Current prophylactic and therapeutic uses of a recombinant Lactococcus lactis strain secreting biologically active interleukin-12.

The noninvasive and food-grade Gram-positive bacterium Lactococcus lactis is well adapted to deliver medical proteins to the mucosal immune system. In the last decade, the potential of live recombinant lactococci to deliver such proteins to the mucosal immune system has been investigated. This approach offers several advantages over the traditional systemic injection, such as easy administration and the ability to elicit both systemic and mucosal immune responses. This paper reviews the current research and advances made with recombinant L. lactis as live vector for the in situ delivery of biologically active interleukin-12, a potent pleiotropic cytokine with adjuvant properties when co-delivered with vaccinal antigens, at mucosal surfaces. Three well-illustrated examples demonstrate the high potential of interleukin-12-secreting lactococci strains for future prophylactic and therapeutic uses.