Foxp3+ regulatory T cells are required for recovery from severe sepsis.

The role of regulatory T cells (Tregs) in bacterial sepsis remains controversial because antibody-mediated depletion experiments gave conflicting results. We employed DEREG mice (DEpletion of REGulatory T cells) and a caecal ligation and puncture model to elucidate the role of CD4(+)Foxp3(+) Tregs in sepsis. In DEREG mice natural Tregs can be visualized easily and selectively depleted by diphtheria toxin because the animals express the diphtheria toxin receptor and enhanced green fluorescent protein as a fusion protein under the control of the foxp3 locus. We confirmed rapid Treg-activation and an increased ratio of Tregs to Teffs in sepsis. Nevertheless, 24 h after sepsis induction, Treg-depleted and control mice showed equally strong inflammation, immune cell immigration into the peritoneum and bacterial dissemination. During the first 36 h of disease survival was not influenced by Treg-depletion. Later, however, only Treg-competent animals recovered from the insult. We conclude that the suppressive capacity of Tregs is not sufficient to control overwhelming inflammation and early mortality, but is a prerequisite for the recovery from severe sepsis.

The role of the vagus nerve: modulation of the inflammatory reaction in murine polymicrobial sepsis.

The particular importance of the vagus nerve for the pathophysiology of peritonitis becomes more and more apparent. In this work we provide evidence for the vagal modulation of inflammation in the murine model of colon ascendens stent peritonitis (CASP). Vagotomy significantly increases mortality in polymicrobial sepsis. This effect is not accounted for by the dilatation of gastric volume following vagotomy. As the stimulation of cholinergic receptors by nicotine has no therapeutic effect, the lack of nicotine is also not the reason for the reduced survival rate. In fact, increased septic mortality is a consequence of the absent modulating influence of the vagus nerve on the immune system: we detected significantly elevated serum corticosterone levels in vagotomised mice 24 h following CASP and a decreased ex vivo TNF-alpha secretion of Kupffer cells upon stimulation with LPS. In conclusion, the vagus nerve has a modulating influence in polymicrobial sepsis by attenuating the immune dysregulation.

Outcomes and prognostic factors in gallbladder cancer: a single-centre experience.

INTRODUCTION: Gallbladder cancer is the most common malignant tumour of the biliary system with an extraordinarily poor prognosis. In this study, we retrospectively evaluated forty-two patients with histologically proven gallbladder cancer. PATIENTS AND METHODS: Estimated survival rates were calculated by the Kaplan-Meier method, and differences were assessed using the logrank test. The GKR (combined registry of cancer) and demographic data were used to gain information on community cancer statistics. RESULTS: In this study, patients with metastases showed poorer survival rates. Furthermore, the survival was significantly better in patients with R0 resections, smaller tumour sizes and without lymph node infiltration. T stage, M stage and R stage were independent prognostic parameters. Sex and age had no significant effect on survival. Also, we found that patients with incidental gallbladder cancer and those with cholecystolithiasis showed significantly better survival rates. Demographic analyses of the study group confirmed a high coverage of our institution for incident cases in our catchment area and no significant regional deviations from the expected incidence of gallbladder cancer. CONCLUSION: Despite differences in the incidence in different geographical areas, gallbladder cancer appears to be fairly normally distributed in Western Pomerania, a predominantly rural area of Northeastern Germany. Coverage of incident cases in our catchment area was high. T stage, M stage and R stage were independent prognostic factors in our study. We conclude that, whenever possible, an R0 resection should be the surgical goal in all patients staged resectable before surgery, but heroic resections in patients with highly advanced cancer disease or severe accompanying non-tumour diseases are not warranted.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) improves the innate immune response and enhances survival in murine polymicrobial sepsis.

OBJECTIVE: To investigate the role of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) in postoperative polymicrobial abdominal sepsis.Sepsis is the leading cause of death among critically ill surgical patients. TRAIL is commonly known as an apoptosis-inducing agent in cancer cells. It also plays an important role in the regulation of inflammatory reactions. The role of TRAIL in polymicrobial sepsis is still unclear. DESIGN: Experimental animal model. SETTING: University laboratory. SUBJECTS: C57BL/6 mice. INTERVENTIONS: Colon ascendens stent peritonitis (CASP) was induced in female mice. One hour, 24 hrs, and 48 hrs after induction of CASP, murine recombinant TRAIL was given intravenously. MEASUREMENTS AND MAIN RESULTS: This study demonstrates a protective effect of TRAIL in CASP, an experimental model of murine polymicrobial sepsis. Intravenous administration of recombinant TRAIL to mice after CASP induction led to highly significantly prolonged survival. The migration of effector cells into the peritoneal cavity was strongly enhanced. Consequently, TRAIL-treated mice eliminated bacteria significantly better from the peritoneal cavity, the source of infection. Systemic spread of gut bacteria was also reduced by several orders of magnitude. As a result of the reduced systemic spread of bacteria, the accumulation of neutrophils within the spleen and mesenteric lymph nodes was strongly decreased. CONCLUSION: TRAIL-treated mice are highly protected from abdominal sepsis. Because diagnosis and therapy are frequently delayed in human sepsis, it is remarkable that TRAIL is effective when given via a therapeutic approach. Therefore, this study suggests a therapeutic potential for TRAIL in human sepsis. This should be addressed in future trials.

Colon ascendens stent peritonitis (CASP)--a standardized model for polymicrobial abdominal sepsis.

Sepsis remains a persistent problem on intensive care units all over the world. Understanding the complex mechanisms of sepsis is the precondition for establishing new therapeutic approaches in this field. Therefore, animal models are required that are able to closely mimic the human disease and also sufficiently deal with scientific questions. The Colon Ascendens Stent Peritonitis (CASP) is a highly standardized model for polymicrobial abdominal sepsis in rodents. In this model, a small stent is surgically inserted into the ascending colon of mice or rats leading to a continuous leakage of intestinal bacteria into the peritoneal cavity. The procedure results in peritonitis, systemic bacteraemia, organ infection by gut bacteria, and systemic but also local release of several pro- and anti-inflammatory cytokines. The lethality of CASP can be controlled by the diameter of the inserted stent. A variant of this model, the so-called CASP with intervention (CASPI), raises opportunity to remove the septic focus by a second operation according to common procedures in clinical practice. CASP is an easily learnable and highly reproducible model that closely mimics the clinical course of abdominal sepsis. It leads way to study on questions in several scientific fields e.g. immunology, infectiology, or surgery.

Unexpected findings on laparoscopy for suspected acute appendicitis: a pro for laparoscopic appendectomy as the standard procedure for acute appendicitis.

PURPOSE: Evaluation of the feasibility, cost-effectiveness, time of surgery, morbidities, and other/additional findings during laparoscopy for suspected appendicitis. METHODS: Prospective evaluation of 148 laparoscopies for suspected acute appendicitis. RESULTS: Laparoscopic appendectomy was safe and cost-effective. No appendiceal stump leaks or wound infections occurred. Of the patients, 4.7% developed intra-abdominal abscesses. Mean time of all procedures was 47 min: 42 min for simple appendectomies (n = 126), 67 min for perforated appendicitis (n = 15), and 75 min for converted procedures (n = 7). Twenty-one of 148 (14.2%) patients had unexpected findings instead of appendicitis: inflamed epiploic appendices (three times), inflammatory disorders of intestine (five times), intestinal adhesions (two times), ovarian cysts (six times: one time with mesenteric lymphadenitis, one time ruptured), tubo-ovarian abscess (one time), tubal necrosis (one time), adnexitis with mesenteric lymphadenitis (one time), and acute cholecystitis (one time). These diagnoses might have been missed during conventional open appendectomy and were, if necessary, treated during laparoscopy. CONCLUSIONS: Laparoscopic appendectomy should be recommended as standard procedure for acute appendicitis.

Implantation of alloplastic material increases survival of mice subsequently exposed to polymicrobial sepsis.

PURPOSE: Major surgery can modulate the immune system and by this the clinical course of following complications. Effects of minor surgical treatments on the immune system and septic complications are poorly understood. MATERIALS AND METHODS: We investigated the effect of a minor surgical procedure--the implantation of an osmotic pump--on the outcome of experimental polymicrobial sepsis (colon ascendens stent-induced peritonitis, CASP) in mice. RESULTS: Animals with pumps implanted 3 days prior to CASP showed an attenuated clinical course of sepsis and increased survival. While measured serum cytokine levels were not affected by the minor surgical stress of pump implantation, splenocyte secretion of IFN-gamma in response to lipopolysaccharide was increased. CONCLUSION: The early implantation of alloplastic material modulates the immune system and leads to an increased survival of a polymicrobial sepsis. Identifying the molecular nature of this effect might point the way to a new therapeutic approach to reduce sepsis mortality.

Selective depletion of alveolar macrophages in polymicrobial sepsis increases lung injury, bacterial load and mortality but does not affect cytokine release.

BACKGROUND: Resident tissue macrophages exert important functions during severe systemic infection and contribute to changes in local as well as systemic immune responses. Alveolar macrophages (AM) play a crucial role in airway diseases and in the defense against microorganisms invading the body via the bronchopulmonary tract. It has been postulated that AM are involved in the development of acute local disorders as a consequence of extrapulmonary stimuli like pancreatitis, peritonitis, or trauma. OBJECTIVE: The aim of this study was to analyze the local and systemic role of AM during sepsis using selective AM depletion in the murine colon ascendens stent peritonitis (CASP) model of polymicrobial sepsis. METHODS: 48 h prior to CASP surgery, AM of female C57BL/6 mice were selectively depleted by intratracheal application of clodronate liposomes (Lipo-clod). For control purposes, phosphate-buffered saline (PBS) liposomes (Lipo-PBS) were used. RESULTS: CASP led to significantly elevated levels of local and systemic cytokines independent of the presence of AM. In contrast, levels of gut-derived bacteria in bronchoalveolar lavage and lung of septic mice were significantly higher in Lipo-clod-treated animals compared to Lipo-PBS-treated animals. After CASP-induced sepsis, local barrier dysfunction in the lung was detected; AM depletion resulted in severely enhanced development of acute lung injury. Consequently, Lipo-clod-treated animals showed strongly reduced survival rates after CASP. CONCLUSIONS: Contrarily to other macrophage populations, AM do not significantly contribute to local and systemic cytokine release during polymicrobial abdominal sepsis. AM have important protective functions for local clearance of gut-derived bacteria and attenuation of lung injury.

Detrimental role of CC chemokine receptor 4 in murine polymicrobial sepsis.

CC chemokine receptor 4 (CCR4) and its two ligands, CCL17 and CCL22, are critically involved in different immune processes. In models of lipopolysaccharide-induced shock, CCR4-deficient (CCR4(-/-)) mice showed improved survival rates associated with attenuated proinflammatory cytokine release. Using CCR4(-/-) mice with a C57BL/6 background, this study describes for the first time the role of CCR4 in a murine model of polymicrobial abdominal sepsis, the colon ascendens stent peritonitis (CASP). CASP-induced sepsis led to a massive downregulation of CCR4 in lymphoid and nonlymphoid tissues, whereas the expression of CCL17 and CCL22 was independent of the presence of CCR4. After CASP, CCR4(-/-) animals showed a strongly enhanced bacterial clearance in several organs but not in the peritoneal lavage fluid and the blood. In addition, significantly reduced levels of proinflammatory cytokines/chemokines were measured in organ supernatants as well as in the sera of CCR4(-/-) mice. CCR4 deficiency consequently resulted in an attenuated severity of systemic sepsis and a strongly improved survival rate after CASP or CASP with intervention. Thus, our data provide clear evidence that CCR4 plays a strictly detrimental role in the course of polymicrobial sepsis.

Prolactin triggers pro-inflammatory immune responses in peripheral immune cells.

The peptide hormone prolactin (PRL) is produced by specialized cells in the anterior pituitary gland and in a number of sites outside the pituitary. Its biological actions consist of various roles in reproduction, lactation, and of a number of homeostatic biological activities that also include immune functions. Elevated serum PRL concentrations often correlate with abnormalities in immune responses. To determine the influence of PRL on human immune cells, human whole blood cultures were stimulated with lipopolysaccharide (LPS), supplemented with various concentrations of human recombinant PRL. We found that PRL, at concentrations achievable during pregnancy, anesthesia and medication, significantly amplified interleukin (IL)-12 and tumor necrosis factor-alpha (TNF-alpha) synthesis in LPS-stimulated cultures, in a dose-dependent manner. Conversely, synthesis of the anti-inflammatory cytokine IL-10 only increased significantly at very high concentrations of supplemented PRL. PRL alone was not able to induce any measurable secretion of TNF-alpha, IL-10, or IL-12 in non-stimulated, whole blood cultures. However, we demonstrated that PRL, by itself or in combination with LPS, causes an increase in the binding activity of the transcription factors nuclear factor-kappaB (NFkappaB) and interferon regulatory factor-1 (IRF-1), which are known to promote TNF-alpha and IL-12 secretion. These data suggest that PRL promotes pro-inflammatory immune responses via NFkappaB and IRF-1, which may affect pathophysiological processes in physiological hyperprolactinemic states.