La lattoferrina come molecola bioattiva : valutazione dell'attività biologica mediante modelli in vitro e potenzialità legate all'espressione in sistemi eterologhi

everal compounds secreted by the mammary gland in colostrum and milk have been identified as biologically active substances. Among these, there is lactoferrin (LF), an 80 KDa non-haem iron binding glycoprotein. Physiological roles of LF include regulation of iron absorption, immune response modulation, antimicrobial, antiviral and anticarcinogenic activities, prebiotic support to intestinal microflora and trophic effect on intestinal mucosa. The aim of this PhD thesis was the study of lactoferrin s functional properties using several in vitro models of mammary and intestinal epithelium. Moreover, the possibility to express porcine lactoferrin in heterologous expression systems, such as yeasts and plants, was investigated. Our results showed that LF could be involved as regulatory factor in the modulation of mammary and intestinal cell lines growth and that this effect may be exerted by cellular internalization of the protein. Moreover, pregnant and lactating mammary tissue incubated with drugs that block protein synthesis showed that LF localization appeared to differ somewhat from that of other milk proteins, suggesting a role in modulating mammary development. Finally, porcine LF expressed in Pichia pastoris yeast retained his antibacterial and prebiotic activities and the creation of a chimeric construct to express porcine LF in rice will give the opportunity to obtain transgenic plants as nutraceuticals