Enhancement of CD93 expression and interleukin-8 (IL-8) production in the human monocyte-like cell line U937 in response to Taimatsu fermented rice germ gamma-amino butyric acid (GABA)

たいまつ米胚芽発酵GABAによる単球系細胞株(U937)表面上のCD93抗原の発現をモノクローナル抗体を用いた酵素抗体法およびフローサイトメトリー法で解析した。その結果、たいまつ米胚芽発酵GABAで培養したU937細胞はCD93(C1qRp)の発現が有意に増強した。また、CD93の発現増強はprotein kinase C(PKC)阻害剤であるGo6976で抑制された。さらに、たいまつ米胚芽発酵GABAで培養したU937細胞はインターロイキン-8(IL-8)の産生も有意に増強した。以上の結果から、たいまつ米胚芽発酵GABAにはヒトの免疫応答を増強する作用があることがわかった。We examined the modulation of CD93 (receptor for complement component 1, subcomponent qphagocytosis; C1qRp) expression in the human monocyte-like cell line U937 cultured with Taimatsufermented rice germ gamma-amino butyric acid (GABA) using CD93 monoclonal antibodies (mAbs), aglutaraldehyde-fixed cellular enzyme immunoassay (GCEIA), and flow cytometry. The expression ofCD93 in the U937 cells cultured with Taimatsu fermented rice germ GABA was significantly enhanced (P<0.01), compared with that in the control cells (cultured without Taimatsu fermented rice germ GABA) at 24 hrs. This enhancement of CD93 expression was dose-dependent and timedependent. The enhancement of CD93 expression was markedly blocked in the presence of the protein kinase C (PKC) inhibitor Go6976. In addition, the U937 cells cultured with Taimatsu fermented rice germ GABA significantly enhanced (P<0.01) the production of interleukin-8 (IL-8) in the culture supernatants. Together, these findings strongly indicated that Taimatsu fermented rice germ GABA has immunopotentiator effects on some human immune responses