Project description:In this project we performed a comprehensive exploration of monocyte molecular responses in a cohort of patients with septic shock via label-free shotgun proteomics. We enrolled adult (≥18 years old) patients with sepsis from community-acquired infections, diagnosed according to the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) criteria. Blood samples were obtained within the first 72 hours from the diagnosis of sepsis (sepsis phase) and on de day before ICU discharge (recovery phase). The Control group consisted of age matched healthy volunteers. We excluded subjects with AIDS, advanced cancer, hematological diseases, and pregnancy.
Project description:BackgroundHistone deacetylase 2 (HDAC2) is a class I histone deacetylase family member that plays a critical role in suppressing inflammatory gene expression in the airways, lung parenchyma, and alveolar macrophages in patients with chronic obstructive pulmonary disease (COPD). However, the expression of HDAC2 in peripheral blood monocytes (PBMCs), nuclear factor kappa B (NF-?B) p65, and serum inflammatory cytokine levels in COPD patients, smokers, and non-smokers remains unclear.MethodsPBMCs were obtained from COPD patients, healthy smokers, and healthy nonsmokers. The HDAC2 and NF-?B p65 expression were quantified by Western Blot. HDAC activity was assessed by an HDAC fluorometric immunoprecipitation activity assay kit. Serum tumor necrosis factor-alpha (TNF-?) and interleukin-8 (IL-8) levels were measured by ELISA.ResultsHDAC2 expression and HDAC activity were decreased in PBMCs in COPD patients compared with smokers and non-smokers. Increased NF-?B p65 expression, serum TNF-? and IL-8 levels were observed in COPD patients compared with nonsmokers. The FEV1%pred was positively correlated with HDAC2 expression and HDAC activity in COPD patients. Smokers had decreased HDAC activity, increased NF-?B p65 expression and serum TNF-? compared with nonsmokers.ConclusionsHDAC2 expression was decreased in PBMCs of COPD patients and was correlated with disease severity. The reduction of HDAC2 expression not only directly enhances the expression of inflammatory genes, but may account for the activation of NF-?B mediated inflammation. Decreased HDAC2 may serve as a potential biomarker of COPD and predict the decline of lung function.
Project description:Blood monocytes serve as the first line of host defense and are equipped to recognize and respond to infection by triggering an immune-inflammatory response. While most information on these cells comes from in vitro studies in humans or in vivo studies in mice, little is known about monocytes under human disease conditions. We investigated the role of monocytes during sepsis and its resolution in humans. A transcriptomal and functional analysis of blood monocytes from patients during gram negative sepsis and at recovery was performed. Monocytes from sepsis patients showed upregulation of a large number of pro-inflammatory genes and cytokines/chemokines, consistent with an ongoing systemic inflammation. However, these cells showed impairment to ex vivo endotoxin (LPS) challenge, displaying a quantitative decrease in the number of LPS-inducible genes. Moreover, they downregulated the expression of several pro-inflammatory cytokine/chemokine genes, activation marker genes and transcription factors associated with monocyte/macrophage activation, upon ex vivo LPS stimulation. Functionally, they downregulated expression of inflammatory cytokines/chemokines and antigen presentation-related molecules and functions. In contrast, genes and functions related to phagocytosis, anti-microbial activity and tissue remodeling where remained unaffected or even enhanced . Collectively, our observations suggest a genetic and functional re-programming of these cells during human sepsis progression. Understanding the molecular mechanisms which regulate this re-programming will allow to devise strategies which could modulate the response of these cells and hence, disease progression.
Project description:Blood monocytes serve as the first line of host defense and are equipped to recognize and respond to infection by triggering an immune-inflammatory response. While most information on these cells comes from in vitro studies in humans or in vivo studies in mice, little is known about monocytes under human disease conditions. We investigated the role of monocytes during sepsis and its resolution in humans. A transcriptomal and functional analysis of blood monocytes from patients during gram negative sepsis and at recovery was performed. Monocytes from sepsis patients showed upregulation of a large number of pro-inflammatory genes and cytokines/chemokines, consistent with an ongoing systemic inflammation. However, these cells showed impairment to ex vivo endotoxin (LPS) challenge, displaying a quantitative decrease in the number of LPS-inducible genes. Moreover, they downregulated the expression of several pro-inflammatory cytokine/chemokine genes, activation marker genes and transcription factors associated with monocyte/macrophage activation, upon ex vivo LPS stimulation. Functionally, they downregulated expression of inflammatory cytokines/chemokines and antigen presentation-related molecules and functions. In contrast, genes and functions related to phagocytosis, anti-microbial activity and tissue remodeling where remained unaffected or even enhanced . Collectively, our observations suggest a genetic and functional re-programming of these cells during human sepsis progression. Understanding the molecular mechanisms which regulate this re-programming will allow to devise strategies which could modulate the response of these cells and hence, disease progression. Blood monocytes from gram-negative sepsis patients during sepsis (Sepsis) and following their recovery (Recovery/Basal) as well as healthy donor (control) were isolated. Thereafter, these cells were treated ex vivo with or without LPS for 3h and analysed for transcriptomic study.
Project description:BackgroundSepsis is a global burden and the primary cause of death in intensive care units worldwide. The pathophysiological changes induced by the host's systemic inflammatory response to infection are not yet fully understood. During sepsis, the immune system is confronted with a variety of factors, which are integrated within the individual cells and result in changes of their basal state of responsiveness. Epigenetic mechanisms like histone modifications are known to participate in the control of immune reactions, but so far the situation during sepsis is unknown.Methods and findingsIn a pilot approach, we performed combined chromatin immunoprecipitation followed by high-throughput sequencing to assess the genome-wide distribution of the chromatin modifications histone 3 lysine 4 and 27 trimethylation and lysine 9 acetylation in monocytes isolated from healthy donors (n = 4) and patients with sepsis (n = 2). Despite different underlying causes for sepsis, a comparison over promoter regions shows a high correlation between the patients for all chromatin marks. These findings hold true also when comparing patients to healthy controls. Despite the global similarity, differential analysis reveals a set of distinct promoters with significant enrichment or depletion of histone marks. Further analysis of overrepresented GO terms show an enrichment of genes involved in immune function. To the most prominent ones belong different members of the HLA family located within the MHC cluster together with the gene coding for the major regulator of this locus-CIITA.ConclusionsWe are able to show for the first time that sepsis in humans induces selective and precise changes of chromatin modifications in distinct promoter regions of immunologically relevant genes, shedding light on basal regulatory mechanisms that might be contributing to the functional changes occurring in monocytes.
Project description:To study the transcriptional profile of patients with acute RSV or Influenza infection,children of median age 2.4 months (range 1.5-8.6) hospitalized with acute RSV and influenza virus infection were offered study enrollment after microbiologic confirmation of the diagnosis. Blood samples were collected from them within 42-72 hours of hospitalization. We excluded children with suspected or proven polymicrobial infections, with underlying chronic medical conditions (i.e congenital heart disease, renal insufficiency), with immunodeficiency, or those who received systemic steroids or other immunomodulatory therapies. The RSV cohort consisted of 51 patients with median age of 2 months (range 1.5-3.9) and the influenza cohort had 28 patients with median age of 5.5 months (range 1.4-21). Control samples were obtained from healthy children undergoing elective surgical procedures or at outpatient clinic visits. To exclude viral co-infections we performed nasopharyngeal viral cultures of all subjects. We recruited 10 control patients for the RSV cohort with median age of 6.7 months (range 5-10), and 12 control patients for the influenza cohort with median age of18.5 months (range 10.5-26).
Project description:Lactate, the end product of anaerobic glycolysis, is produced in high amounts by innate immune cells during inflammatory activation. Although immunomodulating effects of lactate have been reported, evidence from human studies is scarce. Here we show that expression of genes involved in lactate metabolism and transport is modulated in human immune cells during infection and upon inflammatory activation with TLR ligands in vitro, indicating an important role for lactate metabolism in inflammation. Extracellular lactate induces metabolic reprogramming in innate immune cells, as evidenced by reduced glycolytic and increased oxidative rates of monocytes immediately after exposure to lactate. A short-term infusion of lactate in humans in vivo increased ex vivo glucose consumption of PBMCs, but effects on metabolic rates and cytokine production were limited. Interestingly, long-term treatment with lactate ex vivo, reflecting pathophysiological conditions in local microenvironments such as tumor or adipose tissue, significantly modulated cytokine production with predominantly anti-inflammatory effects. We found time- and stimuli-dependent effects of extracellular lactate on cytokine production, further emphasizing the complex interplay between metabolism and immune cell function. Together, our findings reveal lactate as a modulator of immune cell metabolism which translates to reduced inflammation and may ultimately function as a negative feedback signal to prevent excessive inflammatory responses.
Project description:We analyzed gene expression in human peripheral blood mononuclear cells (PBMCs) from breast cancer patients, patients with benign breast abnormalities, healthy cancer-free individuals as well as patients with other types of cancer (gastrointestinal and brain cancers). Peripheral blood mononuclear cell (PBMC) samples were collected from women with a suspect initial mammogram prior to undergoing a diagnostic biopsy procedure to determine whether the detected abnormality was benign or malignant. In total, we collected blood from 57 women with a diagnosis of breast cancer and 37 with a benign diagnosis. We also collected blood from 31 women with normal initial mammograms as negative controls and 15 breast cancer patients following surgery. All breast cancer patient samples were collected at the Duke University Medical Center (DUMC) under an institutional review board (IRB)-approved protocol (Duke eIRB#12025) after obtaining informed consent and were provided by Dr. Jeffrey Marks. PBMC samples from patients with various gastrointestinal cancers (n=15) were colelcted and stored at DUMC under IRB-approved protocols (Duke eIRB#12010 and 12025) and were provided by Dr. Jeffrey Marks. Peripheral blood leukocyte samples from patients with brain tumors (n=7) were provided by Dr. John Sampson and were collected by leukapheresis under Duke eIRB#00003877 and #00009403.
Project description:Innate immune memory, also refered to as trained immunity (TRIM) is the phenomenon whereby innate immune cells such as monocytes or macrophages undergo functional reprogramming after exposure to microbial components. In this study we performed epigenomic and transcriptomic analysis of HIDS (Hyper IgD Syndrome) patients at baseline, and after 24 hours culture in media (RPMI only) or media + 10ng/mL LPS. HIDS is associated with the accumulation of mevalonate, a monocyte trainer.