Neuronal response to high negative affective stimuli in major depressive disorder: An fMRI study.

BACKGROUND: Disturbed emotion processing underlies depression. We examined the neuronal underpinnings of emotional processing in patients (PAT) with major depressive disorder (MDD) compared to healthy volunteers (HV) using functional magnetic resonance (fMRI) scan. METHODS: Thirty-six MDD patients and 30 HV underwent T2-weighted fMRI assessments during the presentation of an implicit affective processing task in three conditions. They differed regarding their affective quality (=valence, high negative, low negative and neutral stimuli) and regarding the arousal based on stimuli from the International Affective Picture System. RESULTS: Group contrasts showed lower left-sided activation in dorsolateral prefrontal cortex (DLPFC), anterior PFC, precentral and premotor cortex in PAT compared with HV (Cluster-level threshold, 5000 iterations, p<0.01). We found a significant interaction effect of valence and group, a significant effect of emotional valence and a significant effect of group. All effects were shown in brain regions within the emotional network (Cluster-level threshold, 5000 iterations, p<0.01). Higher arousal (rho=-0.33, p<0.01) and higher valence (rho=-0.33, p<0.01) during high negative stimuli presentation as well as more severe depression (Beck Depression Inventory II [BDI II]; r = 0.39, p = 0.01) were significantly negatively associated with left DLFPC activity in patients. LIMITATIONS: Potential influence of psychopharmacological drugs on functional activation is one of the most discussed source of bias in studies with medicated psychiatric patients. CONCLUSIONS: The results highlight the importance of left DLPFC during the processing of negative emotional stimuli in MDD. The integration of a neurophysiological model of emotional processing in MDD may help to clarify and improve therapeutic options.

E-cadherin mediated cell-biomaterial interaction reduces migration of keratinocytes in-vitro.

Percutaneous devices suffer from imperfect sealing of the epidermis-implant interphase, the so-called three-phase junction, allowing invading pathogens access to colonize the implant at the tissue interface and potentially cause an infection. In skin, one of the key components of the epidermal barrier is the E-cadherin mediated adherens junctions. We investigated the response of a human keratinocyte cell line (HaCaT) to a titanium substrate functionalized with the extracellular domain of E-cadherin fused to an Fc domain. Polydopamine was used as a binding layer to attach the E-cadherin to the titanium surface in two ways: 1) by attaching protein A to the polydopamine followed by E-cadherin (aligned orientation) or 2) by direct attachment of the E-cadherin to the polydopamine (random orientation). The E-cadherin surface functionalization was stable for up to two months as determined by ELISA. HaCaTs did attach to the surface irrespective of E-cadherin orientation. However, decreased cell proliferation and increased cell size was observed for cells on aligned E-cadherin surfaces as compared to a positive control coated with fibronectin. The adhesion of the HaCaTs to the surface with aligned E-cadherin was more sensitive to cell media Ca2+ depletion. A confluent layer of HaCaTs was almost immobile on the aligned E-cadherin surface, as compared to a surface coated with fibronectin, whereas cell migration was also observed on randomly oriented E-cadherin. The E-cadherin coated surfaces were non-adhesive for primary human dermal fibroblasts, a cell type not expressing E-cadherin. These results show the potential of using E-cadherin as a functional surface at the three-phase junction of percutaneous implants to ensure epidermal attachment, limit epidermal downgrowth and prevent fibroblast adhesion.

Diagnostic accuracy of cone beam computed tomography used for assessment of apical periodontitis: an ex vivo histopathological study on human cadavers.

AIM: To assess the diagnostic accuracy of Cone Beam Computed Tomography (CBCT) to diagnose apical periodontitis (AP) using histopathology of ex vivo human jaws as the reference standard. METHODOLOGY: Based on periapical radiographs of jaw specimens from human bodies donated for science, a sample of 223 teeth with 340 roots including all tooth groups, and different disease and treatment statuses was selected. Cone Beam Computed Tomography was performed using Cranex® 3Dx (Soredex Oy, Tuusula, Finland), small field-of-view (5 × 5 cm), and isotropic resolution 0.085 mm. Three observers assessed the presence of AP using a probability index. Histopathological examination of the periapical area was used as a reference standard to calculate estimates of diagnostic accuracy. RESULTS: For non-root filled teeth all estimates of diagnostic accuracy; sensitivity (SENS), specificity (SPEC), positive predictive value (PPV) and negative predictive value (NPV) were high. All estimates were lower for root filled teeth. When mild AP was classified as 'AP', SENS, SPEC and NPV were significantly lower in root filled roots (P < 0.001 in all cases). The same tendency was seen when mild AP was classified as 'No AP' but here only the difference in SPEC was significant (P < 0.001). CONCLUSION: The diagnostic accuracy of CBCT used for diagnosis of AP is dependent on the treatment status of the tooth. For non-root filled teeth the diagnostic accuracy of CBCT is high and almost all cases of AP can be diagnosed correctly with only a very small risk of over-diagnosis. All diagnostic accuracy parameters were lower for root filled roots, hence the diagnosis of AP on root filled roots using CBCT was less accurate.

Complex patchy colloids shaped from deformable seed particles through capillary interactions.

We investigate the mechanisms underlying the reconfiguration of random aggregates of spheres through capillary interactions, the so-called "colloidal recycling" method, to fabricate a wide variety of patchy particles. We explore the influence of capillary forces on clusters of deformable seed particles by systematically varying the crosslink density of the spherical seeds. Spheres with a poorly crosslinked polymer network strongly deform due to capillary forces and merge into large spheres. With increasing crosslink density and therefore rigidity, the shape of the spheres is increasingly preserved during reconfiguration, yielding patchy particles of well-defined shape for up to five spheres. In particular, we find that the aspect ratio between the length and width of dumbbells, L/W, increases with the crosslink density (cd) as L/W = B - A·exp(-cd/C). For clusters consisting of more than five spheres, the particle deformability furthermore determines the patch arrangement of the resulting particles. The reconfiguration pathway of clusters of six densely or poorly crosslinked seeds leads to octahedral and polytetrahedral shaped patchy particles, respectively. For seven particles several geometries were obtained with a preference for pentagonal dipyramids by the rigid spheres, while the soft spheres do rarely arrive in these structures. Even larger clusters of over 15 particles form non-uniform often aspherical shapes. We discuss that the reconfiguration pathway is largely influenced by confinement and geometric constraints. The key factor which dominates during reconfiguration depends on the deformability of the spherical seed particles.

Self-consistent gradient flow for shape optimization.

We present a model for image segmentation and describe a gradient-descent method for level-set based shape optimization. It is commonly known that gradient-descent methods converge slowly due to zig-zag movement. This can also be observed for our problem, especially when sharp edges are present in the image. We interpret this in our specific context to gain a better understanding of the involved difficulties. One way to overcome slow convergence is the use of second-order methods. For our situation, they require derivatives of the potentially noisy image data and are thus undesirable. Hence, we propose a new method that can be interpreted as a self-consistent gradient flow and does not need any derivatives of the image data. It works very well in practice and leads to a far more efficient optimization algorithm. A related idea can also be used to describe the mean-curvature flow of a mean-convex surface. For this, we formulate a mean-curvature Eikonal equation, which allows a numerical propagation of the mean-curvature flow of a surface without explicit time stepping.

IgE responses to exogenous and endogenous allergens in atopic dermatitis patients under long-term systemic cyclosporine A treatment.

Atopic dermatitis (AD) patients mount IgE antibody responses to a variety of environmental allergens and also to autoantigens. We analyzed serum samples from four AD patients who had received oral cyclosporine A (CyA) treatment for up to 17 months regarding IgE autoreactivity to nitrocellulose-blotted human epithelial cell extracts and IgE levels to environmental allergens by quantitative ImmunoCap measurements. Skin inflammation was assessed by SCORAD. During full-dose treatment, a strong reduction in T-cell-mediated skin symptoms was observed which reappeared when CyA treatment was reduced or stopped. The intensity of IgE autoreactivity seemed to follow skin inflammation as it was reduced during full-dose treatment and increased upon inflammation. Interestingly, IgE levels to exogenous allergens were boosted by allergen exposure, declined thereafter, and seemed to be unaffected by CyA. Our data thus indicate that allergen-specific IgE production is boosted by allergen contact and cannot be reduced by CyA-mediated T-cell suppression.

NF-κB-dependent DNA damage-signaling differentially regulates DNA double-strand break repair mechanisms in immature and mature human hematopoietic cells.

Hematopoietic stem and progenitor cells (HSPC), that is, the cell population giving rise not only to all mature hematopoietic lineages but also the presumed target for leukemic transformation, can transmit (adverse) genetic events, such as are acquired from chemotherapy or ionizing radiation. Data on the repair of DNA double-strand-breaks (DSB) and its accuracy in HSPC are scarce, in part contradictory, and mostly obtained in murine models. We explored the activity, quality and molecular components of DSB repair in human HSPC as compared with mature peripheral blood lymphocytes (PBL). To consider chemotherapy/radiation-induced compensatory proliferation, we established cycling HSPC cultures. Comparison of pathway-specific repair activities using reporter systems revealed that HSPC were severely compromised in non-homologous end joining and homologous recombination but not microhomology-mediated end joining. We observed a more pronounced radiation-induced accumulation of nuclear 53BP1 in HSPC relative to PBL, despite evidence for comparable DSB formation from cytogenetic analysis and γH2AX signal quantification, supporting differential pathway usage. Functional screening excluded a major influence of phosphatidylinositol-3-OH-kinase (ATM/ATR/DNA-PK)- and p53-signaling as well as chromatin remodeling. We identified diminished NF-κB signaling as the molecular component underlying the observed differences between HSPC and PBL, limiting the expression of DSB repair genes and bearing the risk of an inaccurate repair.

Control of proliferation and osteogenic differentiation of human dental-pulp-derived stem cells by distinct surface structures.

The ability to control the behavior of stem cells provides crucial benefits, for example, in tissue engineering and toxicity/drug screening, which utilize the stem cell's capacity to engineer new tissues for regenerative purposes and the testing of new drugs in vitro. Recently, surface topography has been shown to influence stem cell differentiation; however, general trends are often difficult to establish due to differences in length scales, surface chemistries and detailed surface topographies. Here we apply a highly versatile screening approach to analyze the interplay of surface topographical parameters on cell attachment, morphology, proliferation and osteogenic differentiation of human mesenchymal dental-pulp-derived stem cells (DPSCs) cultured with and without osteogenic differentiation factors in the medium (ODM). Increasing the inter-pillar gap size from 1 to 6 µm for surfaces with small pillar sizes of 1 and 2 µm resulted in decreased proliferation and in more elongated cells with long pseudopodial protrusions. The same alterations of pillar topography, up to an inter-pillar gap size of 4 µm, also resulted in enhanced mineralization of DPSCs cultured without ODM, while no significant trend was observed for DPSCs cultured with ODM. Generally, cells cultured without ODM had a larger deposition of osteogenic markers on structured surfaces relative to the unstructured surfaces than what was found when culturing with ODM. We conclude that the topographical design of biomaterials can be optimized for the regulation of DPSC differentiation and speculate that the inclusion of ODM alters the ability of the cells to sense surface topographical cues. These results are essential in order to transfer the use of this highly proliferative, easily accessible stem cell into the clinic for use in cell therapy and regenerative medicine.

[The improvement of the transfer into daily life of progressive relaxation after an inpatient psychosomatic rehabilitation]. / Verbesserung des Transfers von Progressiver Relaxation in den Alltag der Patienten nach stationärer psychosomatischer Rehabilitation.

AIM OF THE STUDY: The aim of the current study was the identification of predictors for a successful transfer of progressive relaxation (PR) into clinical and daily life. Furthermore the development of tension-related symptoms dependening of the frequency of continuous practise was detected. METHODS: 411 patients of a psychosomatic rehabilitation clinic attended a 6-h-course of progressive relaxation and were interviewed at 3 different times by a modified version of the "diagnostisches und evaluatives Instrumentarium für Entspannungstraining und Entspannungstherapie (ET-EVA)": at the beginning of therapy (T1), at discharge (T2) and 3 months after discharge by postal service (T3). After 3 months 274 patients (78.3%) sent the completed questionnaires back. The frequency of exercising by at least once a week was defined as successful. To detect the extent of symptom improvement, difference values between the different measuring times and effect sizes were calculated. To identify predictors of the frequency of daily practise, bivariate correlations and linear regression were used. RESULTS: 69.4% of the patients continued the exercises successfully beyond the course. The improved experience of relaxation directly after the program (r=-0.184; p<0.01) had a positive influence on the frequency of practising during hospital stay. 3 months after discharge 50.4% of the participants were practising at least once a week. The frequency of practise during hospital stay (r=0.558; p<0.01) and the experience of relaxation at T3 (r=-0.356; p<0.01) could be identified as predictors of a successful transfer into daily life of progressive relaxation. In the context of the linear regression the effect of the frequency of practise during hospital stay (Beta=0.506; p<0.01) and the experience of relaxation after 3 months (Beta=-0.275; p<0.01) remained significant predictors and explaines 40.9% of the variance. The items of all 6 symptom scales decreased significantly from T1 to T2 (p<0.01) and the feeling of discomfort after 3 months was significantly below the base level of T1 (p<0.01). The patients who practised at least once a week - compared to the not-practising patients - declared significantly less tension-related symptoms at T3 (p<0.01) and could achieve a significantly stronger change of wellbeing and relaxation experience at T2 and T3 (p<0.01). CONCLUSION: 50.4% of the patient implemented the relaxation training in their daily routine. The experienced alteration in terms of self-efficacy plays a meaningful role concerning the frequency of practise in hospital stay and daily routine. In future courses attention should be paid to the initial experience of relaxation. The frequency of practise once a week turned out to be the most effective.

The fate of a normal human cell traversed by a single charged particle.

The long-term "fate" of normal human cells after single hits of charged particles is one of the oldest unsolved issues in radiation protection and cellular radiobiology. Using a high-precision heavy-ion microbeam we could target normal human fibroblasts with exactly one or five carbon ions and measured the early cytogenetic damage and the late behaviour using single-cell cloning. Around 70% of the first cycle cells presented visible aberrations in mFISH after a single ion traversal, and about 5% of the cells were still able to form colonies. In one third of selected high-proliferative colonies we observed clonal (radiation-induced) aberrations. Terminal differentiation and markers of senescence (PCNA, p16) in the descendants of cells traversed by one carbon ion occurred earlier than in controls, but no evidence of radiation-induced chromosomal instability was found. We conclude that cells surviving single-ion traversal, often carrying clonal chromosome aberrations, undergo accelerated senescence but maintain chromosomal stability.

Association of allergic patients' phenotypes with IgE reactivity to recombinant pollen marker allergens.

BACKGROUND: During the last decade allergen molecules from several allergen sources have been produced by recombinant DNA technology. The aim of this study was to investigate whether IgE reactivity to recombinant pollen allergens with broad and narrow cross-reactivity is associated with clinical phenotypes of allergic sensitization. METHODS: Serum IgE reactivity to a panel of six recombinant birch and grass pollen allergens was measured by ELISA in pollen sensitized patients from Central Europe to define groups of patients with exclusive IgE reactivity to rBet v 1, with exclusive reactivity to major grass pollen allergens (rPhl p 1, rPhl p 2, rPhl p 5) and with IgE reactivity to cross-reactive pollen allergens (rBet v 2, rPhl p 7). Patients' clinical phenotypes were recorded. IgE responses to tree, grass and weed pollen as well as plant food extracts were evaluated in vitro by CAP-FEIA and clinical sensitivities were confirmed in vivo by skin prick testing. RESULTS: IgE reactivity to the recombinant major birch pollen allergen, rBet v 1, was associated with sensitization to pollen from birch, taxonomically related trees and to certain plant-derived food. Reactivity to the recombinant timothy grass pollen allergens, rPhl p 1, rPhl p 2, rPhl p 5, indicated sensitization to pollen from grasses. Patients reacting with the highly cross-reactive allergen rPhl p 7 were polysensitized to pollen from unrelated trees, grasses and weeds and rBet v 2-positive patients were polysensitized to pollen and plant-derived food from unrelated plants. CONCLUSIONS: IgE reactivity to recombinant marker allergens is associated with clinical phenotypes of allergic sensitization and may be useful for the selection of treatment strategies.

Molecular characterization of a human immunoglobulin G4 antibody specific for the major birch pollen allergen, Bet v 1.

BACKGROUND: Allergen-specific IgG4 antibodies induced by specific immunotherapy are thought to represent a protective immune response. Objective Our aim was the molecular characterization of a human IgG4 antibody (BAB5) specific for the major birch pollen allergen Bet v 1 that was derived from an immunotherapy-treated patient. METHODS: The cDNA coding for BAB5 was obtained by reverse transcriptase-PCR from the BAB5-producing cell line, compared with the germ line sequences and was expressed as a soluble antibody fragment in Escherichia coli. The epitope specificity and cross-reactivity of BAB5 were investigated with recombinant and synthetic Bet v 1 fragments and Bet v 1 homologous allergens from pollen. The ability of BAB5 to block allergic patients IgE was determined by competition experiments and sandwich ELISA. RESULTS: BAB5 is an affinity-matured Bet v 1-specific IgG4 antibody that reacts exclusively with Bet v 1 but not with Bet v 1-related allergens. Unlike an earlier-described monoclonal IgG1-blocking antibody, BAB1, which had been isolated from the same patient, BAB5 did not block allergic patients' IgE reactivity to Bet v 1. CONCLUSION: Our study demonstrates that not all allergen-specific IgG antibodies inhibit IgE recognition of allergens and can contribute to the success of immunotherapy. The epitope specificity and affinity of IgG antibodies but not their isotype are decisive for their protective activity.

[Nora's lesion at the second metacarpal bone of a twelve-year-old female]. / Der interessante Fall: Nora-Läsion am Os metacarpale II eines zwölfjährigen Mädchens.

The extremely rare condition of bizarre parosteal osteochondromatous proliferation (BPOP) was first described in 1983 by the pathologist Nora, and a few more than 100 cases have since been reported. The lesion is defined as a reactive heterotopic ossification and is mostly found in the hands or feet of adults in the third decade of life, although it has also been described in long bones and in other age groups. A high rate of local recurrence of up to 50 % has been noted, but the lesion is benign and does not metastasise. An association with chromosomal rearrangements has recently been described. We here report the case of a 12-year-old girl with a BPOP at the second metacarpal bone, thus at an unusual age. The lesion was marginally resected after biopsy, but recurred locally within 2 years, resulting in subtotal resection of the second metacarpal bone, autologous fibula grafting and temporary external fixation. The clinical, plain radiographic and MRI appearance of the lesion and the prominent histological findings are described, and the difficulties in establishing the correct diagnosis in cases of BPOP are discussed.

Non-anaphylactic surface-exposed peptides of the major birch pollen allergen, Bet v 1, for preventive vaccination.

BACKGROUND: Almost 100 million allergic patients are sensitized to the major birch pollen allergen, Bet v 1, a 17 kDa protein containing most of the IgE epitopes present in pollens of trees belonging to the Fagales order and plant-derived food. OBJECTIVE: Our aim was to develop an approach for the rational design of B cell epitope-derived, non-allergenic peptide allergy vaccines. METHODS: According to the three-dimensional (3-D) structure of birch pollen allergen, Bet v 1, six peptides comprising 25-32 preferably solvent-exposed amino acids were synthesized. RESULTS: Because of lack of secondary structure, the peptides showed no allergenic activity in allergic patients. In a mouse model of birch pollen allergy, peptide vaccination induced Bet v 1-specific IgG and prevented IgE-mediated allergic sensitization to Bet v 1. The protective role of peptide-induced blocking antibodies is demonstrated by inhibition of allergic patients IgE binding to the allergen and by blocking of allergen-induced basophil degranulation. CONCLUSION: Our results indicate the mechanistic importance of blocking antibodies for allergy vaccination and present a B cell epitope-based approach for the rational design of safe peptide allergy vaccines whenever the structure of the disease-eliciting allergen is known.

Component-resolved diagnosis of house-dust mite allergy with purified natural and recombinant mite allergens.

BACKGROUND: Mites belong to the most frequent and potent allergen sources. Immunotherapy with mite allergen extracts is frequently performed if allergen avoidance is not possible or successful. However, highly controversial results have been reported for mite-specific immunotherapy. OBJECTIVE: The aim of this study was to develop diagnostic concepts that may contribute to an improved selection of patients for immunotherapy with Der p allergen extracts and that may be used for immunological monitoring of patients undergoing this treatment. METHODS: The IgE reactivity profiles to Der p extract were determined in a Middle European mite-allergic population by IgE immunoblotting and by using a panel of seven purified natural or recombinant Der p allergens (nDer p 1, nDer p 4, rDer p 2, rDer p 5, rDer p 7, rDer p 8, rDer p 10). Furthermore, we investigated the sensitization and cross-reactivity to house-dust- and storage-mite allergen extracts by CAP FEIA measurements and by IgE competition studies. RESULTS: More than 95% of the patients could be diagnosed with a combination of nDer p 1 and rDer p 2. With the methods used, we could discriminate mite-allergic patients who were mainly sensitized to the major Der p allergens (Der p 1, Der p 2) from patients with a broad sensitization profile, including highly cross-reactive allergens (e.g. Der p 10: tropomyosin) as well as reactivity to storage mites. CONCLUSIONS: Diagnostic tests containing the major mite allergens (i.e. Der p 1, Der p 2) and highly cross-reactive mite allergens (e.g. Der p 10) may improve the diagnostic selection of patients for immunotherapy with Der p extracts. These tests may also be used for the immunological monitoring of patients undergoing immunotherapy.

Vaccines for birch pollen allergy based on genetically engineered hypoallergenic derivatives of the major birch pollen allergen, Bet v 1.

BACKGROUND: We have recently engineered recombinant derivatives of the major birch pollen allergen Bet v 1 (rBet v 1 fragments and trimer) with strongly reduced allergenic activity. OBJECTIVE: The aim of this study was the in vivo characterization of potential allergy vaccines based on Al(OH)3-adsorbed genetically modified rBet v 1 derivatives in mice. METHODS: BALB/c mice were immunized either with courses of nine injections of increasing doses of Al(OH)3-adsorbed rBet v 1 wild-type, rBet v 1 fragments, rBet v 1 trimer or Al(OH)3 alone in weekly intervals or with three high-dose injections applied in intervals of 3 weeks. Humoral immune responses to rBet v 1 wild-type and homologous plant allergens were measured by ELISA and Western blotting, and the ability of mouse antibodies to inhibit the binding of allergic patients IgE to Bet v 1 was studied by ELISA competition experiments. RESULTS: In both schemes, hypoallergenic rBet v 1 derivatives induced low IgE but high IgG1 responses against rBet v 1 wild-type. The IgG1 antibodies induced by genetically modified rBet v 1 derivatives cross-reacted with natural Bet v 1 and its homologues from alder (Aln g 1) as well as hazel (Cor a 1) and strongly inhibited the binding of birch pollen allergic patients' IgE to Bet v 1 wild-type. CONCLUSION: Genetically modified hypoallergenic rBet v 1 derivatives induce blocking antibodies in vivo. Their safety and efficacy for the treatment of birch pollen and associated plant allergies can now be evaluated in clinical immunotherapy studies.

Allergen-specific immunotherapy with a monophosphoryl lipid A-adjuvanted vaccine: reduced seasonally boosted immunoglobulin E production and inhibition of basophil histamine release by therapy-induced blocking antibodies.

BACKGROUND: Allergen-specific immunotherapy represents a causal form of treatment for IgE-mediated allergies. The allergen extract-based analyses of immunotherapy-induced effects yielded highly controversial results regarding a beneficial role of therapy-induced IgG antibodies. OBJECTIVE: We analysed allergen-specific IgE, IgG subclass, and IgM responses in patients treated with a grass pollen allergy vaccine adjuvanted with monophosphoryl lipid A (MPL), a Th1-inducing agent, and in a placebo group using recombinant timothy grass pollen allergen molecules (rPhl p 1, rPhl p 2, rPhl p 5). RESULTS: The strong induction of allergen-specific IgG1 and IgG4 antibodies observed only in the actively treated group was associated with significant clinical improvement. Therapy-induced allergen-specific IgM and IgG2 responses were also noted in several actively treated patients. An inhibition of allergen-dependent basophil histamine release was only obtained with sera containing therapy-induced allergen-specific IgG, but not with sera obtained before therapy or from placebo-treated patients. Moreover, patients with therapy-induced allergen-specific IgG antibodies showed a reduced induction of allergen-specific IgE responses during seasonal grass pollen exposure. CONCLUSION: Successful immunotherapy with the MPL-adjuvanted grass pollen allergy vaccine is associated with the production of allergen-specific IgG antibodies. These blocking antibodies may have protective effects by inhibiting immediate-type reactions and systemic increases of IgE responses caused by seasonal allergen exposure.

Induction of mucosal tolerance with recombinant Hev b 1 and recombinant Hev b 3 for prevention of latex allergy in BALB/c mice.

The prevalence of type I allergy to Hevea brasiliensis latex is particularly high among individuals with frequent exposure to latex products, such as health-care workers (HCW) and patients with spina bifida (SB). Treatment of latex allergy seems problematic as preventive measures, such as allergen avoidance, are not always possible and conventional immunotherapy with standardized latex extracts is not performed routinely. Thus, the aim of the present study was to establish a mouse model of latex allergy using two major latex allergens for HCWs and SB patients, Hev b 1 and Hev b 3, for sensitization. Prophylactic measures on the basis of mucosal tolerance induction with the recombinant allergens were tested in this model. Female BALB/c mice immunized intraperitoneally with recombinant (r)Hev b 1 or rHev b 3 displayed strong immune responses in vivo and in vitro. Intranasal treatment with rHev b 1 and rHev b 3 prior to sensitization led to reduced allergen-specific IgG1/IgE levels and significantly suppressed allergen-induced basophil degranulation. Moreover, lymphocyte proliferation and cytokine production (IL-4, IL-5, IFN-gamma) in vitro were significantly suppressed after pretreatment with both allergens. Suppressive cytokines, such as interleukin (IL)-10 and transforming growth factor (TGF)-beta, remained unchanged after the intranasal pretreatment, indicating mechanism of anergy rather than active immunosuppression. Taken together, these results suggest that mucosal tolerance induction with recombinant allergens could present a promising prevention strategy against latex allergy.

Microarrayed recombinant allergens for diagnosis of allergy.

We suggest that the coapplication of recombinant allergens and microarray technology can lead to the development of new forms of multi-allergen tests which allow the determining and monitoring of complex sensitization profiles of allergic patients in single assays. The allergen extracts which have so far been used for diagnosis only allowed the determining of whether an allergic patient is sensitized against a particular allergen source, but the disease-eliciting allergens could not be identified. Through the application of recombinant DNA technology a rapidly growing panel of recombinant allergen molecules has become available which meanwhile comprises the epitope spectrum of most of the important allergen sources. We demonstrate that microarray technology can be used to establish multi-allergen tests consisting of microarrayed recombinant allergen molecules. Microarrayed recombinant allergens can be used to determine and monitor the profile of disease-eliciting allergens using single tests that require minute amounts of serum from allergic patients. The wealth of diagnostic information gained through microarray-based allergy testing will likely improve diagnosis, prevention and treatment of allergy.