RESUMO
Polymerase chain reactions with degenerate V gene segment primers were used to isolate the putative T-cell receptor alpha-chain gene (TCRA) from Japanese pufferfish (Takifugu rubripes). The putative TCRA chain cDNA is composed of an N-terminus leader peptide followed by the variable region and the constant region. The variable portion of the TCRA gene is encoded by V and J gene segments separated in the germline. As in mammals, the V-J junction sequences are GC rich and highly diversified. Amino acid residues that are required to maintain the function and structural integrity of the TCRA polypeptide, including the conserved Trp-Tyr-Lys and Tyr-Tyr-Cys motifs in the V gene segments, the Lys-Leu-X-Phe-Gly-X-Gly-Thr-X-Leu motif in the J gene segment, the three cysteine residues in the constant region and the charged residues in the transmembrane region are all preserved in the pufferfish. These conserved features suggest that the TCRA gene families in fish and mammals have evolved from a common ancestor.
Assuntos
Evolução Molecular , Peixes Venenosos/genética , Peixes Venenosos/imunologia , Genes Codificadores da Cadeia alfa de Receptores de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA Complementar/genética , Éxons/genética , Duplicação Gênica , Rearranjo Gênico da Cadeia alfa dos Receptores de Antígenos dos Linfócitos T , Genoma , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido NucleicoAssuntos
DNA Complementar/genética , Peixes Venenosos/genética , Peixes Venenosos/imunologia , Genes MHC Classe I , Sequência de Aminoácidos , Animais , Apresentação de Antígeno/genética , Clonagem Molecular , Evolução Molecular , Genoma , Humanos , Dados de Sequência Molecular , Família Multigênica , Filogenia , Homologia de Sequência de Aminoácidos , VertebradosRESUMO
Preliminary immunologic studies of ciguatera poisoning were performed with serum samples from patients and extracts from both toxic and nontoxic fish. Counterimmunoelectrophoresis disclosed precipitin lines with toxic fish extracts and effectively discriminated between samples established as toxic or nontoxic on the basis of human toxic reactions and by an in vivo mouse bioassay. However, it is not currently possible to conclude that affected individuals had specific antibody to ciguatoxin, since putative immune and nonimmune serum samples gave equally clear precipitin reactions with toxic extracts.
Assuntos
Ciguatera , Peixes Venenosos/imunologia , Toxinas Marinhas/intoxicação , Animais , Anticorpos/análise , Ciguatoxinas/imunologia , Contraimunoeletroforese , Humanos , Camundongos , Testes de PrecipitinaRESUMO
Suggesting an immunologic participation in the pathogeny of the ciguateric syndroms, the authors have prepared a proteic antigen from the flesh of poisonous and edible fish of the same species. They have shown that there is a total common antigenicity between toxic and non toxic extracts. They suggest a new immunologic approach, in the matter of intoxication by ciguateric fish.
