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Camelidae

The Experts below are selected from a list of 300 Experts worldwide ranked by ideXlab platform

Serge Muyldermans – 1st expert on this subject based on the ideXlab platform

  • Single Domain Antibodies
    Methods Mol Biol, 2012
    Co-Authors: Aurelien Olichon, Ario De Marco, Cécile Vincke, Serge Muyldermans

    Abstract:

    The preparation of antibody libraries starting from lymphocytes recovered from immunized members of the Camelidae enables to collect binders that underwent somatic maturation. However, the time and costs necessary to prepare a library for each new antigen may urge to look for alternatives such as those offered by large one-pot libraries. Here we describe how to obtain a suitable naïve library using material from nonimmunized llamas. Despite the lack of somatic maturation, the selection based on phage display allowed to isolate from such naïve libraries VHHs with af fi nity in the subnanomolar range and suitable for the standard immunoapplications.

  • Antibody repertoire development in camelids
    Developmental and Comparative Immunology, 2006
    Co-Authors: Erwin De Genst, Dirk Saerens, Serge Muyldermans, Katja Conrath

    Abstract:

    The humoral immune response of the Camelidae is unique as these animals are the only known mammals that seem to possess functional homodimeric heavy-chain antibodies besides the classical heteromeric antibodies composed of heavy (H) and light (L) chains. By definition, the heavy-chain antibodies lack the L-chain, and it was noticed that their H-chain is devoid of the typical first constant domain (CH1) and contains a dedicated variable domain, referred to as VHH. The VHH exon is assembled from separate V-D-J gene segments. The recombined VHH region is subjected to somatic hypermutations; however, the timing and actual mechanism of the class switch from μ to the dedicated γ-isotype remains elusive. Interestingly, antigen-specific VHHs are easily retrieved after panning of a phage-displayed rearranged V-gene pool cloned from an immunised camelid. These single-domain antigen binding entities possess a number of biophysical properties that offer particular advantages in various medical and biotechnological applications. © 2005 Elsevier Ltd. All rights reserved.

  • emergence and evolution of functional heavy chain antibodies in Camelidae
    Developmental and Comparative Immunology, 2003
    Co-Authors: Katja Conrath, Serge Muyldermans, Ulrich Wernery, Viet Khong Nguyen

    Abstract:

    Antibodies of jawed-vertebrates are composed of paired heavy (H) and light (L) polypeptide chains. Surprisingly, the sera of camelids, nurse shark and wobbegong shark, and possibly ratfish contain antibodies that lack L-chains. In camelids, these Heavy-chain antibodies (HCAbs) are γ-isotypes, and are functional in antigen binding. In this review we focus on the dedicated immunoglobulin (Ig) genes that encode the HCAb in Camelidae (camels, dromedaries and llamas), about their origin, and how these camel immunoglobulins evolved and acquire a large and diverse repertoire of antigen binding sites in absence of the H–L combinatorial diversity.

Ario Marco – 2nd expert on this subject based on the ideXlab platform

  • Molecular dynamics simulations and docking enable to explore the biophysical factors controlling the yields of engineered nanobodies
    Scientific Reports, 2016
    Co-Authors: Miguel A. Soler, Ario Marco, Sara Fortuna

    Abstract:

    Nanobodies (VHHs) have proved to be valuable substitutes of conventional antibodies for molecular recognition. Their small size represents a precious advantage for rational mutagenesis based on modelling. Here we address the problem of predicting how Camelidae nanobody sequences can tolerate mutations by developing a simulation protocol based on all-atom molecular dynamics and whole-molecule docking. The method was tested on two sets of nanobodies characterized experimentally for their biophysical features. One set contained point mutations introduced to humanize a wild type sequence, in the second the CDRs were swapped between single-domain frameworks with Camelidae and human hallmarks. The method resulted in accurate scoring approaches to predict experimental yields and enabled to identify the structural modifications induced by mutations. This work is a promising tool for the in silico development of single-domain antibodies and opens the opportunity to customize single functional domains of larger macromolecules.

  • bacterial cytoplasm as an effective cell compartment for producing functional vhh based affinity reagents and Camelidae igg like recombinant antibodies
    Microbial Cell Factories, 2014
    Co-Authors: Selma Djender, Aurelie Schneider, Anne Beugnet, Ronan Crepin, Klervi E. Desrumeaux, Chiara Romani, Sandrine Moutel, Franck Perez, Ario Marco

    Abstract:

    Background: The isolation of recombinant antibody fragments from displayed libraries represents a powerful alternative to the generation of IgGs using hybridoma technology. The selected antibody fragments can then be easily engineered into (multi)-tagged constructs of variable mass and complexity as well as reconstituted into Camelidae IgG-like molecules when expressed fused to Fc domains. Nevertheless, all antibody constructs depend on an oxidizing environment for correct folding and consequently still belong to the proteins difficult to express in bacteria. In such organisms they are mostly produced at low yields in the periplasmic space. Results: We demonstrate that fusion constructs of recombinant antibodies in combination with multiple tags can be produced at high yields and totally functional in the cytoplasm of bacteria expressing sulfhydryl oxidase. The method was applied to structurally demanding molecules such as VHHs fused to SNAP and Fc domains and was validated using the antibody-derived reagents in a variety of immune techniques (FACS, ELISA, WB, IP, SPR, and IF). Conclusions: The collected data demonstrate the feasibility of a method that establishes a totally new approach for producing rapidly and inexpensively functional Camelidae IgG-like monoclonal antibodies and antibody-based reagents containing multiple disulfide bonds and suitable for both basic research and clinical applications.

  • Bacterial cytoplasm as an effective cell compartment for producing functional VHH-based affinity reagents and Camelidae IgG-like recombinant antibodies
    Microbial Cell Factories, 2014
    Co-Authors: Selma Djender, Aurelie Schneider, Anne Beugnet, Ronan Crepin, Klervi E. Desrumeaux, Chiara Romani, Sandrine Moutel, Franck Perez, Ario Marco

    Abstract:

    © 2014 Djender et al.; licensee BioMed Central Ltd. Background: The isolation of recombinant antibody fragments from displayed libraries represents a powerful alternative to the generation of IgGs using hybridoma technology. The selected antibody fragments can then be easily engineered into (multi)-tagged constructs of variable mass and complexity as well as reconstituted into Camelidae IgG-like molecules when expressed fused to Fc domains. Nevertheless, all antibody constructs depend on an oxidizing environment for correct folding and consequently still belong to the proteins difficult to express in bacteria. In such organisms they are mostly produced at low yields in the periplasmic space. Results: We demonstrate that fusion constructs of recombinant antibodies in combination with multiple tags can be produced at high yields and totally functional in the cytoplasm of bacteria expressing sulfhydryl oxidase. The method was applied to structurally demanding molecules such as VHHs fused to SNAP and Fc domains and was validated using the antibody-derived reagents in a variety of immune techniques (FACS, ELISA, WB, IP, SPR, and IF). Conclusions: The collected data demonstrate the feasibility of a method that establishes a totally new approach for producing rapidly and inexpensively functional Camelidae IgG-like monoclonal antibodies and antibody-based reagents containing multiple disulfide bonds and suitable for both basic research and clinical applications.

Jane C Wheeler – 3rd expert on this subject based on the ideXlab platform

  • mitochondrial dna variation and systematics of the guanaco lama guanicoe artiodactyla Camelidae
    Journal of Mammalogy, 2008
    Co-Authors: Juan Marin, Jane C Wheeler, Benito A Gonzalez, Eduardo R Palma, Angel E Spotorno, Cristian Bonacic, Ciara S Casey, Michael William Bruford, Elie Poulin

    Abstract:

    Guanacos (Lama guanicoe) are the most important native herbivorous species in the South American steppes and the dominant ungulate in a fauna rich in rodents but poor in large mammal species. Between 2 and 4 subspecies are usually recognized within Lama guanicoe, based on subtle morphological differences and geographic distribution. To evaluate whether molecular variation is consistent with the latter hypotheses, we analyzed the complete cytochrome-b and partial control region mitochondrial DNA sequences of L. guanicoe from 22 localities in Peru, Bolivia, Argentina, and Chile. Sequence analyses of both genes support the monophyly of the species but failed to distinguish the occurrence of subspecies along the geographic range. Despite that, the northernmost populations (Peru and northern Chile) showed some degree of genetic differentiation with respect to southern representatives from Argentina, Bolivia, and rest of Chile. Analysis of genetic diversity also showed a strong signal of past low population size and a recent population expansion.

  • evolution and present situation of the south american Camelidae
    Biological Journal of The Linnean Society, 1995
    Co-Authors: Jane C Wheeler

    Abstract:

    Abstract This paper provides a review of South American camelid evolution, classification and present status. Particular attention is paid to the debate concerning origins of the domestic alpaca and Llama and the contribution of research on faunal remains from Andean archaeological sites towards resolving this issue. Changes in incisor morphology during the domestication process suggest that the alpaca may be descended from the vicuna, while a comparison of fibre production characteristics in preconquest and extant llama and alpaca breeds indicates that extensive hybridization between the two species is likely to have occurred since European contact. The potential role of hybridization in the formation of extant South American camelid populations has not been studied, and may be the root cause of taxonomic disputes.

  • molecular evolution of the family Camelidae a mitochondrial dna study
    Proceedings of The Royal Society B: Biological Sciences, 1994
    Co-Authors: Helen F Stanley, Miranda Kadwell, Jane C Wheeler

    Abstract:

    We report the first molecular evolutionary analysis of the family Camelidae by analysing the full DNA sequence of the mitochondrial cytochrome b gene. Estimates for the time of divergence of the Old World (Camelini) and New World (Lamini) tribes obtained from sequence data are in agreement with those derived from the fossil record. The DNA sequence data were also used to test current hypotheses concerning the ancestors of the domesticated llama and alpaca. The results show that hybridization has occurred in the ancestry of both domesticated camelids, obscuring the origin of the domestic species.