Active Hexose Correlated Compound and T Cell Response in Hind - Limb - Unloaded BALB/c Mice

Introduction: Microgravity - induced immune dysfunction is a potential risk for infection and cancer in astronauts. Active hexose correlated compound (AHCC), a compound obtained from fermented extract of the mycelia of Basidiomycetes mushrooms, has immunomodulating effects. As a nutritional countermeasure, we examined the effect of AHCC on microgravityinduced immune changes by using a hind-limb unloading (HLU) of mice as a microgravity analog. Methods: BALB/c mice were divided into non-HLU and HLU groups. Each group was further divided into subgroups receiving drinking water containing 0, 0.1, 1, and 10 g/kg/day AHCC. After 7 days of HLU and feeding treatment, the proliferative response of popliteal lymph nodes (PLN) to alloantigen was assessed to evaluate in vivo T cell function. Furthermore, LPS-stimulated inflammatory cytokine and chemokine production in splenocytes was examined. Results: The response of PLN was significantly decreased in the HLU group and AHCC supplementation significantly reversed the response. LPS-stimulated cytokine and chemokine production was increased in the HLU group compared to that in the non- HLU group, and AHCC supplementation tended to increase those levels further. Discussion: AHCC enhances in vivo T cell function in microgravity, suggesting that AHCC supplementation under microgravity may have a beneficial role in maintenance of the immune system.