Salmonella flagellin activates NAIP/NLRC4 and canonical NLRP3 inflammasomes in human macrophages

Infection of human macrophages with Salmonella enterica serovar Typhimurium (S. Typhimurium) leads to inflammasome activation. Inflammasomes are multi-protein complexes facilitating caspase–1 activation and subsequent gasdermin D-mediated cell death and interleukin–1β and interleukin–18 cytokine release. The NAIP/NLRC4 inflammasome is activated by multiple bacterial protein ligands including flagellin from the flagellum and the needle protein PrgI from the S. Typhimurium type III secretion system. Here we show that transfected ultrapure flagellin from S. Typhimurium induced cell death and cytokine secretion in THP–1 cells and primary human monocyte-derived macrophages (hMDM). In THP–1 cells, NAIP/NLRC4 and NLRP3 played redundant roles in inflammasome activation during infection with S. Typhimurium. Knock-out of NAIP or NLRC4 in THP–1 cells revealed that flagellin, but not PrgI, now activated the NLRP3 inflammasome through a ROS- and/or cathepsin-dependent mechanism that was independent of caspase–4/5 activity. In conclusion, our data suggest that NLRP3 can be activated by flagellin to act as a “safety net” to maintain inflammasome activation under conditions of suboptimal NAIP/NLRC4 activation, as observed in THP–1 cells, possibly explaining the redundant role of NLRP3 and NAIP/NLRC4 during S. Typhimurium infection.Wellcome Trus

Efferocytosis is an innate antibacterial mechanism

Mycobacterium tuberculosis persists within macrophages in an arrested phagosome and depends upon necrosis to elude immunity and disseminate. Although apoptosis of M. tuberculosis-infected macrophages is associated with reduced bacterial growth, the bacteria are relatively resistant to other forms of death, leaving the mechanism underlying this observation unresolved. We find that after apoptosis, M. tuberculosis-infected macrophages are rapidly taken up by uninfected macrophages through efferocytosis, a dedicated apoptotic cell engulfment process. Efferocytosis of M. tuberculosis sequestered within an apoptotic macrophage further compartmentalizes the bacterium and delivers it along with the apoptotic cell debris to the lysosomal compartment. M. tuberculosis is killed only after efferocytosis, indicating that apoptosis itself is not intrinsically bactericidal but requires subsequent phagocytic uptake and lysosomal fusion of the apoptotic body harboring the bacterium. While efferocytosis is recognized as a constitutive housekeeping function of macrophages, these data indicate that it can also function as an antimicrobial effector mechanism.Behar, Fortune, and Remold labs for reagents, helpful discussion, and insights. TIM4-blocking antibodies were a generous gift of Vijay Kuchroo. Members of the Harvard Electron Microscopy Core Facility helped in the preparation, staining, and operation of the electron microscope. The Small Animal Biocontainment (ABC) Suite is supported by CFAR 5P30AI060354. T.R.R and S.M.F were supported by CFAR 5P30AI060354, DP2-0d001378, and T32-AI07387. C.N.A. is the recipient of a fellowship from FCT. S.M.B and H.G.R. were supported by R56AI084161 and R01AI072143

Macrophage-Derived Extracellular Succinate Licenses Neural Stem Cells to Suppress Chronic Neuroinflammation.

Neural stem cell (NSC) transplantation can influence immune responses and suppress inflammation in the CNS. Metabolites, such as succinate, modulate the phenotype and function of immune cells, but whether and how NSCs are also activated by such immunometabolites to control immunoreactivity and inflammatory responses is unclear. Here, we show that transplanted somatic and directly induced NSCs ameliorate chronic CNS inflammation by reducing succinate levels in the cerebrospinal fluid, thereby decreasing mononuclear phagocyte (MP) infiltration and secondary CNS damage. Inflammatory MPs release succinate, which activates succinate receptor 1 (SUCNR1)/GPR91 on NSCs, leading them to secrete prostaglandin E2 and scavenge extracellular succinate with consequential anti-inflammatory effects. Thus, our work reveals an unexpected role for the succinate-SUCNR1 axis in somatic and directly induced NSCs, which controls the response of stem cells to inflammatory metabolic signals released by type 1 MPs in the chronically inflamed brain

Prevalensi Labioschisis Di Rsup. Prof. Dr. R. D. Kandou Manado Periode Januari 2011 – Oktober 2012

: Cleft lip or labioschisis is an inherited disorder that can occur on the lips to the ceiling. Cleft lip is a disruption in the face of growth since the fourth week of embryonic life. Method: This research in retrospection description research for knowning prevalence cleft lip or labioschisis in surgical department RSUP. Prof. Dr. R. D. Kandou Manado, period of Januari 2011 – October 2012. Output: Prevalence of Labioschisis and Labiopalatochisis on Januari 2011 – October 2012 is 57% and 43%. Presentation for each of kind harelipped are : unilateral labioschisis 47%, bilateral labioschisis 5%, unilateral palatum of labioshisis 28%, and bilateral palatum of labioschisis 12%, submucosa 1%, and cleft palate lips 7%. Presentation according to the place of defect : right 18%, left 57%, bilateral 25%, and status not complete 54%. Presentation according to age for doing operation : 0-4 years 73%, 5-9 years 10%, 10-14 years 7%, and >15 years 10%. Presentation labioschisis according to sex : Man 58%, and women 42%. Presentation labioschisis according to etiology : genetic factor 25%, environment factor 62%, and unknown factor 13%. Presentation of labioschisis that be surgery 93%, and not surgery 7%. Presentation of labioschisis according to complication surgery : bleeding post surgery 1%, secunder infection 4%, dehisensi/establish scar 4%, and not complication 91%. Conclusion: Prevalence labioschisis still decrease in each year, kind of labioschisis that large is unilateral labioschisis and localization defect is often on left edge. Labioschisis is happen more to man. Factor that to cause labioschisis between : genetic factor, environment factor and unknown factor. Labioschisis is often more to surgery 0-4 years old

Analysis of MEFV exon methylation and expression patterns in familial Mediterranean fever

<p>Abstract</p> <p>Background</p> <p>MEFV mutations and decreased expression level of the gene are related to FMF pathology. DNA methylation at CpG islands is a well-known mechanism for transcriptional silencing. MEFV has a CpG island, spanning a part of the first intron and the whole of the second exon of the gene covering 998 bp region. Here, we tested the hypothesis that the MEFV transcript level in FMF patients correlates with its methylation level, and methylation, by allowing transcription silencing, has a role in FMF ethiopathogenesis.</p> <p>Methods</p> <p>The study group was composed of pediatric FMF patients (N = 51) and age-gender matched healthy controls (N = 21). The relative expression level of MEFV was assessed via quantitative real-time PCR (qRT-PCR) and bisulfite sequencing (BS) was performed to analyse the methylation level quantitatively.</p> <p>Results</p> <p>MEFV expression in FMF patients were decreased compared to healthy controls (<it>P </it>= 0.031). Methylation level of exon 2 of MEFV was found to be slightly higher in FMF patients compared to healthy controls (76% versus 74%) (<it>P </it>= 0.049). The expression level of the MEFV was negatively correlated with the methylation level of the CpG island in both FMF and healthy controls groups (cor = -0.29, <it>P </it>= 0.041) but more so in the FMF only group (cor = -0.36, <it>P </it>= 0.035).</p> <p>Conclusions</p> <p>In this study, the relation between reduced MEFV expression level and FMF was confirmed. Observed slight increase in methylation in FMF patients, and correlation of methylation with expression might be indicative of its role in FMF, however a larger dataset is needed to confirm our preliminary findings.</p

C5aR2 regulates STING-mediated interferon beta production in human macrophages

The complement system mediates diverse regulatory immunological functions. C5aR2, an enigmatic receptor for anaphylatoxin C5a, has been shown to modulate PRR-dependent pro-inflammatory cytokine secretion in human macrophages. However, the specific downstream targets and underlying molecular mechanisms are less clear. In this study, CRISPR-Cas9 was used to generate macrophage models lacking C5aR2, which were used to probe the role of C5aR2 in the context of PRR stimulation. cGAS and STING-induced IFN-β secretion was significantly increased in C5aR2 KO THP-1 cells and C5aR2-edited primary human monocyte-derived macrophages, and STING and IRF3 expression were increased, albeit not significantly, in C5aR2 KO cell lines implicating C5aR2 as a regulator of the IFN-β response to cGAS-STING pathway activation. Transcriptomic analysis by RNAseq revealed that nucleic acid sensing and antiviral signalling pathways were significantly up-regulated in C5aR2 KO THP-1 cells. Altogether, these data suggest a link between C5aR2 and nucleic acid sensing in human macrophages. With further characterisation, this relationship may yield therapeutic options in interferon-related pathologies