Western blot detection of mIL-2 in culture supernatants. Lane 1, mIL-2; lane 2, L. lactis FI10586; lane 3, L. lactis FI10537; lane 4, intracellular contents of L. lactis FI10608; lane 5, culture supernatant of L. lactis FI10608; lane L, MagicMark Western protein standard.