Immunomodulatory effects of dead Lactobacillus on murine splenocytes and macrophages

To elucidate the immunomodulation effects of dead lactobacilli, whole cells and gastrointestinal enzymatic hydrolysates of supernatants and precipitates from Lactobacillus paracasei subsp. paracasei NTU 101 and L. plantarum NTU 102 on RAW264.7 macrophages and splenocytes were investigated. Increased NO, COX-2 expression, IL-10 and IL-12 were observed in high-dose precipitates and whole cells of both strains after 24-h stimulation. All of the hydrolysates and whole cells from both strains induced lower pro-inflammatory cytokines (IL-1 beta and IL-6) than LPS. The supernatants activated cell division to the S phase or promoted advance to the G2/M phase. Regardless of the Lactobacillus strains, higher levels of TNF-alpha, IL-6, IL-10 and IL-12 in splenocytes were induced by the precipitates. Supernatant of NTU 101 increased the amounts of IFN-gamma than precipitate in splenocytes. It shows that hydrolysates of NTU 101 induce the proliferations of macrophage and splenocyte and the release of IL-10 and IL-12 cytokines to modulate the innate and adaptive immune systems and inflammatory response.