title: Evolution of B cell immunity.
abstract: Two types of adaptive immune strategies are known to have evolved in vertebrates: the VLR-based system, which is present in jawless organisms and is mediated by VLRA and VLRB lymphocytes, and the BCR/TCR-based system, which is present in jawed species and is provided by B and T cell receptors expressed on B and T cells, respectively. Here we summarize features of B cells and their predecessors in the different animal phyla, focusing the review on B cells from jawed vertebrates. We point out the critical role of nonclassical species and comparative immunology studies in the understanding of B cell immunity. Because nonclassical models include species relevant to veterinary medicine, basic science research performed in these animals contributes to the knowledge required for the development of more efficacious vaccines against emerging pathogens.
authors.affiliation: Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: David
authors.initials: D
authors.lastname: Parra
authors.affiliation: Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: Fumio
authors.initials: F
authors.lastname: Takizawa
authors.affiliation: Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
authors.forename: J Oriol
authors.initials: JO
authors.lastname: Sunyer
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D005075:Biological Evolution; D007111:Immunity, Cellular / Q000235:genetics* / Q000502:physiology*; D007448:Invertebrates / Q000235:genetics / Q000276:immunology; D014714:Vertebrates / Q000235:genetics* / Q000276:immunology*