Mkc Brunialti

Leptospira interrogans activation of peripheral blood monocyte glycolipoprotein demonstrated in whole blood by the release of IL-6

Glycolipoprotein (GLP) from pathogenic serovars of Leptospira has been implicated in the pathogenesis of leptospirosis by its presence in tissues of experimental animals with leptospirosis, the inhibition of the Na,K-ATPase pump activity, and induced production of cytokines. The aims of the present study were to investigate the induction of IL-6 by GLP in peripheral blood mononuclear cells (PBMC) and to demonstrate monocyte stimulation at the cellular level in whole blood from healthy volunteers. PBMC were stimulated with increasing concentrations (5 to 2500 ng/ml) of GLP extracted from the pathogenic L. interrogans serovar Copenhageni, lipopolysaccharide (positive control) or medium (negative control), and supernatants were collected after 6, 20/24, and 48 h, and kept at -80 degrees C until use. Whole blood was diluted 1:1 in RPMI medium and cultivated for 6 h, with medium, GLP and lipopolysaccharide as described above. Monensin was added after the first hour of culture. Supernatant cytokine levels from PBMC were measured by ELISA and intracellular IL-6 was detected in monocytes in whole blood cultures by flow-cytometry. Monocytes were identified in whole blood on the basis of forward versus side scatter parameters and positive reactions with CD45 and CD14 antibodies. GLP ( > or = 50 ng/ml)-induced IL-6 levels in supernatants were detected after 6-h incubation, reaching a peak after 20/24 h. The percentage of monocytes staining for IL-6 increased with increasing GLP concentration. Thus, our findings show a GLP-induced cellular activation by demonstrating the ability of GLP to induce IL-6 and the occurrence of monocyte activation in whole blood at the cellular level.

Inflammasome gene profile is modulated in septic patients, with a greater magnitude in non-survivors

Inflammasome signalling induces the processing and secretion of interleukin (IL)‐1β and IL‐18 which, coupled with pyroptosis, activate further the inflammatory response. In the present study we evaluated the expression of genes involved in inflammasome signalling pathways in septic patients, their interaction networks and the predicted functions modulated in survivors and non‐survivors. Twenty‐seven patients with sepsis secondary to community‐acquired pneumonia admitted to intensive care units from three general hospitals in São Paulo were included into the study. We performed a polymerase chain reaction (PCR) array encompassing 35 genes related to the nucleotide‐binding oligomerization domain and leucine‐rich repeat‐containing (NLR)‐inflammasome in peripheral blood mononuclear cells obtained at admission and after 7 days of follow‐up. Eleven healthy volunteers were used as the reference group. Increased NLRC4 and NLRP3 and decreased nucleotide‐binding oligomerization domain (NOD1), and NLRP1 expression was observed in septic patients compared to healthy individuals; the IL‐1β and IL‐18 expression levels were also high in the patients. The gene expression changes followed the same patterns in surviving and non‐surviving patients, with higher magnitudes observed in non‐survivors. Functional analyses revealed, however, that activation and inhibition intensity for representing functions were different in survivors and non‐survivors, as for production of reactive oxygen species, synthesis of nitric oxide and for the control of bacterial infections. Our results showed that the genes involved in the activation of the NLR‐inflammasome cascades were altered substantially in septic patients, with a higher number of altered genes and a higher intensity in the disturbance of gene expression found among patients dying of sepsis.

Pathogenetic Aspects of Sepsis and Possible Targets for Adjunctive Therapy

The outcome of patients with sepsis arises from multiple factors affecting both the host and the invading microorganisms. Age, presence of underlying disease, source of infection and some specific etiological agents have been related to prognosis. Appropriateness of antimicrobial therapy, considering the in vitro susceptibility tests for the infecting bacteria, has been strongly associated with the outcome. Therefore even after the cascade of sepsis has been triggered, the control of bacteria growth is still fundamental for the outcome of the infection. This is a major distinction point from experimental studies in which whole killed bacteria and their products are used as model of sepsis. However, even within the setting of adequate antimicrobial use, patients still die of sepsis. Thus, strategies focusing on further therapy targets are an important area of interest for basic and clinical research. Although such adjunctive sepsis therapy has failed to achieve consistent better survival rates so far, nevertheless, it improved our understanding of the pathophysiological events seen in sepsis that the possibility that a new and effective treatment may arise has been warmly considered. In this paper we aim to review some aspects of the pathogenesis of sepsis, focusing on recent advances and on possible targets for adjunctive therapy. Published clinical trials and experimental data supporting such trials are commented on.

Is persistent hypotension after transient cardiogenic shock associated with an inflammatory response

We evaluated the recovery of cardiovascular function after transient cardiogenic shock. Cardiac tamponade was performed for 1 h and post-shock data were collected in 5 domestic large white female pigs (43 +/- 5 kg) for 6 h. The control group (N = 5) was observed for 6 h after 1 h of resting. During 1 h of cardiac tamponade, experimental animals evolved a low perfusion status with a higher lactate level (8.0 +/- 2.2 vs 1.9 +/- 0.9 mEq/L), lower standard base excess (-7.3 +/- 3.3 vs 2.0 +/- 0.9 mEq/L), lower urinary output (0.9 +/- 0.9 vs 3.0 +/- 1.4 mL x kg(-1) x h(-1)), lower mixed venous saturation, higher ileum partial pressure of CO2-end tidal CO2 (EtCO2) gap and a lower cardiac index than the control group. Throughout the 6-h recovery phase after cardiac tamponade, tamponade animals developed significant tachycardia with preserved cardiac index, resulting in a lower left ventricular stroke work, suggesting possible myocardial dysfunction. Vascular dysfunction was present with persistent systemic hypotension as well as persistent pulmonary hypertension. In contrast, oliguria, hyperlactatemia and metabolic acidosis were corrected by the 6th hour. The inflammatory characteristics were an elevated core temperature and increased plasma levels of interleukin-6 in the tamponade group compared to the control group. We conclude that cardiovascular recovery after a transient and severe low flow systemic state was incomplete. Vascular dysfunction persisted up to 6 h after release of tamponade. These inflammatory characteristics may also indicate that inflammatory activation is a possible pathway involved in the pathogenesis of cardiogenic shock.

An imbalance of naive and memory/effector subsets and altered expression of CD38 on T lymphocytes in two girls with hyper-IgM syndrome

In this report we evaluated CD4+ T, CD8+ T and natural killer (NK) cell counts, the levels of naive/memory subsets within the CD4+ T lymphocyte population, expression of CD38 on T lymphocytes, and CD4+ and CD8+ T cell cytokine production in two girls with hyper‐IgM (HIM) syndrome. Both girls developed recurrent infections early in infancy, presenting a wide spectrum of clinical manifestations, with a strikingly different disease severity between them. CD4+ T cell counts were low in both children (patient 1: 214 cells/mm3 and patient 2: 392 cells/mm3), and the CD4/CD8 T cell ratio was 0·4 for patient 1, the patient with the more severe disease, and 1·4 for patient 2. NK cell numbers were low in patient 1 (60 cells/mm3) and borderline (286 cells/mm3) with regard to normal levels in patient 2. An imbalance of naive and memory/effector cell subsets was found in both girls, with the percentage of CD45RA+ 27+ (naive) CD4+ T lymphocytes being 5·8 and 12·4 for patients 1 and 2, respectively. Expression of CD38 on the surface of T lymphocytes was low in patient 1. Detection of intracellular interferon (IFN)‐γ and tumour necrosis factor (TNF)‐α in CD4+ and CD8+ T lymphocytes upon PMA‐Io stimulus was preserved in both children. In conclusion, we found low numbers of CD4+ T lymphocytes and a dramatic redistribution of naive and memory/effector CD4+ T lymphocytes in two girls with non‐X‐linked HIM syndrome. Furthermore, we found low expression of CD38 on T lymphocytes and low numbers of NK cells in the patient with the more severe disease, indicating a possible role for these cells in the pathogenesis of this immunodeficiency.

Induction of interleukin-10 by HIV antigens in peripheral mononuclear cells of health care workers after occupational exposure to HIV-1-positive blood

Evaluation of HIV-induced IL-2 production by peripheral blood mononuclear cells (PBMC) and HIV-specific T helper and cytotoxic T lymphocyte (CTL) responses in health care workers (HCW) occupationally exposed to HIV reveals a high rate of response to HIV among non-seroconverters. IL-10 is also known to interfere with HIV infection in vitro. To evaluate the induction of IL-10 by HIV antigens in HCW occupationally exposed to HIV, 18 HCW with percutaneous injury were enrolled in this study, 9 of them exposed to HIV-contaminated blood, and 9 exposed to HIV-negative blood. PBMC were incubated on plates coated with HIV-1 antigens, and IL-10 was measured in supernatants by ELISA. Five of nine HCW exposed to HIV-contaminated blood presented HIV-induced IL-10. Two of nine HCW exposed to HIV-negative source patients also had detectable levels of HIV-induced IL-10, one of them in the sample obtained on the day of accidental exposure. There was a relationship between the type of device involved in injury and IL-10 production. Individuals exposed to hollow needles or scalpels presented HIV-induced IL-10, whereas those exposed to solid needles and to digital puncture did not, suggesting a relationship between infectious load and IL-10. Although occupational exposure to HIV leads to a low rate of seroconversion, these individuals can develop an antigen-specific immune response characterized in our study by induction of IL-10 in PBMC in vitro.

Plasma levels of IL-6 and IL-10 in septic patients at admission and during follow-up and association with clinical outcomes

Sepsis is a systemic inflammatory syndrome triggered by infection. It has been recognized that a dynamic interaction between proinflammatory and anti-inflammatory response is present in this syndrome, which is balanced by as yet unknown mechanisms. We and others showed that inflammatory cytokines are upregulated in the early phase and downregulated in the late phases of sepsis, while anti-inflammatory cytokines are preserved. However, there are few data about the dynamics of these cytokines during follow-up of patients and their relation with clinical outcome. The aim of this study was to evaluate the plasma levels of a proinflammatory, IL-6, and an anti-inflammatory, IL-10, cytokine in septic patients.

Th17 lymphocytes and alternatively activated monocytes are upregulated in clinical sepsis

Sepsis is a systemic inflammatory response triggered by infection. Inflammatory response is modulated during sepsis and upregulation and downregulation of cellular activity is observed, depending on the cells and functions evaluated. Nevertheless, the interaction of innate and adaptative immune responses has been little studied in clinical sepsis.