scholarly journals MyD88 Primes Macrophages for Full-Scale Activation by Interferon-γ yet Mediates Few Responses to Mycobacterium tuberculosis

2003 ◽  
Vol 198 (7) ◽  
pp. 987-997 ◽  
Author(s):  
Shuangping Shi ◽  
Carl Nathan ◽  
Dirk Schnappinger ◽  
Jörg Drenkow ◽  
Michele Fuortes ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Large Scale ◽  
Nuclear Factor Κb ◽  
Interferon Γ ◽  
Full Scale ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ifn Γ ◽  
Microbial Products ◽  
Oxide Synthase

Macrophages are activated from a resting state by a combination of cytokines and microbial products. Microbes are often sensed through Toll-like receptors signaling through MyD88. We used large-scale microarrays in multiple replicate experiments followed by stringent statistical analysis to compare gene expression in wild-type (WT) and MyD88−/− macrophages. We confirmed key results by quantitative reverse transcription polymerase chain reaction, Western blot, and enzyme-linked immunosorbent assay. Surprisingly, many genes, such as inducible nitric oxide synthase, IRG-1, IP-10, MIG, RANTES, and interleukin 6 were induced by interferon (IFN)-γ from 5- to 100-fold less extensively in MyD88−/− macrophages than in WT macrophages. Thus, widespread, full-scale activation of macrophages by IFN-γ requires MyD88. Analysis of the mechanism revealed that MyD88 mediates a process of self-priming by which resting macrophages produce a low level of tumor necrosis factor. This and other factors lead to basal activation of nuclear factor κB, which synergizes with IFN-γ for gene induction. In contrast, infection by live, virulent Mycobacterium tuberculosis (Mtb) activated macrophages largely through MyD88-independent pathways, and macrophages did not need MyD88 to kill Mtb in vitro. Thus, MyD88 plays a dynamic role in resting macrophages that supports IFN-γ–dependent activation, whereas macrophages can respond to a complex microbial stimulus, the tubercle bacillus, chiefly by other routes.

A Summary of the Third Global Interferon-γ Release Assay Symposium

2013 ◽  
Vol 34 (6) ◽  
pp. 619-624 ◽  
Author(s):  
Antonino Catanzaro ◽  
Charles Daley
Keyword(s):  
Immune Response ◽  
Tuberculin Skin Test ◽  
Skin Test ◽  
Interferon Γ ◽  
Enzyme Linked Immunosorbent Assay ◽  
In Vitro Tests ◽  
The Third ◽  
Specific Antigens ◽  
Ifn Γ

Studies over the past several decades have dramatically increased our understanding of the immune response to Mycobacterium tuberculosis infection, and advances in proteomics and genomics have led to a new class of immune-diagnostic tests, termed interferon-γ (IFN-γ) release assays (IGRAs), which appear to obviate many of the problems encountered with the tuberculin skin test (TST). Worldwide, 2 IGRAs are currently commercially available. QuantiFERON-TB Gold In-Tube (Cellestis) is a third-generation product that uses an enzyme-linked immunosorbent assay to measure IFN-γ generated in whole blood stimulated with M. tuberculosis–specific antigens. T-Spot-TB (Oxford Immunotec) employs enzyme-linked immunosorbent spot technology to enumerate the number of purified lymphocytes that respond to M. tuberculosis–specific antigens by producing IFN-γ. These in vitro tests measure the host immune response to M. tuberculosis–specific antigens, which virtually eliminates false-positive cross reactions caused by bacillus Calmette-Guérin vaccination and/or exposure to environmental nontuberculous mycobacteria that plague the interpretation and accuracy of the tuberculin skin test (TST). The high specificity of IGRAs, together with sensitivity commensurate with or better than that of the TST, promises an accurate diagnosis and the ability to focus tuberculosis-control activities on those who are actually infected with M. tuberculosis. The Third Global Symposium was held over a 3-day period and was presented by the University of California, San Diego, Continuing Medical Education department; slides and sound recordings of each presentation are available at http://cme.ucsd.edu/igras/syllabus.html. A moderated discussion is also available at http://cme.ucsd.edu/igrasvideo. This document provides a summary of the key findings of the meeting, specifically focusing on the use of IGRAs in screening healthcare worker populations.

scholarly journals Effect ofTityus serrulatusvenom on cytokine production and the activity of murine macrophages

2002 ◽  
Vol 11 (1) ◽  
pp. 23-31 ◽  
Author(s):  
Vera L. Petricevich
Keyword(s):  
Cytokine Production ◽  
Peritoneal Macrophages ◽  
Interferon Γ ◽  
Enzyme Linked Immunosorbent Assay ◽  
No Production ◽  
Dependent Manner ◽  
Immune Functions ◽  
Macrophage Activity ◽  
Ifn Γ

The purpose of this study was to investigate the effects ofTityus serrulatusvenom (TSV) on murine peritoneal macrophages evaluated in terms of activation. The effects of crude TSV were analysed by detection of cytokines, oxygen intermediate metabolites (H2O2) and nitric oxide (NO) in supernatants of peritoneal macrophages. Several functional bioassays were employed including anin vitromodel for envenomating: cytotoxicity of TSV was assessed using the lyses percentage. Tumor necrosis factor (TNF) activity was assayed by measuring its cytotoxic activity on L-929 cells, and interleukin-6 (IL-6) and interferon-γ (IFN-γ) were assayed by enzyme-linked immunosorbent assay, whereas NO levels were detected by Griess colorimetric reactions in culture supernatant of macrophages incubated with TSV and subsequently exposed to either lipopolysaccharide or IFN-γ. Incubation of macrophages with TSV increased production of IL-6 and IFN-γ in a dose-dependent manner. TNF production was not detected in supernatants treated with TSV at any concentration. The increase in IL-6 secretion was not associated with concentration-dependent cytoxicity of TSV on these cells. These data suggest that the cytotoxicity does not appear to be the main cause of an increased cytokine production by these cells. Although NO is an important effector molecule in macrophage microbicidal activity, the inducing potential of the test compounds for its release was found to be very moderate, ranging from 125 to 800 mM. Interestingly, NO levels of peritoneal macrophages were increased after IFN-γ. Moreover, NO production had an apparent effect on macrophage activity. The results obtained here also shown that the TSV induces an important elevation in H2O2release. These results combined with NO production suggest that TSV possesses significant immunomodulatory activities capable of stimulating immune functionsin vitro.

scholarly journals Inducible Nitric Oxide Synthase in the Anterior Pituitary Gland: Induction by Interferon-γ in a Subpopulation of Folliculostellate Cells and in an Unidentifiable Population of Non-hormone-secreting Cells

1997 ◽  
Vol 45 (6) ◽  
pp. 847-857 ◽  
Author(s):  
Hugo Vankelecom ◽  
Patrick Matthys ◽  
Carl Denef
Keyword(s):  
Nitric Oxide ◽  
Cell Cultures ◽  
Anterior Pituitary ◽  
Hormone Secretion ◽  
Endocrine System ◽  
Interferon Γ ◽  
S 100 ◽  
Ifn Γ ◽  
Oxide Synthase

In the context of immune-endocrine relationships, we have previously shown that interferon-γ (IFN-γ) inhibits hormone secretion in anterior pituitary (AP) cell cultures. The non-hormone-secreting folliculostellate (FS) cells were found to mediate this inhibitory action. Because in the immune system IFN-γ is a strong stimulator of nitric oxide (NO) release through the induction of NO synthase (NOS), we investigated whether the inducible form of NOS (iNOS) is present in (rat) AP cell cultures, and whether its expression is stimulated by IFN-γ. Immunocytochemistry revealed that under basal in vitro conditions only a very few AP cells contained iNOS. Treatment with IFN-γ caused a sixfold rise in the number of iNOS-positive cells and augmented the intensity of the staining. The increased number of iNOS-expressing cells was paralleled by elevated production of NO. Some of the iNOS-positive cells extended cytoplasmic processes between hormone-secreting cells, which is a characteristic of FS cells. Immunostaining of FS cell-poor and FS cell-enriched populations (obtained by gradient sedimentation) also suggested the presence of iNOS in a subpopulation of FS cells. By double immunofluorescence techniques we found that about 65% of iNOS-expressing cells were positive for S-100, a marker protein for FS cells. However, around 80% of the S-100-positive cells were not labeled for iNOS. On the other hand, the majority of the S-100-negative iNOS-containing cells could not be further identified by antisera against the classical AP hormones, suggesting the presence of iNOS in a still unidentified non-hormone-secreting cell type of the AP gland. This report is the first to demonstrate the expression of the inducible form of NOS in the AP gland. IFN-γ upregulates this expression, showing that cytokines may use the same signaling mechanisms in both the immune and the endocrine system. In addition, a putative new function of a subpopulation of FS cells in the paracrine regulation of the AP gland is suggested.

scholarly journals Reprogramming of the Macrophage Transcriptome in Response to Interferon-γ and Mycobacterium tuberculosis

2001 ◽  
Vol 194 (8) ◽  
pp. 1123-1140 ◽  
Author(s):  
Sabine Ehrt ◽  
Dirk Schnappinger ◽  
Stefan Bekiranov ◽  
Jörg Drenkow ◽  
Shuangping Shi ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Macrophage Activation ◽  
Interferon Γ ◽  
Altered Expression ◽  
Transcriptional Signature ◽  
Number Of Genes ◽  
Phagocyte Oxidase ◽  
Ifn Γ ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Macrophage activation determines the outcome of infection by Mycobacterium tuberculosis (Mtb). Interferon-γ (IFN-γ) activates macrophages by driving Janus tyrosine kinase (JAK)/signal transducer and activator of transcription–dependent induction of transcription and PKR-dependent suppression of translation. Microarray-based experiments reported here enlarge this picture. Exposure to IFN-γ and/or Mtb led to altered expression of 25% of the monitored genome in macrophages. The number of genes suppressed by IFN-γ exceeded the number of genes induced, and much of the suppression was transcriptional. Five times as many genes related to immunity and inflammation were induced than suppressed. Mtb mimicked or synergized with IFN-γ more than antagonized its actions. Phagocytosis of nonviable Mtb or polystyrene beads affected many genes, but the transcriptional signature of macrophages infected with viable Mtb was distinct. Studies involving macrophages deficient in inducible nitric oxide synthase and/or phagocyte oxidase revealed that these two antimicrobial enzymes help orchestrate the profound transcriptional remodeling that underlies macrophage activation.

scholarly journals Expression of the Nitric Oxide Synthase 2 Gene Is Not Essential for Early Control of Mycobacterium tuberculosis in the Murine Lung

2000 ◽  
Vol 68 (12) ◽  
pp. 6879-6882 ◽  
Author(s):  
Andrea M. Cooper ◽  
John E. Pearl ◽  
Jason V. Brooks ◽  
Stefan Ehlers ◽  
Ian M. Orme
Keyword(s):  
Nitric Oxide ◽  
Mycobacterium Tuberculosis ◽  
Nitric Oxide Synthase ◽  
Low Dose ◽  
Interleukin 12 ◽  
Infection Model ◽  
Rapid Progression ◽  
Ifn Γ ◽  
Nitric Oxide Synthase 2 ◽  
Oxide Synthase

ABSTRACT The interleukin-12 and gamma interferon (IFN-γ) pathway of macrophage activation plays a pivotal role in controlling tuberculosis. In the murine model, the generation of supplementary nitric oxide by the induction of the nitric oxide synthase 2 (NOS2) gene product is considered the principal antimicrobial mechanism of IFN-γ-activated macrophages. Using a low-dose aerosol-mediated infection model in the mouse, we have investigated the role of nitric oxide in controllingMycobacterium tuberculosis in the lung. In contrast to the consequences of a systemic infection, a low dose of bacteria introduced directly into the lungs of mice lacking the NOS2 gene is controlled almost as well as in intact animals. This is in contrast to the rapid progression of disease in mice lacking IFN-γ or a key member of the IFN signaling pathway, interferon regulatory factor 1. Thus while IFN-γ is pivotal in early control of bacterial growth in the lung, this control does not completely depend upon the expression of the NOS2 gene. The absence of inducible nitric oxide in the lung does, however, result in increased polymorphonuclear cell involvement and eventual necrosis in the pulmonary granulomas of the infected mice lacking the NOS2 gene.

scholarly journals Desnutrição neonatal e produção de IFN-γ IL-12 e IL-10 por macrófagos/linfócitos: estudo da infecção celular, in vitro, por Staphylococcus aureus meticilina sensível e meticilina resistente

2012 ◽  
Vol 25 (5) ◽  
pp. 607-619 ◽  
Author(s):  
Thacianna Barreto da Costa ◽  
Natália Gomes de Morais ◽  
Thays Miranda de Almeida ◽  
Maiara Santos Severo ◽  
Célia Maria Machado Barbosa de Castro
Keyword(s):  
Staphylococcus Aureus ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ifn Γ

OBJETIVO: Avaliar a influência da desnutrição neonatal sobre a produção de Interferon gama, Interleucina-12 e Interleucina-10 em cultura de macrófagos alveolares e linfócitos infectados, in vitro, com Staphylococcus aureus sensível/resistente à meticilina. MÉTODOS: Ratos machos Wistar foram amamentados por mães cuja dieta, durante a lactação, continha 17% de proteína no grupo nutrido e 8% no grupo desnutrido. Após desmame, ambos os grupos receberam a dieta normoproteica. Os macrófagos foram obtidos após traqueostomia, através da coleta do lavado broncoalveolar. Para obtenção dos linfócitos, foi realizado o procedimento cirúrgico de punção cardíaca. Após o isolamento dos diferentes tipos celulares, procedeuse à realização dos estímulos com as cepas de estudo. A dosagem das citocinas foi realizada pelo método de Enzyme-Linked Immunosorbent Assay, a partir de amostras coletadas do sobrenadante das culturas após 24 horas de incubação. RESULTADOS: A desnutrição acarretou diminuição do crescimento ponderal, redução na produção de Interferon gama em cultura de macrófagos alveolares e linfócitos e diminuição na produção de Interleucina-12 em cultura de macrófagos alveolares. Apenas a produção de Interferon gama e Interleucina-10 em cultura de macrófagos alveolares apresentou diferença entre as cepas analisadas, em ambos os grupos estudados. CONCLUSÃO: O modelo de desnutrição neonatal produziu sequela no peso corporal e reduziu a produção de citocinas próinflamatórias (Interleucina-12 e Interferon gama), indicando que esse modelo de desnutrição pode comprometer a resolução de um processo infeccioso. A cepa de Staphylococcus aureus resistente à meticilina estimulou uma maior produção de Interferon gama e Interleucina-10 por macrófagos alveolares, o que sugeriu estimulação imunológica mais intensa, por essa cepa, nesse tipo celular especificamente.

scholarly journals PERCENTAGE OF CD3+ T LYMPHOCYTES EXPRESSING IFN-γ AFTER CFP-10 STIMULATION (Persentase Limfosit T-CD3+ yang Mengekspresikan Interferon Gamma Setelah Stimulasi Antigen CFP-10)

2018 ◽  
Vol 23 (1) ◽  
pp. 31
Author(s):  
Yulia Nadar Indrasari ◽  
Betty Agustina Tambunan ◽  
Jusak Nugraha ◽  
Fransiska Sri Oetami
Keyword(s):  
Flow Cytometry ◽  
Mycobacterium Tuberculosis ◽  
T Lymphocytes ◽  
Interferon Gamma ◽  
Tuberculosis Antigen ◽  
Mycobacterium Tuberculosis Antigen ◽  
Ifn Γ

Tuberkulosis (TB) merupakan penyakit infeksi menular, disebabkan oleh Mycobacterium tuberculosis. Respons imun adaptif yangdiperantarai oleh limfosit T berperan sangat penting dalam menyingkirkan bakteri intraseluler. Hasilan sitokin IFN-γ merupakanmekanisme efektor utama dari limfosit T. Pengembangan vaksin yang efektif dalam melawan infeksi TB mempertimbangkan faktor yangmengatur hasilan IFN-γ. CFP-10 merupakan antigen yang disekresikan oleh Mycobacterium tuberculosis. Antigen ini dikenal sebagaikomponen vaksin potensial untuk TB. Tujuan penelitian ini adalah membandingkan respons imun seluler yaitu persentase limfosit T-CD3+yang mengekspresikan IFN-γ setelah dirangsang antigen CFP-10 di pasien TB paru kasus baru, TB laten dan orang sehat. Penelitianini menggunakan desain eksperimen murni di laboratorium secara in vitro pada kultur PBMC pasien TB paru kasus baru, TB latendan orang sehat. Subjek penelitian adalah 8 pasien TB paru kasus baru, 7 TB laten dan 7 orang sehat di RS Khusus Paru Surabaya.Pemeriksaan persentase limfosit T-CD3+ yang mengekspresikan IFN-γ dengan metode Flow cytometry (BD FACSCalibur). Hasil dianalisisdengan Kruskal-Wallis atau ANOVA satu arah. Rerata persentase limfosit T-CD3+ yang mengekspresikan IFN-γ di TB paru kasus barusetelah stimulasi antigen CFP-10 (4,36%) lebih tinggi daripada sebelum stimulasi (3,50%) (nilai P=0,015). Rerata persentase limfositT-CD3+ yang mengekspresikan IFN-γ di TB laten setelah stimulasi antigen CFP-10 (3,96%) lebih tinggi dibandingkan sebelum stimulasi(2,50%) tetapi tidak bermakna (nilai P=0,367). Rerata persentase limfosit T- CD3+ yang mengekspresikan IFN-γ di orang sehat setelahstimulasi (1,66%) lebih rendah daripada sebelum stimulasi (2,89%) tetapi tidak bermakna (nilai P=0,199). Perubahan persentaselimfosit T-CD3+ yang mengekspresikan IFN-γ setelah stimulasi antigen CFP-10 antarkelompok tidak berbeda bermakna (nilai P=0,143).Berdasarkan hasil telitian ini dapat disimpulkan bahwa terdapat peningkatan persentase limfosit T-CD3+ yang mengekspresikan IFN-γdi TB paru kasus baru setelah stimulasi antigen CFP-10. Hal ini menunjukkan limfosit T-CD3+ yang mengekspresikan IFN-γ berperandalam perlindungan terhadap infeksi TB paru.

scholarly journals Preliminary Serological Study of Helicobacter pylori Infection in Some University Students

2020 ◽  
Vol 6 ◽  
pp. 1
Author(s):  
Abdullah A Mahrazi ◽  
Mohammad A Khibrani ◽  
Khatib S Ismail ◽  
Emad Abada ◽  
◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
University Students ◽  
Large Scale ◽  
Confirmatory Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Blood Collection ◽  
Igg Antibodies ◽  
Igm Antibodies ◽  
H Pylori

Helicobacter pylori has been associated with peptic ulcer and gastric carcinoma. This study aimed to find the seroprevalence of H. pylori infection in some male students of Jazan University, Saudi Arabia. Twenty students were enrolled in the study (n = 20). Informed consent was obtained from the students. About 2 ml blood was collected intravenously in Improvacuter® evacuated blood collection tubes. The blood was allowed to clot at room temperature. The serum was collected and stored at –20°C for further use. The separated serum was used to detect IgG and IgM antibodies by Enzyme Linked Immunosorbent Assay (ELISA) against H. pylori for the in vitro diagnosis. A total of 11 (55.00%) students tested positive for IgG antibodies against H. pylori indicating previous infection. All the samples tested negative for IgM antibodies against H. pylori indicating no active infection. The seroprevalance of IgG antibodies against H. pylori was found to be very high in some male university students and is a cause of concern regarding their health. Obesity (p < 0.05; Value statistically significant), stress and bad eating habits, eating out, drinking carbonated beverages, and eating spicy food were some of the factors found to be associated with IgG seropositive students. The students were counseled and were instructed to undergo a confirmatory test and get medical intervention. Further large-scale studies need to be performed to plan action against this disease causing organism and to improve the health of students.

scholarly journals Evaluation of a lateral flow assay for rapid and simple detection of IFN-γ for the diagnosis of Mycobacterium tuberculosis infection

2020 ◽  
Author(s):  
Jeong-Ran Kim ◽  
Hae Yeong Kang ◽  
Su-Bin Seong ◽  
Nari Kim ◽  
Tae Sun Shim ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Lateral Flow ◽  
Lateral Flow Assay ◽  
Tuberculosis Infection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mycobacterium Tuberculosis Infection ◽  
Blood Samples ◽  
Simple Detection ◽  
Laboratory Workers ◽  
Ifn Γ

Abstract Background: Interferon-gamma (IFN-γ) release assays (IGRAs) are useful for the diagnosis of Mycobacterium tuberculosis infection. Current IGRAs use either enzyme-linked immunosorbent assay (ELISA) or enzyme-linked immunospot assay, which require complex procedures and techniques to determine IFN-γ secretion. We aimed to compare the usefulness of the easy-to-use lateral flow assay (LFA) with that of the QuantiFERON-TB Gold In-Tube (QFT-GIT) or QuantiFERON-TB Gold Plus (QFT-plus) ELISAs for detecting IFN-γ, produced by the blood T cells stimulated by tuberculosis (TB) antigen. Methods: Following informed consent, 176 participants, including health care workers such as TB laboratory workers and radiologists, were enrolled for the study from June 2017 to June 2018. Blood samples were collected and tested using QFT-GIT and QFT-plus. The secreted IFN-γ was quantified by LFA, which took approximately 15 min, and ELISA, which took approximately 3 h. Results: A total of 176 blood samples were screened. The positive rates of QFT-GIT and QFT-plus were 34.1% and 37.5%, respectively. Overall agreement between QFT-GIT and QFT-plus was 93.1% ( κ = 0.86). The positive rates of LFA with QFT-GIT tube and QFT-plus tube were 25.6% and 31.3%, respectively, overall agreement of LFA being 90.3% ( κ = 0.78) and 89.2% ( κ = 0.77), respectively, compared to the QFT-GIT and QFT-plus ELISA. Conclusion: The ability of LFA to measure IFN-γ was similar to that of ELISA. The current findings suggested that the new LFA could be more conveniently utilized for diagnosing TB infection.

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