33,34 DC projections may extend to, or near, the luminal surface

33,34 DC projections may extend to, or near, the luminal surface and present antigens to lamina propria target cells. This is why genital ulcerations35 or any breach of epithelial integrity, including micro-trauma that can exist after consensual intercourse,4 heightens the risk of HIV-1 transmission. SP contains a potent inhibitor of the attachment of HIV-1 to DC-SIGN, which

inhibits the capture and transmission of HIV-1 to T CD4+ cells.33 A significant inhibition of HIV-1 capture was observed for both HIV-1 IIIB (CXCR4) and HIV-1 BaL (CCR5) using SP dilutions as high as 1:104.33 The effect of SP was not related to cell cytotoxicity, as cell viability was higher than 90% in these models.33 This group also incubated HIV-1 with B-THP-DC-SIGN cells and found that SP in dilutions up check details to 1:103 diminished capture of HIV-1

IIIB and HIV-1 BaL to the levels observed for DC-SIGN negative cells, while significant levels of inhibition were observed even at SP dilutions as great as 1:105.33 Monocytes, activated PBMCs, and the T cell line SupT-1 (all of which do not express DC-SIGN) were used as negative controls. Capture of HIV-1 by these cell populations was not inhibited by SP, supporting that CD4-dependent mechanisms of HIV-1 capture are Alectinib in vitro not inhibited by SP. Using structural analysis, it was determined that the component of SP with inhibitory effects on DC-SIGN had a molecular weight greater than 100 kDa and was heat stable and resistant

to the action of trypsin.33 SP, like HIV-1, can gain access to sub-epithelial target cellsand decrease the efficiency of HIV-1 transmission via DC-SIGN. Using a rhesus macaque model, Miller et al.36 tested the effects of SP on the efficiency of CF SIV transmission. In general, higher viral inoculums produced persistent viremia in monkeys, with or without the presence of SP. At lower viral load inoculums (e.g., 102 or 10 TCID50), the addition of SP showed a trend toward increasing the efficiency of persistent viremia among animals inoculated with SIV-mac251 grown in huPBMC stock. However, this trend was not clearly demonstrated among animals receiving SIV-mac251 grown in rhPMBcs.36 CA virus is also believed to be an important source of HIV-1 sexual transmission, but may be less efficient N-acetylglucosamine-1-phosphate transferase at crossing the CV mucosa when compared to CF virus.37,38 Semen of treatment-naïve infected men contains a significant number of infected leukocytes (from 3 × 104 to 5.6 × 107 cells/mL, between 10 000 and 80 000 HIV DNA copies/mL).39 Recently, Salle et al.37investigated intravaginal administration of CA SIV prepared from spleen cells obtained directly from two cynomolgus macaques infected with SIVmac251. This experimental design was thought to more accurately reflect the CA HIV-1 present in semen of infected men. Inoculated macaques (n = 9) were pre-treated with depot medroxyprogesterone acetate to thin the vaginal epithelium.

T lymphocytes were a major constituent of reproductive tract leuk

T lymphocytes were a major constituent of reproductive tract leukocytes from all tissues.

Fallopian tubes contained granulocytes as a second major constituent. Granulocytes were significantly less numerous in the other tissues. All tissues contained B-lymphocytes and monocytes as clearly detectable but minor components. The proportions of leukocyte subsets in tissues from pre-menopausal women showed only small differences related to stage of the menstrual cycle. Numbers of leukocytes were decreased in post-menopausal endometrial samples relative to pre-menopausal samples, when analyzed on a percentage of total cells or per gram basis, possibly reflecting, in part, a decreased population of immune cells in post-menopausal endometrium. The complete antimicrobial repertoire in FRT secretions is unknown. Furthermore, there is considerable variability in reports of antimicrobial concentrations within the FRT. While the best-studied ICG-001 mouse antimicrobials present in the FRT are shown in Table I, this list is incomplete in that other molecules exist in the FRT whose functional capacity is understudied (Table II). Endogenous antimicrobials are small peptides mainly produced by epithelial and immune cells (leukocytes) that possess antibacterial, antifungal, and antiviral activity against a broad range of pathogens.8 They

buy Bafilomycin A1 have distinct immunomodulatory functions including chemotaxis, cell proliferation, cytokine induction, and regulation of antigen uptake, which can be independent of or complementary to their direct protective effects.9 Importantly, while each antimicrobial is addressed individually below, in vivo they function as part of an intricate interconnected system. Several antimicrobials, for example, human beta defensin (HBD)2 and cathelicidin antimicrobial peptide LL-37,10 secretory leukocyte protease inhibitor (SLPI) and lysozyme,11 lactoferrin and lysozyme,11 display synergistic effects that potentially increase innate immune protection

in the FRT.5 Despite their structural and functional differences, antimicrobials possess some common elements. They are generally cationic amphipathic molecules that can directly interact with cell membranes with high acidic phospholipid content, subsequently forming pores that tetracosactide destabilize cells through the abolition of pH and ionic concentration gradients.5,9,12,13 The varying composition of cell membranes has been postulated as a reason for the differential activity of antimicrobials toward a range of pathogens.12 In addition, they are susceptible to the effects of pH, ion concentration (e.g. Na+, Mg2+), serum proteins, and protease inhibitor levels in the FRT, many of which, especially at higher physiological concentrations, are antagonistic toward antimicrobial activity.9,12,14–19 Human defensins cluster on chromosome 8 and are composed of two main functional families: alpha and beta defensins.

Thanks are also due to the many individuals who also help out wit

Thanks are also due to the many individuals who also help out with the CARI Critical Appraisal Training Day, the members of other various CARI Guideline Groups, those involved in Implementation activities and the CARI Steering Committee members for their continued support of CARI. Thanks are also due to the DNT Committee, KHA and the ANZSN Council for their wise and constructive governance of CARI. “
“Date written: June 2007 Final submission: October 2008 No recommendations possible based on Level I or II evidence (Suggestions are based on Level III and IV evidence) There is no evidence of increased problems with fertility or pregnancy complications in female

donors. No recommendation. A frequent question of potential donors of child-bearing age is whether donation will affect the ability to have a normal pregnancy. Furthermore, there is a theoretical concern that increased renal blood flow and GFR during pregnancy could be deleterious check details to a solitary kidney. The purpose of these guidelines is to review the available evidence relating to pregnancy outcomes following live kidney donation. Databases searched: MeSH terms and text words for kidney transplantation and living donor were combined with MeSH terms and text words for pregnancy. The search was carried out in

Medline (1966 – September Week 2, 2006). The Cochrane Renal Group Trials IWR-1 mouse Register was also searched for trials not indexed in Medline. The National Transplantation Pregnancy Registry (NTPR) [[email protected]] in the U.S. was contacted to provide any additional sources of abstracts. Date of search: 26 September 2006. Update search: Databases searched: MeSH terms and text words for kidney transplantation were combined with MeSH terms and text words for living donor and combined with MeSH terms and text words for open and laparoscopic nephrectomy. The search was carried out in Medline (1966

– March Week 1, 2009). The Cochrane Renal Group Trials Register was also searched for trials not indexed in Medline. Date of searches: 9 March 2009. The largest study by Wrenshall et al.1 is a retrospective questionnaire of female donors. Of 144 respondents (65%) the self-reported incidence Vasopressin Receptor of infertility and miscarriage was no different from those previously reported in a normal population. Pre-eclampsia was self-reported in 4.4% of donors (normal population incidence approximately 6–8%). There was no data on renal function and the true incidence of problems may have been underestimated because of the need for self-reporting. A retrospective review of 39 pregnancies (32 live births)2 in 23 women who had previously donated kidneys did not demonstrate any significant incidence of hypertension or proteinuria during the pregnancies. Ibrahim et al.3 reported on the outcome of 216 donors who had at least one pregnancy after donating a kidney. Of the 1537 female donors attending one centre, 939 responded to a survey regarding pregnancy.

81 Similarly, murine regulatory T cells (Tregs) transferred into

81 Similarly, murine regulatory T cells (Tregs) transferred into T cell-deficient hosts lost forkhead box P3 (Foxp3) expression acquired Tfh cell characteristics.90 Furthermore, in the scenario Navitoclax chemical structure of Th2 cells for example, they maintained IL-4 secretion and gata3 expression while gaining attributes of Tfh cells (CXCR5, Bcl-6, IL-21 expression). This suggests Tfh cells

may not represent a discrete lineage, but a state of differentiation that can be superimposed onto other Th subsets when B cell helper activity is required. This is supported by human studies, wherein the CD4+ CXCR5+ fraction could be subdivided into CXCR3+ Th1-like, CCR6+ Th17-like and CXCR3− CCR6− Th2-like Tfh cells.25 Th2- and Th17-like Tfh cells secreted IL-21 and could subsequently induce antibody production by naive B cells, while Th1-like Tfh cells did not express IL-21, nor could they support antibody production by B cells. Consistently, Th17- and Th2-like, but not Th1-like, Tfh cells were found to be elevated in juvenile dermatomyositis, a chronic multi-systemic autoimmune condition.25 The field of Tfh cells has evolved at an extremely rapid pace, which has helped to improve our understanding of this cell type. However, find more as it stands currently,

it appears that multiple varieties of Tfh cells exist. Thus, one of the interesting areas of future endeavour will be to determine whether Tfh cells are a discrete lineage or a state of activation of Th cell lineages when B cell helper function is required. Dysregulation of these cells underpins numerous Epothilone B (EPO906, Patupilone) human disorders, therefore, addressing this question will facilitate our ability to intervene in these diseases by altering the development and/or function of Tfh cells. This work was funded by grants and fellowships awarded by the Australian NHMRC to CSM and EKD. The authors have no conflicts of interest to disclose. “
“Studies

have indicated that interleukin (IL)-10 has a pathogenic role in systemic lupus erythematosus (SLE); however, a protective effect of IL-10 in SLE was also observed. Because the exact mechanism of IL-10 signalling in the pathogenesis of SLE is unclear, this study sought to assess the expression and signalling of interleukin-10 receptor (IL-10R) in peripheral leucocytes from patients with SLE. We used flow cytometry to examine the expression of IL-10R1 on different peripheral leucocytes from 28 SLE patients, of whom 14 had lupus nephritis (LN) and 14 were healthy controls. We also examined the effects of IL-10 on phosphorylation of signal transducer and activator of transcription (STAT)-3 and STAT-1 in peripheral blood mononuclear cells (PBMCs) obtained from 13 SLE patients and seven healthy controls. Plasma cytokines were detected by flow cytometric bead array (CBA) techniques.

By immunohistochemical staining, we confirmed Thy-1 expression on

By immunohistochemical staining, we confirmed Thy-1 expression on ECs derived from OVA-immunized WT mice (Fig. 4B) and a lack of Thy-1 expression on ECs in Thy-1−/− mice (Fig. 4D). Most importantly, Thy-1 was also not detectable on ECs in the lungs of chimeric mice, but several cells in the inflammatory infiltrate (most likely TCs) were Thy-1 positive Epacadostat mw (Fig. 4F). To exclude any effects of the lack of Thy-1 on TCs on the control of the extravasation of eosinophils during acute inflammation, chimeric mice were immunized with OVA, according to the standard protocol. Thy-1−/− mice and WT mice were immunized as controls. As shown in Fig. 5A, the total number of inflammatory cells in the BAL

was significantly diminished in Thy-1−/− mice as well as in chimera, APO866 mouse compared to WT mice. Differential staining showed that the number of both eosinophils and macrophages in the BAL fluid was diminished

in Thy-1−/− mice as well as in chimera, compared to WT mice (Fig. 5B). Thus, although Thy-1−/− BM chimera expressed Thy-1 on 70% of TCs and Thy-1−/− mice did not express Thy-1 on TCs, in both mice the extravasation of leukocytes, especially eosinophils, was significantly reduced, compared to the WT mice. These results confirm that the decreased infiltration of the lung in Thy-1−/− mice was not merely a consequence of the lack of Thy-1 expression on TCs. We have shown that Thy-1 is involved in the control PLEK2 of leukocyte recruitment during inflammation. Next, we ask whether Thy-1-dependent leukocyte extravasation during inflammation has further functional

consequences, such as the release of chemokines, cytokines, and proteases by the leukocytes. To address this issue, BAL and peritoneal fluid of WT and Thy-1−/− mice were compared. Cytokine and chemokine expression in the BAL was analysed by a membrane-based cytokine/chemokine array. The array results represent the chemokine/cytokine profile of three different WT and Thy-1−/− mice, respectively (Fig. 6). In the BAL of WT mice IL-4, IL-5, eotaxin-2 (CCL24), TARC (CCL17), and MIP-1α (CCL3) were augmented (quotient >1.25), compared to Thy-1−/− mice (Fig. 6A). Analysis of mRNA expression of CCL3, CCL17, CCL24, IL-4, and IL-5 by semi-quantitative PCR revealed that these mediators were expressed by eosinophils and monocytes (Fig. 6B). In peritoneal fluid of WT mice, eotaxin-2 was also enhanced twofold, compared to Thy-1−/− mice (data not shown). In addition, we quantified the amount of MMP-9 since it is an important protease for the degradation of basement membrane components and, thus, plays a critical role during the transmigration of cells through basement membranes. MMP-9 was analysed by ELISA in the BAL and peritoneal fluid of WT mice and Thy-1−/−mice. Induction of lung inflammation by OVA challenges upregulated MMP-9 in BAL (Fig. 6C). Indeed, a significant decrease of MMP-9 levels was seen in the BAL of Thy-1−/− mice, compared to WT mice (Fig. 6C).

Results are

expressed as means ± standard deviation (SD)

Results are

expressed as means ± standard deviation (SD) and were compared using an unpaired Student’s t test. To determine the effectiveness of the sublingual immunization, mice were immunized with 25k-hagA, 25k-hagA-MBP, or PBS. Sublingual immunization with 25k-hagA-MBP induced significant serum IgG and IgA 7 days after the final immunization (Fig. 1a). In contrast, 25k-hagA-immunized and nonimmunized mice induced low or no detectable titers, respectively, after sublingual immunization. In addition, the serum IgG and IgA Ab responses MAPK Inhibitor Library molecular weight induced by 25k-hagA-MBP persisted for almost 1 year (Fig. 1b). When the subclasses of antigen-specific IgG antibodies induced by sublingual 25k-hagA or 25k-hagA-MBP

Roxadustat challenge were determined, all IgG subclasses were significantly enhanced in 25k-hagA-MBP group. On the other hand, 25k-hagA-immunized group showed a low level of IgG1 (and sparse IgG2b) (Fig. 1c). Sublingual immunization of 25k-hagA-MBP induced high levels of 25k-hagA-MBP-specific IgA Ab responses in saliva (Fig. 2a). In contrast, essentially no IgA was detected in the saliva of mice sublingually treated with 25k-hagA or PBS. The most 25k-hagA-MBP-specific IgA AFCs were detected in the salivary glands suspensions (Fig. 2b). As sublingual immunization with 25k-hagA-MBP elicited 25k-hagA-MBP-specific Ab responses in both mucosal and systemic compartments, establishing the nature of the T cell help supporting the responses was important. When mononuclear cells from the SMLs of immunized mice were restimulated with 25k-hagA-MBP in vitro, significant levels of proliferative responses were induced (Fig. 3a). In contrast, no significant proliferation or cytokine production was observed in hagA-immunized mice (data not shown). Furthermore, mononuclear cells isolated from SMLs immunized with 25k-hagA-MBP showed higher production

of IL-4, IFN-γ, and TGF-β (Fig. 3b). These data Mirabegron indicate that sublingually immunized 25k-hagA-MBP-specific Th1-type and Th2-type responses are induced in SMLs. Given that sublingual immunization with 25k-hagA-MBP elicited long-term antigen-specific Ab responses in sera, we sought to determine whether these antibodies were capable of suppressing the alveolar bone absorption caused by P. gingivalis infection. Thus, mice given 25k-hagA, 25k-hagA-MBP, and PBS were infected orally with P. gingivalis 7 days after the last immunization. Mice immunized with 25k-hagA-MBP showed a significant protection and reduced bone loss caused by P. gingivalis infection (Fig. 4). In contrast, mice immunized with 25k-hagA alone did not show the reduced level of bone loss by P. gingivalis infection. These findings indicate that sublingual immunization with 25k-hagA-MBP is protective against oral infection by P. gingivalis.

The urinary NGF levels of OAB, IC/PBS and controls from previous

The urinary NGF levels of OAB, IC/PBS and controls from previous studies were used for comparison. NGF levels were compared among subgroups and between urinary tract diseases with or without associated OAB symptoms. The urinary NGF levels

Selleckchem PARP inhibitor were also compared among natural filling, after normal saline filling and after potassium chloride test in a group of OAB and IC/PBS patients. Results: Patients with acute bacterial cystitis, urinary tract stones or urothelial cell carcinoma had elevated NGF levels that were not associated with the presence of OAB symptoms. Symptomatic cystitis patients who had resolved OAB symptoms after antibiotic treatment had a significant decrease in urinary NGF levels. The urinary NGF levels decreased significantly in OAB patients with effective antimuscarinic treatment for 6 months, but remained stationary and higher than the controls for up to 12 months after treatment. Conclusion: Urinary NGF is not produced solely in patients with OAB or IC/PBS. Acute bacterial cystitis, urinary tract stones and urothelial cell carcinoma can have high PS-341 chemical structure urinary NGF production. “
“Overactive bladder syndrome (OAB), characterized by urinary frequency, nocturia and urgency with or without incontinence, is a widespread medical condition

with significant impact on quality of life. Three main factors have been proposed regarding the cause of OAB: myogenic, neurogenic and urotheliogenic. Disturbance of any of the three factors or a combination of these factors can attribute to OAB. Metabolic derangement, bladder outlet obstruction and inflammation can increase the excitability of nerve, detrusor muscle and alter the sensory Ribonucleotide reductase and barrier functions of the urothelium. The detection of proteins in the urine such as NGF, PGE2, and proinflammatory chemokines may advance our understanding of the pathophysiology of OAB and offer novel

diagnostic biomarkers of OAB. Overactive bladder syndrome (OAB) is a common medical condition with significant impact on quality of life across the world. It is characterized by urinary frequency, nocturia and urgency with or without incontinence.1 It has been estimated that the prevalence of OAB was 10.7% in the worldwide population in 2008, and will increase to 20.1% in 2018.2 It occurs more frequently in women than in men, and its incidence increases with age.3 Although many basic and clinical studies have been performed, the cause of OAB remains to be established.4 The mainstay of current pharmacological treatment involves the use of muscarinic antagonists, but their therapeutic effectiveness is limited by a combination of limited efficacy and troublesome side-effects.5,6 Therefore, finding the etiology of OAB is important for developing effective treatments. Here we review recent research in the pathophysiology of OAB and focus on bladder outlet obstruction (BOO), metabolic syndrome and inflammation (Fig.

The CHOICE study performed by Jaar et al 11 studied 1041 patients

The CHOICE study performed by Jaar et al.11 studied 1041 patients on HD and PD from 81 dialysis clinics in the United States. They were prospectively studied for up to 7 years after commencement. Data were gathered on coexisting diseases and disease severity along with age, sex, ethnicity, serum albumin, Hb, C-reactive protein, residual urine output and BMI. After adjustment, the risk of death did not differ between HD and PD patients undergoing treatment for the first 12 months. However, after the second year, the mortality risk was significantly higher in the PD group. This study did not find an increased risk of death with

PD for diabetic or elderly patients; however, there was a somewhat greater risk of death for some groups on Selleckchem Erlotinib PD if the patient had a history of CVD (not statistically significant in all subgroups). Limitations: Measured dialysis adequacy was not available for all patients to make a comparison between modalities and possibly associate with survival. A selection bias could influence results due to the observational nature of this study. This study allowed for modality switching without analysis of the reasons and the survival outcome. Registry data analysis from

the USA, the Netherlands, Canada, Italy and Denmark is included here. Canadian Organ Replacement Register data analysis by Fenton et al.5 studied 11 970 patients with stage 5 kidney disease commencing find more treatment in Canada from 1990 until 1994 with up to 5 years of follow up. Deaths were allocated to the treatment the patient was

receiving at the time of their death. Data were adjusted for age, primary renal disease, centre size and predialysis comorbidities. Ribonucleotide reductase Results indicated that the mortality risk for patients commencing treatment with PD was 73% that of those commencing with HD when adjusting for various prognostic factors; however, this became less pronounced when various subgroups were teased out (especially for those with diabetes and over the age of 65 years). The mortality rate for those on PD tended to increase over time while the HD survival was represented by a U shape. Limitations: This study did not adjust registry data for the impact of dialysis adequacy, nutritional status, patient compliance, comorbidity severity and the effect of late referral on patient mortality. United States Renal Data System (USRDS) registry data analysis. This registry data study by Vonesh and Moran3 extracted mortality data on nearly 204 000 patients from the USRDS for incident and prevalent patients over a 7-year period from 1987 to 1993. The results showed significant variations in mortality rates according to specific cohorts studied such as age, diabetes and gender. Importantly, there were no statistically significant differences in the adjusted death rates among non-diabetic PD and HD patients across age, gender or race.

This study was supported by Alzheimers Research UK and Alzheimer’

This study was supported by Alzheimers Research UK and Alzheimer’s Society through their funding of the Manchester Brain Bank under the Brains for Dementia Research (BDR) initiative. Nancy Allen did immunohistochemistry, all microscopical assessments and data analysis, and helped with paper writing.

Andrew Robinson prepared sections for staining and immunohistochemistry. Julie Snowden helped with statistical advice and clinical data. Yvonne Davidson provided technical support and training. David Mann provided study design, supervision and wrote the paper. “
“Primitive polar spongioblastoma Luminespib concentration was first described by Russell and Cairns in 1947. However, the polar spongioblastoma pattern is often seen in many neuroepithelial tumors, and this category was deleted in the previous World Health Organization (WHO) classification. In 2010, Nagaishi et al. reported on a case involving a neuroepithelial

tumor with the typical histological pattern of polar spongioblastoma and suggested that this tumor might FDA approved Drug Library cell line not be suited to any of the neuroepithelial tumors in the current WHO classification. We report on an autopsy case involving an unclassified high-grade glioma with polar spongioblastoma pattern that was very similar to the case described by Nagaishi et al. A 44-year-old man who presented with a headache exhibited a tumor of the right frontal lobe on MRI. Histological diagnosis of the tumor obtained by gross total resection was high-grade glioma, which was composed of the parallel palisading of spindle tumor cells expressing

GFAP, without microvascular proliferation (MVP) and necrosis. Conventional chemoradiotherapy was performed, but the case was complicated by cerebrospinal fluid (CSF) dissemination that resulted in multiple extraneural metastases through systemic diversionary CSF shunting. Finally, the patient died approximately 13 months after the initial treatment. Both the cerebral and Douglas pouch tumors that were obtained at autopsy were diagnosed as typical glioblastomas, and they were composed of the proliferation of atypical astrocytes with MVP and pseudopalisading necrosis without the formation of rhythmic palisading. Although O-methylated flavonoid the histological findings were different from that of the first operation, immunohistochemical and genetic profiles demonstrated almost the same results. This tumor was not classified as a typical glioblastoma by the initial findings, but it had the nature of a glioblastoma. These findings suggest that the tumor might be classified as a new subset of glioblastoma called glioblastoma with polar spongioblastoma pattern. “
“The effect of combustion smoke inhalation on the respiratory system is widely reported but its effects on the central nervous system remain unclear. Here, we aimed to determine the effects of smoke inhalation on the cerebellum and hippocampus which are areas vulnerable to hypoxia injury.

Therefore, it might be concluded that neutrophils experience a di

Therefore, it might be concluded that neutrophils experience a different apoptosis response over time and in comparison with other cell types of the Vincristine molecular weight respiratory compartment. In a first phase of acute injury, a delay in apoptosis would provide neutrophils with a longer life-span, possibly inducing or aggravating

injury as described in patients with sepsis and sepsis-induced ARDS [22]. In a later phase concerning resolution of an injury, apoptosis rate increases. Under hypoxic conditions, apoptosis rate of epithelial cells and alveolar macrophages did not change. Neutrophils, however, again experienced a different reaction regarding apoptosis rate compared to the other cell types. Hypoxia decreased caspase-3 activity in neutrophils after 4 h of exposure, while at time-points of 8 and 24 h caspase-3 activity was increased. Current data indicate that many factors operating at the inflamed site such as hypoxia and acidosis serve a dual function in both priming

and activating neutrophils by delaying apoptosis as well as decreased accumulation and function by increasing apoptosis [23]. As observed for alveolar epithelial cells, activation pathway of apoptosis is not clear in neutrophils. Saracatinib research buy In conclusion, our data show that the three cell types from the respiratory compartment alveolar and trachebronchial epithelial cells as well as alveolar macrophages show the same pattern of apoptosis regarding caspase-3 activity upon exposure to endotoxin and hypoxia. The apoptotic answer of neutrophils, however, is different. The functional implications of these inflammatory answers need to be analysed further. This study was supported by the Olga Mayenfisch Stiftung, Zurich, Switzerland and the Jubiläumsstiftung der Schweizerischen Lebensversicherungs-

Chloroambucil und Rentenanstalt, Zurich, Switzerland. None. “
“IL-10-producing CD4+ type 1 regulatory T (Tr1) cells, defined based on their ability to produce high levels of IL-10 in the absence of IL-4, are major players in the induction and maintenance of peripheral tolerance. Tr1 cells inhibit T-cell responses mainly via cytokine-dependent mechanisms. The cellular and molecular mechanisms underlying the suppression of APC by Tr1 cells are still not completely elucidated. Here, we defined that Tr1 cells specifically lyse myeloid APC through a granzyme B (GZB)- and perforin (PRF)-dependent mechanism that requires HLA class I recognition, CD54/lymphocyte function-associated antigen (LFA)-1 adhesion, and activation via killer cell Ig-like receptors (KIRs) and CD2. Notably, interaction between CD226 on Tr1 cells and their ligands on myeloid cells, leading to Tr1-cell activation, is necessary for defining Tr1-cell target specificity. We also showed that high frequency of GZB-expressing CD4+ T cells is detected in tolerant patients and correlates with elevated occurrence of IL-10-producing CD4+ T cells.