Accelerated induction of apoptosis in insect cells by baculovirus-expressed SARS-CoV membrane protein.

It has been shown that severe acute respiratory syndrome-associated coronavirus (SARS-CoV) 3a and 7a proteins, but not membrane (M) protein, induce apoptosis in mammalian cells. Upon expression of SARS-CoV M protein using the baculovirus/insect cell expression system, however, we found that the expressed M protein triggered accelerated apoptosis in insect cells, as characterized by rapid cell death, elevated cytotoxicity, cell shrinkage, nuclear condensation and DNA fragmentation. Conversely, the M protein expressed in mammalian cells did not induce apoptosis.

Determination of the baculovirus transducing titer in mammalian cells.

Baculovirus has emerged as a promising vector for in vivo or ex vivo gene therapy. To date, the infectious titer and multiplicity of infection (MOI) based on the ability of baculovirus to infect insect cells are commonly adopted to indicate the virus dosage. However, the infectious titer and MOI do not reliably represent the baculovirus transducing ability, making the comparison of baculovirus-mediated gene transfer difficult.

A novel oscillating bioreactor BelloCell: implications for insect cell culture and recombinant protein production.

BelloCell is a novel packed bed bioreactor that allows alternating nutrient and gas transfer to a culture. Spodoptera frugiperda Sf-9 grown in the BelloCell (300 ml culture) reached 1.3-1.