The lack of a focused expansion of particular TCR-bearing CD4+ T cells in the primary and secondary infection models also suggests to us that multiple (rather than dominant) parasite antigens are recognized by the host. This study provides important information for the control of Leishmania infection. We thank Mardelle Susman and Dr Jiaren Sun for critical reading of this manuscript, Dr Zhong Kou from the BioMed Immunotech

for insightful discussion and TCR analyses and Dr Alai Tan for statistical analyses. This research was supported by National Institutes of Health Grants AI043003 to L. Soong. Figure S1. TCR Vβ usage in naive and parasite-stimulated CD4+ T cell. “
“Glucocorticoids buy Belinostat (GCs) are amongst the most effective anti-inflammatory drugs, but are often associated with

serious adverse side effects or inadequate therapeutic responses. Here, we utilize activation of different Toll-Like Receptors (TLRs) by their respective ligands to evaluate context-specific GC sensitivity in the macrophage. Recruitment and activation of TGF-β activated Kinase 1 (TAK1), downstream of TLR engagement is crucial in activating multiple inflammatory pathways, and contributes to inflammatory disorders. We hypothesize that GCs exert anti-inflammatory effects through regulation of TAK1. Both in vivo and in vitro, in comparison to other TLRs, we observe limited GC potency in Morin Hydrate restricting TLR4 ligand-mediated secretion of IL-6, TNF-α and IL-12. Also, we found that inactivation of TAK1 both in vivo and in vitro strongly inhibits Barasertib datasheet TLR4-induced inflammation-associated genes beyond the suppressive effects from GC treatment. However, there was no effect of TAK1 inactivation on GC inhibition of TLR3 or TLR9 initiated inflammatory actions. Together, our findings demonstrate that GC resistance for TAK1 activation associated

with TLR4 engagement may be an important contributor to GC resistance in inflammatory disorders. This article is protected by copyright. All rights reserved. “
“Sialic-acid-binding immunoglobulin-like lectins, siglecs, are important immune receptors expressed widely in mammals. A unique feature of siglecs is their ability to bind sialylated glycans and transmit signals to immune cells. The CD33-related siglecs (CD33rSiglecs) form a major subfamily of the siglecs, containing a large, rapidly evolving group of genes that expanded in mammals through an inverse duplication event involving a primordial cluster of siglec genes over 180 million years ago. Humans express a much larger set of CD33rSiglecs than mice and rats, a feature that can be explained by a dramatic loss of CD33rSiglec genes in rodents. Most CD33rSiglecs have immune receptor tyrosine-based inhibitory motifs and signal negatively.

B6Idd3 mice exhibit an increased suppressor activity compared to NOD CD4+CD25+ T cells. To determine whether the protection mediated by NOD.B6Idd3 CD4+CD25+ T cells was due to quantitative or qualitative differences within the pool of CD62LhiFoxP3+Tregs, the suppressor

activity of these immunoregulatory effectors was tested in vitro. CD62Llo- and CD62Lhi-expressing CD4+CD25+ T cells were FACS sorted from the PaLN of 16-wk-old NOD.B6Idd3 and NOD female mice, and then cultured at various ratios with naïve CD4+ T cells from the spleen of NOD mice. As expected, CD62LloCD4+CD25+ T cells from either NOD.B6Idd3 or NOD female mice were inefficient at suppressing proliferation of the stimulated CD4+ T cells (Fig. 5D). On the other hand, CD62LhiCD4+CD25+ T cells effectively suppressed proliferation of the responder CD4+ selleckchem T cells. Furthermore, no significant difference in suppressor activity of NOD.B6Idd3 and NOD

CD62LhiFoxP3+Tregs was detected (Fig. 5D). Therefore, the enhanced suppressor activity detected in the PaLN of NOD.B6Idd3 mice is due to an increased number of CD62LhiFoxP3+Tregs, consistent with results obtained in the above co-adoptive transfer experiments (Fig. 5C). Since IL-2 Cabozantinib molecular weight secretion by conventional T cells is limited in NOD mice compared with NOD.B6Idd3 animals (Supporting Information Fig. 1) 38, then increasing the level of “endogenous” IL-2 would be expected to enhance the frequency of CD62LhiFoxP3+Tregs in vivo. To test this hypothesis, 10-wk-old NOD female mice were injected intramuscularly with a doxycycline inducible adeno-associated virus (AAV) recombinant encoding IL-2 (AAV-Tet-IL-2). No difference was detected in the frequency of CD4+CD25+Foxp3+ T cells

in AAV-Tet-IL-2 treated but uninduced NOD mice or animals left untreated (Fig. 6A and B). In contrast, NOD mice treated with AAV-Tet-IL-2 and in enough which IL-2 transgene expression was induced exhibited an increased frequency of CD4+CD25+Foxp3+ in all tissues tested (Fig. 6A and B), and showed a significant increase in CD62Lhi-expressing CD4+CD25+Foxp3+ T cells in the PLNs (Fig. 6C). Furthermore, addition of IL-2 to FACS-sorted CD62Llo-expressing CD4+CD25+ T cells upregulated expression of CD62L in vitro (Fig. 6D). These results indicate that: (i) IL-2 availability in vivo regulates the frequency of CD62LhiFoxP3+Tregs, and (ii) IL-2 can “convert” CD62LloFoxP3+Tregs into CD62LhiFoxP3+Tregs in vitro. Analyses of NOD mice congenic for protective Idd3 intervals have shown that aberrant expression of IL-21 and IL-2 influences various aspects of β-cell autoimmunity in NOD mice 34–38. Increased expression of IL-21 and IL-21R by T cells is associated with enhanced development of pathogenic T effectors in NOD mice through, for instance, disruption of T-cell homeostasis 34, 36, 40–42. IL-21 has also been reported to render conventional T cells resistant to the suppressor effects of FoxP3+Tregs 43, 44.

CS responses were elicited on day 4 after sensitization by painting both sides of the ears with 10 μl of 0.4% TNP-Cl in acetone and olive oil (1:1). Non-immunized controls were challenged identically. Ear thickness was measured with selleck kinase inhibitor a micrometre 1 day prior to challenge (baseline) and then 2 h (peak of the CS-initiating phase) and 24 h (peak of the CS-effector phase) following challenge. Ear swelling units were expressed in mm × 10−2. Each

bar represents the average response ±SE in a group of four mice. Hepatic lipid extraction from contact-sensitized mice.  Wild-type BALB/c mice were contact-sensitized or sham-sensitized as described earlier. Thirty minutes later, mice were killed by cervical dislocation. Livers were isolated and placed in 2 ml of water on ice for several minutes to allow for hypotonic cell lysis before homogenization with tissue tearor at 17 000 rpm for 1 min. Samples were then sonicated while on ice for 1–2 min. Lipids were subsequently isolated from the lysate by two serial cycles of chloroform and methanol extraction (10 volumes each per gram of tissue per cycle; incubations were 12 h followed by 4 h, each at 4 °C). We recognize that the extracts we obtained also contained

DNA and RNA, but herein for convenience we refer to them as ‘lipid extracts. Isolation of iNKT cell-containing liver mononuclear cells (LMNC).  Liver mononuclear cells isolation was performed as described previously [9]. LMNC were obtained from wild-type BALB/c mice Cyclooxygenase (COX) except as otherwise indicated in the text. Viability HDAC inhibitor was >90%, and ∼0.5−1 × 106 LMNC were obtained per mouse. iNKT cells constitute approximately 70% of wild-type LMNC; hepatic iNKT cells have previously been shown to play a key role in CS [9]. For simplicity, iNKT cell-containing LMNC will be referred to as ‘iNKT cells’ in the text. In vitro treatment of iNKT cells with lipid extracts.  Naïve wild-type iNKT

cell-containing LMNC were incubated in vitro with α-GalCer or hepatic lipid extracts from wild-type mice (after either contact sensitization or sham sensitization), with or without anti-CD1d antibody (at a concentration of 10 μg/ml for 1 h at 37 °C). Lipid donors and LMNC donors were age-, sex- and size-matched. The ratio of number of lipid donors to number of LMNC donors was 1:1 in incubations. Isolation of peritoneal B-1 B cells.  Peritoneal cells of wild-type CBA/J were harvested by lavage with 4 ml of cold 1% foetal bovine serum (Gibco BRL, Carlsbad, CA, USA) containing heparin (10 U/ml; Sigma) in PBS, washed three times and resuspended in RPMI 1640 containing 10% FBS, 25 mm Hepes, 100 units/ml penicillin and 100 μg/ml streptomycin; 5 × 106 peritoneal cells were obtained per mouse. Peritoneal cells contain approximately 20% B-1 B cells; the vast majority of murine B-1 B cells reside in the peritoneum.

4a). Given these results, and the delay in B-cell maturation check details suggested by flow cytometric analysis of the bone marrow, we next considered the possibility that over-expression of the dnRAG1 transgene might render V(D)J recombination inefficient, resulting in a restricted B-cell repertoire. To test this possibility, we examined

the immunoglobulin heavy chain repertoire by amplifying VH-D-JH junctions from genomic DNA isolated from WT and dnRAG1 mouse spleens, and analysing nested runoff PCR products by sequencing gel electrophoresis as illustrated in Fig. 4(b).24 Three different VH gene families (J558, 7183, and Q52) were evaluated using this approach. In this assay, small differences in fragment length among amplicons from a given gene family reflect junctional diversification of CDR3 that occurs during V(D)J recombination: the pattern of the CDR3 length distribution is proportional to the fractional abundance of each rearrangement in the original sample. We found that the profile selleck compound of runoff products from several WT animals shows a largely Gaussian distribution for all three VH families

tested, indicative of a highly diverse repertoire. In contrast, the CDR3 length distributions of all three VH gene families from three different dnRAG1 mice are clearly skewed toward a smaller number of fragment lengths (Fig. 4c,d). These data suggest that while splenic B cells in dnRAG1 mice are clonally diverse, the CDR3 repertoire among these cells is more restricted than in their normal counterparts. buy Atezolizumab Because B220lo CD19+

B cells in 12-week-old dnRAG1 mice account for about 20% of splenic B cells at this age, we considered the possibility that the molecular features of the B220hi CD19+ B cells may partly mask those of the B220lo CD19+ B-cell population in a bulk splenic B-cell preparation. To address this issue, we sorted the two populations (Fig. 5a), and isolated genomic DNA or total RNA to compare immunoglobulin gene rearrangement patterns and immunoglobulin light chain gene sequences (Fig. 5b,c). Consistent with results obtained with bulk splenocytes, B220hi CD19+ B cells from WT and dnRAG1 mice showed fairly similar patterns of VH-to-DJH and Vκ-to-Jκ rearrangements (Fig. 5b). Interestingly, however, skewing was clearly evident in the rearrangement patterns detected from B220lo CD19+ B cells, particularly in the Igκ locus, where Jκ1 segment usage predominates over other Jκ rearrangements (Fig. 5b). This finding is confirmed by the preponderance of light chain genes containing the Jκ1 segment cloned from B220lo CD19+ B cells (11/15 clones sequenced), whereas Jκ usage is more evenly distributed between Jκ1, Jκ2 and Jκ5 segments among clones sequenced from B220hi CD19+ B cells sorted from WT and dnRAG1 mice (Fig. 5c, lower left panel).

3 In the systematic review by Balk et al.,2 published after the three meta-analyses, the authors reviewed all uncontrolled and controlled data in total. The authors identified 2 RCTs, 8 comparative studies and 25 cohort studies and found that when considering all evidence there was a better BP reduction (8 mmHg) in the angioplasty versus medical treatment arm. However, the studies were uncontrolled mTOR inhibitor and non-randomized so many methodological issues existed in the majority and in particular, there was the suggestion that the ‘intensive

medical therapy’ was not equal between the groups. In addition, the combined adverse event rates included death by 30 days which was 3% with the other complications of transient deterioration in kidney function

of up to 13%, renal artery injury of 5% and peri-procedural cardiovascular system (CVS) events of 3%. Thus, one can conclude that the review does not favour one treatment modality, that there is weak evidence for similar CVS outcomes and the small improvement in BP (mainly in bilateral renal disease) is likely outweighed by the morbidity. Leertouwer et al.9 performed a meta-analysis of renal arterial stent placement in comparison with renal angioplasty in patients with RAS, including studies published up to August 1998. This systematic review did not report on the quality of the studies as did Balk et al.2 and included uncontrolled RG 7204 Forskolin solubility dmso studies. It suggested that stents are better but is very weak in the quality of its conclusions because of the uncontrolled nature of the data it surveyed. Despite achieving changes in arterial patency,

none of the four studies mentioned above has shown significant advantage in slowing renal progression through renal angioplasty over and above conventional medical therapy. Interpretation is limited by the fact that each of these studies has focused on patients with hypertension rather than those with documented progressive renal impairment. In the ASTRAL study the rate of progression of renal impairment (as shown by the slope of the reciprocal of the serum creatinine level) was −0.07 × 10−3 L/µmol per year in the revascularization group, compared with −0.13 × 10−3 L/µmol per year in the medical therapy group, a nonsignificant difference favouring revascularization of 0.06 × 10−3 L/µmol per year (95% confidence interval, −0.002–0.13; P = 0.06).3 This nonsignificant trend is weakened by the fact that the number of patients able to be reported on at 5 years was 72 (revascularization) versus 61 (medical).

IL-7Rα levels, as measured by mean RFI, were not significantly changed in the post-selection DP and CD8SP populations, although in the CD4SP (p=<0.05), and CD4+CD8lo thymocytes (p<0.002), mean RFI values were lower in Egr2f/fCD4Cre mice

relative to Egr2f/f X-396 littermates (Fig. 6A and Supporting Information Fig. 3). Therefore, IL-7R is present on post-selection cells, and there is a partial defect in its upregulation post-selection in some Egr2f/fCD4Cre subsets, perhaps attenuating the survival signal. Although the loss of high-level IL-7R signaling in post-selection CD4+CD8lo cells may be of importance, regulation of survival during selection itself is accomplished by suppressor of cytokine signaling 1 (Socs1), a protein that functions downstream of cytokine receptors, and takes part in a negative feedback loop to attenuate cytokine signaling. Pre-selection DP are susceptible to apoptosis because cytokine signal transduction is suppressed by high levels of Socs1, and cytokine responsiveness, and hence protection from apoptosis is only restored when

Socs1 is downregulated in response to TCR signaling during selection 30. Loss of Socs1 during thymocyte development results in an increase in the Nivolumab concentration CD8SP subset 33, as also observed here in Egr2-Tg mice. To determine whether Egr2 was able to influence Socs1 expression, thymocytes from Egr2-Tg and Egr2f/fCD4Cre knockout mice and littermate controls were sorted as shown in Fig. 1A, and Socs1 mRNA levels determined by qRT-PCR. Figure 6B demonstrates that relative to controls, levels of Socs1 were higher in both pre- and post-selection DP in Egr2f/fCD4Cre knockout mice, and lower in the same populations from Egr2-Tg animals. In CD8 and CD4SP thymocytes, Socs1 was downregulated normally irrespective of genotype. Therefore, Egr2 is able to regulate Socs1 expression during selection, but does not thereafter. Socs1 prevents cytokine signaling through inhibition of Stat5 phosphorylation 34, and so pStat5 levels following cytokine stimulation Cediranib (AZD2171) should be lowered in Egr2f/fCD4Cre mice, where Socs1 is increased. CD69+ post-selection thymocytes

were purified from Egr2f/fCD4Cre and Egr2f/f thymuses, and stimulated with IL-7 for 0, 10 and 20 min, after which pStat5 induction was assessed by Western blotting. As shown in Fig. 6C, relative to total Stat5 protein, pStat5 was reduced in the absence of Egr2. We then went on to assess whether IL-7-mediated survival was impaired. Although we did not observe gross changes in the survival profile of total thymocytes in the presence of IL-7 (data not shown), Fig. 6D shows that loss of Egr2 resulted in impaired survival of purified post-commitment CD4+CD8lo cells when cultured in the presence of IL-7 over a 3-day period. Therefore, loss of Egr2 results in Socs1 de-repression, and this, perhaps combined with the defect in IL-7R upregulation, causes a decrease in Stat5 phosphorylation and survival.

In the general population, a meta analysis of the Physicians’ Health Study I and II (healthy male physicians, aged 40–84 years) and Women’s Health Study (healthy female physicians aged >45 years) showed that there was no significant reduction in SCD in participants taking aspirin for primary prevention (91 SCD/61947, HR = 0.78, 95% CI = 0.52–1.18).[19] The event rate was see more small. Aspirin-prescribing habits in haemodialysis patients vary widely in different countries, from 8% in Japan to 41% in Australia and New Zealand. In observational studies, this was associated with no increase in gastrointestinal bleeds.[20] There should be future RCTs to validate whether aspirin is effective in preventing SCD in haemodialysis

patients. High aldosterone levels are reported to be an independent risk factor for SCD in non-dialysis CKD; an increase of 50 pg/mL of aldosterone was associated with an adjusted HR of 1.32 (P < 0.001, 95% CI = 1.15–1.52).[21] In an analysis B-Raf assay of randomized trials utilizing ACEIs in patients without renal disease and post-myocardial infarction, ACEI was associated

with a reduction in SCD (OR = 0.80, 95% CI = 0.70–0.92).[22] The proposed mechanisms include blood pressure reduction, inhibition of neuro-humoral activation and regression of LVH.[22] No equivalent RCT data exist for CKD-5D. To date, RCTs have been undertaken which primarily explore the effect of ACEI on cardiovascular mortality and events, rather than SCD specifically. In the Fosinopril in Dialysis Acyl CoA dehydrogenase Trial (FOSIDIAL), 397 haemodialysis patients were randomized to fosinopril or placebo. After a 2 year follow-up, there was no reduction in cardiovascular events (RR = 0.929; 95% CI = 0.68–1.26) with fosinopril.[23] After adjustments for risk factors, there was a trend towards benefit in the treatment arm (adjusted RR = 0.79, 95% CI 0.59–1.1, P = 0.099), but like so many studies in dialysis patients, this one was underpowered. A further small open-label RCT[24] investigated the effect of candesartan (4–8 mg/day) versus placebo in 80 haemodialysis patients without cardiomyopathy. After a median follow-up of 19.4 ± 1.2

months, there were more cardiovascular events and increased mortality in the control group versus the treatment group (cardiovascular events: 45.9% vs 16.3%, and mortality: 18.9% vs 0.0%, P =< 0.01). There were only three SCD in the control group and none in the treatment group.[24] The study was therefore inconclusive on the effects of candesartan on SCD. Nevertheless, a sound theoretical basis exists for potential benefits of renin-angiotensin blockade in CKD-5D. Further studies are required to test these hypotheses. In the general population, the Randomised Aldactone Evaluation Study (RALES Study) randomized 1663 patients with LVEF <35%, including 792 with CKD who had baseline estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 cm2, to spironolactone or placebo.

The advances in understanding of DC biology and function led to the development of anticancer DC vaccine concepts [3]. For this purpose, the DC are most commonly generated ex vivo from patient’s monocytes [4], matured and loaded with tumour-specific antigens before injecting them back into the patient’s body. The basic idea of this approach is that the DC will migrate to secondary lymphoid organs and induce an immune response towards the tumour. Even though some promising SCH772984 in vitro results have been obtained in multiple clinical trials with different cancer types [5], this approach still needs improvement.

Renal transplant recipients (RTR) have a high risk of tumour development, especially cutaneous squamous cell carcinomas (SCC), due to long-term immunosuppressive therapy [6, 7].

The problem of SCC in RTR is the Atezolizumab high risk of developing multiple lesions. These lesions often develop at anatomical sites where surgical excision with primary closure is not straightforward. In a subgroup of these patients, this gives rise to an increased morbidity and mortality due to more aggressive SCC with a higher risk of local recurrence and metastasis [8-12]. Thus, management of patients with a high tumour burden is challenging and often requires a multidisciplinary approach [13]. Therefore, new therapeutic approaches such as immunotherapy are required. One possible Arachidonate 15-lipoxygenase explanation for the increased risk of SCC might be impaired immune surveillance in RTR due to a reduction in DC subsets in blood [14-17] and in skin [18]. The immunosuppressive drugs affect not only T lymphocytes, but have also an effect on differentiation and maturation of DC, indicated by lower numbers and functional deficits of various circulating DC populations in immunosuppressed patients [17, 19-22]. It is less clear, however, if it is possible to generate fully functional monocyte-derived dendritic cells (moDC) from these patients

as there exist inconsistent reports on this issue [20, 23]. To evaluate the possible use of a moDC-based vaccination strategy for the treatment of SCC in immunosuppressed patients, we here analysed the phenotype and cytokine profile of moDC from long-term immunosuppressed patients. The Norwegian Renal Registry was used to identify RTR living in Hordaland County in western Norway as described elsewhere [17]. The baseline characteristics of the patients and controls are summarized in Table 1. The study was performed according to the Declaration of Helsinki and was approved by the Regional Committee for Research Ethics (176.08) and the Data Inspectorate.

1 MHC II expression is tightly controlled at several levels. Transcriptional regulation confines constitutive MHC II expression to professional

APCs and thymic epithelial cells and allows up-regulation on other cell types after exposure to inflammatory cytokines.2 Post-translational events also regulate cellular localization of MHC II, thereby influencing MHC II half-life. In immature dendritic cells (DCs), MHC II molecules are efficiently targeted to lysosomes by the clathrin adaptor protein complex 2 (AP-2) and/or by the E3 ubiquitin ligase, membrane-associated RING-CH protein 1 (MARCH-I) and are degraded within a few hours; surface expression remains relatively low. DC activation stimulates a transient burst of MHC II synthesis, this website turn-off of MARCH-I and deposition of peptide/MHC II complexes at the plasma membrane, where they are long-lived (> 100 hr). Data from B-cell lines, melanoma lines and human monocytes see more implicate similar pathways in control of MHC II levels in these cell types.3–6 Expression levels of MHC II are also influenced by interaction with accessory molecules that regulate MHC II peptide loading: MHC II-associated invariant chain (Ii) and HLA-DM

(DM). Nascent MHC II molecules assemble in the endoplasmic reticulum with Ii; in cells from animals lacking Ii, surface levels of most MHC II alleles are substantially reduced because of inefficient assembly and egress.7–9 After assembly, MHC II/Ii complexes travel to endocytic compartments, directed by sequences in the Ii cytoplasmic tail; there, Ii is sequentially degraded by cathepsins.10 Groove-bound Ii remnants, the class TCL II-associated Ii peptides (CLIPs), are exchanged for antigenic peptides with the assistance of the peptide exchange factor DM.11 Chaperoning effects of DM provide further regulation of MHC II preservation/degradation1,2 (C. Rinderknecht and S. Roh, unpublished data). DM editing of peptides in favour of strong binders is also a factor, as the quality of peptide cargo is thought to influence

MHC II half-life.12–14 Despite active regulation of expression at the level of proteolysis, MHC II molecules must be relatively resistant to proteolytic attack. MHC II molecules traverse acidic, proteolytic endosomal compartments, where peptide loading occurs, for several hours en route to the plasma membrane.15–17 Moreover, in inflammatory settings, myeloid and stromal cells may release proteases into the extracellular fluid, yet MHC II molecules are abundantly expressed in such settings and must remain functional to allow local antigen presentation. The paradox of regulated turnover in the face of inherent proteolytic resistance is only beginning to be addressed. Only limited information exists regarding the proteases involved in constitutive or regulated MHC II turnover, or the factors that render MHC II molecules at least partially resistant to proteolytic attack.

Both types of memory B cells consistently upregulate the orphan receptor EBI-2 (T. Kaji and T. Takemori, unpublished), allowing them

to migrate into the outer B cell follicle [11]. However, it remains uncertain whether GC-independent memory B cells develop at the border of T- and B-cell zones or in the follicle. Although T-cell CXCR5 is needed for optimal GC responses, CXCR5-deficient GSK-3 cancer T cells are able to access follicles and induce GCs, albeit smaller in size compared with wild-type T cells [36, 40]. Likewise, a small number of GC B cells were generated in the spleen of mice in the absence of TFH cells at day 7 after immunization [2], raising the possibility that non-TFH cells may also access follicles and help B cells to respond at an early stage of the immune response. TFH cells secrete IL-21 [41]. IL-21 signaling profoundly affects GC function by promoting the proliferation of GC B cells and their differentiation into memory B cells. Accordingly, in mice deficient for IL-21, memory B cells exhibit lower levels

of somatic mutations in rearranged Ig V region genes compared with memory B cells from wild-type controls [8]. There is no specific cell surface marker known for memory B cells, although PD-L1, PD-L2, CD35, CD80, and ecto-5′-nucleotidase CD73 have Maraviroc solubility dmso been reported to be expressed on memory B cells in the spleen in contrast to naïve B cells [26] or naïve and GC B cells [42]. Along these lines, we have confirmed that the levels

of PD-L2 and CD80 expression are significantly increased in both GC-independent and -dependent memory B cells compared with those in naïve and GC B cells [2] (Fig. 1). However, as previously reported [9], CD73 is expressed on GC B cells and a subset of memory B cells in wild type mice as the immune response progresses. On GC-independent memory B cells, CD73 is expressed at a low level. In our study, approximately 80% of CD73+ memory B cells in wild-type mice carried somatically mutated Ig V region gene segments [2]. Thus, CD73 expression may preferentially mark somatically mutated memory cells. Although we observed costimulatory MHC class II, CD40, and CD80 molecules to be almost next equally expressed on both day 7 and day 40 GC-independent and -dependent memory B cells, the cell surface expression level of PD-L2 increased from day 7 to day 40 after immunization on both types of cells [2]. Thus, GC-independent and -dependent memory cells express several common surface markers at comparable levels, except for CD73. The memory B-cell population consists of clones that have proliferated in response to an antigen and then remain in a resting state for a long period of time [23]. Their survival is independent of T-cell help and of continuous contact with cognate antigen [43, 44]. It has been suggested that memory B cells localize in spleen and other secondary lymphoid organs [26], and also circulate in blood [6].