著者
Yasuhiro TAKAGI Shigekazu KURIHARA Natsumi HIGASHI Saeko MORIKAWA Tetsuo KASE Akiko MAEDA Harumi ARISAKA Susumu SHIBAHARA Yukio AKIYAMA
出版者
JAPANESE SOCIETY OF VETERINARY SCIENCE
雑誌
Journal of Veterinary Medical Science (ISSN:09167250)
巻号頁・発行日
vol.72, no.2, pp.157-165, 2010 (Released:2010-03-03)
参考文献数
36
被引用文献数
24 44

Cell-mediated and humoral immune responses are attenuated with aging. Intracellular glutathione (GSH) levels also decrease with aging. Previously, we have reported that combined administration of L-cystine and L-theanine enhances antigen-specific IgG production, partly through augmentation of GSH levels and T helper 2-mediated responses in 12-week-old mice. These findings suggest that combined administration of L-cystine and L-theanine to aged mice improves immune responses via increase of GSH synthesis. Here, we examined the effects of combined administration of L-cystine and L-theanine on antigen-specific antibody production and influenza virus infection in aged mice. Combined administration of these amino acids for 14 days before primary immunization significantly enhanced the serum antigen-specific IgM and IgG levels in 24-month-old mice. Furthermore, 13-month-old mice co-treated with these amino acids orally for 10 days had significantly lower lung viral titers than controls at 6 days after influenza virus infection. In addition, this co-treatment also significantly prevented the weight loss associated with infection. Enhancement of anti-influenza-virus IgG antibodies by combined administration of L-cystine and L-theanine was seen 10 days after infection. The significantly elevated serum interleukin-10/interferon-γ ratio and γ-glutamylcysteine synthetase mRNA expression, which is the rate-limiting enzyme of GSH synthesis, in the spleen 3 days after infection may have contributed to the observed beneficial effects. These results suggest that combined administration of L-cystine and L-theanine enhances immune function and GSH synthesis which are compromised with advanced age, and may become a useful strategy in healthy aging.