Type 2 T-Cell Responses against Distinct Epitopes of the Desmoglein 3 Ectodomain in Pemphigus Vulgaris.

Pemphigus vulgaris (PV) is an autoimmune blistering disorder of the skin and/or mucous membranes caused by IgG autoantibodies that predominantly target two transmembrane desmosomal cadherins: desmoglein (DSG)1 and DSG3. DSG-specific T cells play a central role in PV pathogenesis because they provide help to autoreactive B cells for autoantibody production. In this study, we characterized DSG3-specific peripheral T cells in a cohort of 52 patients with PV and 41 healthy controls with regard to cytokine profile and epitope specificity. By ELISpot analysis, type 2 T cells reactive with the DSG3 ectodomain were significantly increased in patients with PV compared with those in healthy controls. By dextramer analysis, CD4+ T cells specific for an epitope within the extracellular domain of DSG3, DSG3(206-220), were found at significantly higher frequencies in patients with PV than in HLA-matched healthy controls. T-cell recognition of two distinct DSG3 epitopes, that is, DSG3(206-220) and DSG3(378-392), correlated significantly, suggesting a synergistic effect in B-cell help. Immunization of HLA-DRB1∗04:02-transgenic mice with PV with the same set of DSG3 peptides induced pathogenic DSG3-specific IgG antibodies, which induced loss of keratinocyte adhesion in vitro. Thus, DSG3 peptide-specific T cells are of particular interest as surrogate markers of disease activity and potential therapeutic targets in PV.

The Lectin LecB Induces Patches with Basolateral Characteristics at the Apical Membrane to Promote Pseudomonas aeruginosa Host Cell Invasion.

The opportunistic bacterium Pseudomonas aeruginosa can infect mucosal tissues of the human body. To persist at the mucosal barrier, this highly adaptable pathogen has evolved many strategies, including invasion of host cells. Here, we show that the P. aeruginosa lectin LecB binds and cross-links fucosylated receptors at the apical plasma membrane of epithelial cells. This triggers a signaling cascade via Src kinases and phosphoinositide 3-kinase (PI3K), leading to the formation of patches enriched with the basolateral marker phosphatidylinositol (3,4,5)-trisphosphate (PIP3) at the apical plasma membrane. This identifies LecB as a causative bacterial factor for activating this well-known host cell response that is elicited upon apical binding of P. aeruginosa. Downstream from PI3K, Rac1 is activated to cause actin rearrangement and the outgrowth of protrusions at the apical plasma membrane. LecB-triggered PI3K activation also results in aberrant recruitment of caveolin-1 to the apical domain. In addition, we reveal a positive feedback loop between PI3K activation and apical caveolin-1 recruitment, which provides a mechanistic explanation for the previously observed implication of caveolin-1 in P. aeruginosa host cell invasion. Interestingly, LecB treatment also reversibly removes primary cilia. To directly prove the role of LecB for bacterial uptake, we coated bacterium-sized beads with LecB, which drastically enhanced their endocytosis. Furthermore, LecB deletion and LecB inhibition with l-fucose diminished the invasion efficiency of P. aeruginosa bacteria. Taken together, the results of our study identify LecB as a missing link that can explain how PI3K signaling and caveolin-1 recruitment are triggered to facilitate invasion of epithelial cells from the apical side by P. aeruginosa. IMPORTANCE An intriguing feature of the bacterium P. aeruginosa is its ability to colonize highly diverse niches. P. aeruginosa can, besides forming biofilms, also enter and proliferate within epithelial host cells. Moreover, research during recent years has shown that P. aeruginosa possesses many different mechanisms to invade host cells. In this study, we identify LecB as a novel invasion factor. In particular, we show that LecB activates PI3K signaling, which is connected via a positive feedback loop to apical caveolin-1 recruitment and leads to actin rearrangement at the apical plasma membrane. This provides a unifying explanation for the previously reported implication of PI3K and caveolin-1 in host cell invasion by P. aeruginosa. In addition, our study adds a further function to the remarkable repertoire of the lectin LecB, which is all brought about by the capability of LecB to recognize fucosylated glycans on many different niche-specific host cell receptors.

Occipital Nerve Stimulation in Chronic Migraine: The Relationship Between Perceived Sensory Quality, Perceived Sensory Location, and Clinical Efficacy-A Prospective, Observational, Non-Interventional Study.

INTRODUCTION: Occipital nerve stimulation (ONS) is used to treat therapy-resistant chronic migraine. Clinical use has resulted in a wide intraindividual and interindividual variation of clinical efficacy. The aim of this study was to analyze a potential relationship between sociodemographic variables, headache parameters, perceived sensory quality, perceived sensory location, as well as clinical efficacy. METHODS: Thirty-two subjects (21.9% male, mean age 45.77 years) suffering from chronic migraine refractory to other treatment and therefore treated with ONS were included in this study. We used a computer-based imaging method for mapping the ONS-induced perceived sensory location, the perceived spatial sensory field size, as well as the perceived sensory quality in a long-term course over 21 months in weekly time intervals. Additionally, the effect of ONS on the migraine headache was documented weekly by the participants using a verbal rating scale. Over the observation period, a total of 808 individual weekly data sets were recorded and a potential relationship between ONS-induced perceptions and headache parameters could be analyzed. RESULTS: We found that 48.9% of stimulation intervals were reported as effective by patients. Women displayed a significantly higher responder rate than men. The reported effectiveness did not differ depending on age, the average number of migraine days per month, the MIDAS score, or the duration of the migraine disorder prior to ONS treatment. Implantation with trial period led to significantly lower responder rates than without the trial period. The most frequently perceived sensory quality of "tingling" was found significantly more frequently in non-responders than in responders. Responders displayed significantly lower pleasantness scores for their reported perceptions than non-responders. Sensations that were spatially perceived above the line connecting the external acoustic meati with the external occipital protuberance (MOP line) led to patients reporting a positive clinical effect significantly more frequently than sensations spatially perceived below the MOP line. Spatially small fields of sensory perception were correlated with a higher responder rate than those covering broader areas. CONCLUSIONS: The ONS-induced sensory location, the size of the spatial sensory field, as well as the sensory quality are significantly correlated with the reported clinical effectiveness. The results suggest that besides surgical technique, the individual and continuous programming of the stimulation parameters is clinically relevant in increasing the therapeutic effectiveness.

Effect of calcitonin gene-related peptide (-receptor) antibodies in chronic cluster headache: Results from a retrospective case series support individual treatment attempts.

OBJECTIVE: To assess the efficacy of monoclonal antibodies targeting calcitonin gene-related peptide (CGRP) or its receptor in chronic cluster headache (CCH) treatment under real world conditions. BACKGROUND: Calcitonin gene-related peptide has an important pathophysiological role in cluster headache. Although the randomised controlled trial with the calcitonin gene-related peptide antibody galcanezumab was negative, chronic cluster headache patients with insufficient response to other preventive treatments have been receiving individual off-label treatment attempts with calcitonin gene-related peptide-(receptor) antibodies. METHODS: Data from 22 chronic cluster headache patients who received at least one dose of a calcitonin gene-related peptide(-receptor) antibody and recorded attack frequency in a headache diary were retrospectively collected at eight headache centres. RESULTS: The number of previous preventive therapies was 6.5 ± 2.4 (mean ± standard deviation, range: 2-11). The average number of attacks per week was 23.3 ± 16.4 at baseline and significantly decreased by -9.2 ± 9.7 in the first month of treatment with a calcitonin gene-related peptide(-receptor) antibody (p < 0.001). Fifty-five percent of the patients were 50% responders and 36% were 75% responders with respect to attack frequency. Significant reduction of attack frequency started at week 1 (-6.8 ± 2.8 attacks, p < 0.01). Results were corroborated by significant decreases in weekly uses of acute headache medication (-9.8 ± 7.6, p < 0.001) and pain intensity during attacks (-1.2 ± 2.0, numerical rating scale (NRS) [0-10], p < 0.01) in the first month. In months 2 (n = 14) and 3 (n = 10), reduction of attack frequency from baseline was -8.0 ± 8.4 (p = 0.004) and -9.1 ± 10.0 (p = 0.024), respectively. CONCLUSION: Under real-world conditions, individual treatment with calcitonin gene-related peptide(-receptor) antibodies was effective in 55% of our chronic cluster headache patients. This finding supports individual off-label treatment attempts with calcitonin gene-related peptide-(receptor) antibodies in chronic cluster headache patients insufficiently responding to other therapies.

[Modern migraine therapy-interdisciplinary long-term care]. / Moderne Migränetherapie ­ fachübergreifende Versorgung im Langzeitverlauf.

Migraine has a very high lifetime prevalence with a severe illness-related burden. As a result, extensive long-term and regular treatment is required, which cannot be covered solely by neurologists. This is particularly the case for the long-term monitoring of migraine, which often takes place over several decades. The diagnosis is made using the diagnostic criteria of the International Headache Society (ICHD-3) based on the clinical phenotype. Owing to often complex neurological symptoms, a detailed weighing up of the differential diagnoses is required, which calls for specialist neurological expertise. The same is true for follow-up appointments of more complex therapy issues. Acute therapy with antiemetics, analgesics, and triptans can, so long as it is effective and is administered not longer than 10 days per month, be carried out by the general practitioner or specialist in internal medicine. This is also true for medical prophylactic treatment with dietary supplements, antihypertensive drugs, and tricyclic antidepressants. If this therapy is unsuccessful, prophylactic substances must be used that require more specialized knowledge, which is also reflected in the formal prescription requirements. Neurologists and pain therapists should then be involved in the treatment. This is particularly true for the use of Onabotulinumtoxin A and monoclonal CGRP-(receptor)-antibodies.

Pseudomonas aeruginosa lectin LecB inhibits tissue repair processes by triggering ß-catenin degradation.

Pseudomonas aeruginosa is an opportunistic pathogen that induces severe lung infections such as ventilator-associated pneumonia and acute lung injury. Under these conditions, the bacterium diminishes epithelial integrity and inhibits tissue repair mechanisms, leading to persistent infections. Understanding the involved bacterial virulence factors and their mode of action is essential for the development of new therapeutic approaches. In our study we discovered a so far unknown effect of the P. aeruginosa lectin LecB on host cell physiology. LecB alone was sufficient to attenuate migration and proliferation of human lung epithelial cells and to induce transcriptional activity of NF-κB. These effects are characteristic of impaired tissue repair. Moreover, we found a strong degradation of ß-catenin, which was partially recovered by the proteasome inhibitor lactacystin. In addition, LecB induced loss of cell-cell contacts and reduced expression of the ß-catenin targets c-myc and cyclin D1. Blocking of LecB binding to host cell plasma membrane receptors by soluble l-fucose prevented these changes in host cell behavior and signaling, and thereby provides a powerful strategy to suppress LecB function. Our findings suggest that P. aeruginosa employs LecB as a virulence factor to induce ß-catenin degradation, which then represses processes that are directly linked to tissue recovery.

Imaging sensory effects of occipital nerve stimulation: a new computer-based method in neuromodulation.

BACKGROUND: Within the last years, occipital nerve stimulation (ONS) has proven to be an important method in the treatment of severe therapy-resistant neurological pain disorders. The correspondence between lead placement as well as possible stimulation parameters and the resulting stimulation effects remains unclear. OBJECTIVE: The method aims to directly relate the neuromodulatory mechanisms with the clinical treatment results, to achieve insight in the mode of action of neuromodulation, to identify the most effective stimulation sets and to optimize individual treatment effects. METHODS: We describe a new computer-based imaging method for mapping the spatial, cognitive and affective sensory effects of ONS. The procedure allows a quantitative and qualitative analysis of the relationship between lead positioning, the stimulation settings as well as the sensory and clinical stimulation effects. CONCLUSION: A regular mapping of stimulation and sensory parameters allows a coordinated monitoring. The stimulation results can be reviewed and compared with regards to clinical effectiveness.

[Comparison of risk factors and guideline oriented prevention and therapy of diabetic retinopathy between type 2 diabetes patients undergoing laser therapy and type 2 diabetes outpatients]. / Vergleich der Risikoparameter der diabetischen Retinopathie und der leitliniengerechten Prävention für Patienten einer diabetischen Schwerpunktambulanz und eines Lasertherapiezentrums.

PURPOSE: The purpose of this study was the comparison of risk factors for development or progression of diabetic retinopathy in patients with type 2 diabetes between patients of a laser therapy center and a diabetes outpatient clinic. Furthermore, the implementation of the guidelines of the German Diabetic Association for the prevention and therapy of diabetic retinopathy was analysed. PATIENTS AND METHODS: In a prospective study, patients with type 2 diabetes and diabetic retinopathy of the laser therapy center at the ophthalmology department, Leipzig University, were interviewed and examined. Patients of the reference group without diabetic retinopathy were recruited from the diabetes outpatient clinic Leipzig University. RESULTS: Between August 2004 and May 2008, a total of 180 patients with type 2 diabetes were included (48 patients with non-proliferative diabetic retinopathy (NPDR), 59 patients with proliferative diabetic retinopathy (PDR) and 73 patients belonging to the reference group). Patients with diabetic retinopathy had significantly higher mean blood pressures of 112 and 110 mmHg as compared to patients without diabetic retinopathy (96 mmHg). ACE/ AT1-inhibitors were used significantly less by patients with as compared to patients without diabetic retinopathy. Only 37% of patients with diabetic retinopathy were treated according to DDG and ADA guidelines. CONCLUSION: There are striking deficits for the implementation of guideline oriented prevention and therapy of diabetic retinopathy in daily practice. The possible reasons are insufficient compliance of patients who consulted medical advice only when complications of diabetes occurred, the necessary improvement of the medical therapy and the suboptimal cooperation between ophthalmology and diabetes specialists.

Genome-wide association study of migraine implicates a common susceptibility variant on 8q22.1.

Migraine is a common episodic neurological disorder, typically presenting with recurrent attacks of severe headache and autonomic dysfunction. Apart from rare monogenic subtypes, no genetic or molecular markers for migraine have been convincingly established. We identified the minor allele of rs1835740 on chromosome 8q22.1 to be associated with migraine (P = 5.38 × 10⁻9, odds ratio = 1.23, 95% CI 1.150-1.324) in a genome-wide association study of 2,731 migraine cases ascertained from three European headache clinics and 10,747 population-matched controls. The association was replicated in 3,202 cases and 40,062 controls for an overall meta-analysis P value of 1.69 × 10⁻¹¹ (odds ratio = 1.18, 95% CI 1.127-1.244). rs1835740 is located between MTDH (astrocyte elevated gene 1, also known as AEG-1) and PGCP (encoding plasma glutamate carboxypeptidase). In an expression quantitative trait study in lymphoblastoid cell lines, transcript levels of the MTDH were found to have a significant correlation to rs1835740 (P = 3.96 × 10⁻5, permuted threshold for genome-wide significance 7.7 × 10⁻5. To our knowledge, our data establish rs1835740 as the first genetic risk factor for migraine.

Replication study of the insulin receptor gene in migraine with aura.

We performed the first replication study for the reported association of the insulin receptor gene (INSR) with migraine with aura (MA). Two of 35 SNPs (rs1052371 and rs2860174) reached borderline significance (best uncorrected allelic p value of 0.052 for rs2860174) in stage 1 of our study (270 MA patients, 280 controls). As rs2860174 was 1 of the 5 SNPs with prior evidence of association, we also genotyped this SNP in our stage 2 sample (679 MA patients, 368 controls), and it was nonsignificant (allelic p value 0.478). The combined analysis of our samples showed just a nonsignificant trend for rs2860174 (p=0.1). However, the joint analysis of our study and the initial study reporting an association-including 1278 Caucasian MA patients and 1337 Caucasian controls altogether-displayed a significant allelic p value of 0.005. In conclusion, further association studies for rs2860174 with even larger numbers of individuals are required to exclude or confirm definitely a small effect of this SNP on migraine susceptibility.

Genetic association studies of the chromosome 15 GABA-A receptor cluster in migraine with aura.

Recently, a novel susceptibility locus for migraine with aura (MA) on chromosome 15q containing three GABA-A receptor subunits has been identified by linkage analysis in several large pedigrees. To further study the role of this locus in MA etiology we genotyped 56 SNPs capturing the known common haplotype variations of these three candidate genes in a sample comprising 270 MA patients and 273 matched controls. In a single marker analysis, four SNPs displayed nominally significant (P < 0.05) association with MA. However, after permutation-based correction for the number of tests performed, the P-values of these SNPs were non-significant. Furthermore, a replication study of two of these SNPs in a second independent sample of 379 MA patients and 379 controls did not result in a significant finding. We also compared haplotype estimates based on case-control genotypes. Again we could not demonstrate a significant association with the phenotype after correction for multiple testing. In summary, we found no convincing evidence for an involvement of common SNPs at the GABA-A receptor cluster on 15q11-q12 in the pathophysiology of MA.