[19] and illustrated in the Maximum parsimony tree based on the I

[19] and illustrated in the Maximum parsimony tree based on the ITS region (Fig. 2) are mixed in the ACT, TEF and RPB1 trees (data not shown) as well as in the multi-locus tree (Fig. 1) within arrhizus and delemar, respectively. The variety tonkinensis was represented in our study by 4 strains, which were all morphologically assigned to this variety by Zheng et al. [17]: CBS 257.28, CBS 330.53, CBS 399.95 and the ex-type strain of var. tonkinensis,

CBS 400.95. The variety was neither detected in the single locus trees using the ML approach nor in the ITS tree using the maximum parsimony approach (Fig. 1 and Fig. 2). Figure 3 illustrates schematically the maximum intra- and interspecific distances within the Rhizopus arrhizus/R. delemar complex for both possible scenarios: (i) lineages arrhizus and delemar belong to a single FDA-approved Drug Library solubility dmso variable species and represent varieties, or (ii) lineages arrhizus and delemar represent separate species. In the latter scenario (Fig. 3b) the intraspecific variability of arrhizus and delemar, and especially the distance between both entities, is very small compared to distances

to other species. In accordance with single-gene and multi-gene genealogies, the AFLP banding patterns, when clustered with UPGMA in BioNumerics v. 4.61, clearly revealed two different groups for arrhizus and delemar (Fig. 4). Forty-eight strains of arrhizus and 34 strains of delemar were analyzed statistically in order to establish whether the click here entities differ significantly in ecology, geographic

distribution or clinical relevance. The proportions were as follows (illustrated with colored squares in Fig. 1): 14 clinical strains, 8 food strains and 2 environmental strains in arrhizus and 4 Teicoplanin clinical and 8 food strains but no environmental strain in delemar. Remaining strains originated from unknown sources. No significant difference was found between sources and clusters (chi square = 2.86, P = 0.091, critical level = 0.05), and no difference in geographic distributions between arrhizus and delemar was detected. No physiological difference was detected between arrhizus and delemar (Table 3). All tested strains were negative for laccase, cellulose, and tyrosinase and positive for lipase and amylase. The majority of strains were positive for gelatin liquefaction and siderophore production, but no significant correlation was observed between negative strains and taxonomic entities or source of isolation. A few strains showed urease activity, while the activity of this enzyme could not be related to taxonomy or ecology. All tested strains (20 of arrhizus and 20 of delemar) grew well (average 64 mm/days) with 30–36 °C as optimum temperature range. At 40 °C strains were inhibited for about 50%. According to our experimental design, the maximum growth temperature was 45 °C with reduced growth for all strains tested.

25 mL kg−1) and ketamine chlorhydrate (1 mL kg−1)

25 mL kg−1) and ketamine chlorhydrate (1 mL kg−1). Daporinad manufacturer All groups received a total of three doses of the vaccine on days 1, 15 and 30. Each hamster was sampled under anaesthesia directly by heart puncture before the first immunization and 15 days after the last one, in order to evaluate the immune response

induced. Fifteen days after the last immunization, hamsters were administered by gavage clindamycin (Dalacine®) at a single dose of 50 mg kg−1 to disrupt the barrier microbiota in order to predispose them to CDI. Five days later, hamsters were challenged orogastrically with 2 × 103 CFU of spores of the 79-685 toxigenic strain of C. difficile. From the day after infection, hamsters were observed three times a day. The conclusions of the first experiment led us to perform a second one, with a higher number of animals, Cabozantinib ic50 with the route of immunization inducing the best animal survival results. Hence, the second experiment was performed with the use of the rectal route, as per the same immunization regimen as described above. A group of 18 animals was immunized by 100 μg of the protease Cwp84 and 10 μg of cholera toxin and a control group of 16 animals

was immunized by PBS and cholera toxin 10 μg. To confirm the excretion of C. difficile after challenge with spores (12 animals immunized with Cwp84 and 10 animals of the control group randomly selected), faeces were sampled each day and C. difficile was numerated by culture. Hamster faecal pellets were cultured before clindamycin administration and daily for 1 week after C. difficile challenge, to assess the colonization rate and its onset. Faecal sample were processed as described previously (Pechine et al., 2007). The limit of

detection was estimated to be 104 CFU g−1 of faeces. To evaluate the antibody response in sera, blood samples (200–400 μL) were withdrawn before the first immunization and 15 days after the last immunization, before C. difficile Temsirolimus challenge. The blood was left to clot for 1 h at room temperature and 3 h at 4 °C. Serum was obtained by centrifugation and frozen at −20 °C until use. Indirect ELISA was used to detect antibodies in the sera as described before (Pechine et al., 2007). Wells of a 96-well microtitre plate (MaxiSorp, Nunc) were coated with 100 μL of a 5 μg mL−1 solution of recombinant purified Cwp84. Sample dilutions tested were 1 : 100; 1 : 200; 1 : 400; 1 : 800; 1 : 1600; 1 : 3200; 1 : 6400; and 1 : 12 800. After washings, positive reactions were detected by successive incubations with a rabbit anti-hamster immunoglobulins conjugated to biotin (1 : 8000 dilution; Biovalley) for 30 min at 37 °C and with a streptavidin–horseradish peroxidase conjugate (1 : 1000 dilution; Sigma) for 30 min at 37 °C. The specificity of the ELISA was confirmed by immune absorption. A preincubation for 30 min at 37 °C of control and immunized hamster serum samples with the protease Cwp84 at 50 μg mL−1 was carried out.

2B) Thus, early depletion of DCs before MOG immunization only mi

2B). Thus, early depletion of DCs before MOG immunization only mildly reduced the disease severity but did not influence the incidence of EAE. To examine the effect of DC depletion on FoxP3+ Treg cells, the Treg-cell numbers were assessed. DCs were depleted in vivo 1 day before MOG immunization and the frequency of absolute number

of FoxP3+ CD3+ Treg cells per spleen was measured 10 days after MOG immunization by flow cytometry. The mean number of Treg cells per spleen did not differ between DC-depleted and control CD11c-DTR mice (Fig. 3). Thus, in contrast to constitutive DC ablation, short-time depletion of DCs does not appear to affect learn more the Treg-cell responses in this system. When the experiments described above were performed, low mortality of CD11c-DTR

mice (one to two mice/experiment) was observed within the first week after DTx injection. In our hands, mortality increased over time when we ran new experiments (data not CP690550 included), as described by others [6]. Mortality was observed to the same extent in mice that had not received MOG injection, and the mortality was thus not caused by the MOG immunization (data not included), but probably due to aberrant DTR expression in nonimmune cells. To assure that immune cells were not depleted by the DTx injection, the frequency of B cells, CD11b+ cells, T cells and Ly6Chi CD11b+ monocytes were analyzed 24 h after DTx injection in the spleen from CD11c-DTR mice (Supporting Information Figure 1). The frequency of these cells was not affected by the DTx injection and EGFP expression was undetected in these cell types (data not included). Therefore, the increased mortality in CD11c-DTR mice was unlikely due to aberrant expression of DTR in immune cells other than mDCs. To reduce the mortality in CD11c-DTR mice following DTx injection [6] and obtain a better experimental design, bone marrow chimeras were generated. Bone marrow from CD11c-DTR donors was injected into lethally irradiated C57BL/6 hosts 6 weeks before EAE induction. No mortality was observed in the bone marrow chimeras following DTx injection (data not included). The efficiency of the DC depletion was again assessed

after DTx injection. Dermal DCs and mDCs from skin-draining LNs and spleen were depleted after DTx injection (Fig. 1D–F Methane monooxygenase and Supporting Information Table 1). Similar to CD11c-DTR mice, around 50% of inflDC were depleted (Fig. 1E–F) but not pDCs (data not included). Depletion of mDCs and inflDCs in the CNS was analyzed at peak of EAE (day 13 after MOG immunization) when detectable amounts of DCs are present in the CNS [15]. mDCs and inflDCs were abundant in both DC-depleted and controls and were as expected not depleted at this late time point (Fig. 1G). The inflDCs of the CNS expressed very high levels of CD11b (data not included). Thus, mDCs but not pDCs were depleted by the DTx injection in bone marrow chimeras to the same extent as in CD11c-DTR mice.

Most importantly, mature surCD3+ T cells appeared only in the HLA

Most importantly, mature surCD3+ T cells appeared only in the HLA-B7+ fraction of mice with chimeric human haematopoiesis (14% of all HLA-B7+CD45+ spleen cells, Fig. 2A). Notably, these

peripheral T cells were almost exclusively CD4+TCRαβ+. The reason for this CD4-dominance remains unexplained so far; however, huCD34+CD38− recently also showed an exclusive outgrowth of CD4+ T cells after in vitro culture on OP9/DLL1+-cells 11. These CD4+ T cells Autophagy Compound Library clinical trial could have been selected on various MHC-class-II molecules as CD11c+HLA-DR+ cells could be detected from HLA-B7+ and from HLA-B7− backgrounds (Supporting Information Fig. 3C). Functional assays showed that after polyclonal stimulation these CTLP-derived T cells produced IFN-γ but not IL-4 (Fig. 2C). CDR3-size spectratyping showed BV-fragments in 7/26 analysed BV-families in chimeric mice, whereas in huCD34+ HSC controls faint bands could be detected in two BV-families (Fig. 2D). In our model, T-cell progenitors such as CD7+CD5+ as well as CD4+CD8+ descending both from CTLPs and from huCD34+ HSCs could be found in spleen (Fig. 2A), thymus (Supporting Information Fig. 3B) and BM (data not shown). However, CD7+CD5+CD1a+ early cortical T cells could be detected only in the HLA-B7− fractions, indicating that HLA-B7+ CTLPs had already differentiated beyond that checkpoint and lost their potential for long-term T-cell renewal (Fig. 2A).

This observation was especially obvious in thymus, where almost no HLA-B7+ T-cell precursors were detectable on day 28 anymore, whereas in the HLA-B7− Prostatic acid phosphatase fraction CD7+CD5+CD1a+ cells dominated (Supporting Information Fig. 3B), which were all cytoCD3+surCD3− (data not Birinapant nmr shown). Collectively, these data show that in vitro-pre-differentiated CTLPs have lost their capacity to engraft after intravenous transfer in an adult xenogenic environment, probably due to a lack of appropriate niches that foster homing, survival and differentiation of CTLPs. However, with support of undifferentiated huCD34+ HSCs, these CTLPs give rise

to an early wave of de novo-generated, mature CD4+ T cells in the host and show some degree of lineage plasticity. Simultaneously, more sustained T-cell neogenesis from huCD34+ HSCs proceeds at a slower pace, resulting in mature, peripheral CD4+ and CD8+ T cells 8–10 wk after transplantation (9 and unpublished data). Most intriguingly, we found mature T cells differentiated from CTLPs not only in thymus but also in the periphery. This apparent discrepancy to the previous reports can be explained by substantial differences in the realisation of transplantation experiments: one group applied a one-log lower CTLP dose with a similar IL-7 supplementation 6, the other used equivalent numbers of CTLPs but no IL-7 7. However, the most important difference is that we co-transplanted CTLPs with huCD34+ HSCs whereas in the other studies, huCD34+ HSCs were used only as a separate control group.

In this study, the activation of other TLRs such as TLR4 and TLR5

In this study, the activation of other TLRs such as TLR4 and TLR5 had no effect on Treg generation, supporting our results for TLR4 activation. In our study, TLR7 and TLR9 ligands triggered stronger IL-6 and IL-12 responses in DC–T-cell cocultures than TLR4 ligand LPS.

The defect in stable Foxp3 expression caused by addition of TLR7 ligands to the coculture Talazoparib mw could be mimicked by supernatants of TLR7-stimulated DCs, but not by supernatants of unstimulated DCs or TLR7 ligand-stimulated DCs, which had been pretreated with neutralizing antibody against IL-6. These results suggest that IL-6 produced by splenic DCs early during the coculture in response to TLR7 ligand is largely responsible for the observed loss of Foxp3 expression after transient induction. The addition of neutralizing antibodies to the DC–T-cell cocultures confirmed the major RGFP966 role of IL-6 and additionally revealed a minor role for IFN-γ and IL-4 in inhibiting Treg generation in the presence of TLR7

ligand, which is in accordance with a recent report describing the influence of Th1/Th2-polarizing cytokines on Treg differentiation 22. In the study by Hall et al. using lamina propria DCs stimulated with TLR9 ligand CpG, the inhibitory effects of IL-4 and IFN-γ prevailed over the inhibitory effect of IL-6 on Treg generation. Thus, IL-6 appears to play a less prominent

role for inhibiting Foxp3 expression in the context of lamina propria DCs stimulated with TLR9 ligand than in our study using splenic DCs stimulated with TLR7 ligand 27. It has been previously shown that IL-6 Thymidylate synthase inhibits conversion of naïve T cells into Tregs and supports Th17 differentiation 28, 29. In fact, we also observed higher concentrations of IL-17 in cocultures stimulated with TLR7 and TLR9 ligands correlating with reduced numbers of Tregs. Expression of RORγτ and IL-17 mRNA in Foxp3+ T cells generated in the presence of TLR7 ligand (Supporting Information Fig. S3B) suggests that this population contains cells which are in transition to Th17 cells resembling the recently described proinflammatory “ex Foxp3” cells 26. LPS induced even higher IL-17 production disproportionate to the low amounts of IL-6 induced by LPS compared with TLR7 and TLR9 stimulation. These results support the finding that Th17 induction can also occur independently of IL-6 29. IL-23 did not play a role in our experimental system since it was not induced in DC–T-cell cocultures stimulated with TLR7 or TLR9 ligands. We can exclude that the lower Treg numbers generated in DC–T-cell cocultures in the presence of TLR7 ligands are due to a proliferation or survival advantage of Foxp3− T cells, which could have outgrown Foxp3-expressing Tregs.

All together these findings unveil the ability of c-Cbl to regula

All together these findings unveil the ability of c-Cbl to regulate inducible Hrs monoubiquitination. Hrs is found in the cytosol and on limiting membranes of early endosomes [22, 23]. Urbè and coauthors [23] have proposed that Hrs tyrosine phosphorylation may relocate Hrs from endosomal limiting membranes to the cytosol. Moreover, a more recent study [28] supported a role for Hrs poly-ubiquitination downstream of EGF stimulation in regulating LDK378 research buy Hrs cytosolic relocation and degradation. Thus, we initially examined the distribution

of phosphorylated and ubiquitinated Hrs species between particulate-membrane and cytosolic constituents of an RBL-2H3 cell postnuclear supernatant. After having established the validity of our fractionation procedure by anti-β and anti-tubulin immunoblot

performed on total proteins from membranes and cytosol fractions (Fig. 5A), equal protein amounts of both fractions obtained from unstimulated (-) and stimulated cells were immunoprecipitated with an anti-Hrs Ab and sequentially immunoblotted as indicated (Fig. FK506 solubility dmso 5B). Five minutes after receptor cross-linking, phosphorylated Hrs was highly enriched in membrane fraction (Fig. 5B, upper panel), and this enrichment correlated with accumulation of Syk on the same location (Fig. 5A, bottom panel), suggesting that Syk-dependent Hrs phosphorylation occurs at membrane level. Interestingly, a persistence of phosphorylated Hrs in membrane compartment was observed after longer time of stimulation (data not shown). Conversely, the anti-Ub and anti-Hrs immunoblots showed that the majority of monoubiquitinated Hrs was enriched in the cytosol upon Ag stimulation (Fig. 5B, middle and bottom panels). Based on these results, we conclude that tyrosine phosphorylated Hrs preferentially localizes in the membrane fraction whereas monoubiquitinated forms of Hrs to are predominantly cytosolic. To investigate whether Hrs modifications could affect protein stability, RBL-2H3

cells were pretreated with cycloheximide to block protein synthesis before antigen stimulation, and the levels of Hrs were analyzed by western blot of whole-cell lysates (Supporting Information Fig. 5). While a time-dependent decrease of Syk expression (∼50%) was observed in line with previous reported susceptibility of Syk to proteolysis [17, 31, 32], Hrs expression remained substantially stable until 8 h after FcεRI engagement, supporting the notion that Hrs modifications do not act as a degradation signal on mast cells. All together, our findings indicate that Syk/Cbl-induced Hrs modifications, without affecting protein stability, might impact on the ability of Hrs to function as endocytic adapter. In addition to its key role in IR-mediated signaling transduction events, Syk is also required for endocytosis of engaged BCR and FcεRI in B and mast cells, respectively [8, 10, 11].

“Differences in infant distress and regulatory behaviors b

“Differences in infant distress and regulatory behaviors based on the quality of attachment to mother, emotion CHIR-99021 chemical structure context (frustration versus fear), and whether or not mothers were actively

involved in the emotion-eliciting tasks were examined in a sample of ninety-eight 16-month-old infants and their mothers. Dyads participated in the Strange Situation, a limiting task designed to elicit infant frustration, and a novelty task designed to elicit infant fear. Mothers were asked to remain uninvolved during the first minute of each task and then instructed to engage with their infants as they wished for the remaining 3 min. Independent of concurrent maternal sensitivity, resistant infants were significantly more distressed than secure and avoidant infants. Avoidant infants engaged in fewer active mother-oriented regulation behaviors than secure and resistant infants and engaged in more self-soothing in the mother-involved condition than the mother-uninvolved condition. Resistant infants engaged in more physical comfort with their mothers and more venting than both secure and

avoidant AZD8055 in vivo infants and exhibited a smaller variety of adaptive non-mother-oriented strategies than did secure infants. There were few differences in infant distress and regulatory behaviors as a function of emotion task and maternal involvement. Limitations and implications for future research are discussed. “
“Recent studies demonstrated that in adults and children recognition of Cytidine deaminase face identity and facial expression mutually interact (Bate, Haslam, & Hodgson, 2009; Spangler, Schwarzer, Korell, & Maier-Karius, 2010). Here, using a familiarization paradigm, we explored the relation between these processes in early infancy, investigating whether 3-month-old infants’ ability to recognize an individual face is affected by the positive (happiness) or neutral emotional expression displayed. Results

indicated that infants’ face recognition appears enhanced when faces display a happy emotional expression, suggesting the presence of a mutual interaction between face identity and emotion recognition as early as 3 months of age. “
“Languages instantiate many different kinds of dependencies, some holding between adjacent elements and others holding between nonadjacent elements. In the domain of phonology–phonotactics, sensitivity to adjacent dependencies has been found to appear between 6 and 10 months. However, no study has directly established the emergence of sensitivity to nonadjacent phonological dependencies in the native language. The present study focuses on the emergence of a perceptual Labial-Coronal (LC) bias, a dependency involving two nonadjacent consonants. First, Experiment 1 shows that a preference for monosyllabic consonant-vowel-consonant LC words over CL (Coronal-Labial) words emerges between 7 and 10 months in French-learning infants.

gondii infection could be mediated by this cell population Howev

gondii infection could be mediated by this cell population. However, as can be observed in a representative FACS analysis (Fig. 2A), the percentage of CD4+Foxp3+ cells BGB324 cost decreased at 7 dpi, and markedly dropped at 14 dpi. Results from several experiments showed that Treg-cell percentage decreased by 16.3% at 7 dpi and by 50.4% at 14 dpi (Fig. 2B)

when compared with control animals. A similar reduction in the absolute number of Foxp3+ cells was also detected (Fig. 2C), demonstrating that the decline in Treg-cell percentage is not consequence of a disparity in the proportion of other cell subsets. Further analysis of the residual Treg cells showed that at 7 dpi the percentage of natural Treg cells (Helios+) and induced Treg cells (Helios−) is comparable to that observed in uninfected animals, whereas at 14 dpi a slight reduction in the proportion of natural Treg cells was observed (Fig. 2D and E). The above results indicate that T. gondii-induced suppression concurs with a reduction in Treg cell number. In order to explain this apparent contradiction, we analysed the expression of activation markers in the residual Treg-cells. We focused on cells from mice at 7 dpi because at this time point immunosuppression was already detected and the number of Treg cells still allowed a proper analysis. Expression of CD25, CTLA-4 and GITR rose up in Foxp3+ cells from infected mice (2.5-, 3- and 0.5-fold,

respectively); the proportion LY294002 of Treg cells expressing these molecules was also slightly increased (Fig. 3). Analysis of additional activation molecules showed that the percentage of CD69+ and CD62L− cells increased 1.9- and 1.3-fold, respectively. Modulation of these molecules has already been reported after Treg-cell activation 25, 35–37. A significantly enhanced expression of CD69 was also detected; expression of CD62L and CD103 remained unchanged. DNA ligase Thus, although infection leads to a reduction in Treg-cell number, the residual cells display an activated phenotype. Treg-cell activation observed after

infection suggested that these cells might also increase their suppressive capacity. We thus compared the suppression capacity of Treg cells from infected and uninfected mice against target cells from uninfected animals. We initially carried out suppression assays using CD4+CD25+ cells as Treg cells and CD4+CD25− cells as target cells, and found a slight increase in the suppression capacity of CD4+CD25+ cells obtained from infected mice (data not shown). Although this separation protocol is the most commonly used, an increase in the CD4+Foxp3−CD25+ cell population, corresponding to activated T cells, is observed in infected mice (Fig. 4A, 1.3 versus 17.5%). Therefore, the CD4+CD25+ fraction used in that system was enriched with activated T cells, and the suppression capacity of Treg cells from infected animals cannot be addressed.

Higher FGF23 concentrations have been consistently associated wit

Higher FGF23 concentrations have been consistently associated with increased risk of mortality at all stages of CKD, independent of traditional renal and cardiovascular risk factors.[91-94] In animal studies FGF23 excess as a result of direct intracardiac administration of a mutant FGF23 (and where klotho is absent) has been shown to lead to left ventricular hypertrophy and provides a plausible mechanism of direct cardiac injury at the high concentrations observed in advanced disease.[95] The significance that these experiments were carried out with mutant FGF23 resistant to furin PD0325901 order protease digestion is not known. However, supporting independent links between FGF23

and cardiovascular outcomes and mortality is the integrity of such associations after adjusting for phosphate, PTH and vitamin D levels.[91-94] It has yet to be established whether specifically lowering FGF23 or antagonizing its action would yield clinical benefit. Indeed, antagonizing FGF23 with a specific antibody increased vascular calcification and mortality in animals with renal impairment.[96] The downregulation of klotho expression in tissues where it is expressed has been linked to enhancement of the klotho-independent effects of FGF23 in other tissues. One explanation is that with less

binding to the klotho–FGFR STA-9090 complex, more FGF23 is left in the circulation to bind ‘off-target’ to other FGFR, where specificity to the receptor is low, yet ligand present in excess so causing activation of other low specificity FGFR at non-physiological sites. A consistent finding in CKD is the overall decrease in mKl expression in the kidney, parathyroid glands and vasculature.[97] Although human studies Interleukin-3 receptor of mKl have been

limited due to difficulty in obtaining tissue to determine expression, there appears to be good evidence of reduced kidney mKl expression in animal CKD models.[31, 98] A low level of sKl in plasma and urine of mice with CKD has also been reported.[31] Human studies reporting on associations between circulating sKl and renal function have been capricious even using the same assay (Table 1). Seiler et al. reported no correlation between sKl levels and renal function[43] while other investigators report an increase in sKl with declining GFR.[49, 50, 55] More than half of the human studies in patients with CKD however have documented a reduction in sKl levels with reduced GFR.[39-41, 52-54] The aforementioned issues with assay performance may underpin the apparent discordant results, but may also relate to differences in study setting or simply reflect intricacies of klotho metabolism, which as yet we do not understand. Nonetheless, reductions seen in mKl suggest a relative deficiency of klotho in CKD.


However, the proportion of 2B4-expressing


However, the proportion of 2B4-expressing selleck kinase inhibitor cells was decreased significantly in CD56+ NK cells and CD14+ monocytes from patients with SLE compared to healthy controls (Fig. 4c,d). Although all monocytes are known to express 2B4, monocytes from two patients with SLE (patient 7, SLEDAI = 8 and patient 17, SLEDAI = 4) showed almost no expression of 2B4. Interestingly, when we compared the expression of 2B4 at the single-cell level, the MFIR of 2B4 was down-regulated significantly by all 2B4-expressing cells, including total PBMCs, CD3+ T cells, CD56+ NK cells and CD14+ monocytes (Table 2). Consistent with the 2B4 splice variant result, these data indicate clearly that the expression of 2B4 is altered in SLE. In the present study we have analysed the expression and differential splicing of 2B4 and CS1, two members of the SLAM family in PBMCs from patients with SLE. The important roles of SLAM family receptors are recognized increasingly due to their broad expression in immune cells, including haematopoietic stem and progenitor Acalabrutinib molecular weight cells [47]. As most SLAM family receptors are self-ligands, one important feature of these receptors is their capability to mediate both homotypic and heterotypic cell-to-cell interactions. For example, CS1-expressing B cells can interact not only with nearby CS1-expressing B cells but also with other immune cells expressing CS1, such as dendritic cells. Unlike other members of the SLAM

family, the ligand for 2B4 is CD48. However, 2B4-expressing cells can also interact homotypically with each other ADP ribosylation factor because CD48 is expressed on all haematopoietic

cells, including 2B4-expressing cells. There is an accumulation of data demonstrating a critical role played by SLAM family receptors in immune regulation [48–50]. SLE is characterized by hyperreactive B cells that produce pathogenic autoantibodies. However, detailed features of B cell abnormalities are largely unknown. Recently, a number of different subsets of circulating B cells were reported in SLE, including naive B cells, memory B cells, plasma cells and plasmablasts [51]. Our flow cytometry study also found distinct subsets of CD19-positive B cells in PBMCs of SLE patients, based on CS1 expression; CS1-negative B cells (CD19-middle), CS1-low B cells (CD19-high) and CS1-high B cells (CD19-low) (Fig. 3). According to a recent study, the majority of CD19+ B cells are IgD+ and CD27-, indicating naive B cells [52]. They also reported CD19-high B cells as autoreactive memory B cells, and the frequency of this population correlates with disease activity [52,53]. Also, active SLE disease has been shown to correlate with a high frequency of plasma cells, which express high levels of CD27 and low levels of CD19 [54,55]. Based on these studies, we believe that CS1-negative, CD19-middle B cells are naive B cells; CS1-low, CD19-high B cells are memory B cells; and CS1-high, CD19-low B cells are plasma cells.