title: Receptor specificity and functional comparison of recombinant sea bass (Dicentrarchus labrax) gonadotropins (FSH and LH) produced in different host systems.
abstract: Different yields, biopotency, and in vivo pharmacokinetics are obtained for recombinant sea bass gonadoltropins depending on the production system and DNA construct, but they show specific activation of their corresponding receptors. Gonadotropins (GTHs) are glycoprotein hormones that play a major role in the regulation of gonadal functions. Recently, we succeeded in isolating the native sea bass Fsh from sea bass pituitaries, but to ensure the availability of bioactive GTHs and no cross-contamination with other related glycoproteins, recombinant sea bass GTHs were produced using two expression systems-insect and mammalian cells-and different constructs that yielded tethered or noncovalently bound dimers. Their production levels, binding specificity to their homologous cognate receptors, and bioactivity were investigated and compared. Both expression systems were successful in the generation of bioactive recombinant GTHs, but insect Sf9 cells yielded higher amounts of recombinant proteins than mammalian Chinese Hamster Ovary (CHO) stable clones. All recombinant GTHs activated their cognate receptors without cross-ligand binding and were able to stimulate sea bass gonadal steroidogenesis in vitro, although with different biopotencies. To assess their use for in vivo applications, their half-life in sea bass plasma was evaluated. Sf9-GTHs had a lower in vivo stability compared with CHO-GTHs due to their rapid clearance from the blood circulation. Cell-dependent glycosylation could be contributing to the final in vivo stability and biopotency of these recombinant glycoproteins. In conclusion, both insect and mammalian expression systems produced bioactive sea bass recombinant gonadotropins, although with particular features useful for different proposes (e.g., antibody production or in vivo studies, respectively).
authors.affiliation: Department of Fish Physiology and Biotechnology, Instituto de Acuicultura de Torre la Sal, Consejo Superior de Investigaciones Cientiíficas, Ribera de Cabanes, Castellón, Spain.
authors.forename: Gregorio
authors.initials: G
authors.lastname: Molés
authors.forename: Silvia
authors.initials: S
authors.lastname: Zanuy
authors.forename: Iciar
authors.initials: I
authors.lastname: Muñoz
authors.forename: Berta
authors.initials: B
authors.lastname: Crespo
authors.forename: Iago
authors.initials: I
authors.lastname: Martínez
authors.forename: Evaristo
authors.initials: E
authors.lastname: Mañanós
authors.forename: Ana
authors.initials: A
authors.lastname: Gómez
mesh_terms: D000818:Animals; D001492:Bass / Q000502:physiology*; D002460:Cell Line; D006224:Cricetinae; D005640:Follicle Stimulating Hormone / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D007313:Insecta; D007986:Luteinizing Hormone / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone