Successful treatment and re-treatment of resistant B-cell chronic lymphocytic leukemia with the monoclonal anti-CD 20 antibody rituximab

We report on two patients with chemoresistant B-cell chronic lymphocytic leukemia who were treated successfully with the monoclonal anti-CD 20 antibody rituximab. Both patients suffered from severe thrombocytopenia requiring platelet transfusions over a period of several months. Neither chemotherapy nor immunosuppressive agents (corticoids, immunoglobulins) were effective. After four doses of rituximab (375 mg/m2 weekly), both patients recovered within a few weeks to hematological partial remission. One patient was re-treated successfully three times after relapses. Both patients were premedicated with prednisone (100 mg) 30 min prior to the infusion to prevent cytokine release and the antibody infusions were well tolerated.

Increase in immune activation, vascular endothelial growth factor and erythropoietin after an ultramarathon run at moderate altitude

The present study was performed to investigate the effects of exhaustive long lasting exercise at moderate altitude on the time course of serum immunomodulatory peptides, vascular endothelial growth factor (VEGF) and serum erythropoietin (EPO). Thirteen well trained runners participated at the Swiss Alpine Marathon of Davos (distance 67 km, altitude difference 2300 m). Interleukin-6 was significantly elevated in the first 2h after the run. In contrast, tumor necrosis factor-alpha and both soluble tumor necrosis factor-a receptors I and II were increased after exercise termination and showed sustained serum concentrations the following days. Neopterin, a serum marker for the activation of the cellular immune system, was increased until day two after the run. Immediately after the run VEGF was significantly elevated and further increased 2.4-fold until day five post exercise (p = 0.005). EPO was also increased after exercise but reached its maximum 2 h after the run (2-fold increase; p = 0.004) and decreased thereafter. The main findings of our study are that prolonged strenuous exercise at moderate altitude induced a significant long lasting increase in serum VEGF and EPO which was accompanied by an activation of the immune system.

Low platelet count and elevated serum thrombopoietin after severe trauma

Platelet count is regularly low in patients after multiple trauma, mainly due to blood loss and dilution. Thrombopoietin (TPO) is the main regulator of the circulating platelet mass. Under several clinical conditions an inverse correlation between TPO and the circulating platelet mass was reported. Since platelets bind and internalize TPO, a platelet-dependent regulation of TPO was suggested. Thus, acute blood loss should be accompanied by elevated TPO. We measured serum TPO, platelets, interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) in 17 multiple traumatized victims. Blood was collected within 12 h after trauma as well as in the morning of days 2, 4, 6 and 9 after admission at the intensive care unit. Platelet count was low at admission and remained low until day 4. Thereafter platelets increased until day 9. TPO nearly doubled within the first 2 d, reaching its maximum on day 6. IL-6 was initially very high and steadily decreased until day 9. VEGF increased 3-fold during the 9 d. Statistically significant correlations of TPO were found with platelets and IL-6, but not with VEGF. In multiple traumatized patients low platelet count is followed by a rapid increase in serum TPO. This fits into the concept of a feedback regulation between circulating TPO and platelet mass.

Associations between cellular immune effector function, iron metabolism, and disease activity in patients with chronic hepatitis C virus infection

We studied the associations of macrophage activity, T-helper cell types 1 and 2 (Th-1/Th-2) responses, and iron status in 55 patients with hepatitis C virus (HCV)-related liver disease and 28 control patients with noninfectious liver disease. Serum concentrations of soluble tumor necrosis factor receptor type II (sTNFrec 75), a macrophage activation marker, were higher in cirrhotic than in noncirrhotic patients (P<.001) regardless of their HCV status, whereas levels of neopterin, interleukin (IL)-4 and IL-10 did not differ significantly. In HCV-positive patients, sTNFrec 75 levels and transferrin saturation (TfS) correlated positively with levels of aspartate transaminase (P<.001 for sTNFrec 75 and P=.028 for TfS) and alanine transaminase (P=.003 for sTNFrec 75 and P=.039 for TfS). Increased TfS correlated significantly with both advanced liver disease and a predominant Th-2 pattern in HCV patients. Our data suggest that an association exists between macrophage activation and hepatic dysfunction, and that iron status may affect the clinical course of HCV infection by modulating Th-1/Th-2 responses in vivo.

Unconventional medicine in Central Europe: a misuse of public health insurance?

OBJECTIVE

To scrutinize the presumption maintained by critics that patients seeking medical treatment at a health resort may be more motivated by the prospect of a pleasant sojourn paid for by health insurance than by the impairment caused by a disease.

DESIGN

Variables for mobility (occiput-to-wall distance, cervical rotation, chest expansion, thoracic flexion, lumbar flexion, and finger-to-floor distance) and C-reactive protein were determined in 181 patients (male 134, female 47; age 52.4 +/- SEM 0.8 years) with ankylosing spondylitis (AS) whose costs were covered by their health insurance (group A) and in 77 AS patients (male 66, female 11; age 51.6 +/- 1.2 years) who paid their own costs (group B).

SUBJECTS

A group of 258 patients with AS presenting for 3- or 4-week speleotherapeutic radon treatment at the Gasteiner Heilstollen Hospital, a medical institution located at Badgastein in the Austrian Alps.

RESULTS

After Bonferroni correction for multiple calculations no significant difference was seen between the two groups.

CONCLUSIONS

The results suggest that patients presenting for medical treatment at a health resort suffer a like degree of disease impairment, whether they pay their own costs or not. There was no evidence that seeking treatment at a health resort may be an attempt by patients to misuse the health insurance for "sponsored" holidays.

Technical advance: transcriptional activator TGV mediates dexamethasone-inducible and tetracycline-inactivatable gene expression

A chemically regulated gene expression system that can be switched on with dexamethasone and switched off with tetracycline was constructed. It is based on a transcriptional activator (TGV) that consists of the Tn10 encoded Tet repressor, the rat glucocorticoid receptor hormone binding domain and the transcriptional activation domain of Herpes simplex virion protein VP16. When stably expressed in transgenic tobacco plants, it mediates dexamethasone-inducible transcription from a synthetic promoter (PTop10) consisting of seven tet operators upstream of a TATA-box. Tetracycline interferes with induction by negatively regulating the DNA-binding activity of the TetR moiety of TGV. The boundaries of the expression window of the TGV-driven PTop10 reach from undetectable levels of the reporter enzyme beta-glucuronidase in the absence of dexa- methasone to induced levels reaching 15-20% of the Cauliflower Mosaic Virus 35S promoter (PCaMV35S). By modifying the sequence of PTop10, we generated a new target promoter (PTax) that is stably expressed over several generations and that can be activated to levels comparable to PCaMV35S, while yielding only slightly elevated background activities.

Inducer-specific bidirectional regulation of endothelial interleukin-8 production by thalidomide

Interleukin-8 (IL-8) is a potent neutrophil chemotaxin, which can also be produced by endothelial cells to facilitate leukocyte emigration. The aim of this study was to determine the effects of the anti-inflammatory drug thalidomide (THD) on chemotaxin release from endothelial cells. Human umbilical vein endothelial cells (HUVEC) were stimulated with tumor necrosis factor alpha (TNFalpha) or endotoxin (LPS) in the presence or absence of various concentrations of THD. Endothelium-derived interleukin-8 (eIL-8) in supernatants was measured using an enzyme-linked immunosorbent assay (ELISA) and biological activity of the harvested eIL-8 was tested in Boyden chamber chemotaxis assays on PMNL. THD itself had no effect on eIL-8 release. Upon stimulation with TNFalpha or LPS, HUVEC produced increased amounts of eIL-8 and THD affected this process in a bidirectional manner, with augmentation of TNFalpha- and inhibition of LPS-effects. Functionality of eIL-8 was confirmed in chemotaxis experiments and by inhibition of chemotactic effects of supernatants with anti-human IL-8 monoclonal antibodies. Results explain and emphasize immunomodulatory properties of THD in cytokine- and endotoxin-induced inflammation and regulation of transendothelial migration.

[Changes of renal blood flow during organ-associated foot reflexology measured by color Doppler sonography]

Using colour Doppler sonography blood flow changes of the right kidney during foot reflexology were determined in a placebo-controlled, double-blind, randomised study. 32 healthy young adults (17 women, 15 men) were randomly assigned to the verum or placebo group. The verum group received foot reflexology at zones corresponding to the right kidney, the placebo group was treated on other foot zones. Before, during and after foot reflexology the blood flow of three vessels of the right kidney was measured using colour Doppler sonography. Systolic peak velocity and end diastolic peak velocity were measured in cm/s, and the resistive index, a parameter of the vascular resistance, was calculated. The resistive index in the verum group showed a highly significant decrease (p </= 0.001) during and an increase (p = 0.001) after foot reflexology. There was no difference between men and women and no difference between smokers and non-smokers. Verum and placebo group significantly differed concerning alterations of the resistive index both between the measuring points before versus during foot reflexology (p = 0.002) and those during versus after foot reflexology (p = 0.031). The significant decrease of the resistive index during foot reflexology in the verum group indicates a decrease of flow resistance in renal vessels and an increase of renal blood flow. These findings support the hypothesis that organ-associated foot reflexology is effective in changing renal blood flow during therapy.

Heterologous expression of Arabidopsis phytochrome B in transgenic potato influences photosynthetic performance and tuber development

Transgenic potato (Solanum tuberosum) plants expressing Arabidopsis phytochrome B were characterized morphologically and physiologically under white light in a greenhouse to explore their potential for improved photosynthesis and higher tuber yields. As expected, overexpression of functional phytochrome B caused pleiotropic effects such as semidwarfism, decreased apical dominance, a higher number of smaller but thicker leaves, and increased pigmentation. Because of increased numbers of chloroplasts in elongated palisade cells, photosynthesis per leaf area and in each individual plant increased. In addition, photosynthesis was less sensitive to photoinactivation under prolonged light stress. The beginning of senescence was not delayed, but deceleration of chlorophyll degradation extended the lifetime of photosynthetically active plants. Both the higher photosynthetic performance and the longer lifespan of the transgenic plants allowed greater biomass production, resulting in extended underground organs with increased tuber yields.

Decrease of respiratory burst in neutrophils of patients with ankylosing spondylitis by combined radon-hyperthermia treatment

OBJECTIVE

To define the respiratory burst activity of neutrophils, the total anti-oxidative status of plasma, and the parameters of systemic inflammation in patients with ankylosing spondylitis (AS) before and after a combined radon-hyperthermia treatment in the thermal tunnels of Böckstein-Bad Gastein in Austria.

METHODS

In 20 patients with AS the effects of a total of 15 hours of radon-hyperthermia-treatment spread over a period of three weeks were studied. The respiratory burst activity of neutrophils was measured fluorometrically using dichlorofluorescein diacetate, the total anti-oxidant status was measured using azinodiethyl-benzthiazoline-sulphonate, and inflammation parameters were determined by routine laboratory assays.

RESULTS

Before treatment, the basal neutrophil respiratory burst in patients (n = 20) was 409 +/- 62 fluorescence arbitrary units (AU; mean +/- SEM) and 359 +/- 37 AU in controls (n = 9; p > 0.5); the stimulated respiratory burst (fMet-Leu-Phe, 10(-6) M) was 1,027 +/- 133 AU in patients and 1,152 +/- 218 AU in controls (p > 0.5). After treatment, the basal neutrophil respiratory burst in patients (n = 19) was 137 +/- 16 and in controls it was 174 +/- 35 AU (n = 8; p > 0.1); the stimulated respiratory burst was 670 +/- 66 and 1,305 +/- 82 AU, in patients and controls respectively (p < 0.001). No effects of treatment on the total anti-oxidant status of the plasma or on the parameters of inflammation were detected.

CONCLUSION

Combined radon-hyperthermia treatment reduces the respiratory burst activity of the blood circulating neutrophils in patients with AS. If respiratory burst activity from the neutrophils plays a role in the pathophysiology of ankylosing spondylitis, the observed reduction may be related to the beneficial effects of radon-hyperthermia treatment.

Cellular and humoral immune responses in patients with metastatic renal cell carcinoma after vaccination with antigen pulsed dendritic cells

PURPOSE

Dendritic cells are the most potent stimulators of immune responses including antitumor responses. We performed a pilot study of cultured antigen loaded dendritic cells in patients with metastatic renal cell carcinoma.

MATERIALS AND METHODS

Dendritic cells were obtained by culturing plastic adherent mononuclear cells from peripheral blood for 5 days in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4. Day 5 dendritic cells were loaded with cell lysate from cultured autologous tumor cells and with the immunogenic protein keyhole-limpet hemocyanin (KLH) which serves as a helper antigen and as a tracer molecule. During the antigen pulse dendritic cells were activated with a combination of tumor necrosis factor-alpha and prostaglandin E2. Dendritic cells were administered by 3 intravenous infusions at monthly intervals. Cellular and humoral immune responses to KLH and cell lysate were measured in vitro before and after the vaccinations.

RESULTS

Preparation of 12 dendritic cell vaccines from patients with advanced renal cell carcinoma was successful. Treatment with fully activated CD83+ dendritic cells was well tolerated with moderate fever as the only side effect. Potent immunological responses to KLH and, most importantly, against cell lysate could be measured in vitro after the vaccinations.

CONCLUSIONS

Our data demonstrate that a dendritic cell based vaccine can induce antigen specific immunity in patients with metastatic renal cell carcinoma. Dendritic cell based immunotherapy represents a feasible, well tolerated and promising new approach for the treatment of advanced renal cell carcinoma.

Expression of stress proteins, adhesion molecules, and interleukin-8 in endothelial cells after preservation and reoxygenation

Endothelial activation is a central feature of preservation-induced allograft injury. The present study aims at a quantitative assessment of stress proteins, adhesion molecules, and interleukin-8 in a cell culture-based model of organ preservation. Human umbilical vein endothelial cells were exposed to cold, hypoxic storage in University of Wisconsin (UW), histidine-tryptophane-ketoglutarate (HTK), and EuroCollins solutions for 8 h with subsequent rewarming/reoxygenation (rew/reox) for 1 and 4 h. A cell-based ELISA was designed for detection of heat shock proteins (HSP) 60 and 70, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leukocyte adhesion molecule-1 (ELAM-1). Immunohistochemical staining was performed for comparison. Interleukin-8 was quantified by ELISA. HSP 70 was expressed after cold storage in HTK and EuroCollins solution and after rew/reox in all groups. A constitutive expression of HSP 60 was observed with further upregulation after rew/reox following cold storage in all experimental groups. ICAM-1 was clearly upregulated, but VCAM-1 showed only weak expression after cold storage and rew/reox. ELAM-1 was detectable in minimal amounts after cold storage but was considerably upregulated after 4 h of rew/reox. A significant increase of interleukin-8 release could be found after 4 h of rew/reox following storage in EuroCollins solution. Expression of stress proteins can be considered as a new parameter of preservation-associated endothelial activation. Apart from possible protective effects, allograft vasculopathy could be in part a consequence of the antigeneic potential of heat shock proteins connected with effects caused by adhesion molecules and inflammatory cytokines.

Cellular and humoral immune responses in patients with metastatic renal cell carcinoma after vaccination with antigen pulsed dendritic cells

PURPOSE

Dendritic cells are the most potent stimulators of immune responses including antitumor responses. We performed a pilot study of cultured antigen loaded dendritic cells in patients with metastatic renal cell carcinoma.

MATERIALS AND METHODS

Dendritic cells were obtained by culturing plastic adherent mononuclear cells from peripheral blood for 5 days in the presence of granulocyte-macrophage colony-stimulating factor and interleukin-4. Day 5 dendritic cells were loaded with cell lysate from cultured autologous tumor cells and with the immunogenic protein keyhole-limpet hemocyanin (KLH) which serves as a helper antigen and as a tracer molecule. During the antigen pulse dendritic cells were activated with a combination of tumor necrosis factor-alpha and prostaglandin E2. Dendritic cells were administered by 3 intravenous infusions at monthly intervals. Cellular and humoral immune responses to KLH and cell lysate were measured in vitro before and after the vaccinations.

RESULTS

Preparation of 12 dendritic cell vaccines from patients with advanced renal cell carcinoma was successful. Treatment with fully activated CD83+ dendritic cells was well tolerated with moderate fever as the only side effect. Potent immunological responses to KLH and, most importantly, against cell lysate could be measured in vitro after the vaccinations.

CONCLUSIONS

Our data demonstrate that a dendritic cell based vaccine can induce antigen specific immunity in patients with metastatic renal cell carcinoma. Dendritic cell based immunotherapy represents a feasible, well tolerated and promising new approach for the treatment of advanced renal cell carcinoma.

Mediator-dependent effects of pentoxifylline on endothelium for transmigration of neutrophils

In the present study, we investigated the effects of the anti-inflammatory drug pentoxifylline (PTX) on activation of endothelial cells for enhanced adhesion and transmigration of neutrophils by lipopolysaccharide (LPS), tumor necrosis factor-alpha (TNF), interleukin-1 (IL-1) and granulocyte colony-stimulating factor (G-CSF). To evaluate the mechanism by which PTX exerts its effect, human umbilical vein endothelial cells (HUVEC) were pretreated with theophylline, 2'-O-dibutyryl-3', 5'-cyclic adenosine monophosphate (db cAMP), and 3-isobutyl-1-methylxanthine, respectively, prior to stimulation. Pretreatment of HUVEC with PTX significantly antagonized TNF-, IL-1-, and G-CSF-activated transmigration of neutrophils. Additive stimulatory effects of PTX were seen with LPS. With the exception of theophylline, all other test cAMP-raising agents stimulated transmigration in similar fashion to PTX. Upon stimulation with TNF or LPS, HUVEC produced IL-8 and PTX affected this process in opposing fashions, with inhibition of the effects of TNF and augmentation of those of LPS. These results demonstrate that PTX differentially affects mediator-induced activation of HUVEC. The present IL-8 dependent and cAMP-regulated augmentation of LPS-induced stimulation of transmigration is the first description of an additive effect of PTX with a pro-inflammatory agent.

In ankylosing spondylitis serum interleukin-6 correlates with the degree of mobility restriction, but not with short-term changes in the variables for mobility

The aim of this study was to evaluate whether the serum concentration of interleukin-6 (IL-6) reflects disease activity in ankylosing spondylitis (AS). A group of 271 AS patients were enrolled in the study, 261 of whom completed the entire protocol (201 males, 60 females, median age of 53 years). Serum IL-6 was measured three times (I, baseline; II, after 10-12 days; III, after 17-24 days) during a 3- or 4-week treatment at the health resort. At the same times, the variables for mobility were measured, and the patients were asked to assess their complaints (score) in a self-styled questionnaire. The serum concentration of IL-6 correlated with the measurements of occiput-to-wall distance, cervical rotation, finger-floor distance and Schober sign, and with morning pain at all three evaluations. Comparisons between changes in IL-6 and changes in the variables (measures of mobility, scores of the questionnaires) did not reveal significant correlations. Present data would suggest that in AS the serum concentration of IL-6 indicates the degree of mobility restriction resulting from previous disease progression, but is not a reliable marker of current disease activity.

Vascular endothelial growth factor in serum and in the follicular fluid of patients undergoing hormonal stimulation for in-vitro fertilization

A cross-sectional study regarding endocrine and cytokine parameters in human follicular fluid (FF) as compared to serum values following hormonal stimulation for in-vitro fertilization was conducted. The patients (n = 32) were treated sequentially with the luteinizing hormone-releasing hormone (LHRH) agonist buserelin followed by a combination of buserelin plus highly purified follicle stimulating hormone and finally human chorionic gonadotrophin, in order to induce ovulation. The FF content of pro-inflammatory (IL-1, IL-6), and anti-inflammatory (IL-1ra, IL-10) cytokines, of the immune response-related soluble interleukin-2 receptor (sIL-2R), as well as the mitogens vascular endothelial growth factor (VEGF) and basic fibroblastic growth factor (bFGF) were determined. Routine evaluation included peripheral blood cell counts, morphological data of the ovary and ova, ovarian steroids, prolactin concentrations and thyroid function parameters [free thyroxine (fT4), thyroglobulin]. The concentrations of IL-6, IL1-ra, sIL-2R, VEGF and bFGF in the FF compartment were higher than in serum in the majority of cases. Regression analysis showed a significant association between the serum and FF concentrations of fT4 (P = 0.04; y = 0.37 + 0.34x) and IL-6 (P = 0.002; y = 0.78 + 0.5x). Multiple regression analysis revealed that progesterone played a role in determining VEGF concentrations in the FF (P = 0.07; y = 0.37 + 0.86x). Thyroglobulin concentrations within the FF were extremely low, whereas fT4 concentrations in the FF were similar to those in serum. Patients with a previously diagnosed hypothyroidism tended to have lower serum oestradiol and higher serum progesterone when compared to euthyroids. We conclude that the human FF represents a functional compartment that integrates endocrine, immunological, and mitogenic signalling that is unique for each ovarian follicle. The close association between progesterone and VEGF within the FF suggests a close association of this mitogen to gonadotrophin stimulation, confirming the ovary as a production site of VEGF.

CDTect-RIA and CDTect-EIA for determination of serum carbohydrate-deficient transferrin compared

CDTect-RIA and CDTect-EIA for determination of serum carbohydrate-deficient transferrin (CDT) by radioimmunoassay and enzyme immunoassay respectively were tested for equality and precision in four European laboratories. For correlational studies, serum samples with CDT concentrations up to 130 U/l were analysed in accordance with a uniform trial schedule. The regression of CDT values obtained by the two procedures was computed for each laboratory using the method of Passing and Bablok. Slopes and intercepts of the regression functions did not differ significantly from the values 1 or 0, as proved by the corresponding 95% confidence intervals. Precision studies were computed using analysis of variance. For CDT concentrations at the upper reference limit for men, the within-day coefficients of variation (CVs) ranged between 0.7 and 6.4% (median 5.2%) for CDTect-RIA and from 4.3 to 9.2% (median 6.2%) for CDTect-EIA. The corresponding pure between-day CVs were 5.0-18.5% (median 9.8%) and 3.5-14.5% (median 10.9%). The study demonstrates the equality of CDT values obtained by CDTect-RIA and CDTect-EIA. According to this study, the two methods can be used interchangeably without getting fluctuating CDT values, e.g. in longitudinal studies.

Interferon-gamma in the treatment of systemic sclerosis: a randomized controlled multicentre trial

We report the results of a randomized controlled multicentre study on interferon-gamma (IFN-gamma) treatment of systemic sclerosis as determined by skin sclerosis, renal and other organ involvement, global assessment, subjective symptoms and quality of life. Forty-four patients were enrolled into the trial, 27 in the treatment group and 17 in the control group. All patients presented with type I or type II scleroderma. Twenty-nine patients (64%) finished the study. The mean duration of Raynaud's phenomenon and skin sclerosis was 15.3 and 10.8 years, respectively. The skin scores tended to improve in the treatment group (P > 0.05). Mouth aperture increased significantly from 38.5 to 47.7 mm in the treatment group (P < 0.001). Subanalysis of IFN-gamma treated patients with normalized skin sclerosis scores >/=1 showed significant improvement in both skin involvement and subjective symptoms (P < 0.05). Organ involvement improved in eight of 18 treatment patients and in three of 11 control patients. It worsened in three of 18 treatment patients and in four of 11 control patients. One control patient died due to cardiorespiratory failure during the study. No deterioration of renal function occurred during IFN-gamma treatment. There was a significant improvement in quality of life parameters in the control group but not in the treatment group. Plasma levels of neopterin increased significantly during IFN-gamma treatment but not in the control group, whereas N-terminal procollagen III peptide levels did not change in either group. There was a high frequency of mild to moderate influenza-like adverse events during IFN-gamma treatment. Only four of nine drop-out patients, however, experienced symptoms most probably associated with IFN-gamma treatment. We conclude that IFN-gamma therapy has mild beneficial effects on skin sclerosis and disease-associated symptoms in type I and II scleroderma. IFN-gamma treatment was associated with acceptable tolerability and did not induce major renal dysfunction in our patients.

Interleukin 1beta mediates the modulatory effects of monocytes on LNCaP human prostate cancer cells

Proliferative and secretory responses in androgen-sensitive prostate cancer LNCaP cells are regulated by steroid and peptide hormones and by differentiation-promoting substances. In the present study, we evaluated whether peripheral blood monocytes that exhibit anti-tumour activity in haematopoietic and solid tumours influence growth and secretion in the LNCaP cell line. For this purpose, LNCaP cells were incubated with monocyte-conditioned medium (MCM), and proliferation as well as expression of androgen receptor (AR) and secretion of prostate-specific antigen (PSA) were assessed. Conditioned medium from monocytes reduced proliferation in a dose-dependent manner. Incubation with 40% MCM caused a 50% reduction in cell proliferation. AR protein decreased by 70% and PSA levels in supernatants from LNCaP cells were reduced by approximately 80% following treatment with MCM. We focused on the contribution of two major products of activated monocytes, prostaglandin E2 and interleukin 1beta (IL-1beta), to the MCM modulatory action. LNCaP cells treated with prostaglandin E2 showed neither a reduction in proliferation nor a down-regulation of AR and PSA levels. The effects of MCM on cellular proliferation, AR protein and PSA secretion were abolished by pretreatment of MCM with a neutralizing anti-IL-1beta antibody. In addition, recombinant IL-1beta was able to replace MCM for the inhibition of proliferation and down-regulation of AR and PSA proteins. LNCaP cells were shown to express the IL-1beta receptor type 1, which transduces IL-1beta signal. Our findings reveal that monocyte-derived IL-1beta inhibits the proliferation of androgen-responsive prostate tumour cells and reduces AR and PSA levels.

The acute phase protein alpha-1-antitrypsin inhibits transferrin uptake in PLC/PRF/5 cells and increases release of hepatitis B virus surface antigen and alpha-fetoprotein

BACKGROUND/AIMS

The present study was designed to investigate whether the acute phase protein alpha-1-antitrypsin (alpha1-AT), which has an inhibitory effect on transferrin (tf) receptor-mediated iron uptake in K562 and THP1 cells, has a similar effect in PLC/PRF/5 cells. This hepatic cell line is of specific interest because it is infected with hepatitis B virus (HBV). Therefore, we addressed the additional question whether alpha1-AT has any effect on cellular protein synthesis and replication of HBV in PLC/PRF/5 cells.

METHODS

Cells were incubated with various concentrations of alpha1-AT, dexamethasone, IL-6 and desferrioxamine. HBs-AG, alpha-fetoprotein and albumin concentrations in culture media were measured using commercially available methods. For equilibrium inhibition binding experiments, cells were incubated with 85-182 pmol/l [125I]tf. To study the potential effect of alpha1-AT on DNA synthesis we measured the incorporation of [3H]thymidine into DNA.

RESULTS

In equilibrium saturation binding experiments, [125I]tf bound to PLC/PRF/5 cells with K(D) 17.45 +/- 4.57 nM and a maximum density of binding sites of 267,285 +/- 39,915 sites/cell. In inhibition studies alpha1-AT demonstrated an apparently monophasic inhibition of [125I]tf to its receptor. At concentrations > 30 micromol/l alpha1-AT inhibited the growth of PLC/PRF/5 cells up to approximately 50%. The inhibitory effect of alpha1-AT on DNA synthesis was not as potent as that on growth. At the highest concentration of 100 micromol/l, alpha1-AT produced a 35% maximum inhibition of [3H]thymidine incorporation. Incubating PLC/PRF/5 cells with corticosteroids enhanced HBs-AG release significantly. Interestingly, alpha1-AT showed the same pattern of effects on cell metabolism and HBs-AG release as the corticosteroids. When we incubated the cells with 50 micromol/l alpha1-AT, alpha-fetoprotein production increased significantly and HBs-AG release almost doubled.

CONCLUSION

We have to assume that there is a specific mechanism inducing HBs-AG release by alpha1-AT, as has been shown to be the case with steroids.

Modulation of alloimmune response in vitro by an IgM-enriched immunoglobulin preparation (Pentaglobin)

The mode of action of intravenous immunoglobulins (IVIG) in autoimmune and immunoregulatory disorders is still poorly understood. In vitro, direct effects of IVIG on cytokine release and on cytokine receptors have been described, as well as naturally occurring, neutralizing anticytokine antibodies. The aim of our study was to investigate whether the enrichment in IgM and IgA would have any impact on the in vitro immunomodilatory capacity of IVIG. The preparation tested (Pentaglobin) contains 76% IgG and 12% IgM and IgA, respectively. We could demonstrate a significant inhibition of alloantigen-induced proliferation in the mixed lymphocyte reaction (MLR) even at a Pentaglobin concentration of 1.0 mg/ml. About 10-fold higher concentrations of standard 7S IVIG containing only trace amounts of IgM and IgA were necessary to achieve equivalent suppression of the alloimmune response. Similarly, phytohaemagglutinin (PHA)-induced lymphocyte proliferation was more effectively inhibited by Pentaglobin than by standard 7S IVIG. Cytokine analyses in culture supernatants of MLR provide evidence that Pentaglobin not only modulates interleukin-2 (IL-2), which has already been observed with standard 7S IVIG, but, moreover, modulates interferon-gamma production with a subsequent impact on monocyte-derived tumour necrosis factor-alpha and IL-6 release. Based on these results we conclude that in vitro the IgM- and IgA-enriched Pentaglobin has a more potent immunomodulatory capacity than conventionally used standard 7S IVIG.