Selective effects of Lactobacillus casei Shirota on T cell activation, natural killer cell activity and cytokine production

• Published in: Clinical and experimental immunology 2010-08, Vol.161 (2), p.378-388
• Main Authors: Dong, H, Rowland, I, Tuohy, K.M, Thomas, L.V, Yaqoob, P
• Format: Article
• Language: English
• Subjects: Adult; Analytical, structural and metabolic biochemistry; Antigens, CD - metabolism; Antigens, Differentiation, T-Lymphocyte - metabolism; Basic Science; Biological and medical sciences; Blood - drug effects; Blood - immunology; Blood - metabolism; CD25 antigen; CD4-Positive T-Lymphocytes - drug effects; CD4-Positive T-Lymphocytes - immunology; CD4-Positive T-Lymphocytes - metabolism; CD56 antigen; CD69 antigen; CD8-Positive T-Lymphocytes - drug effects; CD8-Positive T-Lymphocytes - immunology; CD8-Positive T-Lymphocytes - metabolism; Cell activation; Cell Separation; Cells, Cultured; Concanavalin A - pharmacology; Cytokines; Cytokines - metabolism; Cytotoxicity; Cytotoxicity, Immunologic - immunology; Fundamental and applied biological sciences. Psychology; Humans; Immune response; Immune system; Immunity; immunomodulation; Inflammation; Interleukin 1; Interleukin 10; Interleukin 12; Interleukin 6; Interleukin-2 Receptor alpha Subunit - metabolism; Interleukins - metabolism; Killer Cells, Natural - immunology; L. casei Shirota; Lactobacillus casei; Lactobacillus casei - immunology; Lectins, C-Type - metabolism; Leukocytes, Mononuclear - cytology; Leukocytes, Mononuclear - drug effects; Leukocytes, Mononuclear - immunology; Leukocytes, Mononuclear - metabolism; Lipopolysaccharides; Lipopolysaccharides - pharmacology; Lymphocyte Activation - drug effects; Lymphocyte Activation - immunology; Lymphocytes T; Monocytes; Monocytes - cytology; Monocytes - immunology; Monocytes - metabolism; Natural killer cells; NK cell activity; Peripheral blood mononuclear cells; Probiotics; T cell receptors; T lymphocytes; T-Lymphocytes - drug effects; T-Lymphocytes - immunology; T-Lymphocytes - metabolism; Tumor necrosis factor-a; Tumor Necrosis Factor-alpha - metabolism
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2010.04173.x

Modulation of host immunity is an important potential mechanism by which probiotics confer health benefits. This study was designed to investigate the effects of a probiotic strain, Lactobacillus casei Shirota (LcS), on immune function using human peripheral blood mononuclear cells (PBMC) in vitro. In addition, the role of monocytes in LcS-induced immunity was also explored. LcS promoted natural killer (NK) cell activity and preferentially induced expression of CD69 and CD25 on CD8⁺ and CD56⁺ subsets in the absence of any other stimulus. LcS also induced production of interleukin (IL)-1β, IL-6, tumour necrosis factor (TNF)-α, IL-12 and IL-10 in the absence of lipopolysaccharide (LPS). In the presence of LPS, LcS enhanced IL-1β production but inhibited LPS-induced IL-10 and IL-6 production, and had no further effect on TNF-α and IL-12 production. Monocyte depletion reduced significantly the impact of LcS on lymphocyte activation, cytokine production and natural killer (NK) cell activity. In conclusion, LcS activated cytotoxic lymphocytes preferentially in both the innate and specific immune systems, which suggests that LcS could potentiate the destruction of infected cells in the body. LcS also induced both proinflammatory and anti-inflammatory cytokine production in the absence of LPS, but in some cases inhibited LPS-induced cytokine production. Monocytes play an important role in LcS-induced immunological responses.