Immune-enhancing effects of Lactobacillus johnsonii JERA01-supplemented feed additive in immune system: T cells, B cells, Dendritic cells

Lactobacillus johnsonii JERA01-supplemented feed additive (Lj-A) was produced by fermenting dried porcine blood with Lactobacillus johnsonii (Lj). Lj-A has highly digestible nutrients, bioactive peptides, and probiotic effects. To assess the immunomodulatory potential of Lj-A, it was tested on splenocytes of C57BL/6 mouse. Lj-A was treated on splenocytes in a range of concentration, 0-100 µg/ml. The metabolic activity of splenocytes was enhanced by Lj-A, as shown in MTT assay. Also, some splenocyte clusters were observed under a bright-field microscope on the wells treated with Lj-A. The splenocyte clusters indicated that the cells were activated and proliferating in response to Lj-A. These findings suggest that Lj-A stimulates splenocytes to promote immune cell activation, as evidenced by increased tumor necrosis factor-alpha and interleukin-12 production, thereby enhancing immunological defense functions. In vitro treatment of splenocytes with Lj-A increased the proportions of T cells, B cells, and CD25+ cells. In vivo, immune cell activity was evaluated in C57BL/6 mice orally administered with Lj-A at a dose of 100 mg/day. The proportion of dendritic cells in peritoneal cells was increased along with elevated CD54+ expression. Additionally, the proportions of B cells, CD25+ cells in Peyer’s patch cells increased as well. These results suggest that Lj-A may contribute to the enhancement of immune function and the maintenance of long-term health in animals.