Effect of soy protein hydrolysate on MDCK cell growth and influenza virus proliferation

Abstract

Objective To study the improvement by soy protein hydrolysate on Madin-Darby canine kidney (MDCK) cell growth and influenza virus replication. Methods MDCK cells were cultured in 10% imported fetal bovine serum(FBS)-Dulbecco’s modified Eagle’s medium (DMEM), 10% domestic newborn calf serum (NCS)-DMEM and 10% NCS-DMEM supplemented with 2, 4, 8 g/L soy protein hydrolysate SHEFF-VAX PLUS PF ACF (PF ACF), respectively. The growth of MDCK cells in different media and hemagglutinin (HA) titers after H7N9 influenza virus inoculation were compared. Results The peak numbers of MDCK cells statically cultured with 5 culture systems in culture flask on day 3 reached (8.67±1.54)×106, (4.78±0.64)×106, (10.60±0.23)×106, (9.17±0.51)×106 and (4.79±0.19)×106, respectively. The highest densities of MDCK cells on microcarrier in spinner flask were(2.56±0.68)×106, (1.93±1.85)×106, (2.20±1.48)×106 and (2.50±1.25)×106 cells/ml when cultured in FBS-DMEM, NCS-DMEM and NCS-DMEM supplemented with 2, 4 g/L PF ACF, respectively. The HA titers of H7N9 virus replicated in FBS-DMEM, NCS-DMEM and NCS-DMEM supplemented with 4 g/L PF ACF were 8.0, 3.5 and 8.0 log2HAU/50 μl. Conclusions Adding 4 g/L PF ACF to domestic NCS-containing medium could enhance cell density and HA titer equivalent to imported FBS-containing medium. Thus soy protein hydrolysate can be used as a medium supplement for MDCK cell culture and influenza virus replication. Key words: Soybean proteins; Protein hydrolysates; Cell culture techniques; Influenza A virus