Four Lactobacillus strains - Lactobacillus plantarum CJLP133, L. plantarum CJLP243, L. plantarum CJNR26, and Lactobacillus gasseri CJMF3 - were isolated from Korean fermented food or healthy infant feces, and their capacity to modulate cellular and humoral immune responses was studied. Feeding of the tested lactobacilli for 8 weeks did not alter the weight of and cell numbers in the spleen of mice. However, CJLP133 and CJLP243 strains increased the T lymphocyte population in the spleen of mice, while CJNR26 and CJMF3 increased the B lymphocyte population. In splenocytes treated with concanavalin A, ingestion of CJLP133 and CJLP243 promoted T lymphocyte proliferation and secretion of T cell cytokines, whereas feeding of the CJNR26 and CJMF3 strains enhanced B lymphocyte proliferation in splenocytes treated with lipopolysaccharide and plaque formation. These results suggest that CJLP133 and CJLP243 have immunostimulating activity through the enhancement of T cell activation, while CJNR26 and CJMF3 exhibit immunopotentiation through the increment of B cell activation.

Activated macrophages have been simply de?ned as cells that secrete in?ammatory mediators and kill intracellular pathogens until few years ago. Recent studies have proposed a new classification system to separate activated macrophages based on their functional phenotypes: host defense, wound healing, and immune regulation. Regulatory macrophages can arise following innate or adaptive immune responses and hinder macrophage-mediated host defense and inflammatory functions by inhibiting the production of pro-inflammatory mediators. In this study, we investigated whether PD-1 and PD-L1 interaction between macrophages and T cells alters macrophage activities. Our data provide evidence for PD-1/PD-L1 engagement inducing a regulatory profile in macrophages. Regulatory macrophages derived from PD-L1 signaling lost their host defense activity, which consists of the production of pro-inflammatory cytokine IL-6 and the exhibition of increased IL-10, SPHK1 and LIGHT gene levels in early phases of LPS stimulation. This differentiation seems to occur through excessive activation of TLR4 downstream MAPK signaling pathways. Regulatory macrophages induced from PD-1/PD-L1 interaction decrease inflammatory mediators and produce anti-inflammatory cytokines, so this macrophage subset has been under considerable attention as a possible immune regulation mechanism. Understanding and modulating regulatory macrophages may lead to new approches to treat or prevent auto-immune diseases such as type I diabetes, rheumatic syndrome and hypersensitivity-related diseases, which are concerned with the overproduction of inflammatory cytokines in macroages. 

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Peroxiredoxin is a well-studied antioxidant enzyme. Enzymes in this category eliminate ROS in order to protect cells from oxidative stresses. PRX-1 exerts a protective antioxidant role in cells through its peroxidase activity, reCorrespondence Kwang Woo Hwang, Laboratory of Host Defense Modulation, College of Pharmacy, Chung-Ang University, 221 Heukseok-dong, Dongjakgu, Seoul, Korea. Tel: +82 2 820 5597; Fax: +82 2 823 5597; e-mail: khwang@cau.ac.kr List of Abbreviations: DMEM, Dulbecco's modified Eagle's medium; dNTP, deoxyribonucleotide triphosphate; FACS, fluorescence-activated cell sorting; GFP, green fluorescent protein; IL, interleukin; IκBα, nuclear factor of kappa light polypeptide gene enhancer in B-cells inhibitor, alpha; iNOS, inducible nitric acid synthase; LPS, lipopolysaccharide; NF-κB , nuclear factor kappa-light-chain-enhancer of activated B cells; NK, natural killer; PMA, phorbol 12-myristate 13-acetate; PRX, peroxiredoxin; ROS, reactive oxygen species; shPRX-1, shRNA lentiviral vector targeting peroxiredoxin-1; STAT, signal transducers and activators of transcription; TNF, tumor necrosis factor. ducing H 2 O 2 , peroxynitrite, and a wide range of organic hydroperoxides for detoxification (1).The mammalian PRX family can be classified into six distinct groups (types I through VI). Other,