Search

Multiple myeloma (MM) is an incurable disease, characterized by malignant plasma cells in the bone marrow. MM growth is largely dependent on the tumor microenvironment (TME), consisting of complex cellular networks that shape a tumor-permissive environment. Within the TME, tumor-associated cells (TAC) comprise heterogeneous cell populations that collectively support immunosuppression. Reshaping the TME toward an immunostimulatory environment may enhance effectiveness of immunotherapies. Here, we investigated interactions between donor-derived natural killer (NK) cells and TAC, like tumor-associated macrophages (TAM) and M1 macrophages, and assessed whether anti-tumor effector functions of NK cells could be enhanced by an ADCC-triggering antibody targeting macrophages. Monocytes were polarized in vitro toward either M1 or TAM before co-culture with high-dose IL-2-activated NK cells. NK cell responses were assessed by measuring degranulation (CD107a) and IFN-γ production. We found that NK cells degranulated and produced IFN-γ upon interaction with both macrophage types. NK cell responses against PD-L1+ M1 macrophages could be further enhanced by Avelumab, an anti-PD-L1- and ADCC-inducing antibody. Additionally, NK cell responses were influenced by HLA class I, shown by stronger degranulation in NK cell subsets for which the corresponding HLA ligand was absent on the macrophage target cells (KIR-ligand mismatch) compared to degranulation in the presence of the HLA ligand (KIR-ligand match). Our results suggest that NK cells could, next to killing tumor cells, get activated upon interaction with TAC, like M1 macrophages and TAMs, and that NK cells combined with PD-L1 blocking antibodies with ADCC potential could, through IFN-γ secretion, promote a more immune-favorable TME.

The human leukocyte antigen (HLA) genes are amongst the most polymorphic in the human genome. Alternative splicing could add an extra layer of complexity, but has not been studied extensively. Here, we applied an RNA based approach to study the influence of allele polymorphism on alternative splicing of HLA-C in peripheral blood. RNA was isolated from these peripheral cells, converted into cDNA and amplified specifically for twelve common HLA-C allele groups. Through subsequent sequencing of HLA-C, we observed alternative splicing variants of HLA-C*04 and *16 that resulted in exon 5 skipping and were co-expressed with the mature transcript. Investigation of intron 4 sequences of HLA-C*04 and *16 compared to other HLA-C alleles demonstrated no effect on predicted splice sites and branch point. To further investigate if the unique polymorphic positions in exon 5 of HLA-C*04 or *16 may facilitate alternative splicing by acting on splicing regulatory elements (SRE), in-silico splicing analysis was performed. While the HLA-C*04 specific SNP in exon 5 had no effect on predicted exonic SRE, the HLA-C*16 specific exon 5 SNP did alter exonic SRE. Our findings provide experimental and theoretical support for the concept that polymorphisms within the HLA-C alleles influence the alternative splicing of HLA-C. This article is protected by copyright. All rights reserved.

Natural killer (NK) cells mediate potent anti-tumor responses, which makes them attractive targets for immunotherapy. The anti-tumor response of endogenous- or allogeneic NK cells can be enhanced through clinically available monoclonal antibodies that mediate antibody-dependent cellular cytotoxicity (ADCC). NK cell activation is regulated by interaction of inhibitory receptors with classical- and non-classical human leukocyte antigens (HLA) class I molecules. Inhibitory receptors of the killer immunoglobulin-like receptor (KIR) family interact with HLA-A, -B or -C epitopes, while NKG2A interacts with the non-classical HLA-E molecule. Both types of inhibitory interactions may influence the strength of the ADCC response. In the present review, we provide an overview of the effect of inhibitory KIRs and NKG2A on NK cell-mediated ADCC, which highlights the rationale for combination strategies with ADCC triggering antibodies and interference with the NK cell relevant inhibitory immune checkpoints, such as KIR and NKG2A.

Studies have shown that employees react negatively towards negative supervisory behaviour. Therefore, a questionnaire that could measure the quality of various aspects of the employment relationship could be a useful tool for managing and promoting healthy employment relationships. In the light of this, the aim of this study was to develop a questionnaire that measured the perceived quality of the employment relationship from the employee’s perspective. A quantitative cross-sectional survey was conducted on a non-probability convenience sample of 248 employees from various organisations and sectors in South Africa. Although a 39-item questionnaire was developed across four theoretical dimensions, namely trust, fairness, good faith and justice, the analysis revealed that only two dimensions, labelled social factors and compliance factors and measured by 20 items, were sufficient to measure the desired construct. This questionnaire, which measures the perceived employment relationship quality, could be used as a diagnostic tool by management and HR professionals to determine the state of supervisory relationships in an organisation, and to address any problems brought to the fore, thereby avoiding turnover costs related to negative workplace relationships.

Simple Summary Natural killer (NK) cells are potent killers of tumor cells. Many tumors, including breast cancers, develop mechanisms to suppress anti-tumor immune responses, requiring the development of strategies to overcome suppression. Here, we tested a combination therapy that aims to (1) enhance NK cell activation and (2) reduce NK cell inhibition mediated by suppressive factors in tumors or in the tumor microenvironment. We cultured cell lines under hypoxia to mimic the tumor microenvironment or used patient-derived breast cancer cells that were primed by the patient’s tumor environment. Our results demonstrated that cytokine-activated NK cells remained active under hypoxia and that tumor-targeting antibodies enhanced the NK cell anti-breast cancer response. Moreover, we observed that NK cell suppression by inhibitory ligands on the tumor cells can be reduced by the selection of NK cell donors with NK receptors that are incompatible with these ligands. Collectively, we present two powerful strategies to enhance the NK cell responses against breast cancer. Abstract Natural killer (NK)-cell-based immunotherapies are an attractive treatment option for cancer. We previously showed that alloreactive mouse NK cells cured mice of 4T1 breast cancer. However, the tumor microenvironment can inhibit immune responses, and these suppressive factors must be overcome to unfold the NK cells’ full anti-tumor potential. Here, we investigated the combination of antibody-dependent cellular cytotoxicity (ADDC) and the selection of KIR-HLA-ligand mismatched NK cells to enhance NK cell anti-breast cancer responses in clinically relevant settings. Donor-derived and IL-2-activated NK cells were co-cultured with patient-derived breast cancer cells or cell lines MCF7 or SKBR3 together with the anti-HER2 antibody trastuzumab. NK cells mediated anti-breast cancer cytotoxicity under normoxic and hypoxic conditions. Under both conditions, trastuzumab vigorously enhanced NK cell degranulation (CD107a) against HER2-overexpressing SKBR3 cells, but we observed a discrepancy between highly degranulating NK cells and a rather modest increase in cytotoxicity of SKBR3. Against patient-derived breast cancer cells, the anti-tumor efficacy was rather limited, and HLA class I expression seemed to contribute to inhibited NK cell functionality. KIR-ligand-mismatched NK cells degranulated stronger compared to the matched NK cells, further highlighting the role of HLA. In summary, trastuzumab and KIR-ligand-mismatched NK cells could be two strategies to potently enhance NK cell responses to breast cancer.

Simple Summary Antibodies with their high specificity to antigens have been widely used in cancer immunotherapy. Natural killer (NK) cells are a group of innate immune cells which have strong cytotoxicity against cancerous cells, virus infected cells, or transformed cells. NK cells express abundant Fc receptors that can bind tumor-specific antibodies, thus allowing them to precisely redirect and eliminate cancer cells. In this study, we demonstrated that NK cells cytotoxicity toward MUC1-positive hematologic and solid tumor can be further enhanced by a humanized 5E5 anti-MUC1 antibody. Furthermore, Fc defucosylation of the antibodies further boosted the kill capacity of NK cells. We believe that our humanized anti-MUC1 antibody is a promising therapeutic candidate for clinical cancer treatment. Abstract Antibodies are commonly used in cancer immunotherapy because of their high specificity for tumor-associated antigens. The binding of antibodies can have direct effects on tumor cells but also engages natural killer (NK) cells via their Fc receptor. Mucin 1 (MUC1) is a highly glycosylated protein expressed in normal epithelial cells, while the under-glycosylated MUC1 epitope (MUC1-Tn/STn) is only expressed on malignant cells, making it an interesting diagnostic and therapeutic target. Several anti-MUC1 antibodies have been tested for therapeutic applications in solid tumors thus far without clinical success. Herein, we describe the generation of fully humanized antibodies based on the murine 5E5 antibody, targeting the tumor-specific MUC1-Tn/STn epitope. We confirmed that these antibodies specifically recognize tumor-associated MUC1 epitopes and can activate human NK cells in vitro. Defucosylation of these newly developed anti-MUC1 antibodies further enhanced antigen-dependent cellular cytotoxicity (ADCC) mediated by NK cells. We show that endocytosis inhibitors augment the availability of MUC1-Tn/STn epitopes on tumor cells but do not further enhance ADCC in NK cells. Collectively, this study describes novel fully humanized anti-MUC1 antibodies that, especially after defucosylation, are promising therapeutic candidates for cellular immunotherapy.

High salt in diet elevates blood pressure in man. Berries and fruits are regarded beneficial in antagonizing hypertension and related vascular complications. We aimed to test whether lingonberry juice shows beneficial and anti-inflammatory effects in salt induced hypertension rat model. Male Wistar–Kyoto rats were fed with 8% sodium chloride enriched pellets for 10 weeks having tap water or diluted lingonberry juice as drinking fluid. Blood pressure was recorded weekly and mesenteric artery functions tested ex vivo. Urine was collected in metabolic caging. Salt loading had only minor effects on blood pressure or endothelial function. Increased urine excretion of 8-isoprostane, cGMP and albumin reflected general or renal inflammation. Elevated expression (mRNA) of proinflammatory COX-2 by salt was normalized by lingonberry. Salt increased kidney, heart and left ventricle masses and changed serum chloride, alkaline phosphatase, albumin and lipid concentrations. Taken together the results show that l0 weeks’ high-salt diet impaired kidney function of young rats without clear effect on blood pressure or vascular function. Lingonberry juice moderately reduced biomarkers of low-grade inflammation probably due to its high polyphenol concentrations.

Lingonberries ( Vaccinium vitis-idaea ) are rich in polyphenols, such as proanthocyanidins, anthocyanins, flavonols and flavanols. Polyphenol-rich foods affect vascular health. We previously described improved endothelium-dependent vascular function as well as anti-inflammatory and anti-atherothrombotic effects in spontaneously hypertensive rats (SHR) fed with lingonberry juice. In the present study, we investigated the effects of lingonberry juice dose on blood pressure, vascular function and vascular inflammation in SHR in an 8 weeks’ study. Diluted (1:5) cold-compressed lingonberry juice was given as drinking fluid ad libitum to 5 week old SHR for 8 weeks. Control group (SHR) and normotensive reference group (Wistar-Kyoto) received tap water. Systolic blood pressure (SBP) was monitored weekly. Function of mesenteric artery rings was assessed in standard organ-bath chambers after 8 weeks. Biochemical and clinical chemistry variables were measured from plasma and urine. Lingonberry juice lowered SBP of SHR ( p = 0.007). Endothelium-dependent vascular relaxation was not improved. Lingonberry treatment slightly affected plasma inflammatory markers (reduction of NOx and sICAM-1) and clinical chemistry variables (decreased alkaline phosphatase and increased chloride and calcium levels). In conclusion, Lingonberry juice at small concentrations lowers blood pressure in a long-term treatment in SHR.

Flavonoids and other phenolic compounds affect low-grade inflammation related to cardiovascular diseases among other positive health effects. Cardioprotective actions are mainly due to enhanced endothelial function and production of nitric oxide (NO). We investigated vascular anti-inflammatory effects of cranberry (Vaccinium oxycoccos), lingonberry (Vaccinium vitis-idaea) and blackcurrant (Ribes nigrum) juices given as drinking fluid ad libitum to spontaneously hypertensive rats (SHR), a widely used model of human hypertension, in an 8 week intervention study. The animals were sacrificed, the aortas cleaned and RNA was extracted. cDNA was prepared for real-time PCR and blood was collected for biochemical analyses. The mRNA expressions of angiotensin-converting enzyme 1 (ACE1), cyclooxygenase 2 (COX2), monocyte chemoattractant protein 1 (MCP1) and P-selectin were significantly reduced in the cranberry and lingonberry groups. These findings suggest that cranberry and lingonberry cold-compressed juices have anti-inflammatory and anti-atherothrombotic actions in long-term treatment of SHR.

In this study, we investigated the synergistic effects of plant sterols (PS) and casein-derived tripeptides on arterial tone and blood pressure in experimental hypertension. We hypothesized that PS and tripeptides could have positive, synergistic effects on the development of hypertension and endothelial dysfunction in young spontaneously hypertensive rats (SHR). Six-week-old male SHR were divided into 3 groups to receive milk products containing PS, or PS with tripeptides, or a control containing no active components for 8 weeks. Systolic blood pressure (SBP) was measured weekly, and vascular reactivity measurements with isolated mesenteric arteries were performed at the end of the study. Biochemical measurements for several parameters were performed by enzyme-linked immunosorbent assay using plasma samples. Levels of angiotensin-converting enzyme 1, cyclooxygenase-2, endothelial nitric oxide synthase, and P-selectin messenger RNA expressions were determined from aortic tissue by real-time polymerase chain reaction. The study showed that long-term treatment with PS + tripeptides attenuated the development of hypertension in SHR (SBP, 187 ± 5 mm Hg vs 169 ± 4 mm Hg in control group; P < .01). Plant sterols alone did not affect SBP significantly. Endothelial dysfunction was observed in all SHR; however, treatment with PS resulted in poorer endothelium-dependent and nitric oxide–mediated relaxation compared with other groups. Aortic cyclooxygenase-2 and P-selectin were significantly down-regulated in PS and PS + tripeptides groups when compared with the control group. The expression of endothelial nitric oxide synthase was significantly lower in PS than in PS + tripeptides group. In conclusion, long-term treatment with PS has a slight but not significant antihypertensive effect. Plant sterols do not provide any beneficial effects on endothelial function in hypertensive rats; however, treatment with both PS and tripeptides showed mild anti-inflammatory effects.

Phenolic compounds of berries, fruits and vegetables affect vascular health. Endothelium-dependent vasodilatation has an important role in blood pressure development by controlling the vascular tone. Endothelial cells produce and release various relaxing and contracting factors, like nitric oxide (NO), cyclo-oxygenase (COX)-derived prostanoids and endothelium-derived hyperpolarizing factor (EDHF). The purpose of this study was to investigate whether 8 weeks treatment with Finnish berry juices, cranberry (Vaccinium oxycoccos), lingonberry (Vaccinium vitis-idaea) and blackcurrant (Ribes nigrum) affects blood pressure and vascular function of spontaneously hypertensive rats (SHR). After 8 weeks treatment the mesenteric arteries of the rats were taken for vascular reactivity studies. Lingonberry treatment normalized the impaired endothelium-dependent relaxation seen in the cranberry, blackcurrant and control rats. In the arteries of lingonberry treated rats the relaxation was partly due to NO, but also dependent on EDHF. It can be concluded that long-term lingonberry juice treatment improves endothelium-dependent vasodilatation of SHR.

Casein-derived tripeptides isoleucine-proline-proline (Ile-Pro-Pro) and valine-proline-proline (Val-Pro-Pro) lower blood pressure (BP) in long-term clinical studies. Their acute effects on BP and vascular function, important for daily dosing scheme, were studied in a placebo-controlled double-blind crossover study using a single oral dose of a fermented milk product containing Ile-Pro-Pro and Val-Pro-Pro as well as plant sterols. Twenty-five subjects with untreated mild hypertension received in random order 250 g of study product (25 mg peptides and 2 g plant sterols) or placebo. Ambulatory BP was monitored for 8 h post-dose and arterial stiffness measured by pulse wave analysis at 2, 4, and 8 h. Blood and urine samples were analyzed for markers of the renin-angiotensin system (RAS) and endothelial function. Baseline adjusted treatment effect for systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial BP was -2.1 mmHg (95% CI: -4.1 to -0.1, p = 0.045), -1.6 mmHg (95% CI: -3.1 to -0.1, p = 0.03), and -1,9 mmHg (95% CI: -3-3 to -0.4, p = 0.0093), respectively, in favor of the active treatment for 8 h post- dose. No significant differences between the treatments were seen in brachial or aortic augmentation index, pulse wave velocity, or markers of RAS. Urinary excretion of cGMP, the second messenger of endothelial nitric oxide, was higher in the active group vs. placebo (p = 0.01). The results indicate that a single dose of a fermented milk product containing Ile-Pro-Pro and Val-Pro-Pro and plant sterols acutely lowers brachial SBP and DBP in mildly hypertensive subjects.

Milk casein-derived bioactive tripeptides isoleucine-proline-proline (Ile-Pro-Pro) and valine-proline-proline (Val-Pro-Pro) lower blood pressure in animal models of hypertension and humans. In some studies, their angiotensin-converting enzyme (ACE)-inhibitory effect has been demonstrated. Besides classical ACE-angiotensin II-AT(1)-receptor pathway (ACE-Ang II- AT(1)), the significance of ACE2-angiotensin-(1-7)-Mas-receptor (ACE2-Ang-(1-7)-Mas) axis in the blood pressure regulation has now been acknowledged. The present study was aimed to further evaluate the renin-angiotensin system (RAS)-related vascular effects of Ile-Pro-Pro in vitro using rat mesenteric arteries.Superior mesenteric arteries of spontaneously hypertensive rat (SHR) were isolated, cut into rings and mounted in standard organ bath chambers. Endothelium-intact arterial rings were incubated in Krebs solution either with Ile-Pro-Pro, proline-proline (Pro-Pro), isoleucine (Ile), proline (Pro) or captopril for 6h at +37°C and vascular reactivity was measured.In the presence of AT(1)-antagonist valsartan, Ang II induced vasodilatation, which was more pronounced in the arteries incubated with Ile-Pro-Pro (P0.05) compared to the other compounds. Ang-(1-7)-induced vasodilatation was augmented by Ile-Pro-Pro or Pro (P0.001 vs. control). Mas-receptor antagonist A-779 did not alter the responses. Ile-Pro-Pro and Pro augmented also bradykinin-induced relaxations (P0.001 vs. control). Control arteries and arteries incubated with captopril showed only slight relaxations at higher bradykinin concentrations.Casein-derived tripeptide Ile-Pro-Pro and amino acid Pro enhance the vasodilatory effect of Ang-(1-7) and bradykinin. The role of ACE2-Ang-(1-7)-Mas axis in the modulation of vascular tone by these compounds seems probable.

Once the diagnosis of food allergy is established by double-blind, placebo-controlled food challenges, the only proven therapy is a strict elimination diet. Special food exclusion diets exist that allow patients to avoid food allergens while maintaining a good quality of life. If the allergen provokes anaphylactic reactions, the restriction diet has to be combined with the prescription of an emergency medication (antihistamine, corticosteroid, adrenaline). As symptomatic food allergy is often "lost" over time, food challenges can be repeated at intervals of 1 - 2 years under monitored conditions. Immunotherapy with food extracts should only be used in controlled studies for the treatment of food hypersensitivity. Concerning their associated food allergy, patients with tree pollen illergy may profit from a specific immunotherapy with tree pollen extract. An induction of oral tolerance using increasing amounts of raw food is only useful in selected, highly compliant patients and in instances of not reliably avoidable foods. Antihistamines may partially mask symptoms of oral allergy syndrome and IgE-mediated skin symptoms. In allergic reactions with gastrointestinal disorders, cromoglycate might be used for a short time. Alternative therapies such as rotation diets, electroacupuncture or bioresonance should be disapproved.

Summary Background Adverse reactions after ingestion of alcoholic beverages are common. Metabolic differences in individuals and also the histamine content in alcoholic beverages have been implicated. By contrast pure ethanol has rarely been reported as a cause of hypersensitivity reactions and its mechanism has not been clarified yet. Objective To determine whether ethanol itself accounts for alcohol hypersensitivity in patients with anaphylactic reactions after alcohol intake. In search of possible pathomechanisms all patients were analysed by skin prick testing and sulfidoleukotriene production of peripheral leucocytes using ethanol and its metabolites. Methods Double-blind, placebo-controlled food challenges with a cumulated amount of 30 mL ethanol were performed in 12 adult patients with a positive history of adverse reactions after consumption of different alcoholic beverages. Skin prick tests and measurement of sulfidoleukotriene production were performed using different concentrations of ethanol and acetaldehyde from 50 to 1000 mm. Results Oral challenges with pure ethanol were positive in six out of eleven patients. All challenge-positive patients, but also four out of five challenge-negative patients, showed an increased sulfidoleukotriene production in-vitro compared with healthy controls. Skin prick tests using alcoholic beverages, ethanol, acetaldehyde and acetic acid were negative in all patients (12/12). Conclusion Our study shows that ethanol itself is a common causative factor in hypersensitivity reactions to alcoholic beverages. These reactions occur dose-dependent and a non-IgE-mediated pathomechanism is likely, because skin prick tests were negative in all cases. Increased sulfidoleukotriene production was determined in some patients, but is no reliable predictor. Therefore oral provocation tests remain indispensable in making the diagnosis of ethanol hypersensitivity.

Plant-climate interactions have a strong influence on the global carbon cycle. We aim to study those interactions as well as climate variability retrospectively using tree rings, to detect possible acclimation on time scales of centuries. The abundance of the stable hydrogen isotope, deuterium (D) in plant material is influenced both by climate and physiology. The D abundance of precipitation water carries a climate (temperature) signal, which is transferred to plant material. Besides this, transpiration creates a humidity signal, and enzyme isotope effects create physiological signals. Finally, these signals can be modified by hydrogen exchange during cellulose synthesis. If climate and physiological signals can be separated and detected simultaneously, they can be used to infer plant-climate interactions. Among the processes determining the D abundance in plant material, biosynthetic reactions and hydrogen exchange during cellulose synthesis are enzyme-catalyzed processes. Therefore, they affect the D abundance in individual C-H groups, that is, they determine the Deuterium Isotopomer Distribution (DID). Deuterium Nuclear Magnetic Resonance allows measuring the DID. In a D labelling experiment, we have studied hydrogen exchange during cellulose synthesis in oak and spruce trees. Our results show that hydrogen exchange with water is high for the C2-H group of glucose. This means that C2-H acquires the temperature signal present in source water. In a CO2 enrichment experiments, we have investigated relationships between DID and metabolic fluxes of primary C metabolism. We have evidence that the D abundances in the C6-H2 group of glucose reflect the photosynthesis/photorespiration ratio. This has been observed both in leaves and tree rings in manipulative CO2 fumigation experiments but also in a 150 year tree-ring series. We conclude that DID measurements can be used for climate reconstruction from tree rings, and to investigate plant-climate interactions on long-time scales, such as CO2 fertilisation since industrialisation.

In the fermentation of milk by certain lactic acid bacteria, casein is degraded into bioactive tripeptides shown to lower blood pressure in experimental animal models and in mildly hypertensive humans. This effect is suggested to result mainly in inhibition of angiotensin converting enzyme 1 (ACE-1). Due to the complexity of renin-angiotensin system (RAS), several other enzymes than ACE-1 can participate in the production of vasoactive components. Therefore, in the present study we investigated effects of tripeptides isoleucine-proline-proline (IPP), valine-proline-proline (VPP) and leucine-proline-proline (LPP) on some endothelial enzymes that are important in RAS or otherwise have a role in the endothelial function. The enzymes investigated were renin, chymase, neutral endopeptidase (NEP), prolyl oligopeptidase (POP), cathepsin G, endothelin converting enzyme 1 (ECE-1), and cyclooxygenase 1 and 2 (COX -1 and COX-2). The tripeptides inhibited prolyl oligopeptidase (POP) dose-dependently. IPP was the most potent inhibitor (IC 50 486±95 µM). Contrary, cathepsin G was activated by IPP, VPP and LPP as well as the amino acids proline and isoleucine. The other investigated enzymes were not affected. Inhibition of POP and activation of cathepsin G do not explain the blood pressure lowering effects of the tripeptides. Thus the inhibition of ACE-1 remains the most plausible mechanism of the antihypertensive effects of the tripeptides.

Contents 26.1 Regulation of Blood Pressure 561 26.2 Lactic Acid Bacteria as Producers of Bioactive Peptides 56326.2.1 Description of Bioactive Peptides 563 26.2.2 Formation of Bioactive Peptides 56326.3 Antihypertensive Peptides from Milk Proteins 564 26.3.1 Casein-Derived Tripeptides Ile-Pro-Pro and Val-Pro-Pro 565

Milk casein-derived angiotensin-converting enzyme (ACE)-inhibitory tripeptides isoleucine-proline-proline (Ile-Pro-Pro) and valine-proline-proline (Val-Pro-Pro) have been shown to have antihypertensive effects in human subjects and to attenuate the development of hypertension in experimental models. The aim of the present study was to investigate the effect of a fermented milk product containing Ile-Pro-Pro and Val-Pro-Pro and plant sterols on already established hypertension, endothelial dysfunction and aortic gene expression. Male spontaneously hypertensive rats (SHR) with baseline systolic blood pressure (SBP) of 195 mmHg were given either active milk (tripeptides and plant sterols), milk or water ad libitum for 6 weeks. SBP was measured weekly by the tail-cuff method. The endothelial function of mesenteric arteries was investigated at the end of the study. Aortas were collected for DNA microarray study (Affymetrix Rat Gene 1.0 ST Array). The main finding was that active milk decreased SBP by 16 mmHg compared with water (178 (sem 3) v. 195 (sem 3) mmHg; P 1·2 and P P = 0·047). In conclusion, long-term treatment with fermented milk enriched with tripeptides and plant sterols decreases SBP, improves endothelial dysfunction and affects signalling pathways related to inflammatory responses in SHR.

Background Pathogens such as Aggregatibacter actinomycetemcomitans (Aa) and Chlamydia pneumoniae (Cpn) associate with an increased risk for cardiovascular diseases by inducing inflammation. We hypothesized that the pathogens affect the vascular wall by disturbing cholesterol homeostasis and endothelial function. Methods Aa- and Cpn-infections were induced in apoE-deficient mice by intravenous and intranasal applications, respectively. Cholesterol efflux from mouse peritoneal macrophages to apo(lipoprotein)A-I was assessed. The efflux capacity of mouse sera as acceptors of cholesterol from RAW264.7-macrophages was determined. Additionally, endothelial function was studied by following the relaxation capacity of rat mesenteric arteries after incubation in the conditioned culture media of the peritoneal macrophages isolated from the mice. Results Infection increased serum phospholipid transfer protein (PLTP) and lipopolysaccharide (LPS) activity, as well as serum amyloid A (SAA) and TNF-α concentrations. Peritoneal macrophages of mice with Aa-infection showed increased cholesterol uptake and reduced cholesterol efflux. Sera of Cpn and Cpn + Aa-infected mice had reduced cholesterol efflux capacity from RAW264.7-macrophages. Conditioned macrophage medium from mice with chronic C. pneumoniae infection induced endothelial dysfunction. Additionally, concentrations of serum adhesion molecules, intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM) in Cpn-groups and E-selectin in Cpn + Aa-group, were elevated. The serum markers of endothelial function correlated positively with SAA. Conclusions Aa- and Cpn-infections may generate proatherogenic changes in the vascular wall by affecting the macrophage cholesterol homeostasis and endothelial function.

Adverse reactions to food have been recognized sinceancient times, but only recently the many heterogeneousmechanisms have been identified. These include not onlyimmunological IgE-mediated food allergy and nonimmu-nological reactions like pseudoallergy, enzyme deficien-cies, toxic effects of food, but also rare reactions like fooddependent exercise-induced anaphylaxis. The frequencyof perceived adverse reactions to food is higher than thenumber of confirmed reactions (1, 2). However, thediagnosis of adverse reactions to food is very sophisti-cated and till date there is no large population-basedstudy worldwide investigating all kinds of adverse reac-tions to food using the required selective patient-orientedapproach.Investigationofnonimmunologicalreactionsisdifficult because of the lack of simple in vitro and in vivotests, but even for allergic, IgE-mediated reactions andespecially cross-reactions these tests have low predictivevalue (3–7). The recommended way of diagnosis,therefore, in addition to skin and blood tests, is toestablish food intolerance by dietary exclusion anddouble-blind, placebo-controlled food challenge tests(DBPCFC) (8–10).Due to this difficult situation and the lack of existingdata, the German Ministry of Health initiated this studyto investigate the prevalence of food intolerance in theGerman population and to identify the eliciting agents.The study was performed in the Berlin population, asingle-center approach was chosen since an especiallyequipped allergy centre was required, to handle severeanaphylactic reactions during provocation tests and toavoid an inter-investigator bias. Data were then compu-ted for the whole German adult population on the basisof the existing data of the nationwide German healthSurvey from 1998, which was performed in the age groupof 18–79 years concentrating on general health issues butnot on food allergy in particular.Objective:A population study was performed to identify the prevalence of allkinds of adverse reactions to food.Methods: In a representative cross-sectional survey performed in 1999 and 2000in Berlin, 13 300 inhabitants of all ages were addressed by questionnaire. Thisquestionnaire was answered by 4093 persons. All respondents mentioning anysign of food intolerance or the existence of allergic diseases (n ¼ 2298) werefollowed up by telephone and, in case food intolerance could not be ruled out bypatient history, were invited to attend to the clinic for personal investigationincluding double-blind, placebo-controlled food challenge tests (DBPCFC).Results: The self-reported lifetime prevalence of any adverse reaction to food inthe Berlin population (mean age 41 years) was 34.9%. Eight hundred andfourteen individuals were personally investigated according to the guidelines.The point prevalence of adverse reactions to food confirmed by DBPCFC testsin the Berlin population as a mean of all age groups was 3.6% (95% confidenceinterval [3.0–4.2%]) and 3.7% in the adult population (18–79 years, 95% con-fidence interval [3.1–4.4.%]). Two and a half percent were IgE-mediated and1.1% non-IgE-mediated, females were more frequently affected (60.6%). Basedon a statistical comparison with available data of adults from the nationwideGerman Health Survey from 1998, adverse reactions to food in the adult pop-ulation of Germany (age 18–79) were calculated with 2.6% [2.1–3.2%]).Conclusions: The study gives for the first time information about the pointprevalence of both immunological and nonimmunological adverse reactions tofood and underlines the relevance of this issue in public health. The data alsoshow that an individualized stepwise approach including provocation tests ismandatory to confirm the diagnosis.T.Zuberbier

Adverse reactions after ingestion of alcoholic beverages are common. Metabolic differences in individuals and also the histamine content in alcoholic beverages have been implicated. By contrast pure ethanol has rarely been reported as a cause of hypersensitivity reactions and its mechanism has not been clarified yet.To determine whether ethanol itself accounts for alcohol hypersensitivity in patients with anaphylactic reactions after alcohol intake. In search of possible pathomechanisms all patients were analysed by skin prick testing and sulfidoleukotriene production of peripheral leucocytes using ethanol and its metabolites.Double-blind, placebo-controlled food challenges with a cumulated amount of 30 mL ethanol were performed in 12 adult patients with a positive history of adverse reactions after consumption of different alcoholic beverages. Skin prick tests and measurement of sulfidoleukotriene production were performed using different concentrations of ethanol and acetaldehyde from 50 to 1000 mm.Oral challenges with pure ethanol were positive in six out of eleven patients. All challenge-positive patients, but also four out of five challenge-negative patients, showed an increased sulfidoleukotriene production in-vitro compared with healthy controls. Skin prick tests using alcoholic beverages, ethanol, acetaldehyde and acetic acid were negative in all patients (12/12).Our study shows that ethanol itself is a common causative factor in hypersensitivity reactions to alcoholic beverages. These reactions occur dose-dependent and a non-IgE-mediated pathomechanism is likely, because skin prick tests were negative in all cases. Increased sulfidoleukotriene production was determined in some patients, but is no reliable predictor. Therefore oral provocation tests remain indispensable in making the diagnosis of ethanol hypersensitivity.

Many atopic dermatitis (AD) patients follow elimination diets for long periods of time because of true or--even more often--suspected food allergies or hypersensitivities. In the present study we investigated the nutritional status of adult AD patients by evaluating food intake protocols followed by measuring different serum parameters. Evaluation of the food intake protocols over 3 days (n = 47) showed that the total calorie intake met recommended intake in 12 patients (group A), ranged between 75-100% of the requirements in 23 patients (group B) and was 50-75% in 12 patients (group C). The relative intake of different nutritional factors approached normal limits in group A and B; the intake of several of these factors was significantly decreased in group C. Various serum parameters in group C patients were different from those found in patients suffering from other chronic skin diseases. Taken together, our results show that a subgroup of AD patients have dietary habits which result in significant nutritional deficiency which are important for homeostasis. This indicates the necessity of professional guidance in these patients in order to only eliminate foods which have been proven to elicit adverse reactions by oral provocation tests.

Recently, we identified a subgroup of patients with atopic dermatitis (AD) with a clinical relevant food intolerance proven by double blind placebo controlled challenge. In search of possible pathomechanisms involved in this food intolerance, which leads to aggravation of the disease, the aim of the present study was to determine sulfidoleukotriene production in these patients using isolated leucocytes from the peripheral blood after stimulation with different food additives. Leukotriene production of peripheral leucocytes was detected by incubation of isolated cells with the food additives at different concentrations ranging from 0.2 to 200 microg/mL after pre-stimulation with IL-3. Ten non-atopic donors (A), nine AD patients of the diet responder group with negative oral provocation test against food additives (B) and nine patients of the responder group with positive reactions after the oral provocation test (C) were investigated. In the non-atopic group (A), no increased sulfidoleukotriene (sLT) release was observed for all food additives tested. In group B, increased sLT production was determined using tartrazine in one patient (1/9) and using nitrite in two patients (2/9), whereas sLT production remained below the cut-off range in all patients of group B (9/9) using benzoate, metabisulfite and salicylate. By contrast, in group C increased sLT production was observed with food colour mix in 1/9, with tartrazine in 3/9, with benzoate in 4/9, with nitrite in 5/9, with salicylate in 2/9 and with metabisulfite in 1/9. However, no increased sLT concentration was determined in the presence of the tested food additives in two patients of group C. Increased sLT production by peripheral leucocytes in the presence of single food additives was observed in the majority of patients with a proven food intolerance towards food additives proven by double-blind-placebo-controlled challenges. These food additives were particulary tartrazine, benzoate and nitrite. These findings indicate that single food additives as aggravating factors in AD patients may trigger the disease through increased sLT production as a pathophysiological mechanism.

Adverse reactions to food play an important role in the pathogenesis of atopic dermatitis (AD). In infancy and childhood, food allergies are observed in up to 30%, whereas nonallergic hypersensitivity reactions (pseudoallergic reactions) towards food additives have been reported to occur between 2 and 7%. By contrast, sensitizations towards food allergens are rarely of clinical relevance in adults and little data is available on nonallergic hypersensitivity reactions. To date the role of pseudoallergic reactions as an aggravating factor in AD of adult patients remains controversial. However, many adult patients report on food-related aggravation of the disease and nonallergic hypersensitivity reactions have been incriminated repeatedly.To elucidate the relevance of food additives in adult patients suffering from AD.Fifty patients were monitored over 4 weeks under regular diet followed by 6 weeks of a diet omitting known pseudoallergens. Skin status of patients was assessed every 2 weeks by a standardized scoring, and serum eosinophilic cationic protein (ECP) was determined before and after diet.Nine of fifty patients dropped out, 26 showed a significant improvement of the Costa-score by 57%. In 23/26 patients a corresponding reduction of serum ECP level by 52% on average was determined. Responder patients (24/26) were orally challenged with food rich in pseudoallergens followed by double-blind exposure to food additives (n = 15). A worsening of the eczema was seen in 19/24 patients after intake of pseudoallergen-rich food and in 6/15 patients after exposure to food additives.These results indicate that a subgroup of adult patients with AD clinically improve on low-pseudoallergen diet but only a small subgroup respond to oral provocation with food additives.

Pseudoallergische Reaktionen auf Nahrungsmittel sind bisher kaum systematisch untersucht worden. Aufgrund von Einzelfallberichten und Studien aus den siebziger Jahren wurden diese Reaktionen bisher vor allem auf kunstliche Nahrungsmittelzusatzstoffe und auf naturlich vorkommende Salizylate und Benzoate zuruckgefuhrt [1–4]. Die bisher bekannten chemisch charakterisierten Pseudoallergene sind im folgenden dargestellt.