title: Potency determination of recombinant IFN-alpha based on phosphorylated STAT1 using flow cytometry.
abstract: The interferon (IFN) family of cytokines is recognized as a key component of the innate immune response and the first line of defense against viral infection. The usage of the IFN-alpha as a biopharmaceutical has been mainly applied in the treatment of chronic hepatitis C. In the literature it is possible to find a great variety of methods to determine the potency of these cytokines, and many efforts have been made in order to develop practical bioassays to study the biological activity of IFNs. In this technical note, we present a different approach to determine the potency of a recombinant IFN-alpha preparation based on the activation of the signal transducers and activators of transcription 1 (STAT1) using flow cytometry technique. Under the conditions of this study, this new approach proved to be useful and promising to assess the potency of these biopharmaceuticals and may also be used as an important tool in the quality control of such biological products.
authors: Laboratory of Biotechnology and Physiology of Viral Infections, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil. edsonrao@yahoo.com.br
authors: Edson R A
authors: ER
authors: de Oliveira
authors: Bruna M M P
authors: BM
authors: Lima
authors: Bárbara A F
authors: BA
authors: dos Santos
authors: Wlamir C
authors: WC
authors: de Moura
authors: Ana Cristina M de A
authors: AC
authors: Nogueira
mesh_terms: D001681:Biological Assay / Q000379:methods; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000378:metabolism; D005434:Flow Cytometry / Q000379:methods; D006801:Humans; D016898:Interferon-alpha / Q000032:analysis* / Q000378:metabolism*; D010766:Phosphorylation; D011994:Recombinant Proteins / Q000378:metabolism; D050794:STAT1 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D004268:DNA-Binding Proteins; D016898:Interferon-alpha; D011994:Recombinant Proteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human