GEM preparation
L. lactis MG1363 cultured in M17 medium was centrifuged to obtain
the bacteria. After washing once with sterile distilled PBS, the
bacteria were boiled for 30 min with 10% trichloroacetic acid (TCA) to
obtain GEM particles. After washing three times with PBS, the number of
GEM particles was counted using a C-Chip Burker
Turk Hemocytometers (IN-Cyto, Chungnam-do, Korea), diluted to one unit
(1 U, 2.5×109 particles per 1U) and stored at -70°C.