알긴산 장용 비드에 봉입한 새로운 장 표적성 경구용 장티푸스 Ty21a 백신의 개발 = Development of a New Gut-targeted Oral Typhoid Vaccine Ty21a Encasulated within Alginate Enteric Beads

다국어 초록 (Multilingual Abstract)

To increase the viability of oral typhoid vaccine during the passage through the gastro-intestinal tract, .numerous attempts have been made including the vaccine coating. However, problems such as high death rate during the coating process and its instability in the gastric juice still remain to be solved. In this study, the oral vaccine was made as the micro-enteric beads by adding Salmcnella typhi Ty21a cells to sodium alginate solution and spraying onto calcium chloride solution (ionotropic relation method). The vaccine showed more than 90% of its original viability after treating it for 1 hour in the artificial gastric juice (37oC,300 rpm). The clearance rate of the Ty21a in the liver and spleen of the mice orally administrated with coated Ty21a was similar to that of the mice intraperitoneally administrated with uncoated Ty21a. The peripheral blood Iymphocytes (PBL) isolated from the mice orally administered with this vaccine produced 15.5 fold higher specific IgA antibody titer than that from the control mice administerd with saline solution. Fllrthermore, the mice treated with the coated Ty21a had higher survival rates (50∼87%) than the control mice treated with saline solution (0-10%) in the intraperitoneal challenge test with wild type S. typhi cells. These results suggest that the alginate-based coaling technique is effective to protect live Ty21a from acidic environments, and produces better intestinal immune responses thereby providing a potentially excellent oral typhoid vaccine.