A Novel System for the Efficient Generation of Antibodies Following Immunization of Unique Knockout Mouse Strains

International audienceBACKGROUND: We wished to develop alternate production strategies to generate antibodies against traditionally problematic antigens. As a model we chose butyrylcholinesterase (BChE), involved in termination of cholinergic signaling, and widely considered as a poor immunogen. METHODOLOGY/PRINCIPAL FINDINGS: Jettisoning traditional laborious in silico searching methods to define putative epitopes, we simply immunized available BChE knock-out mice with full-length recombinant BChE protein (having been produced for crystallographic analysis). Immunization with BChE, in practically any form (recombinant human or mouse BChE, BChE purified from human serum, native or denatured), resulted in strong immune responses. Native BChE produced antibodies that favored ELISA and immunostaining detection. Denatured and reduced BChE were more selective for antibodies specific in Western blots. Two especially sensitive monoclonal antibodies were found capable of detecting 0.25 ng of BChE within one min by ELISA. One is specific for human BChE; the other cross-reacts with mouse and rat BChE. Immunization of wild-type mice served as negative controls. CONCLUSIONS/SIGNIFICANCE: We examined a simple, fast, and highly efficient strategy to produce antibodies by mining two expanding databases: namely those of knock-out mice and 3D crystallographic protein-structure analysis. We conclude that the immunization of knock-out mice should be a strategy of choice for antibody production

Chlamydia trachomatis Co-opts the FGF2 Signaling Pathway to Enhance Infection

The molecular details of Chlamydia trachomatis binding, entry, and spread are incompletely understood, but heparan sulfate proteoglycans (HSPGs) play a role in the initial binding steps. As cell surface HSPGs facilitate the interactions of many growth factors with their receptors, we investigated the role of HSPG-dependent growth factors in C. trachomatis infection. Here, we report a novel finding that Fibroblast Growth Factor 2 (FGF2) is necessary and sufficient to enhance C. trachomatis binding to host cells in an HSPG-dependent manner. FGF2 binds directly to elementary bodies (EBs) where it may function as a bridging molecule to facilitate interactions of EBs with the FGF receptor (FGFR) on the cell surface. Upon EB binding, FGFR is activated locally and contributes to bacterial uptake into non-phagocytic cells. We further show that C. trachomatis infection stimulates fgf2 transcription and enhances production and release of FGF2 through a pathway that requires bacterial protein synthesis and activation of the Erk1/2 signaling pathway but that is independent of FGFR activation. Intracellular replication of the bacteria results in host proteosome-mediated degradation of the high molecular weight (HMW) isoforms of FGF2 and increased amounts of the low molecular weight (LMW) isoforms, which are released upon host cell death. Finally, we demonstrate the in vivo relevance of these findings by showing that conditioned medium from C. trachomatis infected cells is enriched for LMW FGF2, accounting for its ability to enhance C. trachomatis infectivity in additional rounds of infection. Together, these results demonstrate that C. trachomatis utilizes multiple mechanisms to co-opt the host cell FGF2 pathway to enhance bacterial infection and spread

Nonlinearity and Topology

The interplay of nonlinearity and topology results in many novel and emergent properties across a number of physical systems such as chiral magnets, nematic liquid crystals, Bose-Einstein condensates, photonics, high energy physics, etc. It also results in a wide variety of topological defects such as solitons, vortices, skyrmions, merons, hopfions, monopoles to name just a few. Interaction among and collision of these nontrivial defects itself is a topic of great interest. Curvature and underlying geometry also affect the shape, interaction and behavior of these defects. Such properties can be studied using techniques such as, e.g. the Bogomolnyi decomposition. Some applications of this interplay, e.g. in nonreciprocal photonics as well as topological materials such as Dirac and Weyl semimetals, are also elucidated

Dendritic cells in cancer immunology and immunotherapy

Dendritic cells (DCs) are a diverse group of specialized antigen-presenting cells with key roles in the initiation and regulation of innate and adaptive immune responses. As such, there is currently much interest in modulating DC function to improve cancer immunotherapy. Many strategies have been developed to target DCs in cancer, such as the administration of antigens with immunomodulators that mobilize and activate endogenous DCs, as well as the generation of DC-based vaccines. A better understanding of the diversity and functions of DC subsets and of how these are shaped by the tumour microenvironment could lead to improved therapies for cancer. Here we will outline how different DC subsets influence immunity and tolerance in cancer settings and discuss the implications for both established cancer treatments and novel immunotherapy strategies.S.K.W. is supported by a European Molecular Biology Organization Long- Term Fellowship (grant ALTF 438– 2016) and a CNIC–International Postdoctoral Program Fellowship (grant 17230–2016). F.J.C. is the recipient of a PhD ‘La Caixa’ fellowship. Work in the D.S. laboratory is funded by the CNIC, by the European Research Council (ERC Consolidator Grant 2016 725091), by the European Commission (635122-PROCROP H2020), by the Ministerio de Ciencia, Innovación e Universidades (MCNU), Agencia Estatal de Investigación and Fondo Europeo de Desarrollo Regional (FEDER) (SAF2016-79040-R), by the Comunidad de Madrid (B2017/BMD-3733 Immunothercan- CM), by FIS- Instituto de Salud Carlos III, MCNU and FEDER (RD16/0015/0018-REEM), by Acteria Foundation, by Atresmedia (Constantes y Vitales prize) and by Fundació La Marató de TV3 (201723). The CNIC is supported by the Instituto de Salud Carlos III, the MCNU and the Pro CNIC Foundation, and is a Severo Ochoa Centre of Excellence (SEV-2015-0505).S

Intellectual Disability and Epilepsy

This book also acknowledges that the impact on the person and on their carers always needs to be taken into account, with treatment programs established with a multi-faceted team approach in mind

Hairy cell leukemia: Clinical, pathological and ultrastructural findings in Asian-Indians

Background: Hairy-cell leukemia (HCL), lymphoproliferative disease of older age, is characterized by projections from surface of abnormal cells. Aim: The aim was to study the clinical presentation and ultrastructural changes in hairy cells (HCs) following cladribine treatment. Settings and Design: Clinical presentation, peripheral smear, bone marrow aspiration and biopsy of HCL cases diagnosed over a period of three years were reviewed. Materials and Methods: Consecutive HCL cases in Hematology clinic of a tertiary care center were enrolled. Tartarate-resistant acid phosphatase (TRAP) test was done to detect HCs and electron microscopy was done to demonstrate initial ultrastructural changes and alterations following cladribine therapy. Results: Fifteen cases of HCL, aged 32-57 years (median 47 years) were studied. The clinical presentation included splenomegaly in 15 (100%), fever in 10 (67%), hepatomegaly and pain abdomen in eight (53%), fatigue in nine (60 %) cases. The commonest laboratory features were monocytopenia in 13 (87%), neutropenia in 12 (80%), anemia in 10 (67 %) and pancytopenia in nine (60%). All patients showed symptomatic improvement on cladribine therapy. Electron microscopy after treatment (three months) showed loss of the finger like projections, characteristic bald lymphocytes, loss of ribosomal lamellar complexes, as well as decrease in mitochondria and vacuoles. Conclusions: Indian patients with HCL are younger. Cladribine is an effective therapy for these patients and leads to complete response in most of the patients. There is a significant improvement in the ultrastructural features following cladribine therapy