A novel kefir product (PFT) activates dendritic cells to induce CD4+T and CD8+T cell responses in vitro

Abstract

Lactobacilli have been widely studied for their probiotic effects and have been reported to function as antiviral and anticancer agents. However, the underlying mechanisms via immune modulation are poorly understood. PFT is a freeze dried compound of Lactobacillus kefiri P-IF with a unique composition and functionality. In this study, we examined the potential stimulatory effects of two concentrations (50 µg and 100 µg/mL) of PFT on human monocyte-derived dendritic cell (DC) function in vitro. Results showed that PFT upregulated the expression of DC surface co-stimulatory and maturation markers CD80, CD86, and HLADR in a concentration dependent manner. PFT at 100 µg/mL markedly increased the secretion of IL-6, IL-10, TNF-α, and IL-1β by DCs. This concentration of PFT also stimulated the production of antiviral cytokines, IFN-α and IFN-λ(IL29) in DCs. Additionally, PFT at 100 µg/mL activated moDCs prime CD4 + T cells and significantly increased the levels of IL-10, IFN-γ, and TNF-α by 1.7, four, three-fold, respectively. Furthermore PFTstimulated DCs were also effective in enhancing the cytotoxic potential of CD8 + T cells via the induction of Granzyme-B and upregulation of CD107a, and CD103 expression, a marker of resident/regulatory CD8 + T cells. These data suggest that PFT functions as a natural adjuvant for DC activation and thus may be used in DC-based vaccine strategies against viral infections and cancer.

Analysis of Health Benefits Conferred by Lactobacillus Species from Kefir

“…PFT is a natural mixture comprised mainly of freeze-dried Lb kefiri P-IF, also including trace amounts of three yeast strains. The authors of this study [68] analyzed this kefir product’s ability to activate dendritic cells (DC). What is particularly significant about this study is that it utilized donated human blood samples.…”

Immune Responses Raised in an Experimental Colon Carcinoma Model Following Oral Administration of Lactobacillus casei

“…The aforementioned components have also been linked with increased interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF-a) production by murine peritoneal macrophages [17] and increase of Th1 cells induced through a highly controlled IL-12 production by immune cells originating from mouse spleen and Peyer's patches (PP) [18]. The same effect has also been observed in human activated peripheral mononuclear cells [19,20].…”

Modulation of Anti-Tumour Immune Responses by Probiotic Bacteria

“…Increased IL-12 production and the suppression of IL-10 was persistent even after stimulation with Escherichia coli-derived lipopolysaccharides (LPS) [36]. In another study, a formulation of Lactobacillus kefiri augmented the expression of co-stimulation and maturation markers on DCs, as well as the production of cytokines including IFN-γ and the effectiveness of CD8+ T cell activation [37]. Similar effects in the priming of human DCs towards IL-12-mediated Th1 polarization and IFN-γ production were also documented following co-culture with other lactobacilli species [38].…”