Prophylactic and therapeutic activity of fully human monoclonal antibodies directed against Influenza A M2 protein

Influenza virus infection is a prevalent disease in humans. Antibodies against hemagglutinin have been shown to prevent infection and hence hemagglutinin is the major constituent of current vaccines. Antibodies directed against the highly conserved extracellular domain of M2 have also been shown to mediate protection against Influenza A infection in various animal models. Active vaccination is generally considered the best approach to combat viral diseases. However, passive immunization is an attractive alternative, particularly in acutely exposed or immune compromized individuals, young children and the elderly. We recently described a novel method for the rapid isolation of natural human antibodies by mammalian cell display. Here we used this approach to isolate human monoclonal antibodies directed against the highly conserved extracellular domain of the Influenza A M2 protein. The identified antibodies bound M2 peptide with high affinities, recognized native cell-surface expressed M2 and protected mice from a lethal influenza virus challenge. Moreover, therapeutic treatment up to 2 days after infection was effective, suggesting that M2-specific monoclonals have a great potential as immunotherapeutic agents against Influenza infection

MessageVortex Transport Independent, Unobservable, and Unlinkable Messaging

In this thesis, we introduce an unobservable message anonymization protocol named MessageVortex. It is based on the zero-trust principle, has a distributed peer-to-peer (P2P) architecture, and avoids central aspects such as fixed infrastructures within a global network. It scores over existing work by blending its traffic into suitable standard transport protocols like SMTP, making it next to impossible to block it without significantly affecting regular users of the transport medium. No additional protocol-specific infrastructure is required in public networks and allows a sender to control all aspects of a message, such as the degree of anonymity, timing, and redundancy of the message transport, without disclosing any of these details to routing or transporting nodes. We have made our prototype implementation publicly available and added an RFC-style document that contains all necessary information to build a MessageVortex node, see https://messagevortex.net/

O2 permeability of additively manufactured silicone membranes

Silicone is already widely used in biomedical applications thanks to its outstanding properties. Now additive manufacturing (AM) of silicone can achieve submillimeter details and is offered by SpectroPlast AG as a service. AM of silicone is particularly interesting for designs with complex internal structures such as bioreactors or oxygenators where oxygen permeability is important. Therefore, the oxygen permeability of additively manufactured silicone membranes made from TrueSil (SpectroPlast AG) is studied. Measurements are performed with two membrane thicknesses (0.5 and 0.8 mm) and four different Shore hardnesses (20A, 35A, 50A, and 60A) at 15, 20, and 25°C. The oxygen increase due to diffusion through the membrane is recorded In a cup sealed by the membrane. The oxygen permeability decreases with increasing Shore hardness. TrueSil 20A is comparable to ELASTOSIL® Film (Wacker Chemie AG) in terms of oxygen permeability. However, there is a percentage difference of approximately 27% between the measured permeability of ELASTOSIL® and the data from the supplier. Membrane thickness does not affect permeability, but the Shore hardness affects the thickness. Membranes with Shore hardness 20A or 35A are manufactured over 0.1 mm thicker than designed, while for Shore hardness 50A and 60A the deviation from the design is less than 0.04 mm.ISSN:1097-4628ISSN:0021-899

Isolation of human monoclonal antibodies by mammalian cell display

Due to their low immunogenicity in patients, humanized or fully human mAbs are becoming increasingly important for the treatment of a growing number of diseases, including cancer, infections, and immune disorders. Here, we describe a technology allowing for the rapid isolation of fully human mAbs. In contrast to previously described methods, B cells specific for an antigen of interest are directly isolated from peripheral blood mononuclear cells (PBMC) of human donors. Recombinant, antigen-specific single-chain Fv (scFv) libraries are generated from this pool of B cells and screened by mammalian cell surface display by using a Sindbis virus expression system. This method allows isolating antigen-specific antibodies by a single round of FACS. The variable regions (VRs) of the heavy chains (HCs) and light chains (LCs) are isolated from positive clones and recombinant fully human antibodies produced as whole IgG or Fab fragments. In this manner, several hypermutated high-affinity antibodies binding the Qβ virus like particle (VLP), a model viral antigen, as well as antibodies specific for nicotine were isolated. All antibodies showed high expression levels in cell culture. The human nicotine-specific mAbs were validated preclinically in a mouse model. Thus, the technology presented here allows for rapid isolation of high-affinity, fully human antibodies with therapeutic potential from human volunteers

Secretory phospholipase A2-IID is an effector molecule of CD4+CD25+ regulatory T cells

Suppression by natural CD4+CD25+ regulatory T cells (Tregs) is one mechanism by which tolerance is maintained. However, the way in which Tregs mediate suppression is not well understood. Here, we show that secreted phospholipase A2 (sPLA2)-IID is selectively produced by Tregs. sPLA2-IID is a potent mediator of Treg function, because it strongly suppressed proliferation of CD4+ and CD8+ T cells in vitro and in vivo in a manner independent of its catalytic activity. Furthermore, sPLA2-IID promoted the differentiation of Tregs, presumably via attenuating signaling through the PI3K/Akt/mammalian target of rapamycin pathway. Importantly, administration of a sPLA2-IID-Fc fusion protein inhibited disease development in murine models of colitis and multiple sclerosis, suggesting that sPLA2-IID's immunosuppressive function might be exploited therapeutically