Zhai W.,Analytical Biochemistry |
Zhang D.N.,Analytical Biochemistry |
Mai C.,Analytical Biochemistry |
Choy J.,Analytical Biochemistry |
And 3 more authors.
PLoS ONE | Year: 2012
Eight cell lines were systematically compared for their permissivity to primary infection, replication, and spread of seven human influenza viruses. Cell lines were of human origin (Caco-2, A549, HEp-2, and NCI-H292), monkey (Vero, LLC-MK2), mink (Mv1 Lu), and canine (MDCK). The influenza viruses included seasonal types and subtypes and a pandemic virus. The MDCK, Caco-2, and Mv1 Lu cells were subsequently compared for their capacity to report neutralization titers at day one, three and six post-infection. A gradient of sensitivity to primary infection across the eight cell lines was observed. Relative to MDCK cells, Mv1 Lu reported higher titers and the remaining six cell lines reported lower titers. The replication and spread of the seven influenza viruses in the eight cell substrates was determined using hemagglutinin expression, cytopathic effect, and neuraminidase activity. Virus growth was generally concordant with primary infection, with a gradient in virus replication and spread. However, Mv1 Lu cells poorly supported virus growth, despite a higher sensitivity to primary infection. Comparison of MDCK, Caco-2, and Mv1 Lu in neutralization assays using defined animal antiserum confirmed MDCK cells as the preferred cell substrate for influenza virus testing. The results observed for neutralization at one day post-infection showed MDCK cells were similar (<1 log2 lower) or superior (>1 log2 higher) for all seven viruses. Relative to Caco-2 and Mv1 Lu cells, MDCK generally reported the highest titers at three and six days post-infection for the type A viruses and lower titers for the type B viruses and the pandemic H9N2 virus. The reduction in B virus titer was attributed to the complete growth of type B viruses in MDCK cells before day three post-infection, resulting in the systematic underestimation of neutralization titers. This phenomenon was also observed with Caco-2 cells. © 2012 Zhai et al.
PubMed | Analytical Biochemistry
Type: Journal Article | Journal: Nature reviews. Drug discovery | Year: 2011
The Fc (crystallizable fragment) region of therapeutic antibodies can have an important role in their safety and efficacy. Although much is known about the structure-activity relationship of antibodies and the factors that influence Fc effector functions, a process has not yet been defined to clearly delineate how Fc functionality should be assessed and controlled during antibody development and manufacturing. In this article, we summarize the current knowledge of antibody Fc functionality, provide a strategy for assessing the effector functions of different classes of therapeutic antibodies (including Fc fusion proteins) and propose a path for routine testing and controls for manufacturers of antibody products.