the IgEki/ki mice express the IgG2a isotype, whereas the WT littermates express IgG2c [33]. This feature of the genetic Ibrutinib mouse manipulation is not due to insufficient backcrossing, but results from the close linkage of the IgG isotypes in the immunoglobulin locus. A contribution of differentially expressed antigen-specific IgG2a versus IgG2c (Fig. 3B and C) to the anaphylaxis phenotype, Glycogen branching enzyme or the moderately increased IgG2b in CD23-competent IgE knock-in (Fig. 3B) is unlikely, because in mice immunized with alum as adjuvant, specific IgG1 is the dominating IgG isotype, resulting in reduced antigen-specific IgG in the IgE knock-in mice

[34]. In summary, IgE-sensitized basophils are most likely responsible for the severe body temperature drop in the late phase of anaphylaxis and contribute to death due to anaphylaxis. However, in the early phase of anaphylaxis, sensitized mast cells do have an important contribution in IgE-dominated systemic anaphylaxis. This is supported by the detection of significantly increased mouse mast cell protease 1 (Mmcp1) in IgEwt/ki mice, but not in IgEki/ki mice (Fig. 4D). Mmcp1 has been identified as a marker that distinguishes IgE- from IgG-mediated anaphylaxis [7]. As basophils do not express this protease, whereas mast cells do – albeit weakly – [35], this suggests that mast-cell degranulation via IgE may partially contribute to the anaphylaxis phenotype.

For T cell subpopulations, 100 µl

of whole blood was incubated with directly conjugated fluorescent Palbociclib order antibodies for 30 min in the dark at room temperature, then red cells were lysed using FACSlyse (Becton-Dickinson), washed in phosphate-buffered saline (PBS) and fixed in PBS with 1% formaldehyde. Samples were acquired using four-colour acquisition on a FACSCalibur and data analysed using CellquestPro software (Becton-Dickinson). Fluorescence minus one gating techniques were employed to evaluated thresholds for positivity of individual antibodies and aid gating of T cell subpopulations. The following CD3+ T cell subpopulations were analysed on CD4 and CD8 cells: naive, central memory

(CM), effector memory (EM) and terminally differentiated determined (TEM) by CCR7 and CD45RA expression; early, intermediate and late differentiation status was determined by CD28/CD27 expression. Other CD4 T cell populations included recent thymic emigrant (defined by CD45RA/CD31), https://www.selleckchem.com/products/AZD6244.html putative follicular T cells (defined by CXCR5/CD45RO) and Tregs (defined by CD25+CD127-). Absolute cell counts were calculated using the CD4 or CD8 T cell counts from the lymphocyte subset analysis. Subpopulations were added together to ensure that the total number of CD4 or CD8 matched those from the lymphocyte subset analysis. All statistical analyses were performed using GraphPad Prism version 4 (GraphPad Software, San Diego, CA, USA). All data were analysed using non-parametric one-way analysis of variance (anova) Kruskal–Wallis with Dunn’s multiple comparison test as a post-hoc test or one-way anova with Tukey’s multiple comparison test as a post-hoc test. T cell subpopulation correlations with age were analysed by Spearman’s correlation. The Venn diagram (Fig. 1) was made using the J.C. Oliveros (2007) VENNY tool from http://bioinfogp.cnb.csic.es/tools/venny/index.html

It was important Thiamet G to age- and gender-match the healthy controls and patient groups, as an effect of age on some T cell subpopulations has been described [21]. This was performed successfully, except for the XLA patients, who were significantly younger and all male (Table 1). There were no significant differences observed between the disease controls (n = 31) and healthy controls (n = 48) in any of the T cell subpopulations studied (see Figs 3 and 4), so the two control groups were combined to determine whether or not there were any relationships between T cell subpopulations and age. No significant correlations between age and any T cell subpopulation were observed in this age range (18·5–84·6years at the time of study) (all r2 values were less than 0·5 or −0·5). Table 1 describes the demographics of the subjects studied and controls, including age of presentation.

, 2004; Rehaume et al., 2010). Very little is known regarding the pathways regulating IL-17 when encountering pathogenic microorganisms, because only artificial

conditions, such as inducing TH17 proliferation with anti-CD3/anti-CD28, have been used. A recent work identified mannose receptors as the most important pathway for IL-17 induction and TLR2/dectin-1 as having a secondary amplification effect on mannose receptor-induced IL-17 production in response to C. albicans (Van de Veerdonk et al., 2009). A study by our group (Moresco et al., 2002) demonstrated that suckling mice pretreated with concanavalin-A (Con-A) survived an intraperitoneal inoculum of 5 × 107 C.  albicans, whereas all control this website mice died within 24–48 h of infection. This effect of Con-A was attributed to IFN-γ production by direct bind to CD3 and TCR on T helper cells and subsequent increase in phagocytic and candidacidal activities of macrophages. On the other hand, IL-12 is a cytokine with links to both see more innate and adaptative immunity systems, and it constitutes an essential component of the adaptative response that leads to the generation of Th1-type cytokine responses such as IFN-γ and TNF-α (Hamza et al., 2010) and protection against disseminated candidiasis (Ashman et al., 2010).

Previously, our group reported that treatment with Con-A for 3 days protected 100% of mice against a lethal inoculum of C. albicans by increasing activity of mannose receptors on peritoneal macrophages, which produced significantly more TNF-α and were more able to kill C. albicans in vitro or over the course of infection with Candida compared to

the control group (Conchon-Costa et al., 2007; Geraldino also et al., 2010). This study tested the hypothesis that greater activity of mannose receptors and dectin-1 on peritoneal macrophages from mice pretreated with Con-A could facilitate the activation of TH1 and TH17 subsets over the course of infection by C. albicans. Candida albicans strain CR15 was isolated from the oral mucosa of a patient with HIV infection at the university hospital and maintained on Sabouraud dextrose agar; the isolate was used after two serial animal passages. C. albicans blastoconidia were obtained by growth in Sabouraud dextrose broth for 24 h at 28 °C, were washed with phosphate-buffered saline (PBS) and resuspended at 107 blastoconidia in 1 mL of RPMI 1640 (Sigma-Aldrich, St. Louis, MO). Subgroups of five male Swiss mice, each weighing 28–32 g and aged 4–6 week old, received sterilized food and water ad libitum. The mice were pretreated with 250 μg of Con-A (Sigma-Aldrich)/250 μL PBS intraperitoneally (i.p.) or 250 μL PBS alone and 3 days later were infected with 1 mL of C. albicans CR15 107 (i.p.). One group of five noninfected mice was used as control.

It has been reported that hepatic B cells are not associated spatially with hepatic blood vessels [21]. In the current study, we confirmed (Supplementary Fig. S2) that hepatic B cells are located

sparsely throughout the liver parenchyma and observed B cells in close proximity to DCs. This suggests a potential functional interaction between these cells. We next tested whether hepatic B cells could affect the maturation and function of liver mDCs. Flt3L-treated mice were stimulated with LPS for 18 h. Liver mDCs were then isolated and analysed. As shown in Fig. 3a, these liver mDCs displayed significantly greater levels of CD86 and major histocompatibility complex (MHC) II when isolated from LPS-treated wild-type compared with μMT mice. This suggests that, in the presence of B cells, liver mDCs are more responsive to LPS stimulation and display a more stimulatory phenotype. To test further the influence of hepatic B cells high throughput screening assay on liver https://www.selleckchem.com/products/ulixertinib-bvd-523-vrt752271.html mDC function, we isolated liver mDCs and analysed their pattern of cytokine secretion in response to ex-vivo LPS stimulation for 48 h. As shown in Fig. 3b, liver mDC from μMT mice showed markedly reduced secretion of proinflammatory IFN-γ, IL-6, IL-12p40 and TNF-α, while they produced significantly more IL-10. These data further suggest a stimulatory influence of hepatic B cells on liver mDC maturation and function. To test the direct influence of hepatic and

splenic B cells on liver mDC maturation, we cultured B cell-depleted liver NPC with or without LPS in the presence or absence of hepatic or splenic B cells for 48 h to analyse the maturation of mDCs. As shown in Supplementary Fig. S3, hepatic B cells 2-hydroxyphytanoyl-CoA lyase up-regulated the expression of CD86 and PD-L1, while splenic B cells down-regulated the expression of CD80 and CD86 on mDCs. This finding suggests that splenic, but not hepatic,

B cells regulate liver mDC maturation negatively. Liver homeostasis is a complex process that involves maintaining tolerance to diverse dietary and other antigens, while retaining the capacity to mount effective immune responses against harmful pathogens [3]. In this report, we provide new evidence supporting a proinflammatory role of hepatic B cells, due probably to a lack of IL-10-producing B cells (B10). The first key observation is that hepatic B cells respond rapidly to LPS stimulation (Fig 1a,b) and secrete proinflammatory cytokines (Fig. 1c,d). Unlike splenic B cells, however, hepatic B cells produce very little, if any, anti-inflammatory IL-10 in response to LPS stimulation. In addition we demonstrate that, compared to splenic B cells, hepatic B cells comprise significantly lower proportions of B1a and MZ-like B cells (Fig. 2), that have been reported to secrete more IL-10 than follicular B cells [19]. Our observation suggests that B10 cells might not be prevalent immune regulatory cells in the liver.