Híbridos estables de ARN/ADN en el genoma de mamíferos: intermediarios inducibles en la recombinación del interruptor
R B Tracy1, C L Hsieh, M R Lieber
1Department of Pathology, University of Southern California Keck School of Medicine, Los Angeles, CA 90089-9176, USA.
Science (New York, N.Y.)
|May 12, 2000
Resumen
Se forman híbridos estables de ARN/ADN durante el cambio de clase de inmunoglobulina en ratones. Estos híbridos son cruciales para el intercambio eficiente de clases de anticuerpos, como lo demuestran los experimentos con la ribonucleasa H.
Área de la Ciencia:
- Inmunología Inmunología.
- Biología Molecular Biología Molecular
- Genética La genética.
Sus antecedentes:
- La recombinación del interruptor de clase de los mamíferos (CSR) es vital para la inmunidad adaptativa, alterando las clases de inmunoglobulinas (anticuerpos).
- Los mecanismos moleculares precisos que subyacen a la RSE han permanecido en gran medida evasivos.
- Comprender la RSE es fundamental para desarrollar terapias para trastornos inmunológicos.
Objetivo del estudio:
- Para aclarar los detalles mecanicistas de la recombinación del interruptor de clase de los mamíferos.
- Investigar el papel de los híbridos de ARN/ADN en el proceso de RSE.
- Para determinar la importancia in vivo de estas estructuras en la función de las células B.
Principales métodos:
- Estimulación de las células B del bazo primario de ratones con citocinas para inducir la recombinación del interruptor de clase.
- Detección y caracterización de híbridos de ARN/ADN en secuencias de conmutación utilizando técnicas moleculares.
- Análisis de la función de las células B y la producción de anticuerpos en ratones transgénicos que expresan la ribonucleasa H. de Escherichia coli.
Principales resultados:
- Se identificaron híbridos estables de ARN/ADN en secuencias de conmutación en el genoma del ratón durante la RSC.
- El ARN hibridado fue transcrito en la orientación fisiológica.
- Los ratones que expresaban la ribonucleasa H mostraron una reducción de los híbridos de ARN/ADN, una disminución de la producción de inmunoglobulina G e inhibición de la RSC.
Conclusiones:
- Los híbridos estables de ARN / ADN están presentes en el genoma nuclear de los mamíferos.
- Estos híbridos funcionan como intermediarios en procesos fisiológicos como la RSE.
- Los híbridos de ARN/ADN son mecánicamente importantes para un eficiente cambio de clase in vivo.
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