Immunomodulatory Effects of Oligosaccharides on Splenic Lymphocytes in Mice

The aim of the present study was to investigate the effects of fructo-oligosaccharides (FOS), galacto-oligosaccharide (GOS), and the mixture of FOS and GOS (FOS+GOS) on the proliferation of splenic lymphocytes, as well as the regulation of Th cell differentiation and Th1/Th2 balance. Spleen lymphocytes of mice were incubated with FOS. GOS and FOS+GOS mixture, respectively, with or without Concanavalin A (ConA) stimulation. Spleen lymphocyte proliferation level wasdetected by MTT colorimetric assay. To explore the differentiation direction of Th cell, the expression ofThl and Th2 cytokines and the transcription factors T-bet and GATA-3 were determined by enzyme linked immunosorbent assay (ELISA) and PCR, respectively. The results showed that the proliferative activities of FOS, GOS and FOS+GOS mixture on mouse splenic lymphocytes were concentration-dependent, and all of them exhibited promoting splenic cell proliferation activity at the concentration of 125 μg/mL, with FOS+GOS mixture having the strongest promotion effect on splenic cell proliferation. There was no significant difference among them on the splenic cell proliferation activity under ConA stimulation. FOS+GOS mixture had the strongest effect on the splenic cell proliferation activity without ConA stimulation. The supplementation of GOS and FOS+GOS mixture increased the secretion of Th1-type cytokine IFN-γ and the mRNA expression levels of IFN-γ and IL-2, and inhibited the expression and secretion levels of Th2-type cytokine-related mRNA including IL-4 and IL-5. In conclusion, both FOS+GOS mixture and GOS possess immunoregulatory activity and regulate Th1/Th2 balance, which deserve them as potential anti-allergic ingredients.