title: Molecular cloning of multiple forms of the ovine B7-2 (CD86) costimulatory molecule.
abstract: To facilitate analysis of the role of costimulatory molecules in the ovine immune system, we cloned and sequenced eight putative alternatively spliced transcripts of the sheep CD86 (B7-2) costimulatory molecule. Using RT-PCR and rapid amplification of cDNA ends (RACE), we cloned the sheep CD86 (B7-2) molecule that encodes eight forms, which differ in the length of the signal peptide, the presence or absence of a transmembrane region and in their cytoplasmic tails. Comparison of the deduced amino acid sequence of the largest ovine CD86 TM form (CD86-2) with the sequence of cattle, pig, human and mouse CD86 indicated that the deduced protein had a higher degree of similarity to cattle (85% of amino acid identity) than to pig (77%), human (59%), and mouse sequence (45% of identity). Our results indicate that mRNA transcripts encoding different CD86 protein forms are expressed in sheep, like in other mammals, and suggest that the expression of this gene may be regulated at the transcriptional or RNA splicing level, which could give rise to tissue-specific expression of CD86. It is possible that, in the sheep, these CD86 mRNA variants could play different regulatory roles in T cell activation.
authors.affiliation: Instituto de Agrobiotecnología (IdAB), Consejo Superior de Investigaciones Científicas-Universidad Pública de Navarra, Campus de Arrosadía, 31006-Mutilva Baja, Navarra, Spain.
authors.forename: Esteban A
authors.initials: EA
authors.lastname: Terzo
authors.forename: Maider Pérez
authors.initials: MP
authors.lastname: de Villarreal
authors.forename: Virginie
authors.initials: V
authors.lastname: Mick
authors.forename: Francisco
authors.initials: F
authors.lastname: Muñoz
authors.forename: Beatriz
authors.initials: B
authors.lastname: Amorena
authors.forename: Damian
authors.initials: D
authors.lastname: de Andrés
authors.forename: José M
authors.initials: JM
authors.lastname: Pérez de la Lastra
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D051940:B7-2 Antigen / Q000235:genetics* / Q000276:immunology*; D001483:Base Sequence; D003001:Cloning, Molecular; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics / Q000276:immunology; D012313:RNA / Q000737:chemistry / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique / Q000662:veterinary; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012756:Sheep / Q000235:genetics / Q000276:immunology*
chemical_list: D051940:B7-2 Antigen; D020033:Protein Isoforms; D012313:RNA