MDCK and Vero cell lines have been used as substrates for influenza virus replication. However, Vero cells produced lower influenza virus titer yield compared to MDCK. Influenza virus needs molecules for internalisation of the virus into the host cell, such as influenza virus receptor and
clathrin.
Human influenza receptor is usually a
membrane protein containing Sia(α2,6) Gal, which is added into the
protein in the golgi apparatus by α2,6
sialyltransferase (SIAT1). Light
clathrin A (LCA), light
clathrin B (LCB) and heavy
clathrin (HC) are the main components needed for virus endocytosis. Therefore, it is necessary to compare the expression of SIAT1 and
clathrin in Vero and MDCK cells. This study is reporting the expression of SIAT1 and
clathrin observed in both cells with respect to the levels of (1)
RNA by using RT-PCR, (2)
protein by using dot blot analysis and confocal microscope. The results showed that Vero and MDCK cells expressed both SIAT1 and
clathrin proteins, and the expression of SIAT1 in MDCK was higher compared to Vero cells. On the other hand, the expressions of LCA, LCB and HC
protein in MDCK cells were not significantly different to Vero cells. This result showed that the inability of Vero cells to internalize H1N1 influenza virus was possibly due to the lack of transmembrane
protein receptor which contained Sia(α2,6) Gal.