El receptor de la hormona de crecimiento humana (hGH) y la proteína de transporte de alta afinidad de la hGH / Human Growth Hormone (GH) Receptor and the High Affinity GH-Binding Protein

La hormona de crecimiento humana (hGH) circula parcialmente unida a su proteína de transporte de alta afinidad (GHBP) la cual resulta del clivaje proteolítico del dominio extracelular del receptor de GH. Recientemente la enzima TACE se identificó como la metaloproteasa responsable del clivaje y liberación de GHBP a circulación. Aunque aún se desconoce la función específica de esta proteína de transporte, distintos trabajos en la literatura demuestran efectos que potencian y efectos inhibitorios sobre la acción de GH. Por otro lado, existen evidencias que demuestran una fuerte relación entre la GHBP y el nivel de receptor de GH en el hígado en situaciones fisiológicas y patológicas. Esto permitió proponer a la determinación de GHBP en suero como un marcador periférico de la abundancia del receptor de GH en los tejidos. La determinación de la concentración de GHBP sería de especial interés para evaluar pacientes con diagnóstico probable de insensibilidad a la acción de GH y orientar el posterior estudio de anormalidades en el gen del receptor de GH. En la presente revisión, también se abordan dificultades metodológicas relacionadas a la medición de GHBP sérica.

Human circulating growth hormone (GH) is partly bound to a high-affinity binding protein (GHBP) which is derived from proteolytical cleavage of the extracellular domain of the GH receptor. Recently, the metalloproteinase TACE has been identified as an important enzyme responsive for inducing GHBP shedding. Although the specific function of GHBP is not fully known, both enhancing and inhibitory roles of this binding protein on GH action have been proposed. Many reports have demonstrated a close relationship between GHBP and the liver GH receptor status in physiological conditions and diseases. Moreover, serum GHBP measurement has been proposed as an useful peripheral index of the GH receptor abundance. Related to the latter, circulating GHBP concentration would be of special interest for the evaluation of GH insensitivity due to GH receptor gene abnormalities. In addition, the present review also focus on methodological problems concerning serum GHBP measurement.

Research on adaptation and cloning of rgh5n1 vaccine reference strain to vero cells

Background: As avian influenza A/H5N1 epidemic spreads rapidly, many corporations, vaccine manufacturers in cooperation with laboratories around the world has conducted research and developed H5N1 vaccine for both humans and poultry. Objective: Evaluate the adaptation and cloning of rgh5n1 vaccine reference strain to vero cells in order to produce master seed virus and working seed virus. Subject and Method: The reverse genetics derived A/H5N1 virus strain (rgH5N1) was studied for adaptation to Vero cells by serial passage. It has been shown that the rgH5N1 strain can be propagated in Vero cells and cause CPE with the highest virus titer 1010,9 PFU/ml at Vero passage 15. The rgH5N1 strain was cloned by using plaque purification method and passaged to obtain a high stable virus titer. Conclusion: The reverse genetics derived A/H5N1 virus strain was propagated in Vero cells. Master seed virus and working seed virus were obtained at passage 6.