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1.  Elevated IP-10 and IL-6 from Bronchoalveolar Lavage Cells are Biomarkers of Non-Cavitary Tuberculosis 
SUMMARY
Objective
Tuberculosis (TB) causes nearly 1.5 million deaths annually worldwide. Active TB disease can destroy lung parenchyma leading to cavities. Immune responses that predispose or protect individuals from lung damage during tuberculosis are poorly defined.
Design
Enrolled subjects (N=73) had bilateral infiltrates and underwent bronchoalveolar lavage (BAL) to sample lung immune cells and assay BAL cell cytokine production.
Results
All had sputum culture demonstrating Mycobacterium tuberculosis and 22/73 (30%) had cavities on their chest radiograph. Those with cavities at presentation had higher percent PMN in BAL as well as lower IP-10 (p<0.01) and IL-6 (p=0.013) in BAL cell supernatants, compared to those without cavities. There was no correlation between cavities and other BAL or serum cytokines. IP-10 was negatively associated with BAL PMN. IP-10 and IL-6 expression above median decrease the odds of cavities by 79% and 78% in logistic regression models. IP-10 and IL-6 clustered with IFN-γ and TNF-α in a principal component analysis while IL-4 clustered with PMN.
Conclusion
Increasing IP-10 and IL-6 production by BAL cells is associated with non-cavitary tuberculosis in patients who present with radiographically advanced TB. IP-10 and IL-6 may reflect an effective Th-1 immune control pathway for TB, attenuating tuberculous lung destruction.
doi:10.5588/ijtld.12.0610
PMCID: PMC4050635  PMID: 23743311
biomarkers; cavitary tuberculosis; Th-1; innate immunity
2.  Cardiovascular Disease Biomarkers Predict Susceptibility or Resistance to Lung Injury in World Trade Center Dust Exposed Firefighters 
Pulmonary vascular loss is an early feature of chronic obstructive pulmonary disease. Biomarkers of inflammation and of metabolic syndrome, predicts loss of lung function in World Trade Center Lung Injury (WTC-LI). We investigated if other cardiovascular disease (CVD) biomarkers also predicted WTC-LI.
This nested case-cohort study used 801 never smoker, WTC exposed firefighters with normal pre-9/11 lung function presenting for subspecialty pulmonary evaluation (SPE) before March, 2008. A representative sub-cohort of 124/801 with serum drawn within six months of 9/11 defined CVD biomarker distribution. Post-9/11/01 FEV1 at subspecialty exam defined cases: susceptible WTC-LI cases with FEV1≤77% predicted (66/801) and resistant WTC-LI cases with FEV1≥107% (68/801). All models were adjusted for WTC exposure intensity, BMI at SPE, age at 9/11, and pre-9/11 FEV1.
Susceptible WTC-LI cases had higher levels of Apo-AII, CRP, and MIP-4 with significant RRs of 3.85, 3.93, and 0.26 respectively with an area under the curve (AUC) of 0.858. Resistant WTC-LI cases had significantly higher sVCAM and lower MPO with RRs of 2.24, and 2.89 respectively; AUC 0.830.
Biomarkers of CVD in serum six-month post-9/11 predicted either susceptibility or resistance to WTC-LI. These biomarkers may define pathways producing or protecting subjects from pulmonary vascular disease and associated loss of lung function after an irritant exposure.
doi:10.1183/09031936.00077012
PMCID: PMC3642231  PMID: 22903969
Airway Inflammation; Cytokines; Pulmonary Funtion Testing
3.  MMP-2 and TIMP-1 predict healing of WTC-lung injury in New York City firefighters 
Respiratory Research  2014;15(1):5.
Rationale
After 9/11/2001, most FDNY workers had persistent lung function decline but some exposed workers recovered. We hypothesized that the protease/anti-protease balance in serum soon after exposure predicts subsequent recovery.
Methods
We performed a nested case–control study measuring biomarkers in serum drawn before 3/2002 and subsequent forced expiratory volume at one second (FEV1) on repeat spirometry before 3/2008. Serum was assayed for matrix metalloproteinases (MMP-1,2,3,7,8,9,12 and 13) and tissue inhibitors of metalloproteinases (TIMP-1,2,3,4). The representative sub-cohort defined analyte distribution and a concentration above 75th percentile defined elevated biomarker expression. An FEV1 one standard deviation above the mean defined resistance to airway injury. Logistic regression was adjusted for pre-9/11 FEV1, BMI, age and exposure intensity modeled the association between elevated biomarker expression and above average FEV1.
Results
FEV1 in cases and controls declined 10% of after 9/11/2001. Cases subsequently returned to 99% of their pre-exposure FEV1 while decline persisted in controls. Elevated TIMP-1 and MMP-2 increased the odds of resistance by 5.4 and 4.2 fold while elevated MMP-1 decreased it by 0.27 fold.
Conclusions
Resistant cases displayed healing, returning to 99% of pre-exposure values. High TIMP-1 and MMP-2 predict healing. MMP/TIMP balance reflects independent pathways to airway injury and repair after WTC exposure.
doi:10.1186/1465-9921-15-5
PMCID: PMC3913317  PMID: 24447332
Biomarkers; Lung disease; Occupational exposure
4.  Early Elevation of Serum MMP-3 and MMP-12 Predicts Protection from World Trade Center-Lung Injury in New York City Firefighters: A Nested Case-Control Study 
PLoS ONE  2013;8(10):e76099.
Objective
After 9/11/2001, some Fire Department of New York (FDNY) workers had excessive lung function decline. We hypothesized that early serum matrix metalloproteinases (MMP) expression predicts World Trade Center-Lung Injury (WTC-LI) years later.
Methods
This is a nested case-control analysis of never-smoking male firefighters with normal pre-exposure Forced Expiratory Volume in one second (FEV1) who had serum drawn up to 155 days post 9/11/2001. Serum MMP-1, 2,3,7,8, 9, 12 and 13 were measured. Cases of WTC-LI (N = 70) were defined as having an FEV1 one standard deviation below the mean (FEV1≤77%) at subspecialty pulmonary evaluation (SPE) which was performed 32 months (IQR 21–53) post-9/11. Controls (N = 123) were randomly selected. We modeled MMP's ability as a predictor of cases status with logistic regression adjusted for time to blood draw, exposure intensity, weight gain and pre-9/11 FEV1.
Results
Each log-increase in MMP-3 and MMP-12 showed reduced odds of developing WTC-LI by 73% and 54% respectively. MMP-3 and MMP-12 consistently clustered together in cases, controls, and the cohort. Increasing time to blood draw significantly and independently increased the risk of WTC-LI.
Conclusions
Elevated serum levels of MMP-3 and MMP-12 reduce the risk of developing WTC-LI. At any level of MMP-3 or 12, increased time to blood draw is associated with a diminished protective effect.
doi:10.1371/journal.pone.0076099
PMCID: PMC3797818  PMID: 24146820
6.  Increased Production of IL-4 and IL-12p40 from Bronchoalveolar Lavage Cells Are Biomarkers of Mycobacterium tuberculosis in the Sputum 
PLoS ONE  2013;8(3):e59461.
Background
Tuberculosis (TB) causes 1.45 million deaths annually world wide, the majority of which occur in the developing world. Active TB disease represents immune failure to control latent infection from airborne spread. Acid-fast bacillus (AFB) seen on sputum smear is a biomarker for contagiousness.
Methods
We enrolled 73 tuberculosis patients with extensive infiltrates into a research study using bronchoalveolar lavage (BAL) to sample lung immune cells and assay BAL cell cytokine production. All patients had sputum culture demonstrating Mycobacterium tuberculosis and 59/73 (81%) had AFB identified by microscopy of the sputum. Compared with smear negative patients, smear positive patients at presentation had a higher proportion with smoking history, a higher proportion with temperature >38.50 C, higher BAL cells/ml, lower percent lymphocytes in BAL, higher IL-4 and IL-12p40 in BAL cell supernatants. There was no correlation between AFB smear and other BAL or serum cytokines. Increasing IL-4 was associated with BAL PMN and negatively associated with BAL lymphocytes. Each 10-fold increase in BAL IL-4 and IL-12p40 increased the odds of AFB smear positivity by 7.4 and 2.2-fold, respectively, in a multi-variable logistic model.
Conclusion
Increasing IL-4 and IL-12p40 production by BAL cells are biomarkers for AFB in sputum of patients who present with radiographically advanced TB. They likely reflect less effective immune control of pathways for controlling TB, leading to patients with increased infectiousness.
doi:10.1371/journal.pone.0059461
PMCID: PMC3603887  PMID: 23527200
7.  Metabolic Syndrome Biomarkers Predict Lung Function Impairment 
Rationale: Cross-sectional studies demonstrate an association between metabolic syndrome and impaired lung function.
Objectives: To define if metabolic syndrome biomarkers are risk factors for loss of lung function after irritant exposure.
Methods: A nested case-control study of Fire Department of New York personnel with normal pre–September 11th FEV1 and who presented for subspecialty pulmonary evaluation before March 10, 2008. We correlated metabolic syndrome biomarkers obtained within 6 months of World Trade Center dust exposure with subsequent FEV1. FEV1 at subspecialty pulmonary evaluation within 6.5 years defined disease status; cases had FEV1 less than lower limit of normal, whereas control subjects had FEV1 greater than or equal to lower limit of normal.
Measurements and Main Results: Clinical data and serum sampled at the first monitoring examination within 6 months of September 11, 2001, assessed body mass index, heart rate, serum glucose, triglycerides and high-density lipoprotein (HDL), leptin, pancreatic polypeptide, and amylin. Cases and control subjects had significant differences in HDL less than 40 mg/dl with triglycerides greater than or equal to 150 mg/dl, heart rate greater than or equal to 66 bpm, and leptin greater than or equal to 10,300 pg/ml. Each increased the odds of abnormal FEV1 at pulmonary evaluation by more than twofold, whereas amylin greater than or equal to 116 pg/ml decreased the odds by 84%, in a multibiomarker model adjusting for age, race, body mass index, and World Trade Center arrival time. This model had a sensitivity of 41%, a specificity of 86%, and a receiver operating characteristic area under the curve of 0.77.
Conclusions: Abnormal triglycerides and HDL and elevated heart rate and leptin are independent risk factors of greater susceptibility to lung function impairment after September 11, 2001, whereas elevated amylin is protective. Metabolic biomarkers are predictors of lung disease, and may be useful for assessing risk of impaired lung function in response to particulate inhalation.
doi:10.1164/rccm.201109-1672OC
PMCID: PMC3297095  PMID: 22095549
metabolic syndrome X; September 11 terrorist attacks; biologic markers
8.  Physician-Diagnosed Respiratory Conditions and Mental Health Symptoms Seven to Nine Years Following the World Trade Center Disaster 
Background
This study examines the prevalence of physician-diagnosed respiratory conditions and mental health symptoms in firefighters and emergency medical service workers up to 9 years after rescue/recovery efforts at the World Trade Center (WTC).
Methods
We analyzed FDNY physician and self-reported diagnoses by WTC exposure and quintiles of pulmonary function (FEV1%predicted). We used screening instruments to assess probable PTSD and probable depression.
Results
FDNY physicians most commonly diagnosed asthma (8.8%) and sinusitis (9.7%). The highest prevalence of physician-diagnosed obstructive airway disease (OAD) was in the lowest FEV1%predicted quintile. Participants who arrived earliest on 9/11 were more likely to have physician-diagnosed asthma (OR=1.4). 7% had probable PTSD. 19.4% had probable depression.
Conclusions
Self-reported and physician-diagnosed respiratory conditions remain common, especially among those who arrived earliest at the WTC site. OAD was associated with the lowest pulmonary function. Since respiratory and mental health conditions remain prevalent, ongoing monitoring and treatment is important.
doi:10.1002/ajim.20993
PMCID: PMC3181470  PMID: 21966080
World Trade Center; Respiratory Health; Mental Health; Occupational Medicine; Firefighters
9.  A strategy of escalating doses of benzodiazepines and phenobarbital administration reduces the need for mechanical ventilation in delirium tremens 
Critical care medicine  2007;35(3):724-730.
Objective
Patients with severe alcohol withdrawal and delirium tremens are frequently resistant to standard doses of benzodiazepines. Case reports suggest that these patients have a high incidence of requiring intensive care and many require mechanical ventilation. However, few data exist on treatment strategies and outcomes for these subjects in the medical intensive care unit (ICU). Our goal was a) to describe the outcomes of patients admitted to the medical ICU solely for treatment of severe alcohol withdrawal and b) to determine whether a strategy of escalating doses of benzodiazepines in combination with phenobarbital would improve outcomes.
Design
Retrospective cohort study.
Setting
Inner-city municipal hospital.
Patients
Subjects admitted to the medical ICU solely for the treatment of severe alcohol withdrawal.
Interventions
Institution of guidelines emphasizing escalating doses of diazepam in combination with phenobarbital.
Measurements and Main Results
Preguideline (n = 54) all subjects were treated with intermittent boluses of diazepam with an average total and maximal individual dose of 248 mg and 32 mg, respectively; 17% were treated with phenobarbital. Forty-seven percent required intubation due to inability to achieve adequate sedation and need for constant infusion of sedative-hypnotics. Intubated subjects had longer length of stay (5.6 vs. 3.4 days; p = .09) and higher incidence of nosocomial pneumonia (42 vs. 21% p = .08). Postguideline (n = 41) there were increases in maximum individual dose of diazepam (32 vs. 86 mg; p = .001), total amount of diazepam (248 vs. 562 mg; p = .001), and phenobarbital use (17 vs. 58%; p = .01). This was associated with a reduction in the need for mechanical ventilation (47 vs. 22%; p = .008), with trends toward reductions in ICU length of stay and nosocomial pneumonia.
Conclusions
Patients admitted to a medical ICU solely for treatment of severe alcohol withdrawal have a high incidence of requiring mechanical ventilation. Guidelines emphasizing escalating bolus doses of diazepam, and barbiturates if necessary, significantly reduced the need for mechanical ventilation and showed trends toward reductions in ICU length of stay and nosocomial infections.
doi:10.1097/01.CCM.0000256841.28351.80
PMCID: PMC3417045  PMID: 17255852
alcohol withdrawal; benzodiazepines; phenobarbital; intensive care unit
10.  Vascular Endothelial Growth Factor Blockade Reduces Plasma Cytokines in a Murine Model of Polymicrobial Sepsis 
Inflammation  2004;28(5):271-278.
Numerous cytokines, including vascular endothelial growth factor (VEGF), are implicated in the pathogenesis of sepsis. While overexpression of VEGF produces pulmonary capillary leak, the role of VEGF in sepsis is less clear. We investigated VEGF in sepsis, utilizing a VEGF trap (VEGFT). Polymicrobial sepsis was induced in C57BL/6 mice by cecal ligation and puncture (CLP) and resulted in significantly increased plasma VEGF levels (234 vs. 46 pg/mL; p = 0.03). Inhibition of VEGF had no effect on mortality or lung leak but did attenuate plasma IL-6 (120 vs. 236 ng/mL; p = 0.02) and IL-10 (16 vs. 41 ng/mL; p = 0.03). These alterations in inflammatory cytokines were associated with increased levels of the dominant negative inhibitory C/EBPβ. In vitro, VEGF stimulated IL-6, IL-10 and reduced the inhibitory isoform of C/EBPβ in cultured macrophages. Together these data suggest VEGF can regulate inflammatory cytokine production in murine polymicrobial sepsis, via regulation of C/EBPβ.
doi:10.1007/s10753-004-6050-3
PMCID: PMC3417046  PMID: 16134000
VEGF; sepsis; IL-6; IL-10; C/EBPβ
11.  CD40 BUT NOT CD154 KNOCKOUT MICE HAVE REDUCED INFLAMMATORY RESPONSE IN POLYMICROBIAL SEPSIS: A POTENTIAL ROLE FOR ESCHERICHIA COLI HEAT SHOCK PROTEIN 70 IN CD40-MEDIATED INFLAMMATION IN VIVO 
Shock (Augusta, Ga.)  2004;22(6):538-542.
The CD40-CD154 system controls various aspects of the host inflammatory response in models of cellular and humoral immunity. Recently, we described a role for CD40 in the innate immune response in polymicrobial sepsis. However, recent data suggests that CD40 maybe activated by CD154 or directly via bacterial heat shock protein (HSP) 70. Therefore, we decided to test the mechanism of CD40 activation in murine polymicrobial sepsis. Wild-type (WT), CD40–/–, and CD154–/– underwent cecal ligation and puncture (CLP). Compared with WT mice, CD40–/– had improved survival in association with attenuated production of IL-12, TNF-α, and IL-6. In contrast, CD154–/– mice behaved similar to WT mice with regard to mortality and cytokine production. The differential response of CD40–/– and CD154–/– mice to CLP was not due to a general attenuated response to inflammatory stimuli, as all three strains had similar survival after LPS administration, and CD40–/– macrophages had normal production of IL-12 in response to lipopolysaccharide. In contrast, CD40–/– macrophages had attenuated IL-12 production in response to Escherichia coli HSP70 (DnaK). Furthermore, intraperitoneal administration of DnaK resulted in a 4-fold increase in IL-12 in WT mice, which was absent in CD40–/– mice. This data demonstrates CD154-independent CD40 activation in polymicrobial sepsis and suggests that bacterial HSP70 is capable of stimulating CD40 in vitro and in vivo.
PMCID: PMC3404132  PMID: 15545825
DnaK; cecal ligation and puncture; IL-12; LPS; macrophage
12.  Comparison of WTC Dust Size on Macrophage Inflammatory Cytokine Release In vivo and In vitro 
PLoS ONE  2012;7(7):e40016.
Background
The WTC collapse exposed over 300,000 people to high concentrations of WTC-PM; particulates up to ∼50 mm were recovered from rescue workers’ lungs. Elevated MDC and GM-CSF independently predicted subsequent lung injury in WTC-PM-exposed workers. Our hypotheses are that components of WTC dust strongly induce GM-CSF and MDC in AM; and that these two risk factors are in separate inflammatory pathways.
Methodology/Principal Findings
Normal adherent AM from 15 subjects without WTC-exposure were incubated in media alone, LPS 40 ng/mL, or suspensions of WTC-PM10–53 or WTC-PM2.5 at concentrations of 10, 50 or 100 µg/mL for 24 hours; supernatants assayed for 39 chemokines/cytokines. In addition, sera from WTC-exposed subjects who developed lung injury were assayed for the same cytokines. In the in vitro studies, cytokines formed two clusters with GM-CSF and MDC as a result of PM10–53 and PM2.5. GM-CSF clustered with IL-6 and IL-12(p70) at baseline, after exposure to WTC-PM10–53 and in sera of WTC dust-exposed subjects (n = 70) with WTC lung injury. Similarly, MDC clustered with GRO and MCP-1. WTC-PM10–53 consistently induced more cytokine release than WTC-PM2.5 at 100 µg/mL. Individual baseline expression correlated with WTC-PM-induced GM-CSF and MDC.
Conclusions
WTC-PM10–53 induced a stronger inflammatory response by human AM than WTC-PM2.5. This large particle exposure may have contributed to the high incidence of lung injury in those exposed to particles at the WTC site. GM-CSF and MDC consistently cluster separately, suggesting a role for differential cytokine release in WTC-PM injury. Subject-specific response to WTC-PM may underlie individual susceptibility to lung injury after irritant dust exposure.
doi:10.1371/journal.pone.0040016
PMCID: PMC3399845  PMID: 22815721
13.  HIV-1 and Bacterial Pneumonia in the Era of Antiretroviral Therapy 
Community-acquired pneumonia affects approximately 4 million people in the United States, with 40,000 deaths per year. The incidence is increased about 35-fold in HIV-infected individuals, and this rate has decreased since the antiretroviral era has begun. Bacterial pneumonia has decreased from 5 to 20 cases per 100 person-years to less than 1 to 5 cases per 100 person-years in the era of antiretroviral therapy. HIV-1 infection impairs the function of neutrophils in the lung and infects CD4+ cells and alveolar macrophages. Opportunistic infections dramatically increase local HIV replication in the lung cells, especially alveolar macrophages and CD4+ cells. This enhanced replication increases viral mutations and provides opportunities for viral escape from latent reservoirs. Mortality is increased with more comorbidities in this highly susceptible population. Immunization with vaccines is recommended, especially pneumococcal vaccines, although the vaccine itself may stimulate viral replication. Recent studies show that the lower respiratory tract is a microbial reservoir in HIV-infected individuals rather than being a sterile environment, as originally thought. This may provide new opportunities for preventing opportunistic infections in HIV-infected subjects. Bacterial pneumonia presents an ongoing challenge in these high-risk individuals, particularly in studying the functions of the innate and acquired immune response.
doi:10.1513/pats.201006-044WR
PMCID: PMC3132786  PMID: 21653529
bacterial pneumonia; HIV antiretroviral therapy
14.  Neutrophils Activate Alveolar Macrophages by producing Caspase-6 Mediated Cleavage of Interleukin-1 Associated Kinase-M (IRAK-M) 
Alveolar macrophages (AM) are exposed to respirable microbial particles. Similar to phagocytes in the gastrointestinal tract, AM can suppress inflammation after exposure to nonpathogenic organisms. IRAK-M is one inhibitor of innate immunity, normally suppressing pulmonary inflammation. During pneumonia, neutrophils (PMN) are recruited by chemotactic factors released by AM to produce an intense inflammation. We report that intact IRAK-M is strongly expressed in resting human AM, but is cleaved in patients with pneumonia via PMN-mediated induction of caspase 6 (CASP-6) activity. PMN contact is necessary and PMN membranes are sufficient for CASP-6 induction in macrophages. PMN fail to fully induce TNF-α in macrophages expressing CASP-6 cleavage resistant IRAK-M. Without CASP-6 expression, PMN stimulation fails to cleave IRAK-M, degrade IκBα or induce TNF-α. CASP-6−/− mice subjected to cecal ligation and puncture have impaired TNF-α production in the lung and decreased mortality. LPS did not induce or require CASP-6 activity demonstrating that TLR2/4 signaling is independent from the CASP-6 regulated pathway. These data define a central role for CASP-6 in PMN-driven macrophage activation and identify IRAK-M as an important target for CASP-6. PMN de-repress AM via CASP-6 mediated IRAK-M cleavage. This regulatory system will blunt lung inflammation unless PMN infiltrate the alveolar spaces.
doi:10.4049/jimmunol.1001906
PMCID: PMC3151149  PMID: 21098228
15.  Gene expression profiles of bronchoalveolar cells in Pulmonary TB 
The host response to Mycobacterium tuberculosis includes macrophage activation, inflammation with increased immune effector cells, tissue necrosis and cavity formation, and fibrosis, distortion, and bronchiectasis. To evaluate the molecular basis of the immune response in the lungs of patients with active pulmonary tuberculosis (TB), we used bronchoalveolar lavage to obtain cells at the site of infection. Affymetrix Genechip micro-arrays and cDNA nylon filter microarrays interrogated gene expression in BAL cells from 11 healthy controls and 17 patients with active pulmonary TB. We found altered gene expression for 69 genes in TB versus normal controls that included cell surface markers, cytokines, chemokines, receptors, transcription factors, and complement components. In addition, TB BAL cell gene expression patternssegregated into 2 groups: one suggestive of a T helper type 1 (Th1) cellular immune response with increased STAT-4, IFN-γ receptor, and MIG expression with increased IFN-γ protein levels in BAL fluid; the other group displayed characteristics of Th2 immunity with increased STAT-6, CD81, and IL-10 receptor expression. We were able to demonstrate that a Th2 presentation could change to a Th1 pattern after anti-tuberculous treatment in one TB patient studied serially. These gene expression data support the conclusion that pulmonary TB produces a global change in the BAL cell transcriptome with manifestations of either Th1 or Th2 immunity.
doi:10.1016/j.tube.2007.07.003
PMCID: PMC3151146  PMID: 17921069
Human; tuberculosis; bronchoalveolar lavage; functional genomics; immunity
16.  Characterization of the insulin sensitivity of ghrelin receptor KO mice using glycemic clamps 
BMC Physiology  2011;11:1.
Background
We and others have demonstrated previously that ghrelin receptor (GhrR) knock out (KO) mice fed a high fat diet (HFD) have increased insulin sensitivity and metabolic flexibility relative to WT littermates. A striking feature of the HFD-fed GhrR KO mouse is the dramatic decrease in hepatic steatosis. To characterize further the underlying mechanisms of glucose homeostasis in GhrR KO mice, we conducted both hyperglycemic (HG) and hyperinsulinemic-euglycemic (HI-E) clamps. Additionally, we investigated tissue glucose uptake and specifically examined liver insulin sensitivity.
Results
Consistent with glucose tolerance-test data, in HG clamp experiments, GhrR KO mice showed a reduction in glucose-stimulated insulin release relative to WT littermates. Nevertheless, a robust 1st phase insulin secretion was still achieved, indicating that a healthy β-cell response is maintained. Additionally, GhrR KO mice demonstrated both a significantly increased glucose infusion rate and significantly reduced insulin requirement for maintenance of the HG clamp, consistent with their relative insulin sensitivity. In HI-E clamps, both LFD-fed and HFD-fed GhrR KO mice showed higher peripheral insulin sensitivity relative to WT littermates as indicated by a significant increase in insulin-stimulated glucose disposal (Rd), and decreased hepatic glucose production (HGP). HFD-fed GhrR KO mice showed a marked increase in peripheral tissue glucose uptake in a variety of tissues, including skeletal muscle, brown adipose tissue and white adipose tissue. GhrR KO mice fed a HFD also showed a modest, but significant decrease in conversion of pyruvate to glucose, as would be anticipated if these mice displayed increased liver insulin sensitivity. Additionally, the levels of UCP2 and UCP1 were reduced in the liver and BAT, respectively, in GhrR KO mice relative to WT mice.
Conclusions
These results indicate that improved glucose homeostasis of GhrR KO mice is characterized by robust improvements of glucose disposal in both normal and metabolically challenged states, relative to WT controls. GhrR KO mice have an intact 1st phase insulin response but require significantly less insulin for glucose disposal. Our experiments reveal that the insulin sensitivity of GhrR KO mice is due to both BW independent and dependent factors. We also provide several lines of evidence that a key feature of the GhrR KO mouse is maintenance of hepatic insulin sensitivity during metabolic challenge.
doi:10.1186/1472-6793-11-1
PMCID: PMC3024223  PMID: 21211044
17.  Differential Role for CD80 and CD86 in the Regulation of the Innate Immune Response in Murine Polymicrobial Sepsis 
PLoS ONE  2009;4(8):e6600.
Background
Inflammation in the early stages of sepsis is governed by the innate immune response. Costimulatory molecules are a receptor/ligand class of molecules capable of regulation of inflammation in innate immunity via macrophage/neutrophil contact. We recently described that CD80/86 ligation is required for maximal macrophage activation and CD80/86−/− mice display reduced mortality and inflammatory cytokine production after cecal ligation and puncture (CLP). However, these data also demonstrate differential regulation of CD80 and CD86 expression in sepsis, suggesting a divergent role for these receptors. Therefore, the goal of this study was to determine the individual contribution of CD80/86 family members in regulating inflammation in sepsis.
Methodology/Principal Findings
CD80−/− mice had improved survival after CLP when compared to WT or CD86−/− mice. This was associated with preferential attenuation of inflammatory cytokine production in CD80−/− mice. Results were confirmed with pharmacologic blockade, with anti-CD80 mAb rescuing mice when administered before or after CLP. In vitro, activation of macrophages with neutrophil lipid rafts caused selective disassociation of IRAK-M, a negative regulator of NF-κB signaling from CD80; providing a mechanism for preferential regulation of cytokine production by CD80. Finally, in humans, upregulation of CD80 and loss of constitutive CD86 expression on monocytes was associated with higher severity of illness and inflammation confirming the findings in our mouse model.
Conclusions
In conclusion, our data describe a differential role for CD80 and CD86 in regulation of inflammation in the innate immune response to sepsis. Future therapeutic strategies for blockade of the CD80/86 system in sepsis should focus on direct inhibition of CD80.
doi:10.1371/journal.pone.0006600
PMCID: PMC2719911  PMID: 19672303
18.  CD40 and CD80/86 Act Synergistically to Regulate Inflammation and Mortality in Polymicrobial Sepsis 
Rationale: Costimulatory molecules, including the CD40–CD154 and CD80/86–CD28 dyads, play a prominent role in regulating inflammation in the adaptive immune response. Studies from our group and others suggest a potentially important role for these costimulatory cascades in innate immunity as well.
Objectives: To determine the role of CD80/86 alone and in combination with CD40 in lethal polymicrobial sepsis in mice and humans.
Methods: The murine cecal ligation and puncture (CLP) model was used to determine the role of CD80/86 alone and in combination with CD40 using wild-type mice, CD80/86−/− mice, and novel CD40/80/86−/− mice. Expression of cell-bound and soluble costimulatory molecules was assessed in humans via ELISA and flow cytometry.
Measurements and Main Results: Lethal CLP was associated with up-regulation of CD40 and CD80/86 and their respective ligands CD28 and CD154 on innate effector cells. Blockade or deletion of CD80/86 attenuated mortality and inflammatory cytokine production during CLP. CD40/80/86−/− mice exhibited further reductions in mortality, lung injury, and inflammatory cytokine production compared with CD80/86−/− mice. Finally, humans with sepsis had increased monocyte expression of CD40 and CD80 compared with healthy control subjects; with higher levels in subjects requiring vasopressor support. Levels of soluble CD28 and CD154 were significantly higher in patients who died compared with those who lived.
Conclusions: These data demonstrate a central role for CD40 and CD80/86 in the innate immune response and suggest that combined inhibition of CD40 and CD80/86 may improve mortality in sepsis. Expression of costimulatory molecules may serve as biomarkers for outcome in septic patients.
doi:10.1164/rccm.200703-515OC
PMCID: PMC2218847  PMID: 17989345
costimulation; innate immunity; sepsis
19.  Exogenous Interferon-α and Interferon-γ Increase Lethality of Murine Inhalational Anthrax 
PLoS ONE  2007;2(8):e736.
Background
Bacillus anthracis, the etiologic agent of inhalational anthrax, is a facultative intracellular pathogen. Despite appropriate antimicrobial therapy, the mortality from inhalational anthrax approaches 45%, underscoring the need for better adjuvant therapies. The variable latency between exposure and development of disease suggests an important role for the host's innate immune response. Type I and Type II Interferons (IFN) are prominent members of the host innate immune response and are required for control of intracellular pathogens. We have previously described a protective role for exogenous Type I and Type II IFNs in attenuating intracellular B.anthracis germination and macrophage cell death in vitro.
Methodology and Principal Findings
We sought to extend these findings in an in vivo model of inhalational anthrax, utilizing the Sterne strain (34F2) of B.anthracis. Mice devoid of STAT1, a component of IFN-α and IFN-γ signaling, had a trend towards increased mortality, bacterial germination and extrapulmonary spread of B.anthracis at 24 hrs. This was associated with impaired IL-6, IL-10 and IL-12 production. However, administration of exogenous IFN-γ, and to a lesser extent IFN-α, at the time of infection, markedly increased lethality. While IFNs were able to reduce the fraction of germinated spores within the lung, they increased both the local and systemic inflammatory response manifest by increases in IL-12 and reductions in IL-10. This was associated with an increase in extrapulmonary dissemination. The mechanism of IFN mediated inflammation appears to be in part due to STAT1 independent signaling.
Conclusions
In conclusion, while endogenous IFNs are essential for control of B.anthracis germination and lethality, administration of exogenous IFNs appear to increase the local inflammatory response, thereby increasing mortality.
doi:10.1371/journal.pone.0000736
PMCID: PMC1937023  PMID: 17710136
20.  Exogenous Gamma and Alpha/Beta Interferon Rescues Human Macrophages from Cell Death Induced by Bacillus anthracis  
Infection and Immunity  2004;72(3):1291-1297.
During the recent bioterrorism-related outbreaks, inhalational anthrax had a 45% mortality in spite of appropriate antimicrobial therapy, underscoring the need for better adjuvant therapies. The variable latency between exposure and development of disease suggests an important role for the host's innate immune response. Alveolar macrophages are likely the first immune cells exposed to inhalational anthrax, and the interferon (IFN) response of these cells comprises an important arm of the host innate immune response to intracellular infection with Bacillus anthracis. Furthermore, IFNs have been used as immunoadjuvants for treatment of another intracellular pathogen, Mycobacterium tuberculosis. We established a model of B. anthracis infection with the Sterne strain (34F2) which contains lethal toxin (LeTx). 34F2 was lethal to murine and human macrophages. Treatment with IFNs significantly improved cell viability and reduced the number of germinated intracellular spores. Infection with 34F2 failed to induce the latent transcription factors signal transducer and activators of transcription 1 (STAT1) and ISGF-3, which are central to the IFN response. Furthermore, 34F2 reduced STAT1 activation in response to exogenous alpha/beta IFN, suggesting direct inhibition of IFN signaling. Even though 34F2 has LeTx, there was no mitogen-activated protein kinase kinase 3 cleavage and p38 was normally induced, suggesting that these early effects of B. anthracis infection in macrophages are independent of LeTx. These data suggest an important role for both IFNs in the control of B. anthracis and the potential benefit of using exogenous IFN as an immunoadjuvant therapy.
doi:10.1128/IAI.72.3.1291-1297.2004
PMCID: PMC356021  PMID: 14977930
21.  CD40 Contributes to Lethality in Acute Sepsis: In Vivo Role for CD40 in Innate Immunity  
Infection and Immunity  2003;71(6):3521-3528.
Sepsis induces an early inflammatory cascade initiated by the innate immune response. This often results in the development of multisystem organ failure. We examined the role of CD40, a costimulatory molecule that is integral in adaptive immunity, by using a murine model of polymicrobial sepsis. CD40 knockout (KO) mice had delayed death and improved survival after cecal ligation and puncture (CLP). In addition, they had less remote organ injury as manifested by reduced pulmonary capillary leakage. The improvements in survival and remote organ dysfunction in CD40 KO mice were associated with reduced interleukin-6 (IL-6) and IL-10 levels in serum and bronchoalveolar lavage fluid compared to the levels in wild-type (WT) controls. Furthermore, in contrast to WT mice, CD40 KO mice had no induction of the Th1 cytokines IL-12 and gamma interferon in serum or lungs after CLP. The alterations in cytokine production in CD40 KO mice were associated with similar changes in transcription factor activity. After CLP, CD40 KO mice had attenuated activation of nuclear factor κB and signal transducer and activator of transcription 3 in both the lung and the liver. Finally, WT mice had increased expression of CD40 on their alveolar macrophages. These data highlight the importance of CD40 activation in the innate immune response during polymicrobial sepsis and the subsequent development of remote organ dysfunction.
doi:10.1128/IAI.71.6.3521-3528.2003
PMCID: PMC155725  PMID: 12761137

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