Interleukin-10 receptor-1 expression in monocyte-derived antigen-presenting cell populations: dendritic cells partially escape from IL-10's inhibitory mechanisms.

Interleukin (IL)-10 is an important immunoregulatory cytokine that mediates its effects via a transmembrane receptor complex consisting of two different chains, IL-10R1 and IL-10R2. While IL-10R2 is ubiquitously expressed and does not bind IL-10 primarily, the expression of IL-10R1 determines cellular responsiveness. However, the current knowledge about the expression and regulation of IL-10R1 is still limited. Here we analyzed the expression of IL-10R1 on monocytic cells and demonstrated that human blood monocytes carried about 720 IL-10-binding sites on their surface. Compared with lymphocytes and various tissue cells and tissues, blood monocytes expressed the highest IL-10R1 levels. The in vitro differentiation of these cells into macrophages provoked a further increase of IL-10R1 surface expression. In contrast, their differentiation into myeloid dendritic cells (mDCs) resulted in reduced surface IL-10R1 levels. The different IL-10R1 levels expressed by monocyte-derived antigen-presenting cell populations were reflected in their different responsiveness toward IL-10. Importantly, also in vivo developed immature macrophages and mDCs showed different IL-10 sensitivity. These data suggest that, compared with monocytes and macrophages, mDCs partially escape from IL-10's inhibitory mechanisms by downregulating IL-10R1.

High weight differences between donor and recipient affect early kidney graft function--a role for enhanced IL-6 signaling.

The frequency of delayed function of kidney transplants varies greatly and is associated with quality of graft, donor age and the duration of cold ischemia time. Furthermore, body weight differences between donor and recipient can affect primary graft function, but the underlying mechanism is poorly understood. We transplanted kidney grafts from commensurate body weight (L-WD) or reduced body weight (H-WD) donor rats into syngeneic or allogeneic recipients. Twenty-four hours posttransplantation, serum creatinine levels in H-WD recipients were significantly higher compared to L-WD recipients indicating impaired primary graft function. This was accompanied by upregulation of IL-6 transcription and increased tubular destruction in grafts from H-WD recipients. Using DNA microarray analysis, we detected decreased expression of genes associated with kidney function and an upregulation of other genes such as Cyp3a13, FosL and Trib3. A single application of IL-6 into L-WD recipients is sufficient to impair primary graft function and cause tubular damage, whereas immediate neutralization of IL-6 receptor signaling in H-WD recipients rescued primary graft function with well-preserved kidney graft architecture and a normalized gene expression profile. These findings have strong clinical implication as anti-IL6R treatment of patients receiving grafts from lower-weight donors could be used to improve primary graft function.

Immune tolerance induction in patients with IgA anaphylactoid reactions following long-term intravenous IgG treatment.

To date, there is very little information regarding the pathomechanism of IgA anaphylactoid reactions and the management of affected patients. Five adult patients with common variable immunodeficiency (CVID) and a history of anaphylactic reactions due to the administration of immunoglobulin preparations were studied. The activity of anti-IgA was determined by the gel agglutination technique using IgA-coated beads. Antibodies to IgA were detected in the serum of all five patients. Initially, IgA 'depleted' intravenous (i.v.) IgG preparations were infused carefully into the patients until the activity of anti-IgA was decreased significantly or became undetectable. Subsequently, unselected i.v. IgG preparations were infused, and the activity of anti-IgA was abolished in all cases. Intravenous IgG long-term administration results in tolerance induction in patients with IgA anaphylactoid reactions. This tolerance appears to be related to antibody blockage in the circulation and an inhibition of antibody production. Most importantly, IgA appears to play an important role in the treatment of CVID. Patients with IgA anaphylactoid reactions can be treated safely with IgA containing i.v. IgG preparations following tolerance induction.

Long-term interleukin-10 presence induces the development of a novel, monocyte-derived cell type.

Interleukin (IL)-10 is one of the most crucial immunoregulatory cytokines. Its short-term effects have been analysed extensively, but little is known about its long-term effects. This is of considerable importance, as high systemic IL-10 levels are present for long periods in patients with persistent viral infections, certain cancers and in critical care patients. Our study investigated the effects of the long-term presence of IL-10 on human peripheral blood monocytes. In vitro, IL-10 treatment of these cells for 7 days induced the development of a novel cell type characterized by unique phenotypical and functional characteristics. These cells showed high HLA-DR expression and low expression of CD86 and other co-stimulatory molecules on their surface. The mRNA levels of both HLA-DR and CD86 were high, but no intracellular accumulation of CD86 protein was observed. With respect to its function, these cells showed strongly diminished tumour necrosis factor-alpha production following lipopolysaccharide stimulation, strongly diminished allogenic CD4(+) T cell stimulatory capacity, and even induced a hyporesponsive state in CD4(+) T cells. The phenotype remained stable despite the removal of IL-10. In vivo, we found monocytic cells from patients exhibiting this phenotype after long-term IL-10 exposure. These results complement our knowledge further about the biological effects of IL-10 and may provide an explanation for the sustained immunodeficiency in cases of the persistent presence of systemic IL-10.

First-in-man study with a novel PEGylated recombinant human insulin-like growth factor-I.

OBJECTIVE: This study is a first time assessment of safety and tolerability, pharmacokinetics, and pharmacodynamics of RO5046013 in human, in comparison with unmodified rhIGF-I. DESIGN: The study was conducted as a single-center, randomized, double-blinded, placebo-controlled, single ascending dose, parallel group study in a clinical research unit in France. A total of 62 healthy volunteers participated in this clinical trial. RO5046013 was given as single subcutaneous injection, or as intravenous infusion over 48h, at ascending dose levels. The active comparator rhIGF-I was administered at 50µg/kg subcutaneously twice daily for 4days. Safety and tolerability, pharmacokinetics, and pharmacodynamics of RO5046013 were evaluated. RESULTS: PEGylation resulted in long exposure to RO5046013 with a half-life of 140-200h. Exposure to RO5046013 increased approximately dose proportionally. RO5046013 was safe and well tolerated at all doses, injection site erythema after SC administration was the most frequent observed AE. No hypoglycemia occurred. Growth hormone (GH) secretion was almost completely suppressed with rhIGF-I administration, whereas RO5046013 caused only a modest decrease in GH at the highest dose given IV. CONCLUSIONS: PEGylation of IGF-I strongly enhances half-life, reduces the negative GH feedback and hypoglycemia potential, and therefore offers a valuable alternative to rhIGF-I in treatment of relevant diseases.

Selective in vivo deletion of alloactivated TH1 cells by OKT3 monoclonal antibody in acute rejection.

The OKT3 monoclonal antibody (mAb) recognizing the CD3 complex on human T-cells has been shown to be an effective immunosuppressive agent for the treatment and the prevention of acute rejection episodes in allograft recipients [1]. Following the initial doses of OKT3 mAb, activation of T lymphocytes and monocytes is observed. This is accompanied by a massive cytokine release, particularly following the first injection. The mAb opsonizes the circulating T-cells and the coated cells disappear quickly from circulation. OKT3 mAb is commonly administered for 5-10 days. The manifestation of side effects weeks (cytomegalovirus infection/disease, bacterial and fungal infections) or even months (Epstein-Barr-Virus related lymphoproliferative disease) after therapy as well as the good long-term effects on graft function suggest long-lasting immunosuppressive effects. Since peripheral T-cells reappear in the circulation already during therapy (with modulated CD3/T-cell receptor complex) and T-cell counts reach commonly pretreatment levels within 2-3 days after cessation of OKT3 mAb, the long-lasting immunosuppressive effects are not simply explainable by T-cell depletion. We wondered whether T-cells reappearing in the circulation after cessation of therapy, were functionally different from those before OKT3 mAb therapy. Our data suggest a selective depletion of activated T-cells particularly of type 1-like T-cells by OKT3 mAb resulting in long-lasting immune deviation that may explain the long-term effects of OKT3 mAb treatment.

Massive elevation of procalcitonin plasma levels in the absence of infection in kidney transplant patients treated with pan-T-cell antibodies.

OBJECTIVE: To determine the value of procalcitonin (PCT) monitoring in transplant patients receiving pan-T-cell antibody therapy. DESIGN: Retrospective clinical study. SETTING: A collaborative study between the Institute of Medical Immunology, the Department of Nephrology and Internal Intensive Care, both Charite, Humboldt University Berlin, and the Department of Laboratory Medicine, Friedrichshain Hospital, Berlin, Germany. PATIENTS AND INTERVENTIONS: Thirty-one patients were included in the study: 8 kidney transplant patients with acute rejection episodes, 5 receiving OKT3 monoclonal antibody therapy, 3 receiving steroid bolus therapy; 21 patients undergoing renal transplantation, 11 receiving ATG perioperatively, 10 without ATG administration; 2 patients undergoing renal transplantation and receiving anti-IL-2R mAb. MEASUREMENTS AND RESULTS: Procalcitonin (PCT) and tumor necrosis factor (TNF) alpha plasma levels were measured in infection-free transplant patients treated with the pan-T-cell antibodies ATG or OKT3. We found PCT plasma concentrations up to 600 ng/ml (reference < 0.5 ng/ ml), which are comparable to those seen in severe sepsis. Increases in TNF-alpha plasma levels preceded the rises in PCT. After peaking on day 1 of therapy the PCT plasma concentrations returned to normal values independently of further antibody administration. In contrast, steroid bolus therapy or anti-interleukin 2 receptor mAb administration did not increase plasma PCT or TNF-alpha levels. CONCLUSIONS: PCT monitoring for evaluating infectious complications in kidney transplant patients must be very careful during pan-T-cell antibody therapy.

Topical therapy of allergic rhinitis in childhood: Allergodil nasal spray--non-sedating in children.

The efficacy and safety of the nasally administered drug Allergodil in the treatment of allergic rhinitis were evaluated in a prospective drug monitoring programme conducted in Germany. Data from 489 children under the age 13 were included. The study was designed to gain knowledge about Allergodil in a normal clinical setting. Dosing was at the judgement of the investigator bearing in mind data sheet recommendations, i.e. one spray-puff (0.14 mg) per nostril twice daily. Patients were treated for four weeks. The occurrence of ten nasal, eye and throat symptoms was rated (0 = never, 1 = sometimes, 2 = often). All symptoms showed a statistically significant improvement at the final visit, as did the overall sums of the scores. These changes were clinically significant. Overall assessment of efficacy by the physicians and the patients was very good and good in more than 85% of patients. 70% of patients required no concomitant medication. 13.5% of patients experienced adverse events, mostly mild or moderate in severity. Safety and tolerance were assessed as very good and good in more than 97% of cases. No sedation was seen. With respect to both efficacy and safety, there were no differences between patients younger than 6 years and those aged 6-12 years. In conclusion, these results suggest that Allergodil is an effective treatment of the symptoms of allergic rhinitis in children. The subgroup of 48 young patients studied shows that Allergodil was safe and well tolerated in patients aged 2-6 years.

[Immunomodulation in sepsis]. / Immunmodulation in der Sepsis.

INTRODUCTION: The systemic inflammatory response syndrome is induced by a strong inflammatory reaction which is called sepsis when it is caused by an infection. However, anti-inflammatory therapeutic strategies in septic patients were not successful, indicating a more complex system. It is now clear that systemic hyper-inflammation induces systemic anti- or hypo-inflammation which can lead to total paralysis of the immune system ("immunoparalysis"). METHODS: Several studies were performed to evaluate parameters for describing the patient's immunocompetence. Based on these parameters, pilot trials were initiated to test immunomodulating therapies depending on the patient's immunocompetence. RESULTS: The measurement of monocytic HLA-DR expression, as well as the measurement of ex vivo LPS-induced TNF-a secretion, are suitable to describe the patient's immunocompetence. In addition to classical inflammation markers, the characterization of the inflammatory and infection status is completed by measurement of the plasma cytokines, LBP and PCT. IFN-g or GM-CSF application as well as the removal of inhibitory plasma mediators by hemofiltration/plasmapheresis can reconstitute the immune function in patients with "immunoparalysis". CONCLUSIONS: Immunomodulating therapeutic strategies in septic patients have to orientate on the patient's immunocompetence and inflammatory as well as infectious status: a patient in a hyper-inflammatory phase may need anti-inflammatory therapy whereas a patient in "immunoparalysis" needs immunoreconstitution/immunostimulating therapy.

[Immune monitoring in SIRS and sepsis based on the PIRO model]. / Immunmonitoring bei SIRS und Sepsis auf Grundlage des PIRO-Modells.

Sepsis is a life-threatening disease characterized by a complex interaction between pathogens and the immune system. The analysis of immune parameters in patients with sepsis or at risk for sepsis may help to identify predisposing factors and infection-specific reaction patterns, as well as to monitor the current functional state of the immune system. This may lead to personalized therapeutic strategies for improving outcome in sepsis. Based on the PIRO model (predisposition, insult, response, organ dysfunction), a pathophysiologically-oriented concept for the development of a new sepsis classification, this article reviews currently used and new parameters for immunomonitoring in SIRS (systemic inflammatory response syndrome) and sepsis.

Immunomodulatory therapies: challenges of individualized therapy strategies.

"Individualized therapy strategies" involve strategies that allow treatment to be guided by patient-specific conditions. For this, robust biomarkers are needed. Examples of biomarker-guided therapies already in use are the treatment of insulin-dependent diabetes (biomarker: blood glucose level) or the treatment of hypertension (biomarker: blood pressure). By contrast, most immunomodulatory therapies are given according to the patient's body weight or the patient's drug blood level rather than according to biomarkers indicating the patient's state of the immune system. Herein we report on new biomarkerguided studies in the immunosuppressive treatment of transplant patients and patients with autoimmune disease and we discuss its benefits and pitfalls.

[Impact of pneumoperitoneum on expression of E-cadherin, CD44v6 and CD54 (ICAM-1) on HT-29 colon-carcinoma cells]. / Einfluss des Pneumoperitoneums auf die Expression von E-Cadherin, CD44v6 und CD54 (ICAM-1) auf HT-29-Kolonkarzinomzellen.

INTRODUCTION: The mechanism of potential tumor cell spread and growth during laparoscopy is poorly understood. Nevertheless, different experimental studies reported a stimulation of tumor cell growth and an increased metastatic potential of carcinoma cells using carbon dioxide as an insufflation medium. Adhesion molecules do play an important and regulatory function in the process of metastatic spread and invasion of cancer cells. Therefore we investigated the influence of CO2 and Helium insufflation on the in-vitro expression of E-Cadherin, CD44v6 and CD54 (ICAM-1) on HT-29 colon carcinoma cells. METHODS: HT-29 carcinoma cells were exposed to either CO2 or helium insufflation. Expression of E-Cadherin, CD44v6 and CD54 (ICAM-1) on HT-29 colon carcinoma cells were measured 1, 12, 24, 48 and 96 h after CO2 and helium insufflation using flowcytometry (FACScan). Data were analyzed by Friedman-test. RESULTS: HT-29 cell line showed a short decrease in E-Cadherin expression after CO2 exposure while helium insufflation had no influence. In contrasts to these findings the expression of CD44v6 and CD54 on HT-29 cells were not influenced significantly by either CO2 or helium. CONCLUSION: CO2 seems only to have a minor influence on the expression of E-Cadherin while expression of other adhesion molecules did not change after CO2 incubation. The alternative gas helium did not cause any significant changes of the expression of either E-Cadherin, CD44v6 and CD54. Further investigations are needed to elucidate the changes of the metastatic potential of tumor cells after laparoscopic and open procedures.

The enigma of CD57+CD28- T cell expansion--anergy or activation?

Expansion of a CD57+CD8+ T lymphocyte subset has been reported in HIV and human cytomegalovirus (HCMV) infection. Almost all of these T cells lack CD28 expression. While CD28- cells are often associated with anergy, some authors believe their expansion in HIV infection precipitates immunodeficiency. We studied 15 randomly chosen patients with immune activation and observed that CD57+CD28- T cell expansion may occur in various conditions and to the same degree as in HIV infection without resulting in immunodeficiency. Triple colour flow cytometry also revealed that the CD57 and CD28 antigens are coexpressed in only 3% of CD8+ T cells, irrespective of the underlying condition, so that almost all CD57+CD8+ cells are always CD28-. Analysis of Fas (CD95) expression with respect to CD28 expression on CD4+ and CD8+ T cells from 10 additional patients indicated no increased commitment to apoptosis in CD28- T cells. Semiquantitative polymerase chain reaction (PCR) comparing CD28+ and CD28-CD8+ T cells with respect to cytokine gene expression (tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), IL-1beta) in five renal transplant patients with expansion of the CD57+ subset detected no cytokine gene expression deficit in CD28- T cells. A direct association of increased proportions of CD57+CD28-CD8+ T cells with immunodeficiency/anergy is disputed.

CD45RA(bright)/CD11a(bright) CD8+ T cells: effector T cells.

An important aspect of peripheral T cell development is the differentiation from naive into memory cells. To distinguish naive from memory cells, CD45RA and CD11a are commonly used: CD45RA+ or CD11a(dim) T cells are regarded as naive, while CD45RA- or CD11a(bright) T cells are thought to be of memory type. There is, however, a CD8+ T cell subset which is CD45RA+ and at the same time CD11a(bright). It increases with age and in patients with systemic viral infections, though its functional role in the immune response is unknown. In the present study, we give evidence that this subset is related to memory-like T cells as it produces IFN-gamma and tumor necrosis factor-alpha, contains high levels of perforin, and expresses CD95 in the same way as memory-type CD45RA-/CD11a(bright) CD8+ T cells. Since it contains a high percentage of CD28- and CD57+ cells, is increased in size and granularity, and is transiently expressed following in vitro stimulation of naive CD8+ T cells, we speculate that this subset mainly represents recently activated effector T cells that are able to interact with CD80 and CD86 (B7-1 and B7-2 respectively) negative tissue cells.