Lactococcus lactis subsp. Cremoris C60 restores T Cell Population in Small Intestinal Lamina Propria in Aged Interleukin-18 Deficient Mice.
Lactic acid bacteria (LAB), a major commensal bacterium in the small intestine, are well known beneficial bacteria which promote establishment of gut-centric immunity, such as anti-inflammation and anti-infection. In this report, we show that a LAB strain Lactococcus lactis subsp. Cremoris C60 possess an ability to activate antigen presenting cells, such as dendritic cells (DCs), and intestinal T cells which possibly support to maintain healthy intestinal immunological environment in aging process. We found that CD4+ T cells in the small intestine are dramatically decreased in aged Interleukin-18 knock out (IL-18KO) mice, associated with the impairment of IFN-γ production in the CD4+ T cells, especially in small intestinal lamina propria (LP). Surprisingly, heat killed-C60 (HK-C60) diet completely recovered the CD4+ T cells population and activity in SI-LP and over activated the population in Peyer's patches (PPs) of IL-18KO mice. The HK-C60 diet was effective approach not only to restore the number of cells, but also to recover IFN-γ production in the CD4+ T cell population in the small intestine of IL-18-deficient mice. As a possible cause in the age-associated impairment of CD4+ T cells activity in IL-18KO mice, we found that the immunological activity was downregulated in the IL-18-deficient DCs. The cytokines production and cellular activation markers expression were downregulated in the IL-18-deficient bone marrow derived dendritic cells (BMDCs) at the basal level, however, both activities were highly upregulated in HK-C60 stimulation as compared to those of WT cells. Antigen uptake was also attenuated in the IL-18-deficient BMDCs, and it was significantly enhanced in the cells as compared to WT cells in HK-60 stimulation. An in vitro antigen presentation assay showed that IFN-γ production in the CD4+ T cells was significantly enhanced in the culture of IL-18-deficient BMDCs compared with WT cells in the presence of HK-C60. Thus, we conclude that HK-C60 diet possesses an ability to restore T cells impairment in the small intestine of IL-18-deficient environment. In addition, the positive effect is based on the immunological modification of DCs function which directory influences into the promotion of effector CD4+ T cells generation in the small intestine.
['Saito|Suguru|S|', 'Kakizaki|Nanae|N|', 'Okuno|Alato|A|', 'Maekawa|Toshio|T|', 'Tsuji|Noriko M|NM|']
D000375:Aging D000818:Animals D015496:CD4-Positive T-Lymphocytes D002452:Cell Count D003713:Dendritic Cells D004032:Diet D007371:Interferon-gamma D020382:Interleukin-18 D007421:Intestine, Small D017045:Lactococcus D051379:Mice D008807:Mice, Inbred BALB C D018345:Mice, Knockout D009092:Mucous Membrane D019936:Probiotics D013601:T-Lymphocytes
small intestine Interleukin-18 dendritic cells lamina propria (LP) IFN-γ+CD4+ T (Th1) cells Peyer’s patch (PP) intestinal immunity probiotics