Lactobacillus casei reduces CD8+ T cell-mediated skin inflammation.
Probiotics, including Lactobacilli, have been postulated to alleviate allergic and inflammatory diseases, but evidence that they exert an anti-inflammatory effect by immune modulation of pathogenic T cell effectors is still lacking. The aim of this study was to examine whether L. casei could affect antigen-specific T cell-mediated skin inflammation. To this end, we used contact hypersensitivity to the hapten 2,4-dinitrofluorobenzene, a model of allergic contact dermatitis mediated by CD8+ CTL and controlled by CD4+ regulatory T cells. Daily oral administration of fermented milk containing L. casei or L. casei alone decreased skin inflammation by inhibiting the priming/expansion of hapten-specific IFN-gamma-producing CD8+ effector T cells. The down-regulatory effect of the probiotics required the presence of CD4+ T cells, which control the size of the hapten-specific CD8+ T cell pool primed by skin sensitization. L. casei cell wall was as efficient as live L. casei to regulate both the CHS response and the hapten-specific CD8+ T cell response, suggesting that cell wall components contribute to the immunomodulatory effect of L. casei. This study provides the first evidence that oral administration of L. casei can reduce antigen-specific skin inflammation by controlling the size of the CD8+ effector pool.
Inserm-U404 "Immunité et Vaccination", CERVI, IFR-128 BioSciences Lyon-Gerland, Lyon, France.
Ludivine
L
Chapat
Karine
K
Chemin
Bertrand
B
Dubois
Raphaëlle
R
Bourdet-Sicard
Dominique
D
Kaiserlian
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003877:Dermatitis, Contact / Q000517:prevention & control*; D005260:Female; D005285:Fermentation; D006241:Haptens / Q000276:immunology; D007074:Immunoglobulin G / Q000096:biosynthesis; D007780:Lacticaseibacillus casei / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008892:Milk; D019936:Probiotics / Q000494:pharmacology*
D006241:Haptens; D007074:Immunoglobulin G