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2.
J Infect Dis ; 227(5): 651-662, 2023 03 01.
Article in English | MEDLINE | ID: mdl-36402141

ABSTRACT

BACKGROUND: The COVIH study is a prospective coronavirus disease 2019 (COVID-19) vaccination study in 1154 people with HIV (PWH), of whom 14% showed reduced antibody levels after primary vaccination. We evaluated whether an additional vaccination boosts immune responses in these hyporesponders. METHODS: The primary end point was the increase in antibodies 28 days after additional mRNA-1273 vaccination. Secondary end points included neutralizing antibodies, S-specific T-cell and B-cell responses, and reactogenicity. RESULTS: Of the 66 participants, 40 previously received 2 doses ChAdOx1-S, 22 received 2 doses BNT162b2, and 4 received a single dose Ad26.COV2.S. The median age was 63 years (interquartile range [IQR], 60-66), 86% were male, and median CD4+ T-cell count was 650/µL (IQR, 423-941). The mean S1-specific antibody level increased from 35 binding antibody units (BAU)/mL (95% confidence interval [CI], 24-46) to 4317 BAU/mL (95% CI, 3275-5360) (P < .0001). Of all participants, 97% showed an adequate response and the 45 antibody-negative participants all seroconverted. A significant increase in the proportion of PWH with ancestral S-specific CD4+ T cells (P = .04) and S-specific B cells (P = .02) was observed. CONCLUSIONS: An additional mRNA-1273 vaccination induced a robust serological response in 97% of PWH with a hyporesponse after primary vaccination. Clinical Trials Registration. EUCTR2021-001054-57-N.


Subject(s)
COVID-19 , HIV Infections , Female , Humans , Male , Middle Aged , 2019-nCoV Vaccine mRNA-1273 , Ad26COVS1 , Antibodies, Neutralizing , Antibodies, Viral , BNT162 Vaccine , ChAdOx1 nCoV-19 , COVID-19 Vaccines , Prospective Studies , SARS-CoV-2 , Vaccination , Aged
3.
Lancet Reg Health Eur ; 23: 100515, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36246146

ABSTRACT

Background: Indicator-condition (IC) guided HIV testing is a feasible and cost-effective strategy to identify undiagnosed people living with HIV (PLHIV), but remains insufficiently implemented. We aimed to promote IC-guided HIV testing in seven ICs. Methods: Relevant departments in five hospitals of the Amsterdam region participated. HIV testing among adult patients without known HIV infection but with an IC was assessed using electronic health records during pre-intervention (January 2015-June 2020) and intervention (July 2020-June 2021) periods. The multifaceted intervention included audit and feedback. The primary endpoint was HIV testing ≤3 months before or after IC diagnosis and the effect of the intervention was evaluated using segmented Poisson regression. Findings: Data from 7986 patients were included, of whom 6730 (84·3%) were diagnosed with an IC in the pre-intervention period and 1256 (15·7%) in the intervention period. The proportion HIV tested ≤3 months before or after IC diagnosis increased from 36.8% to 47.0% (adjusted risk ratio [RR]= 1.16, 95% CI=1.03-1.30, p=0.02). For individual ICs, we observed significant increases in HIV testing among patients with cervical cancer or intraepithelial neoplasia grade 3 (adjusted RR=3.62, 95% CI=1.93-6.79) and peripheral neuropathy (adjusted RR=2.27 95% CI=1.48-3.49), but not the other ICs. Eighteen of 3068 tested patients were HIV positive (0.6%). Interpretation: Overall IC-guided testing improved after the intervention, but not for all ICs. Variations in effect by IC may have been due to variations in implemented developments, but the effect of separate elements could not be assessed. Funding: HIV Transmission Elimination Amsterdam (H-TEAM) initiative, Aidsfonds (grant number: P-42702).

4.
PLoS Med ; 19(10): e1003979, 2022 10.
Article in English | MEDLINE | ID: mdl-36301821

ABSTRACT

BACKGROUND: Vaccines can be less immunogenic in people living with HIV (PLWH), but for SARS-CoV-2 vaccinations this is unknown. In this study we set out to investigate, for the vaccines currently approved in the Netherlands, the immunogenicity and reactogenicity of SARS-CoV-2 vaccinations in PLWH. METHODS AND FINDINGS: We conducted a prospective cohort study to examine the immunogenicity of BNT162b2, mRNA-1273, ChAdOx1-S, and Ad26.COV2.S vaccines in adult PLWH without prior COVID-19, and compared to HIV-negative controls. The primary endpoint was the anti-spike SARS-CoV-2 IgG response after mRNA vaccination. Secondary endpoints included the serological response after vector vaccination, anti-SARS-CoV-2 T-cell response, and reactogenicity. Between 14 February and 7 September 2021, 1,154 PLWH (median age 53 [IQR 44-60] years, 85.5% male) and 440 controls (median age 43 [IQR 33-53] years, 28.6% male) were included in the final analysis. Of the PLWH, 884 received BNT162b2, 100 received mRNA-1273, 150 received ChAdOx1-S, and 20 received Ad26.COV2.S. In the group of PLWH, 99% were on antiretroviral therapy, 97.7% were virally suppressed, and the median CD4+ T-cell count was 710 cells/µL (IQR 520-913). Of the controls, 247 received mRNA-1273, 94 received BNT162b2, 26 received ChAdOx1-S, and 73 received Ad26.COV2.S. After mRNA vaccination, geometric mean antibody concentration was 1,418 BAU/mL in PLWH (95% CI 1322-1523), and after adjustment for age, sex, and vaccine type, HIV status remained associated with a decreased response (0.607, 95% CI 0.508-0.725, p < 0.001). All controls receiving an mRNA vaccine had an adequate response, defined as >300 BAU/mL, whilst in PLWH this response rate was 93.6%. In PLWH vaccinated with mRNA-based vaccines, higher antibody responses were predicted by CD4+ T-cell count 250-500 cells/µL (2.845, 95% CI 1.876-4.314, p < 0.001) or >500 cells/µL (2.936, 95% CI 1.961-4.394, p < 0.001), whilst a viral load > 50 copies/mL was associated with a reduced response (0.454, 95% CI 0.286-0.720, p = 0.001). Increased IFN-γ, CD4+ T-cell, and CD8+ T-cell responses were observed after stimulation with SARS-CoV-2 spike peptides in ELISpot and activation-induced marker assays, comparable to controls. Reactogenicity was generally mild, without vaccine-related serious adverse events. Due to the control of vaccine provision by the Dutch National Institute for Public Health and the Environment, there were some differences between vaccine groups in the age, sex, and CD4+ T-cell counts of recipients. CONCLUSIONS: After vaccination with BNT162b2 or mRNA-1273, anti-spike SARS-CoV-2 antibody levels were reduced in PLWH compared to HIV-negative controls. To reach and maintain the same serological responses as HIV-negative controls, additional vaccinations are probably required. TRIAL REGISTRATION: The trial was registered in the Netherlands Trial Register (NL9214). https://www.trialregister.nl/trial/9214.


Subject(s)
COVID-19 Vaccines , COVID-19 , HIV Infections , Adult , Female , Humans , Male , Middle Aged , Ad26COVS1 , Antibodies, Viral , BNT162 Vaccine , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19 Vaccines/immunology , HIV Infections/immunology , Immunogenicity, Vaccine , Immunoglobulin G , Netherlands/epidemiology , Prospective Studies , RNA, Messenger , SARS-CoV-2 , mRNA Vaccines
5.
Clin Infect Dis ; 75(2): 221-229, 2022 08 25.
Article in English | MEDLINE | ID: mdl-34791074

ABSTRACT

BACKGROUND: We aimed to determine the noninferiority of fosfomycin compared to ciprofloxacin as an oral step-down treatment for Escherichia coli febrile urinary tract infections (fUTIs) in women. METHODS: This was a double-blind, randomized, controlled trial in 15 Dutch hospitals. Adult women who were receiving 2-5 days of empirical intravenous antimicrobials for E. coli fUTI were assigned to step-down treatment with once-daily 3g fosfomycin or twice-daily 0.5g ciprofloxacin for 10 days of total antibiotic treatment. For the primary end point, clinical cure at days 6-10 post-end of treatment (PET), a noninferiority margin of 10% was chosen. The trial was registered on Trialregister.nl (NTR6449). RESULTS: After enrollment of 97 patients between 2017 and 2020, the trial ended prematurely because of the coronavirus disease 2019 pandemic. The primary end point was met in 36 of 48 patients (75.0%) assigned to fosfomycin and 30 of 46 patients (65.2%) assigned to ciprofloxacin (risk difference [RD], 9.6%; 95% confidence interval [CI]: -8.8% to 28.0%). In patients assigned to fosfomycin and ciprofloxacin, microbiological cure at days 6-10 PET occurred in 29 of 37 (78.4%) and 33 of 35 (94.3%; RD, -16.2%; 95% CI: -32.7 to -0.0%). Any gastrointestinal adverse event was reported in 25 of 48 (52.1%) and 14 of 46 (30.4%) patients (RD, 20.8%; 95% CI: 1.6% to 40.0%), respectively. CONCLUSIONS: Fosfomycin is noninferior to ciprofloxacin as oral step-down treatment for fUTI caused by E. coli in women. Fosfomycin use is associated with more gastrointestinal events. CLINICAL TRIAL REGISTRATION: Trial NL6275 (NTR6449).


Subject(s)
COVID-19 , Escherichia coli Infections , Fosfomycin , Urinary Tract Infections , Adult , Anti-Bacterial Agents/adverse effects , Ciprofloxacin/therapeutic use , Double-Blind Method , Escherichia coli , Escherichia coli Infections/complications , Escherichia coli Infections/drug therapy , Female , Fever/drug therapy , Fosfomycin/adverse effects , Humans , Urinary Tract Infections/microbiology
6.
Ned Tijdschr Geneeskd ; 159: A8738, 2015.
Article in Dutch | MEDLINE | ID: mdl-26058767

ABSTRACT

BACKGROUND: Lactococcus garvieae, a Gram-positive lactococcus with a short incubation period and high virulence, is a known fish pathogen responsible for serious outbreaks in both marine and freshwater aquaculture. The first human infection was documented in 1991. This is the first case report of L. garvieae endocarditis in the Netherlands. CASE DESCRIPTION: A 68-year-old woman presented with a three-week history of intermittent fever, increased bleeding tendency and weight loss. Blood tests showed prolonged clotting times and diffuse liver dysfunction. Transoesophageal ultrasound showed a vegetation on the aortic valve. Blood cultures were positive for L. garvieae, leading to a diagnosis of 'infective endocarditis'. Additional examination revealed liver cirrhosis and pandiverticulosis. The patient was treated with intravenous antibiotics for six weeks and made a good recovery. CONCLUSION: Consumption of raw fish, immunosuppression and an abnormality in the gastrointestinal tract are risk factors for L. garvieae infection. Improved determination techniques are likely to lead to more frequent identification of the bacterium.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Endocarditis, Bacterial/diagnosis , Gram-Positive Bacterial Infections/diagnosis , Aged , Endocarditis, Bacterial/drug therapy , Female , Gram-Positive Bacterial Infections/drug therapy , Humans , Lactococcus/isolation & purification , Treatment Outcome
7.
Sex Transm Dis ; 36(2): 84-5, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18971797

ABSTRACT

BACKGROUND: Recently, the incidence of syphilis has risen, mainly among men having sex with men (MSM), many of whom are coinfected with HIV. Current guidelines recommend at least yearly syphilis testing in this group. In this study, we assessed the yield of routine syphilis screening in outpatient HIV-patients. METHODS: From March through June 2003, syphilis serology was routinely performed in HIV-infected patients visiting our outpatient clinic. Serology was repeated six months later. Positive test results of the first episode were compared to historical test results (retrospective analysis). Test results of the second episode were compared to test results from the first episode (prospective analysis). Case records of all patients with a new infection were reviewed for symptomatic disease or testing because of syphilis contacts, versus asymptomatic disease. RESULTS: In the retrospective analysis, 1,105 patients were included. In 68 patients, 81 syphilis infections were identified, of which 33% asymptomatic. 77/81 infections were acquired between 2000 and 2003, resulting in a total incidence of 2.7/100 person years (PY) of follow-up, and 0.9/100 PY for asymptomatic disease. In MSM, the incidence rate was 4.6/100 and 1.5/100 PY respectively. In the prospective analysis, 1,010 patients were included. Seventeen patients, all MSM, had a new or recurrent syphilis infection, of whom 4 asymptomatic, accounting for a total event rate of 3.5/100 PY. In MSM, the event rate was 6.2/100 PY, with an incidence of asymptomatic disease of 1.4/100 PY. CONCLUSION: Routine screening for syphilis identifies significant numbers of asymptomatic syphilis infection in HIV-infected MSM.


Subject(s)
HIV Infections/complications , Homosexuality, Male , Mass Screening/methods , Syphilis/epidemiology , Syphilis/physiopathology , Ambulatory Care Facilities , HIV Infections/diagnosis , HIV Infections/epidemiology , HIV Infections/transmission , Humans , Incidence , Male , Netherlands , Syphilis/complications , Syphilis/diagnosis , Syphilis Serodiagnosis , Treponema pallidum
8.
Clin Immunol ; 116(2): 174-81, 2005 Aug.
Article in English | MEDLINE | ID: mdl-15993364

ABSTRACT

Lipopolysaccharide (LPS) binding protein (LBP) facilitates the transfer of LPS of Gram-negative bacteria to the pattern recognition receptor CD14, resulting in activation of immunocompetent cells. LBP can also facilitate the binding of lipoarabinomannan, a major cell wall component of mycobacteria, to immune cells. To determine the role of LBP in the immune response to pulmonary Mycobacterium tuberculosis infection, LBP gene-deficient (-/-) and normal wild-type (WT) mice were intranasally infected with M. tuberculosis. LBP-/- mice displayed a similar survival and mycobacterial outgrowth in lungs and liver, although they demonstrated a reduced lymphocyte recruitment and activation during the early stages of infection. The clearance of pulmonary infection with the non-pathogenic M. smegmatis was also unaltered in LBP-/- mice. These data suggest that LBP does not contribute to an effective host response in M. tuberculosis infection.


Subject(s)
Acute-Phase Proteins/immunology , Carrier Proteins/immunology , Membrane Glycoproteins/immunology , Tuberculosis, Pulmonary/immunology , Acute-Phase Proteins/deficiency , Acute-Phase Proteins/genetics , Animals , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Carrier Proteins/genetics , Cell Count , Chemokines/metabolism , Cytokines/metabolism , Female , Granulocytes/pathology , Liver/microbiology , Lung/metabolism , Lung/microbiology , Lung/pathology , Lymphocyte Activation/immunology , Lymphocytes/pathology , Macrophages/pathology , Membrane Glycoproteins/deficiency , Membrane Glycoproteins/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Mycobacterium Infections, Nontuberculous/immunology , Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium smegmatis/immunology , Survival Analysis , Tuberculosis, Pulmonary/microbiology , Tuberculosis, Pulmonary/pathology
9.
Shock ; 22(6): 543-7, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15545826

ABSTRACT

Platelet-activating factor (PAF), a glycerophospholipid with proinflammatory properties, exerts its biological effects by interacting with the PAF receptor (PAFR) expressed on many different cell types. The PAFR specifically binds phosphorylcholine, the biologically active component of PAF. However, phosphorylcholine is also a component of the cell wall of nontypeable Haemophilus influenzae (NTHi). In recently published in vitro experiments, the invasion of respiratory epithelial cells by NTHi was mediated by the PAFR. To determine the role of the PAFR in host defense against pneumonia induced by NTHi, PAFR-deficient (PAFR-/-) and normal wild-type mice were intranasally inoculated with NTHi. The absence of a functional PAFR was associated with a normal innate immune response as indicated by similar bacterial counts, myeloperoxidase activity, and inflammation within the pulmonary compartment of PAFR-/- and wild-type mice. These data indicate that the PAFR does not interfere with the clearance of NTHi from the respiratory tract.


Subject(s)
Haemophilus Infections/microbiology , Haemophilus influenzae/immunology , Platelet Membrane Glycoproteins/deficiency , Receptors, G-Protein-Coupled/deficiency , Respiratory System/microbiology , Animals , Chemokine CXCL2 , Chemokines/analysis , Chemokines/metabolism , Cytokines/metabolism , Disease Models, Animal , Female , Haemophilus influenzae/growth & development , Haemophilus influenzae/isolation & purification , Lung/enzymology , Lung/microbiology , Mice , Mice, Inbred C57BL , Mice, Knockout , Peroxidase/metabolism , Platelet Membrane Glycoproteins/genetics , Receptors, G-Protein-Coupled/genetics , Respiratory System/enzymology
10.
Int Immunol ; 16(11): 1605-11, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15452020

ABSTRACT

LPS-binding protein (LBP) can facilitate the transfer of cell wall components of both Gram-negative bacteria (LPS) and Gram-positive bacteria (lipoteichoic acid) to inflammatory cells. Although LBP is predominantly produced in the liver, recent studies have indicated that this protein is also synthesized locally in the lung by epithelial cells. To determine the role of LBP in the immune response to pneumonia, LBP gene-deficient (-/-) and normal wild-type (WT) mice were intra-nasally infected with either Streptococcus pneumoniae or Klebsiella pneumoniae, common Gram-positive and Gram-negative pathogens, respectively. Pneumococcal pneumonia was associated with a 7-fold rise in LBP concentrations in bronchoalveolar lavage fluid of WT mice; LBP-/- mice infected with S. pneumoniae showed a similar survival and a similar bacterial burden in their lungs 48 h post-infection. In Klebsiella pneumonia, however, LBP-/- mice demonstrated a diminished survival together with an enhanced bacterial outgrowth in their lungs. These data suggest that LBP is important for a protective immune response in Klebsiella pneumonia, but does not contribute to an effective host response in pneumococcal pneumonia.


Subject(s)
Acute-Phase Proteins/immunology , Carrier Proteins/immunology , Klebsiella Infections/immunology , Klebsiella pneumoniae/immunology , Membrane Glycoproteins/immunology , Pneumonia, Pneumococcal/immunology , Streptococcus pneumoniae/immunology , Acute-Phase Proteins/genetics , Animals , Carrier Proteins/genetics , Klebsiella Infections/mortality , Klebsiella Infections/pathology , Lipopolysaccharides/immunology , Membrane Glycoproteins/genetics , Mice , Mice, Knockout , Pneumonia, Pneumococcal/mortality , Pneumonia, Pneumococcal/pathology , Teichoic Acids/immunology
11.
J Clin Immunol ; 24(1): 37-41, 2004 Jan.
Article in English | MEDLINE | ID: mdl-14997032

ABSTRACT

Chemokine receptors CXC receptor (CXCR) 1 and 2, and their ligands interleukin (IL)-8 and growth-related oncogene alpha (GRO alpha), are principal regulators of neutrophil activation and migration. To investigate the role of p38 mitogen activated protein kinase (MAPK) in the regulation of CXCR expression during an inflammatory response in vivo, 24 healthy volunteers received an intravenous injection with lipopolysaccharide (LPS) preceded (-3 hr) by a specific p38 MAPK inhibitor (BIRB 796 BS) at a high dose (600 mg) or a low dose (50 mg) or a placebo. The LPS-induced reduction of neutrophil CXCR 1 and 2 expression, as determined by fluorescence-activated cell sorter analysis, was inhibited in volunteers receiving the high dose of the p38 MAPK inhibitor. The kinase inhibitor also dose dependently diminished the LPS-induced rises in plasma IL-8 and GRO alpha levels. These results indicate a principal role for p38 MAPK in regulating factors essential for neutrophil activation and chemotaxis in vivo.


Subject(s)
Endotoxemia/metabolism , Mitogen-Activated Protein Kinases/metabolism , Neutrophils/metabolism , Receptors, Interleukin-8A/metabolism , Receptors, Interleukin-8B/metabolism , Chemokine CXCL1 , Chemokines, CXC/metabolism , Down-Regulation , Endotoxemia/immunology , Humans , Intercellular Signaling Peptides and Proteins/metabolism , Interleukin-8/metabolism , Mitogen-Activated Protein Kinases/immunology , Neutrophils/immunology , Receptors, Interleukin-8A/immunology , Receptors, Interleukin-8B/immunology , p38 Mitogen-Activated Protein Kinases
12.
Int Immunol ; 16(3): 509-16, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14978024

ABSTRACT

Toll-like receptors (TLR) play an essential role in the innate recognition of microorganisms by the host. To determine the role of TLR4 in host defense against lung tuberculosis, TLR4 mutant (C3H/HeJ) and wild-type (C3H/HeN) mice were intranasally infected with live Mycobacterium tuberculosis. TLR4 mutant mice were more susceptible to pulmonary tuberculosis, as indicated by a reduced survival and an enhanced mycobacterial outgrowth. Lung infiltrates were more profound in TLR4 mutant mice and contained more activated T cells. Splenocytes of infected TLR4 mutant mice demonstrated a reduced capacity to produce the protective type 1 cytokine IFN-gamma upon antigen-specific stimulation, indicating that TLR4 may be involved in the generation of acquired T cell-mediated immunity. These data suggest that TLR4 plays a protective role in host defense against lung infection by M. tuberculosis.


Subject(s)
Membrane Glycoproteins/physiology , Receptors, Cell Surface/physiology , Tuberculosis, Pulmonary/immunology , Animals , Hypersensitivity, Delayed/immunology , Hypersensitivity, Delayed/metabolism , Interferon-gamma/immunology , Interferon-gamma/metabolism , Interleukin-4/immunology , Interleukin-4/metabolism , Lung/metabolism , Lung/microbiology , Lung/pathology , Macrophages/immunology , Macrophages/metabolism , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolism , Mice , Mice, Mutant Strains , Mycobacterium tuberculosis/immunology , Mycobacterium tuberculosis/metabolism , Receptors, Cell Surface/genetics , Receptors, Cell Surface/metabolism , Spleen/immunology , Spleen/metabolism , T-Lymphocyte Subsets/immunology , T-Lymphocyte Subsets/metabolism , Toll-Like Receptor 4 , Toll-Like Receptors , Tuberculosis, Pulmonary/metabolism
13.
Infect Immun ; 72(2): 788-94, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14742522

ABSTRACT

To determine the role of Toll-like receptor 4 (TLR4) in the immune response to pneumonia, C3H/HeJ mice (which display a mutant nonfunctional TLR4) and C3H/HeN wild-type mice were intranasally infected with either Streptococcus pneumoniae (a common gram-positive respiratory pathogen) or Klebsiella pneumoniae (a common gram-negative respiratory pathogen). In cases of pneumococcal pneumonia, TLR4 mutant mice showed a reduced survival only after infection with low-level bacterial doses, which was associated with a higher bacterial burden in their lungs 48 h postinfection. In Klebsiella pneumonia, TLR4 mutant mice demonstrated a shortened survival after infection with either a low- or a high-level bacterial dose together with an enhanced bacterial outgrowth in their lungs. These data suggest that TLR4 contributes to a protective immune response in both pneumococcal and Klebsiella pneumonia and that its role is more important in respiratory tract infection caused by the latter (gram-negative) pathogen.


Subject(s)
Gram-Negative Bacterial Infections/immunology , Gram-Positive Bacterial Infections/immunology , Membrane Glycoproteins/physiology , Pneumonia, Bacterial/immunology , Receptors, Cell Surface/physiology , Animals , Gram-Negative Bacterial Infections/pathology , Gram-Positive Bacterial Infections/pathology , Granulocytes/physiology , Immunity, Innate , Lung/pathology , Mice , Mice, Inbred C3H , Pneumonia, Bacterial/pathology , Toll-Like Receptor 4 , Toll-Like Receptors
14.
Blood ; 101(11): 4446-8, 2003 Jun 01.
Article in English | MEDLINE | ID: mdl-12576315

ABSTRACT

P38 mitogen-activated protein kinase (MAPK) is an important component of intracellular signaling cascades that initiate various inflammatory cellular responses. To determine the role of p38 MAPK in the procoagulant response to lipopolysaccharide (LPS), 24 healthy subjects were exposed to an intravenous dose of LPS (4 ng/kg), preceded 3 hours earlier by orally administered 600 or 50 mg BIRB 796 BS (a specific p38 MAPK inhibitor), or placebo. The 600-mg dose of BIRB 796 BS strongly inhibited LPS-induced coagulation activation, as measured by plasma concentrations of the prothrombin fragment F1 + 2. BIRB 796 BS also dose dependently attenuated the activation and subsequent inhibition of the fibrinolytic system (plasma tissue-type plasminogen activator, plasmin-alpha2-antiplasmin complexes, and plasminogen activator inhibitor type 1) and endothelial cell activation (plasma soluble E-selectin and von Willebrand factor). Activation of p38 MAPK plays an important role in the procoagulant and endothelial cell response after in vivo exposure to LPS.


Subject(s)
Blood Coagulation/drug effects , Endothelium, Vascular/drug effects , Endotoxemia/blood , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Mitogen-Activated Protein Kinases/physiology , Adult , Biomarkers/blood , Double-Blind Method , Endothelium, Vascular/cytology , Endothelium, Vascular/metabolism , Endotoxemia/drug therapy , Enzyme Inhibitors/administration & dosage , Enzyme Inhibitors/pharmacology , Fibrinolysis/drug effects , Humans , Lipopolysaccharides/administration & dosage , Lipopolysaccharides/pharmacology , Male , Naphthalenes/administration & dosage , Naphthalenes/pharmacology , Pyrazoles/administration & dosage , Pyrazoles/pharmacology , p38 Mitogen-Activated Protein Kinases
15.
Am J Respir Crit Care Med ; 167(2): 171-9, 2003 Jan 15.
Article in English | MEDLINE | ID: mdl-12406830

ABSTRACT

Alveolar macrophages (AMs) are considered major effector cells in host defense against respiratory tract infections by virtue of their potent phagocytic properties. In addition, AMs may regulate the host inflammatory response to infection by production of cytokines and by their capacity to phagocytose apoptotic polymorphonuclear cells (PMNs). To elucidate the in vivo contribution of AM to host defense against pneumococcal pneumonia, we depleted mice of AMs via pulmonary application of liposomal dichloromethylene-bisphosphonate (AM- mice) before inoculation with Streptococcus pneumoniae; control mice received saline (AM+sal) or liposomal phosphate-buffered saline (AM+lip) before bacterial inoculation. AM- mice displayed a significantly higher mortality compared with AM+ control mice, whereas bacterial clearance did not differ. Poor outcome of AM- mice was accompanied by a pronounced increase of local proinflammatory cytokine production as well as strongly elevated and prolonged pulmonary PMN accumulation. Closer examination of infiltrating PMN in AM- mice disclosed high proportions of apoptotic and secondary necrotic cells, reflecting the lack of efficient clearance mechanisms in the absence of AMs. Furthermore, caspase-3 staining showed only slightly higher activity in AM- mice, arguing against accelerated apoptosis per se. These data suggest that AMs are indispensable in the host response to pneumococcal pneumonia by means of their capacity to modulate inflammation, possibly via elimination of apoptotic PMNs.


Subject(s)
Inflammation Mediators/analysis , Lung/pathology , Macrophages, Alveolar/metabolism , Pneumonia, Pneumococcal/prevention & control , Pneumonia, Pneumococcal/physiopathology , Animals , Apoptosis/physiology , Bronchoalveolar Lavage Fluid/cytology , Disease Models, Animal , Female , Immunohistochemistry , Lung/metabolism , Macrophages, Alveolar/physiology , Mice , Neutrophils , Random Allocation , Reference Values , Sensitivity and Specificity
16.
J Infect Dis ; 186(12): 1748-53, 2002 Dec 15.
Article in English | MEDLINE | ID: mdl-12447760

ABSTRACT

To obtain insight in the capacity of the lipopolysaccharide (LPS)-tolerant host to produce interferon (IFN)-gamma and to respond to this cytokine, whole blood was obtained from healthy humans before and 4 h after intravenous injection of LPS (4 ng/kg) and stimulated ex vivo. LPS exposure in vivo resulted in a diminished capacity to produce IFN-gamma after restimulation with LPS, together with a reduced ability to release the IFN-gamma-inducing cytokines interleukin (IL)-12 and IL-18 and with reduced responsiveness toward these cytokines. In addition, IFN-gamma responsiveness was strongly diminished after in vivo LPS exposure, as shown by the fact that blood obtained after LPS injection could not be primed by IFN-gamma for LPS-induced tumor necrosis factor-alpha release and that peripheral blood monocytes could not be stimulated by IFN-gamma to up-regulate major histocompatibility complex type II expression. Experimentally induced immunoparalysis is associated with strongly reduced IFN-gamma production and responsiveness.


Subject(s)
Immune Tolerance , Interferon-gamma/biosynthesis , Lipopolysaccharides/administration & dosage , Adult , Down-Regulation , Histocompatibility Antigens Class II/biosynthesis , Humans , Injections, Intravenous , Interferon-gamma/pharmacology , Interleukin-12/biosynthesis , Interleukin-18/biosynthesis , Male , Monocytes/immunology , Tumor Necrosis Factor-alpha/biosynthesis
17.
J Immunol ; 168(8): 4070-7, 2002 Apr 15.
Article in English | MEDLINE | ID: mdl-11937566

ABSTRACT

The p38 mitogen-activated protein kinase (MAPK) participates in intracellular signaling cascades resulting in inflammatory responses. Therefore, inhibition of the p38 MAPK pathway may form the basis of a new strategy for treatment of inflammatory diseases. However, p38 MAPK activation during systemic inflammation in humans has not yet been shown, and its functional significance in vivo remains unclear. Hence, we exposed 24 healthy male subjects to an i.v. dose of LPS (4 ng/kg), preceded 3 h earlier by orally administered 600 or 50 mg BIRB 796 BS (an in vitro p38 MAPK inhibitor) or placebo. Both doses of BIRB 796 BS significantly inhibited LPS-induced p38 MAPK activation in the leukocyte fraction of the volunteers. Cytokine production (TNF-alpha, IL-6, IL-10, and IL-1R antagonist) was strongly inhibited by both low and high dose p38 MAPK inhibitor. In addition, p38 MAPK inhibition diminished leukocyte responses, including neutrophilia, release of elastase-alpha(1)-antitrypsin complexes, and up-regulation of CD11b with down-regulation of L-selectin. Finally, blocking p38 MAPK decreased C-reactive protein release. These data identify p38 MAPK as a principal mediator of the inflammatory response to LPS in humans. Furthermore, the anti-inflammatory potential of an oral p38 MAPK inhibitor in humans in vivo suggests that p38 MAPK inhibitors may provide a new therapeutic option in the treatment of inflammatory diseases.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Endotoxemia/enzymology , Endotoxemia/prevention & control , Enzyme Inhibitors/pharmacology , Mitogen-Activated Protein Kinases/antagonists & inhibitors , Mitogen-Activated Protein Kinases/metabolism , Naphthalenes/pharmacology , Pyrazoles/pharmacology , Administration, Oral , Adult , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , C-Reactive Protein/antagonists & inhibitors , C-Reactive Protein/metabolism , Cytokines/antagonists & inhibitors , Cytokines/metabolism , Double-Blind Method , Endotoxemia/immunology , Humans , Injections, Intravenous , Lipopolysaccharides/administration & dosage , Lipopolysaccharides/antagonists & inhibitors , Male , Naphthalenes/administration & dosage , Naphthalenes/therapeutic use , Neutrophil Activation/drug effects , Neutrophil Activation/immunology , Phosphorylation/drug effects , Pyrazoles/administration & dosage , Pyrazoles/therapeutic use , p38 Mitogen-Activated Protein Kinases
18.
J Immunol ; 168(1): 372-8, 2002 Jan 01.
Article in English | MEDLINE | ID: mdl-11751983

ABSTRACT

To determine the role of endogenous IL-18 during pneumonia, IL-18 gene-deficient (IL-18(-/-)) mice and wild-type (WT) mice were intranasally inoculated with Streptococcus pneumoniae, the most common causative agent of community-acquired pneumonia. Infection with S. pneumoniae increased the expression of IL-18 mRNA and was associated with elevated concentrations of both precursor and mature IL-18 protein within the lungs. IL-18(-/-) mice had significantly more bacteria in their lungs and were more susceptible for progressing to systemic infection at 24 and 48 h postinoculation. Similarly, treatment of WT mice with anti-IL-18 was associated with enhanced outgrowth of pneumococci. In contrast, the clearance of pneumococci from lungs of IL-12(-/-) mice was unaltered when compared with WT mice. Furthermore, anti-IL-12 did not influence bacterial clearance in either IL-18(-/-) or WT mice. These data suggest that endogenous IL-18, but not IL-12, plays an important role in the early antibacterial host response during pneumococcal pneumonia.


Subject(s)
Interleukin-18/physiology , Pneumonia, Pneumococcal/immunology , Animals , Bronchoalveolar Lavage Fluid/immunology , Cell Division , Cell Movement , Chemokines/biosynthesis , Colony Count, Microbial , Cytokines/biosynthesis , Interleukin-12/genetics , Interleukin-12/physiology , Interleukin-18/genetics , Lung/immunology , Lung/microbiology , Mice , Mice, Inbred C57BL , Mice, Knockout , Pneumonia, Pneumococcal/microbiology , Pneumonia, Pneumococcal/pathology , RNA, Messenger/biosynthesis , Streptococcus pneumoniae/growth & development
19.
Wien Med Wochenschr ; 152(21-22): 552-4, 2002.
Article in English | MEDLINE | ID: mdl-12506677

ABSTRACT

The innate immune system provides the first line of defence against invading pathogens. Cells that mediate the innate immune response express a variety of receptors that permit recognition of pathogen-associated motifs, subsequently resulting in a cascade of responses that initiates inflammation. Recently, the members of the Toll-like receptor family (TLR) have emerged as key receptors responsible not only for the detection of a variety of microbial cell-wall components and bacterial DNA but also for the initiation of signal transduction events eventually leading to the production of various proinflammatory mediators.


Subject(s)
Drosophila Proteins , Membrane Glycoproteins/physiology , Receptors, Cell Surface/physiology , Systemic Inflammatory Response Syndrome/immunology , Animals , DNA, Bacterial/immunology , Humans , Immunity, Innate/immunology , Inflammation Mediators/metabolism , Lipopolysaccharides/immunology , Signal Transduction/physiology , Toll-Like Receptors
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