Modification of cellular immune responses in experimental autoimmune hepatitis in mice by maitake (Grifola frondosa)

Abstract

Immune response to liver-specific lipoprotein (LSP) is involved in the pathogenesis of chronic active hepatitis. Experimental hepatitis could thus be prepared in C57BL/6 mice by injection of liver-specific protein in a syngeneic liver homogenate with Freund's complete adjuvant. In hepatitic mice treated with maitake (Grifola frondosa) fruit bodies, the values of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) values increased temporarily by 2.24–2.79 times and decreased rapidly thereafter. However, in the mice given normal feed, both values increased constantly. Thus, we examined T cell activities both in the exacerbation and remission stages of hepatitis. We suggest that the activation of CD8⁺ cells is more potentiated than that of CD4⁺ cells by administration of maitake or the D-Fraction-glucan (β-1,6 glucan having β-1,3 branches), which can enhance immuno-competent cells at the exacerbation stage. However, at the remission stage, marked potentiation of CD8⁺ cell activity was not observed. These results suggest that depressed suppressor T cell activity is revived by the X-Fraction-glucan (β-1,6 glucan having α-1,4 branched glucan), while the cytotoxic T cell activity, which is activated by the D-Fraction, is restricted, thereby creating a smooth shift from the exacerbation stage to the remission stage.