Total flap necrosis was noted in 5.5% of flaps, with partial necrosis in 11.6%. While these flaps do enable transfer of local, healthy tissue to the defect site without the need for a microsurgical anastomosis, this rate of flap loss is concerning and appropriate patient selection is crucial. This review provides a brief history and overview of the clinical application and research into distal lower extremity perforator propeller flaps

to place this technique into a clinical CH5424802 clinical trial context. © 2013 Wiley Periodicals, Inc. Microsurgery 33:578–586, 2013. “
“Effects of androgens on angiogenesis are controversial. Hypoxia-inducible factor (HIF)-1α promotes expression of vascular endothelial growth factor (VEGF) that stimulates angiogenesis. This study investigates whether androgens stabilize HIF-1α in endothelial cells, and androgen depletion decreases VEGF concentrations and skin flap survival. Male human umbilical vein endothelial cells (HUVECs) were exposed to dihydrotestosterone (DHT) and HIF-1α expression was measured. In male Wistar rats, standardized proximally based random pattern dorsal skin flaps (3 × 9 cm) were raised 4 weeks after orchiectomy and sham operation, respectively

(n = 10, each). Flap VEGF concentrations (immunohistochemistry), perfusion (Laser Doppler), and viability (digital planimetry) were measured. DHT induced HIF-1α expression in HUVECs. Androgen depletion induced decreased VEGF expression (P = 0.003), flap perfusion (P < 0.05), and survival (44.4% ± 5.2%) compared to controls (35.5%

± 4.5%; P = 0.003). In vitro, androgens may stimulate HIF-1α under buy Midostaurin normoxic conditions. In rats, androgen depletion decrease VEGF expression and flap survival. © 2012 Wiley Periodicals, Inc. Microsurgery much 2012. “
“Despite the sacrifice of rectus abdominis muscle, the vertical rectus abdominis musculocutaneous (VRAM) flap is still a preferred option for perineal reconstruction. This journal has previously reported on the utility of preoperative computed tomographic angiography (CTA) in this setting to identify cases that are both suitable and unsuitable for rectus abdominis flaps after previous surgery. We report a case which highlights a unique example of the benefits of such imaging, with the largest deep inferior epigastric artery (DIEA) perforator described to date identified on imaging, and used to potentiate a donor-site sparing procedure. The use of this dominant perforator was able to limit donor site harvest to only a small cuff of anterior rectus sheath and a small segment of rectus abdominis, potentiating a muscle-sparing and fascia-sparing VRAM flap for perineal reconstruction. As such, preoperative CTA was found to be a useful tool in identifying a unique anatomical variant in the largest DIEA perforator described to date, and was used to potentiate a muscle-sparing and fascia-sparing VRAM flap for perineal reconstruction. © 2011 Wiley-Liss, Inc. Microsurgery, 2011.

Urine levels of soluble CXCL16 are increased in patients with lupus nephritis or renal allograft rejection.53,54 Macrophage migration inhibitory factor (MIF) is a molecule that is produced at sites selleck kinase inhibitor of inflammation and inhibits further macrophage migration in response to chemokines, thereby allowing macrophages to accumulate at the inflammatory site. MIF can also enhance the activity of macrophages and T cells at sites of injury. Increasing levels of MIF in urine correlate with kidney leukocyte accumulation and the severity of renal damage in proliferative forms of glomerulonephritis.55 In addition, elevated

MIF levels in urine can predict episodes of acute renal allograft rejection and discriminate from cyclosporine nephrotoxicity.56 There are also other pro-inflammatory mediators that can indentify inflammation in the injured kidney. Vascular cell adhesion molecules-1 (VCAM-1) is expressed by renal vessels and some kidney cells during renal inflammation and facilitates transendothelial leukocyte migration. Some of this VCAM-1 is enzymatically cleaved PD0325901 and excreted into the urine. Urine levels of soluble VCAM-1 are

elevated during active periods of anti-nuclear cytoplasmic antibody vasculitis and lupus nephritis,53,57 and are useful for determining the severity and type of renal allograft rejection.58 Interleukin-18 (IL-18) is a pro-inflammatory cytokine that is produced by leukocytes, vessels and kidney tubules. During acute renal injury, there is a substantial increase in IL-18 production by tubules. Elevated urine levels of IL-18 are a relatively sensitive and specific marker of acute tubular necrosis (ATN) and delayed graft function in the post ischaemic kidney.59 Urine levels also correlate with disease activity in idiopathic

nephritic syndrome.60 Tumour necrosis factor receptor-1 (TNFR1) is one of the major receptors for the pro-inflammatory cytokine TNF-α, which is expressed on infiltrating leukocytes and some Resveratrol resident kidney cells during renal inflammation. The soluble form of TNFR1 is more stable and easier to detect in serum and urine than TNF-α and it can serve as a surrogate marker of TNF-α activity in kidney disease. Serum and urine levels of soluble TNFR1 are increased during acute and chronic renal inflammation and correlate with the progression of acute renal failure, lupus nephritis and diabetic nephropathy.50,53,61 Another recent inclusion to this family of biomarkers is soluble human leukocyte antigen-DR. Urine levels of soluble human leukocyte antigen-DR are a sensitive and highly specific marker of acute renal allograft rejection, which can be detected up to 5 days before the clinical signs of acute cellular or vascular rejection are evident.62 The development of renal fibrosis is dependent on excessive production of profibrotic growth factors and extracellular matrix, which can be detected in urine by ELISA.

[46] Conversely, BACH1-deficient mice show greatly enhanced expression of the Nrf2 target gene, haeme oxygenase-1 in the thymus.[33] A recent study of human DS thymus also identified decreased expression of another Nrf2 target,

peroxiredoxin 2 and decreased levels of this antioxidant enzyme may also promote increased oxidative stress in DS thymocytes.[41] Insufficient antioxidant production Kinase Inhibitor Library in vitro in the Ts65Dn haematopoietic and lymphoid progenitor populations in the bone marrow and thymus may therefore be inducing a state of redox imbalance and affecting progenitor function, potentially through regulation of IL-7Rα levels. Direct transcriptional regulation of IL-7Rα expression in Ts65Dn was implicated by the nearly twofold decrease in mRNA in total thymus. Notch signalling has been shown to regulate IL-7Rα expression in developing T cells but not B cells,[20] and a small decrease in expression of the Notch signalling target Hes-1 was observed in whole thymuses and lineage-negative haematopoietic progenitors of Ts65Dn mice. Notch-mediated transcription could be down-regulated in Ts65Dn KPT330 through

decreased Nrf2-dependent control of Notch expression,[35] in which down-regulation of Nrf2 function was shown to result in decreased Hes-1 expression. Hence, decreased Nrf2 activation in the Ts65Dn lymphocyte progenitors might be associated Farnesyltransferase with inhibition of Notch-dependent IL-7Rα expression. Another possible mechanism of decreased IL-7Rα-expression is the increased expression of miRNAs that can potentially inhibit IL-7Rα mRNA expression. Mouse chromosome 16 and human chromosome 21 are known to encode five miRNA, including miR-99a, let-7c, miR-125b-2, miR-155 and miR-802 and previous studies found increased levels of miR-155 and miR-125b in tissues from individuals with DS.[36] Sequence analysis indicated consensus binding sites for these miRs in the 3′-untranslated region of IL-7Rα transcripts and PCR analysis found increased expression of miR-125b and miR-155 in the thymus and bone marrow. This analysis is

supported by the findings that transgenic mice over-expressing miR-155 in B cells exhibited decreased IL-7Rα mRNA expression.[39] Hence, regulation of IL-7Rα expression by transcriptional activators and miRNA may contribute to changes in thymocyte function in DS and Ts65Dn mice. In contrast to thymic progenitors, there were only minor differences in cellularity and subset composition of splenic leucocytes in Ts65Dn mice compared with euploid controls although further analysis of the CD4+ and CD8+ T-cell populations revealed an overall decrease in the percentage of naive cells and an increase in the effector/memory populations. Combined with the thymic involution, this increased proportion of memory cells suggests an aged, senescent immune system.

On day 6, fresh medium containing GM-CSF, IL-4, IL-1β, IL-6,

PGE2, and TNF was added to the culture. After additional 48 h of culture, nonadherent cells were harvested and used as APCs. XL184 clinical trial Purified CD4+, CD8+ and DN T cells (1×105/well) from donor A were cocultured with allogeneic mature DC (2.5×104/well) from donor B or with anti-CD3/CD28-coated beads (2.5×104/well; Dynabeads CD3/CD28, Invitrogen) in 96-well U-bottom plates in complete medium supplemented with 3% TCGF. T cells were restimulated weekly with fresh allogeneic DC. Viability and purity of the T cells were monitored by flow cytometry. Further purification via magnetic separation was performed if purity decreased to lower than 95%. T cells were used for functional assays 6 days after last stimulation. Cells were stained with fluorescein isothiocyanate (FITC)-conjugated anti-IFN-γ, anti-CD4, anti-CD8, anti-TCR-γδ, phycoerythrin (PE)-conjugated anti-CD25, anti-CD45RO, anti-TCR-, and allophycocyanin-conjugated anti-CD38, anti-CD45RA, anti-CTLA4 monoclonal antibodies (mAb) (all from BD Biosciences, Heidelberg, Germany). Isotype control mAb, FITC-labeled annexin V, and 7AAD were purchased from BD. Foxp3 stains were performed

with allophycocyanin-conjugated anti-Foxp3 mAb and the respective control from eBioscience (San Diego, USA). For intracellular IFN-γ staining, activated CD4+ T cells were cocultured with DC and DN T cells in the presence Buparlisib ic50 of monensin (GolgiStop, BD) for 5 h. After washing, cells were stained for surface markers, fixed and permeabilized (Cytofix/Cytoperm kit, BD), and then stained for intracellular cytokines. Flow cytometry was performed on a FACSCanto II (BD); cell sorting was accomplished on a MoFlo (Beckman Coulter). Branched chain aminotransferase Data were analyzed with FlowJo software (Treestar, Ashland, OR, USA). CFSE (Sigma, Munich, Germany) labeled CD4+ and CD8+ T cells (5×104/well) from donor A were stimulated in 96-well U-bottom plates with allogeneic DC (2.5×104/well) from donor B, anti-CD3/CD28

beads (2.5×104/well, Invitrogen/Dynal, Oslo, Norway), or plate-bound anti-CD3 (0.25 μg/well, Orthoclone OKT3, Janssen-Cilag) in complete medium in the presence or absence of DN T cells or CD4+CD25+ Tregs (5×104/well). Anti-CD2/CD3/CD28 loaded particles (Treg Suppression Inspector, Miltenyi Biotec) were used according to the manufactures instructions. After 5–6 days of culture, cells were harvested and stained with anti-CD4, anti-CD8, anti-TCR-αβ, and anti-CD25 mAb. Proliferation of cells was determined by flow cytometry. For blocking experiments, mAb to IL-10 (10 μg/mL JES3-19F1; BD), TGF-β (10 μg/mL 1D11; R&D Systems), Fas (10 μg/mL ZB4; Biomol), or isotype-matched controls were added to the MLR. To block TCR-signaling and protein translocation, DN T cells were incubated with Lck-inhibitor II (100 μM; Calbiochem, Darmstadt, Germany) or with monensin (GolgiStop, according to the manufacture’s protocol; BD) for 3 h, and then used as suppressor cells in the MLR.

Altogether, this suggests VX-809 purchase that other mechanisms may have intervened. The expression or upregulation of various NKG2D ligands is tightly regulated in cells by stress, infections and transformation mechanisms. There is ample evidence of pathogens driving the diversity of NKG2D ligands. Numerous studies demonstrated

that viral infections increase the expression of NKG2D ligands but also that some viruses deploy evasive maneuvers to prevent expression of NKG2D ligands on the cell surface. The protein UL16 of human CMV binds to ULBP1, ULBP2, ULBP6 and MICB and retains these ligands intracellularly 28. Other intracellular mechanisms or signaling pathways induced by the presence of microorganisms can also influence NKG2D ligand expression. Belinostat in vivo Notably, TLR signaling results in NKG2D ligand transcription. TLR4 engagement by LPS has been reported to upregulate cell-surface ULBP1 and MICA/B on human myeloid DCs and the expression of ULBP2 was induced by PolyI:C treatment 42. Moreover, various data have been reported in the infection with Mycobacterium tuberculosis. While the infection of DCs with a high MOI (2000) of this bacterium upregulates MICA surface expression 43, the infection of monocytes or macrophages with a low MOI (20) induces only the upregulation of ULBP1 expression 44. Thus, NKG2D ligand expression can be different from one infection to another, from one cell population

to another and their impact on the anti-infectious activity of Vγ9Vδ2 T cells could also vary. In conclusion, this study provides evidence that NKG2D can fine-tune the anti-infectious responses of Vγ9Vδ2 T cells against intracellular bacterium, through its interaction with its ligands. In addition,

it suggests that NKG2D could also be involved in the anti-infectious activity of Vγ9Vδ2 T cells against all microorganisms that have the ability to positively modulate NKG2D ligand expression. In a more general way, this study showed that T cells that do not utilize classical coreceptors, Morin Hydrate such as CD4 and CD8, take advantage of other stimulatory molecules for a more efficient activation as well as for delivery of their effector functions, in this case a bactericidal one. Soluble ULBP1-LZ, ULBP2-LZ, UL16-LZ fusion proteins, M585 and M580 mAbs to human NKG2D and M15 anti-LZ mAb were a generous gift from AMGEN (Seattle, USA). HMB-PP was generously provided by J. L. Montero (Montpellier, France). Anti-ULBP1, ULBP2, ULBP3 and MICA/B mAbs were purchased unconjugated or as FITC- or PE conjugates from R&D Systems (Minneapolis, MN, USA). Anti-ULBP4 was purchased from Santa Cruz Biotechnology (Santa Cruz, CA, USA). Anti-mouse and isotypically matched control mouse Abs (conjugated or not) were all purchased from BD Biosciences (San Jose, CA, USA). Control or NKG2D siRNA were purchased from Dharmacon (Lafayette, CO, USA).

(iii) Type I predominance or type I fibre uniformity and increased variability in fibre size; and (iv) Nuclear internalization and centralization find more in both fibre types, including frequent multiple internalized nuclei. In addition, a discrete increase of endomysial connective tissue was often observed. Noticeably, the muscle biopsies performed at the ages of 4 months for patient 1 and 21 months for patient 2, essentially showed type I fibre predominance, increased endomysial

connective tissue, significant variation in type I or II fibre size and the presence of some small fibres with central nuclei resembling myotubes. No cores were observed. Thereafter, the muscle biopsies performed at the ages of 12 and 14 years for patient 1 and 12 years for patient 2 showed the peculiar morphological pattern observed in all patients.

Nuclear internalization increased with age (Table 1; Figure 3). In patients 1 and 3 to 7, ultrastructural analysis of muscle biopsies in longitudinal sections demonstrated large areas of sarcomeric disorganization (Figure 4d). Such areas were present in one or more regions within a fibre, were variable in width and length, frequently covered the entire fibre diameter in cross section (Figures 4a,b) and extended from 2 to 30 sarcomeres in longitudinal sections (Figures 4b,f). Altered fibres often showed one or several misplaced nuclei that were occasionally found at the border of areas of myofibrillar disorganization (Figures 4b,d). Within learn more such disorganized areas, accumulation of Z-band proteins, Z-band streaming, enlarged Z-bands and myofibrillar compaction were the most frequent alterations (Figures 4c,e). T-triads-repetitions, honeycomb profiles (corresponding to T-tubules proliferations) and occasional minicore-like L-gulonolactone oxidase lesions (Figure 4f)

were also observed amongst other non-specific alterations. Mitochondria were present or not in the disorganized areas. In order to further study the composition of the disorganized intracellular areas, biopsies of patients 2, 3 and 5 were labelled with antibodies to the intermediate filament proteins desmin, αB-crystalline and myotilin. The three markers intensively labelled the disorganized areas, but in serial sections reacting fibres were either labelled with one, two or three of the antibodies used, suggesting a heterogeneous composition of the disorganized zones (Figure 5). Patient 1 and her deceased sister were c.[10348-6C>G; 14524G>A] + c.[8342_8343delTA] compound heterozygous carriers (Table 2). The c.8342_8343delTA frameshift deletion transmitted by the clinically unaffected mother introduced a premature stop codon (p.Ile2781ArgfsX49). The two other variants were inherited from the clinically unaffected father. The c.10348-6C>G change resulted in a loss of splicing of intron 68 and the introduction of a premature stop codon (p.His3449ins33fsX54).

38,39 The medical implications of DC that control a spectrum of

innate and adaptive responses have been reviewed.40 The present review summarizes the current understanding of DC functions in HCV infection and explores the prospects Selleck Rucaparib of DC-based HCV vaccine development. In particular, it describes the biology of DC, the phenotype of DC in HCV-infected patients, the effect of HCV on DC, the studies on new DC-based vaccines against HCV, and strategies to improve the efficacy of DC-based vaccines. Dendritic cells are the most efficient inducers of all immune responses, and are capable of either inducing productive immunity or maintaining a state of tolerance to self and non-self antigens. Two major DC subsets have been characterized to date in humans, based on their development from myeloid or lymphoid precursors of bone marrow pluripotent cells.41 Myeloid dendritic cells (MDC) are CD1a, CD11c, CD13, CD14, CD33+, whereas lymphoid descendants, also called plasmacytoid dendritic cells (PDC) express CD123 and BDCA-2 on their surface. Both MDC and PDC are derived from bone marrow and can be found in peripheral blood in an immature stage. Immature find more dendritic cells (iDC) express low levels of MHC class I and II and co-stimulatory

molecules on their surface and are proficient in endocytosis and antigen processing. Maturation of DC occurs after detecting microbial or host-derived danger signals, or upon contact with pro-inflammatory cytokines, such as tumour necrosis factor-α (TNF-α), interleukin-1 (IL-1), or after engagement of the CD40/CD40 ligand (CD40L) system. The DC play a key role in regulating immunity, serving as the sentinels that capture antigens in the periphery, process these antigens

into peptides, and present these peptides to lymphocytes within lymph nodes. The maturation process includes a series of transformations that lead to a reduction of antigen-capturing capacity, an increase in MHC and co-stimulatory molecule expression and, most importantly, why the development of an exceptional efficiency in presenting antigens to T cells, activating natural killer cells, and producing interferons, so linking the innate and adaptive immune responses.42 Although both MDC and PDC are potent in antigen uptake, processing and presentation, they have fairly distinct cytokine profiles: MDC produce large amounts of IL-12 and IL-10 and make small amounts of IFNs, while PDC are specialized type-I IFN-producing machines and express much lower levels of other cytokines (Table 1). As the frequencies of DC in the peripheral circulation are low, alternative approaches to DC generation for research purposes were sought.

However, patients with CE3b cysts, a stage clinically unresponsive to treatments,

had statistically significantly higher median levels of IL4 and percentage of positive samples for IL4. We conclude that the analysis of serum cytokine dosage, at least in its present form, is not useful as a marker of cyst activity. However, our results support recent findings suggesting the chronic activity of CE3b cysts and suggest that this might be partly because of a skewed Th2 response. Human cystic echinococcosis (CE) is a chronic infection caused by the larval stage of the tapeworm Echinococcus granulosus and is an increasingly important public health problem in many ZD1839 order regions of the world (1). Despite its wide distribution and the heavy economical and sanitary burden imposed on the healthcare systems, funding allotted to this neglected disease is limited (2,3). Moreover,

many aspects of this disease, such as its natural history, the underlying causes of the poor response to treatment https://www.selleckchem.com/products/pexidartinib-plx3397.html and chronicization of some cyst stages, are still poorly known, making its clinical management particularly difficult. The diagnosis and the decisions about clinical management of CE are currently based on imaging methods, mostly ultrasound (US), and, to a lesser extent, on serology. Cyst viability (i.e. presence of viable protoscolices in the cystic liquid) would be the optimal parameter to guide clinical decision-making, but at present no easily implementable noninvasive technique is available in this regard. Serology is hampered by several problems, such as lack of standardization, and its diagnostic performance is a function of many variables including prevalence of infection, cross-reactions with other parasites, and location, stage and size of the cyst (4). Moreover, anti-Echinococcus antibodies (Ab) may persist for years, although often at low titres, even after the complete surgical removal of the cysts (5,6), so serology alone is

not a reliable means to assess cyst viability and should always be coupled with US staging. Biological activity also does not necessarily match US appearance of cysts (7). A long-term follow-up of patients is therefore required, as only changes in the US appearance of the cyst and Ab titres can be relied upon to assess cyst progression towards inactivation (stages CE4 and CE5) or Protein tyrosine phosphatase chronicization (stages CE2 and CE3b) (8,9). It has been suggested that chronicization of CE might be favoured by a skewing of the host’s immune response towards a Th2 response. Indeed, persistently high titres of IgG4 and IgE have been associated with the presence of active and not cured cysts (10–12). Moreover, in vitro studies investigating the cytokines production from peripheral blood mononuclear cells of CE patients showed a predominant Th1 response in patients with inactive or cured cysts and a predominant Th2 profile in those with active or not cured cysts (12–14).

5 ± 26.2 ml/min/1.73 m2. Mean proteinuria was 1.19 ± 1.61 g/day, and mean urinary red blood cells were 36.6 ± 35.3 / high powered field. Histologically, mesangial hypercellularity was present in 47.6% of patients, endothelial hypercellularity in 44.3%, segmental sclerosis in 74.6%, and

tubular atrophy/interstitial fibrosis in 28.8% by Oxford classification. Initial treatment consisted of corticosteroids in 26.9% of patients, renin-angiotensin-aldosterone system inhibitor in 28.9%, and tonsillectomy plus steroids in 11.7%. The 10-, 20-, and 30-year renal survival rates were 84.3, 66.6, and 50.3%, respectively. Cox multivariate regression analysis showed that higher proteinuria, lower eGFR, and higher uric acid at the time of renal biopsy

were independent risk factors for the development of end stage renal disease (ESRD). LY294002 clinical trial Conclusion: IgAN is not R788 mouse a benign disease, with about 50% of patients progressing to ESRD within 30 years despite treatment. LAW MAN CHING, FUNG JANNY SF, LAM MAN PING, CHOW KAI MING, POON KA LAI, LI PHILIP KT Prince of Wales Hospital Introduction: Psychosocial support has been identified as one of the important elements in a successful peritoneal dialysis (PD) first program. With an aim to strengthen the psychosocial support for PD patients, our team have developed comprehensive patient and community educational programs. Methods: In order to empower the PD patients and to build up a secure social network for them, we organize varies education programs to our patients, community stakeholders and the general public. The table 1 below lists the educational programs and the interventions. Results: Majority of the kidney patients accept PD as the first-line dialysis modality for them and make an informed choice on PD. Community stakeholders and the general public understand PD is safe and effective for kidney patients. Over 90% of the program participants have positive feedback on the

programs. Conclusion: Educational strategies could facilitate the implementation of PD-first policy by enhancing the society’s overall knowledge and hence the confidence in PD. MATSUBARA CHIEKO1, KASUGA HIROTAKE1, TAKAHASHI RYO1, KIMURA KEIKO1, KAWASHIMA KIYOHITO1, KAWAHARA HIROHISA1, MATSUO ifenprodil SEIICHI2, ITO YASUHIKO2 1Nephrology, Nagoya Kyoritsu Hospital; 2Nephrology, Nagoya University Graduate School of Medicine Case: A 79-year-old male patient. Chief Complaint: Low grade fever lasting 3 months. Present History: A 79-year-old male patient started peritoneal dialysis in December 2010 and was followed up at the outpatient clinic. He developed fever and his CRP levels were increased. Mediastinal lymphadenopathy was detected by computerized tomography in April 2012, (which was not demonstrated in March, 2011). His QuantiFERON (QFT) was positive and we suspected that his illness and mediastinal lymphadenopathy was due to tuberculosis. It was difficult to biopsy the tissues, and we did not detect other specific findings including laboratory data.

Indeed, treatment with rhIL-10 significantly reduced both CD8+ and CD4+ T-cell proliferation (Fig. 7C), thus proving a central role of IL-10 in the regulation of the T-cell response to allogenic monocytes. In this study, we demonstrated the role of the IRAK4 kinase as a differential switch between TLR-induced pro-inflammatory and anti-inflammatory cytokine production. This observation is of interest as to date IRAK4 is mainly being viewed as a central executor of the MyD88 pathway that unselectively transduces all signals downstream of MyD88. As previously described in IRAK4-deficient mice [26], stimulation of IRAK4 knockdown monocytes with TLR4 and TLR2 ligands resulted in markedly reduced pro-inflammatory cytokine

secretion such as TNF and IL-12 (Fig. 2A–C) and Y27632 concomitant reduction of the NF-κB subunits p50 and p65 responsible for the transcription of these cytokines (Fig. 2D). The results obtained are further in accordance B-Raf inhibitor clinical trial with observations made in cells of IRAK4- and MyD88-deficient patients. There, TLR stimulation fails to activate the NF-κB pathway and cells display an impaired cytokine response after stimulation with agonists for TLR-1, TLR-2, TLR-4, TLR-5, TLR-7, and TLR-8 [17-20]. Similarly, siRNA-mediated silencing of MyD88 caused a significant reduction in TNF and IL-12 cytokine production in human monocytes (Fig. 4C,D), highlighting the cooperative interaction

of MyD88 and IRAK4 in TLR-induced synthesis of pro-inflammatory cytokines such as TNF and IL-12. IRAK4-deficient patients are more susceptible to infections with pyogenic bacteria, especially Gram-positive species such as S. pneumoniae and/or S. aureus [18]. Consistently, the predisposition to S. aureus infections was also reported in IRAK4-deficient mice [26]. Until now, little is known about the role of monocytes in response to these pathogens albeit these cells belong to those first to encounter bacterial pathogens in blood stream infections.

In this study, we tested the role of IRAK4 in the TLR-mediated response of human monocytes to bacterial infections. In particular, our results showed diminished IL-12 Acyl CoA dehydrogenase secretion and elevated TNF and IL-10 levels after treatment with live S. aureus and S. pneumoniae (Fig. 1C). To further assess these findings we conducted MyD88 knockdown experiments, obtaining concomitantly reduced IL-12 and IL-10 secretion. However, TNF levels were only slightly diminished (Fig. 4E). This strongly suggests that IL-12 and IL-10 secretion evoked by bacterial infections is MyD88-dependent, whereas TNF production is also regulated in a MyD88-independent fashion, possibly triggered via TRIF or cytosolic PRR-induced IFN-I [27]. In general, bacteria represent complexes of multiple ligands that can be sensed by membrane-bound as well as cytosolic PRR. The most prominent difference between stimulation with bacteria and single TLR ligands was an increase in TNF release under IRAK4-silencing conditions (Fig. 1C) and under rapamycin treatment (Fig. 5B).