were fused with Salmonella T3SS effector (a protein injected
by T3SS machinery) SopE in recombinant Salmonella.
Expression and secretion of the fusion protein from a Salmonella
strain resulted in an accumulation of fusion protein in
either growth medium or in the cytosol of target host cells.
When cells were applied to a mouse model, immune-response
in the mouse was observed. This is indicative of active antigen
production and secretion, demonstrating the ability of T3SS to
secrete recombinant proteins for live vaccine production and
delivery. T3SSs from other bacteria also found use in the
secretion of recombinant proteins. The Pseudomonas aeruginosa
T3SS naturally delivers large exotoxins up to 74 kDa
into the cytoplasm of target cells in vivo but in vitro, it can
direct secretion to growth medium in calcium-depleted conditions