title: Transient expression of rabies virus G-glycoprotein using BHK-21 cells cultured in suspension.
abstract: OBJECTIVE
  To assess the expression of rabies virus G-glycoprotein (RVGP) expression using Semliki Forest virus as a vector in combination with BHK-21 cells cultured in suspension.
  
  
  RESULTS
  A multilevel factorial design was used to quantify effects of temperature (33-37 °C), fresh medium addition after the viral adsorption step (100-200 % with respect to the initial cell suspension volume before infection) and harvest time (8-40 h) on RVGP production. Experimental runs were performed in 24-well cell culture plates at a multiplicity of infection (MOI) of 16. An additional experiment in spinner-flask was performed at MOI of 9, using the optimal conditions determined in cell culture plates. Values for temperature, fresh medium addition and harvest time of 33 °C, 100 % and 16 h, respectively, ensured the optimal RVGP production in culture plates. The volumetric yield (239 ng ml(-1)) in these conditions was higher than that reported previously for adherent cell culture. In spinner-flasks, the volumetric yield was improved (559 ng ml(-1)).
  
  
  CONCLUSIONS
  These results establish the basis for designing bioprocess to produce RVGP.
authors.affiliation: Laboratório de Células Animais, Departamento de Engenharia Química, Escola Politécnica, Universidade de São Paulo, Av. Prof. Luciano Gualberto, trav. 3, 380, São Paulo, SP, 05508-900, Brazil, eutimiocu@yahoo.com.
authors.forename: Eutimio Gustavo
authors.initials: EG
authors.lastname: Fernández-Núñez
authors.forename: Alexandre Gonçalves
authors.initials: AG
authors.lastname: de Rezende
authors.forename: Ana Lia Pradella
authors.initials: AL
authors.lastname: Puglia
authors.forename: Jaci
authors.initials: J
authors.lastname: Leme
authors.forename: Vera Lucia Lopes
authors.initials: VL
authors.lastname: Boldorini
authors.forename: Celso Pereira
authors.initials: CP
authors.lastname: Caricati
authors.forename: Aldo
authors.initials: A
authors.lastname: Tonso
mesh_terms: D000818:Animals; D000956:Antigens, Viral / Q000096:biosynthesis* / Q000235:genetics; D019149:Bioreactors; D002460:Cell Line; D006224:Cricetinae; D003470:Culture Media / Q000737:chemistry; D004847:Epithelial Cells / Q000378:metabolism*; D015870:Gene Expression; D005822:Genetic Vectors; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics; D012672:Semliki forest virus / Q000235:genetics; D013696:Temperature; D013997:Time Factors; D014759:Viral Envelope Proteins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000956:Antigens, Viral; D003470:Culture Media; D006023:Glycoproteins; D011994:Recombinant Proteins; D014759:Viral Envelope Proteins; C064951:glycoprotein G, Rabies virus