Lactobacillus casei reduces CD8+ T cell-mediated skin inflammation

Eur J Immunol. 2004 Sep;34(9):2520-8. doi: 10.1002/eji.200425139.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD4-Positive T-Lymphocytes / physiology
  • CD8-Positive T-Lymphocytes / immunology*
  • Dermatitis, Contact / prevention & control*
  • Female
  • Fermentation
  • Haptens / immunology
  • Immunoglobulin G / biosynthesis
  • Lacticaseibacillus casei / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Milk
  • Probiotics / pharmacology*


  • Haptens
  • Immunoglobulin G