Genomic transcriptional profiling identifies a candidate blood biomarker signature for the diagnosis of septicemic melioidosis

A diagnostic signature for sepsis caused by Burkholderia pseudomallei infection was identified from transcriptional profiling of the blood of septicemia patients

Host Immune Transcriptional Profiles Reflect the Variability in Clinical Disease Manifestations in Patients with Staphylococcus aureus Infections

Staphylococcus aureus infections are associated with diverse clinical manifestations leading to significant morbidity and mortality. To define the role of the host response in the clinical manifestations of the disease, we characterized whole blood transcriptional profiles of children hospitalized with community-acquired S. aureus infection and phenotyped the bacterial strains isolated. The overall transcriptional response to S. aureus infection was characterized by over-expression of innate immunity and hematopoiesis related genes and under-expression of genes related to adaptive immunity. We assessed individual profiles using modular fingerprints combined with the molecular distance to health (MDTH), a numerical score of transcriptional perturbation as compared to healthy controls. We observed significant heterogeneity in the host signatures and MDTH, as they were influenced by the type of clinical presentation, the extent of bacterial dissemination, and time of blood sampling in the course of the infection, but not by the bacterial isolate. System analysis approaches provide a new understanding of disease pathogenesis and the relation/interaction between host response and clinical disease manifestations

An interferon-inducible neutrophil-driven blood transcriptional signature in human tuberculosis

Tuberculosis (TB), caused by infection with Mycobacterium tuberculosis (M. tuberculosis), is a major cause of morbidity and mortality worldwide and efforts to control TB are hampered by difficulties with diagnosis, prevention and treatment 1,2. Most people infected with M. tuberculosis remain asymptomatic, termed latent TB, with a 10% lifetime risk of developing active TB disease, but current tests cannot identify which individuals will develop disease 3. The immune response to M. tuberculosis is complex and incompletely characterized, hindering development of new diagnostics, therapies and vaccines 4,5. We identified a whole blood 393 transcript signature for active TB in intermediate and high burden settings, correlating with radiological extent of disease and reverting to that of healthy controls following treatment. A subset of latent TB patients had signatures similar to those in active TB patients. We also identified a specific 86-transcript signature that discriminated active TB from other inflammatory and infectious diseases. Modular and pathway analysis revealed that the TB signature was dominated by a neutrophil-driven interferon (IFN)-inducible gene profile, consisting of both IFN-γ and Type I IFNαβ signalling. Comparison with transcriptional signatures in purified cells and flow cytometric analysis, suggest that this TB signature reflects both changes in cellular composition and altered gene expression. Although an IFN signature was also observed in whole blood of patients with Systemic Lupus Erythematosus (SLE), their complete modular signature differed from TB with increased abundance of plasma cell transcripts. Our studies demonstrate a hitherto under-appreciated role of Type I IFNαβ signalling in TB pathogenesis, which has implications for vaccine and therapeutic development. Our study also provides a broad range of transcriptional biomarkers with potential as diagnostic and prognostic tools to combat the TB epidemic

Interferon-driven alterations of the host’s amino acid metabolism in the pathogenesis of typhoid fever

Enteric fever, caused by Salmonella enterica serovar Typhi, is an important public health problem in resource-limited settings and, despite decades of research, human responses to the infection are poorly understood. In 41 healthy adults experimentally infected with wild-type S. Typhi, we detected significant cytokine responses within 12 h of bacterial ingestion. These early responses did not correlate with subsequent clinical disease outcomes and likely indicate initial host–pathogen interactions in the gut mucosa. In participants developing enteric fever after oral infection, marked transcriptional and cytokine responses during acute disease reflected dominant type I/II interferon signatures, which were significantly associated with bacteremia. Using a murine and macrophage infection model, we validated the pivotal role of this response in the expression of proteins of the host tryptophan metabolism during Salmonella infection. Corresponding alterations in tryptophan catabolites with immunomodulatory properties in serum of participants with typhoid fever confirmed the activity of this pathway, and implicate a central role of host tryptophan metabolism in the pathogenesis of typhoid fever

Assessing the human immune system through blood transcriptomics

Blood is the pipeline of the immune system. Assessing changes in transcript abundance in blood on a genome-wide scale affords a comprehensive view of the status of the immune system in health and disease. This review summarizes the work that has used this approach to identify therapeutic targets and biomarker signatures in the field of autoimmunity and infectious disease. Recent technological and methodological advances that will carry the blood transcriptome research field forward are also discussed

A community approach to mortality prediction in sepsis via gene expression analysis.

Improved risk stratification and prognosis prediction in sepsis is a critical unmet need. Clinical severity scores and available assays such as blood lactate reflect global illness severity with suboptimal performance, and do not specifically reveal the underlying dysregulation of sepsis. Here, we present prognostic models for 30-day mortality generated independently by three scientific groups by using 12 discovery cohorts containing transcriptomic data collected from primarily community-onset sepsis patients. Predictive performance is validated in five cohorts of community-onset sepsis patients in which the models show summary AUROCs ranging from 0.765-0.89. Similar performance is observed in four cohorts of hospital-acquired sepsis. Combining the new gene-expression-based prognostic models with prior clinical severity scores leads to significant improvement in prediction of 30-day mortality as measured via AUROC and net reclassification improvement index These models provide an opportunity to develop molecular bedside tests that may improve risk stratification and mortality prediction in patients with sepsis.y NIGMS Glue Grant Legacy Award R24GM102656. J.F.B.-M., R.A., and E.T. were supported by Instituto de Salud Carlos III (grants EMER07/050, PI13/02110, PI16/01156). R.J.L. was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health under award number UL1TR001417. The CAPSOD study was supported by NIH (U01AI066569, P20RR016480, HHSN266200400064C). P.K. is supported by grants from Bill Melinda Gates Foundation, R01 AI125197-01, 1U19AI109662, and U19AI057229, outside the submitted work. The GAinS study was supported by the National Institute for Health Research through the Comprehensive Clinical Research Network for patient recruitment; Wellcome Trust (Grants 074318 [to J.C.K.], and 090532/Z/09/Z [core facilities Wellcome Trust Centre for Human Genetics including High-Throughput Genomics Group]); European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC Grant agreement no. 281824 (to J.C.K.), the Medical Research Council (98082 [to J.C.K.]); UK Intensive Care Society; and NIHR Oxford Biomedical Research Centre. The Duke HAI study was supported by a research agreement between Duke University and Novartis Vaccines and Diagnostics, Inc. According to the terms of the agreement, representatives of the sponsor had an opportunity to review and comment on a draft of the manuscript. The authors had full control of the analyses, the preparation of the manuscript, and the decision to submit the manuscript for publication. For the University of Florida ‘P50’ Study, data were obtained from the Sepsis and Critically Illness Research Center (SCIRC) at the University of Florida College of Medicine, which is supported in part by NIGMS P50 GM111152. This work was supported by Defense Advanced Research Projects Agency and the Army Research Office through Grant W911NF-15-1-0107.

Production of interleukin-27 by human neutrophils regulates their function during bacterial infection.

Septicemia is the most severe form of melioidosis caused by the Gram-negative bacterium, Burkholderia pseudomallei. Here, we show that levels of IL-27p28 transcript and protein were both significantly elevated in patients with sepsis, particularly melioidosis and in patients with unfavorable disease outcome. Moreover, human monocytes/macrophages and neutrophils were the major source of IL-27 during infection. The addition of exogenous IL-27 in vitro resulted in significantly increased bacterial survival, reduced B. pseudomallei-induced oxidative burst, and enhanced IL-1β and TNF-α production by purified neutrophils from healthy subjects. Finally, blockade of endogenous IL-27 in neutrophils using soluble IL-27 receptor antagonist prior to infection led to significantly reduced survival of bacteria and decreased IL-1β, but not TNF-α production. These results indicate a potential role for IL-27 in the suppression of anti-bacterial defense mechanisms that might contribute to disease severity in sepsis. The targeting of this cytokine may be beneficial in the management of human sepsis

Cardioprotective anti-inflammatory activities of Artemisia lactiflora Wall. ex DC. extract and fractions in a rat cardiomyoblast (H9c2) model of inflammatory sepsis

Context: Sepsis is a progressive inflammatory response commonly caused by gram-negative bacteria via activation of the NF-κB-dependent pathway. Severe sepsis can cause cardiac dysfunction and increases the risk of death. Artemisia lactiflora is a Chinese medicinal plant that contains phenolics and flavonoids with probable anti-inflammatory activities. Aims: To investigate the anti-inflammatory activities of A. lactiflora leaves extract in a cardiac sepsis model. Methods: A. lactiflora leaves were extracted and fractioned using solvents of different polarities. The total phenolic and flavonoid content was quantified. The antioxidants were quantified in vitro using DPPH and ABTS radicals. The cytotoxicity of the extract and fractions was evaluated and calculated using the neutral red assay and curve-fitting analysis in cardiomyoblasts (H9c2). The anti-inflammatory activities of A. lactiflora were observed by treating H9c2 with extract and fractions in the presence of Escherichia coli. Expression of pro-inflammatory genes (TNF and IL6) and secretion of pro-inflammatory cytokines (TNF-α and IL-6) were measured by RT-qPCR and ELISA. Results: Extract and fractions of A. lactiflora contained noticeably high quantities of phenolics and flavonoids with considerably high anti-DPPH and anti-ABTS activities. Co-treatment with A. lactiflora extract and all fractions significantly downregulated the expression of TNF and IL6 as well as decreased the secretion of TNF-α and IL-6 (p<0.0001) compared with E. coli-stimulated cardiomyoblasts. The butanol fraction had the highest potency in reducing pro-inflammatory cytokine secretions in cardiomyoblasts under in vitro sepsis conditions. Conclusions: A. lactiflora leaf extract demonstrated therapeutic potential in a cardiac sepsis model by alleviating the inflammatory responses. This plant can potentially be developed as an alternative medicine for inflammation and sepsis

Phytochemicals and Immunomodulatory Effect of Nelumbo nucifera Flower Extracts on Human Macrophages

This research characterizes phytochemicals inherent in lotus flower and investigates the antioxidant and immunomodulatory activity of ethyl acetate (EA) and ethyl alcohol (ET) lotus petal extracts. In the experiment, human monocytes-derived macrophages were stimulated by lipopoly-saccharide to mimic bacteria-induced inflammation. The results showed that ferulic acid, couma-rin, and chlorogenic acid were three dominant polyphenols. The EA and ET lotus petal extracts also possessed high antioxidant capability. Furthermore, the extracts exhibited immunomodulatory properties by suppressing TNF-α secretion in inflammatory-induced human macrophages by in-hibiting NF-κB-dependent inflammatory response. In essence, the lotus petal extracts possess reme-dial attributes beneficial to individuals afflicted with declined immune functions

An Ethyl Acetate Fraction of Moringa oleifera Lam. Inhibits Human Macrophage Cytokine Production Induced by Cigarette Smoke

Moringa oleifera Lam. (MO) has been reported to harbor anti-oxidation and anti-inflammatory activity and useful in the treatment of inflammatory diseases. However, despite these findings there has been little work done on the effects of MO on immune cellular function. Since macrophages, TNF and related cytokines play an important pathophysiologic role in lung damage induced by cigarette smoke, we examined the effects of MO on cigarette smoke extract (CSE)-induced cytokine production by human macrophages. An ethyl acetate fraction of MO (MOEF) was prepared from fresh leaves extract of Moringa and shown to consist of high levels of phenolic and antioxidant activities. Human monocyte derived macrophages (MDM) pre-treated with varying concentrations of MOEF showed decreased production of TNF, IL-6 and IL-8 in response to both LPS and CSE. The decrease was evident at both cytokine protein and mRNA levels. Furthermore, the extract inhibited the expression of RelA, a gene implicated in the NF-kappa B p65 signaling in inflammation. The findings highlight the ability of MOEF to inhibit cytokines (IL-8) which promote the infiltration of neutrophils into the lungs and others (TNF, IL-6) which mediate tissue disease and damage