A pseudotyped baculovirus comprises a deletion, inactivation or reduction
from regulation of a baculovirus envelope protein gene, and is engineered
to express an envelope protein from another virus or cell, or another
protein or molecule that facilitates entry of the baculovirus into a
non-host cell, or provided with a heterologous envelope protein or another
protein or molecule that facilitates entry of the baculovirus into a
non-host cell by other suitable means. Such baculoviruses can be used to
efficiently deliver genes to mammalian cells or organisms, and such genes
can be expressed either from the baculovirus genome, or integrated into
the mammalian cell genome, and can be used for expression of proteins such
that purification of secreted or other protein products does not require
removal of contaminating baculovirus particles or baculovirus envelope
proteins.