[XIV-29-04_06] 畜産物利用（XIV-午前）

[XIV29-06E] Exopolysaccharides of Streptococcus thermophilus has potentials against virus infection

^○Mizuno Hiroya^1,2,3, Sasaki Yasuko⁴, Tomotsune Kae^1,2, Indoh Yuuki^1,2, Albarracin Leonardo⁵, Islam MD Aminul^1,2, Ikeda-Ohtsubo Wakako^1,2,3, Makino Seiya⁶, Aso Hisashi^1,2,3, Vilena Julio⁵, Kitazawa Haruki^1,2,3 (1.Tohoku Univ. (Agri.), 2.CFAI, 3.C-to-C, 4.Meiji Univ., 5.CERELA-CONICET, 6.Meiji Co. Ltd.)

[Objective] In recent years, there has been an increasing interest in functional dairy foods that contain probiotics for health consciousness. Exopolysaccharides (EPSs), likely has immunomodulatory effects, but there are limited reports on EPSs of S. thermophilus used for dairy foods. Therefore, we explored the antiviral potentials of EPSs in vitro by knockout technique.
[Methods] We made epsB and epsC knockout strains of S. thermophilus by double-crossover in pG⁺host6. PIE cells were stimulated by either knockout strains, wild strain, or EPSs extract for 48 h. Subsequently, PIE cells were challenged by poly (I:C) for 3 h. Expression of IFN-b mRNA was quantified by RT-qPCR.
[Results] In wild-type, supernatant increased IFN-b expression but bacteria did not increase it. But, mutants (epsB, epsC) did not increased it in bacteria and culture supernatant. EPSs increased IFN-b expression in a dose-dependent manner. Results suggest EPSs of S. thermophilus has potentials against virus infection.