Immune-Mobilizing Monoclonal T Cell Receptors Mediate Specific and Rapid Elimination of Hepatitis B-Infected Cells.

BACKGROUND AND AIMS: Therapies for chronic hepatitis B virus (HBV) infection are urgently needed because of viral integration, persistence of viral antigen expression, inadequate HBV-specific immune responses, and treatment regimens that require lifelong adherence to suppress the virus. Immune mobilizing monoclonal T Cell receptors against virus (ImmTAV) molecules represent a therapeutic strategy combining an affinity-enhanced T Cell receptor with an anti-CD3 T Cell-activating moiety. This bispecific fusion protein redirects T cells to specifically lyse infected cells expressing the target virus-derived peptides presented by human leukocyte antigen (HLA). APPROACH AND RESULTS: ImmTAV molecules specific for HLA-A*02:01-restricted epitopes from HBV envelope, polymerase, and core antigens were engineered. The ability of ImmTAV-Env to activate and redirect polyclonal T cells toward cells containing integrated HBV and cells infected with HBV was assessed using cytokine secretion assays and imaging-based killing assays. Elimination of infected cells was further quantified using a modified fluorescent hybridization of viral RNA assay. Here, we demonstrate that picomolar concentrations of ImmTAV-Env can redirect T cells from healthy and HBV-infected donors toward hepatocellular carcinoma (HCC) cells containing integrated HBV DNA resulting in cytokine release, which could be suppressed by the addition of a corticosteroid in vitro. Importantly, ImmTAV-Env redirection of T cells induced cytolysis of antigen-positive HCC cells and cells infected with HBV in vitro, causing a reduction of hepatitis B e antigen and specific loss of cells expressing viral RNA. CONCLUSIONS: The ImmTAV platform has the potential to enable the elimination of infected cells by redirecting endogenous non-HBV-specific T cells, bypassing exhausted HBV-specific T cells. This represents a promising therapeutic option in the treatment of chronic hepatitis B, with our lead candidate now entering trials.

Regional differences in medical needs and care for skin cancer across Bavaria: confronting the gap.

BACKGROUND: The management of keratinocyte carcinoma (KC) and actinic keratosis (AK) as well as the number of dermatologists differ across the Bavarian counties in Germany. OBJECTIVES: To determine regions with low utilization rates of dermatological care and a high medical need due to AK and KC burden. MATERIALS AND METHODS: A cross-sectional study of 2,483 people was carried out during the Munich Oktoberfest in September 2016. Participants from urban, semi-urban and rural areas completed a questionnaire and received a medical examination on site by dermatologists. RESULTS: The rate of previous skin cancer screening and previous treatment by dermatologists ranged from 18.8% to 58.6% and from 34.3% to 75.4% for all regions, respectively. Over 60% of people living in the environs or rural areas would consult a dermatologist first if they found a visible skin condition. Thus, people living in urban areas were twice as likely as people living in rural areas to consult a dermatologist first (odds ratio = 2.16; 95% CI: 1.38-3.39). Comparing the three different locations, dermatologists detected the highest AK burden among people living in rural areas (27.3% of the participants) and the highest KC burden among people living in urban areas (3.4% of the participants). CONCLUSION: In rural areas, a high AK burden coupled with a low utilization rate of dermatological care was observed. To effectively address these problems, a broader implementation of alternative medical resources, such as teledermatology, might improve access to health care.

[New perspectives on health prevention. Prevalence of hypertension, hypacusis and balance disorders at the Munich Oktoberfest 2016]. / Neue Perspektiven zur Gesundheitsprävention : Prävalenz von Hypertonie, Hypakusis und Gleichgewichtsstörungen beim Münchner Oktoberfest.

BACKGROUND: The prevalence of hypertension, hypacusis and balance disorders will increase due to demographic change and thus represent an increasing public health problem. OBJECTIVE: To determine the point prevalence of the diseases in focus outside the classical medical setting. METHOD: At the "Bavarian Central Agriculture Festival", on the margins of the Oktoberfest 2016, visitors were offered a free health check with three health stations (blood pressure measurement, hearing test, balance test). By means of standardized examinations, the prevalence of the diseases was recorded. RESULTS: 1,727 people participated in the blood pressure measurement, 510 in the hearing test and 1,320 in the balance test. At all study sites, an increase in prevalence was observed with increasing age. Overall, the prevalence of hypertensive blood pressure values (> 140/> 90 mmHg) was 23.6%, with a high rate of 30.8% among over-65s. In the hearing test, 41.6% of all participants had a low-grade (20-40 dB) and 15.5% a higher-grade (> 40 dB) hypacusis. A balance value in the normal range was achieved by only 25.2% of the participants. CONCLUSION: The prevalence of the investigated diseases was very high, especially older men were more often affected by these health problems. Overall, there is a large primary and secondary prevention potential for the prevention and early treatment of the diseases. In order to increase the use, it would be possible in particular to consider expanding access to prevention programs outside of classic medical settings.

Nonmelanoma skin cancer in mountain guides: high prevalence and lack of awareness warrant development of evidence-based prevention tools.

AIMS OF THE STUDY: Nonmelanoma skin cancer (NMSC) is the most common cancer in Switzerland and Europe. The main causative factor is exposure to ultraviolet radiation, which puts outdoor workers in general at a higher risk of developing NMSC than indoor workers. However, few studies have clinically examined the risk of developing NMSC to outdoor workers, especially mountain guides. We aimed to investigate the prevalence of NMSC and corresponding precancerous lesions, and the associated risk behaviour of mountain and ski guides in order to develop future prevention programmes. METHODS: We conducted a cross-sectional study including mountain and ski guides from southern Germany, who underwent a full-body skin check-up by a dermatologist. We assessed their NMSC awareness and risk behaviour using a paper-based questionnaire. RESULTS: Of the 62 state-certified mountain and ski guides (55 men, 7 women; mean age 52.9 ± 13.4 years) included in this study, 27 (43.5%) were diagnosed with NMSC or its premalignant stages. In addition, 59.7% of the participants expressed the opinion that their protection from ultraviolet radiation exposure needs to be improved; 83.6% requested further information on NMSC, and 48.5% had never undergone a skin check-up or consulted a dermatologist before. CONCLUSIONS: Mountain and ski guides are at a high risk for developing NMSC. Their unmet medical needs indicate an underestimation of NMSC prevalence, which is usually based on reports by insurance companies, and offer the chance for developing evidence-based awareness and prevention tools that can be promoted to individuals with other outdoor jobs.

Structural mechanism of ATP-dependent DNA binding and DNA end bridging by eukaryotic Rad50.

The Mre11-Rad50-Nbs1 (MRN) complex is a central factor in the repair of DNA double-strand breaks (DSBs). The ATP-dependent mechanisms of how MRN detects and endonucleolytically processes DNA ends for the repair by microhomology-mediated end-joining or further resection in homologous recombination are still unclear. Here, we report the crystal structures of the ATPγS-bound dimer of the Rad50(NBD)(nucleotide-binding domain) from the thermophilic eukaryote Chaetomium thermophilum(Ct) in complex with either DNA or CtMre11(RBD)(Rad50-binding domain) along with small-angle X-ray scattering and cross-linking studies. The structure and DNA binding motifs were validated by DNA binding experiments in vitro and mutational analyses in Saccharomyces cerevisiae in vivo Our analyses provide a structural framework for the architecture of the eukaryotic Mre11-Rad50 complex. They show that a Rad50 dimer binds approximately 18 base pairs of DNA along the dimer interface in anATP-dependent fashion or bridges two DNA ends with a preference for 3' overhangs. Finally, our results may provide a general framework for the interaction of ABC ATPase domains of the Rad50/SMC/RecN protein family with DNA.

Targeting IgE in Severe Atopic Dermatitis with a Combination of Immunoadsorption and Omalizumab.

Patients with atopic dermatitis (AD) tend to have greatly elevated levels of serum immunoglobulin E (IgE). However, the role of IgE in the pathogenesis of AD is debated. This investigator-initiated open-label pilot study evaluates an anti-IgE-treatment approach by combining extracorporeal immunoadsorption and anti-IgE antibody omalizumab in 10 patients with severe, therapy-refractory AD. IgE levels decreased after immunoadsorption and decreased continuously in all patients during anti-IgE therapy. The reverse trend was observed during 6 months follow-up without treatment. In parallel with these observations, an improvement in AD was observed during the treatment period, with aggravation during follow-up. Further research is needed, based on the principle of reducing IgE levels in order to improve clinical symptoms, using a combination anti-IgE treatment approach, adjusted according to IgE levels.

Structure of the catalytic domain of Mre11 from Chaetomium thermophilum.

Together with the Rad50 ATPase, the Mre11 nuclease forms an evolutionarily conserved protein complex that plays a central role in the repair of DNA double-strand breaks (DSBs). Mre11-Rad50 detects and processes DNA ends, and has functions in the tethering as well as the signalling of DSBs. The Mre11 dimer can bind one or two DNA ends or hairpins, and processes DNA endonucleolytically as well as exonucleolytically in the 3'-to-5' direction. Here, the crystal structure of the Mre11 catalytic domain dimer from Chaetomium thermophilum (CtMre11(CD)) is reported. CtMre11(CD) crystals diffracted to 2.8 Å resolution and revealed previously undefined features within the dimer interface, in particular fully ordered eukaryote-specific insertion loops that considerably expand the dimer interface. Furthermore, comparison with other eukaryotic Mre11 structures reveals differences in the conformations of the dimer and the capping domain. In summary, the results reported here provide new insights into the architecture of the eukaryotic Mre11 dimer.

Structure of the Rad50 DNA double-strand break repair protein in complex with DNA.

The Mre11-Rad50 nuclease-ATPase is an evolutionarily conserved multifunctional DNA double-strand break (DSB) repair factor. Mre11-Rad50's mechanism in the processing, tethering, and signaling of DSBs is unclear, in part because we lack a structural framework for its interaction with DNA in different functional states. We determined the crystal structure of Thermotoga maritima Rad50(NBD) (nucleotide-binding domain) in complex with Mre11(HLH) (helix-loop-helix domain), AMPPNP, and double-stranded DNA. DNA binds between both coiled-coil domains of the Rad50 dimer with main interactions to a strand-loop-helix motif on the NBD. Our analysis suggests that this motif on Rad50 does not directly recognize DNA ends and binds internal sites on DNA. Functional studies reveal that DNA binding to Rad50 is not critical for DNA double-strand break repair but is important for telomere maintenance. In summary, we provide a structural framework for DNA binding to Rad50 in the ATP-bound state.

Structural studies of DNA end detection and resection in homologous recombination.

DNA double-strand breaks are repaired by two major pathways, homologous recombination or nonhomologous end joining. The commitment to one or the other pathway proceeds via different steps of resection of the DNA ends, which is controlled and executed by a set of DNA double-strand break sensors, endo- and exonucleases, helicases, and DNA damage response factors. The molecular choreography of the underlying protein machinery is beginning to emerge. In this review, we discuss the early steps of genetic recombination and double-strand break sensing with an emphasis on structural and molecular studies.

Structure of Actin-related protein 8 and its contribution to nucleosome binding.

Nuclear actin-related proteins (Arps) are subunits of several chromatin remodelers, but their molecular functions within these complexes are unclear. We report the crystal structure of the INO80 complex subunit Arp8 in its ATP-bound form. Human Arp8 has several insertions in the conserved actin fold that explain its inability to polymerize. Most remarkably, one insertion wraps over the active site cleft and appears to rigidify the domain architecture, while active site features shared with actin suggest an allosterically controlled ATPase activity. Quantitative binding studies with nucleosomes and histone complexes reveal that Arp8 and the Arp8-Arp4-actin-HSA sub-complex of INO80 strongly prefer nucleosomes and H3-H4 tetramers over H2A-H2B dimers, suggesting that Arp8 functions as a nucleosome recognition module. In contrast, Arp4 prefers free (H3-H4)(2) over nucleosomes and may serve remodelers through binding to (dis)assembly intermediates in the remodeling reaction.

Pseudomonas oryzihabitans cutaneous ulceration from Octopus vulgaris bite: a case report and review of the literature.

BACKGROUND: Octopus vulgaris is a common marine animal that can be found in nearly all tropical and semitropical waters around the world. It is a peaceful sea dweller with a parrotlike beak, and its primary defense is to hide through camouflaging adjustments. Bites from animals of the class Cephalopoda are very rare. We describe a boy who was bitten on his forearm by an Octopus vulgaris. OBSERVATION: A 9 -year-old boy was bitten by an Octopus vulgaris while snorkeling. There was no strong bleeding or systemic symptoms; however, 2 days later, a cherry-sized, black, ulcerous lesion developed, surrounded by a red circle that did not heal over months and therefore had to be excised. Histologic examination showed ulceration with extensive necrosis of the dermis and the epidermis. A microbial smear revealed Pseudomonas (formerly known as Flavimonas) oryzihabitans. After excision, the wound healed within 2 weeks, without any complications or signs of infection. CONCLUSIONS: To the best of our knowledge, this case represents the first report of an Octopus vulgaris bite resulting in an ulcerative lesion with slow wound healing owing to P oryzihabitans infection. We recommend greater vigilance regarding bacterial contamination when treating skin lesions caused by marine animals.