Lactobacillus paracasei subsp. paracasei B21060 suppresses human T-cell proliferation.
Recent studies have shown that probiotics are beneficial in T-cell-mediated inflammatory diseases. The molecular mechanism by which probiotics work remains elusive, but accumulating evidence indicates that probiotics can modulate immune cell responses. Since T cells express receptors for bacterial products or components, we examined whether different strains of lactobacilli directly regulate the functions of human T cells. CD4(+) T cells were isolated from blood and intestinal lamina propria (LP) of normal individuals and patients with inflammatory bowel disease (IBD). Mononuclear cells were also isolated from Peyer's patches. Cells were activated with anti-CD3/CD2/CD28 in the presence or absence of Lactobacillus paracasei subsp. paracasei B21060, L. paracasei subsp. paracasei F19, or L. casei subsp. casei DG. Cell proliferation and death, Foxp3, intracellular pH, and cytokine production were evaluated by flow cytometry. We showed that L. paracasei subsp. paracasei B21060 but neither L. paracasei subsp. paracasei F19 nor L. casei subsp. casei DG inhibited blood CD4(+) T-cell growth. This effect was associated with no change in cell survival, expression of Foxp3, or production of gamma interferon, interleukin-4 (IL-4), IL-5, and IL-10. L. paracasei subsp. paracasei B21060-mediated blockade of CD4(+) T-cell proliferation required a viable bacterium and was associated with decreased MCT-1 expression and low intracellular pH. L. paracasei subsp. paracasei B21060 also inhibited the growth of Peyer's patch mononuclear cells, normal lymphocytes, and IBD CD4(+) LP lymphocytes without affecting cytokine production. The data show that L. paracasei subsp. paracasei B21060 blocks T-cell growth, thus suggesting a mechanism by which these probiotics could interfere with T-cell-driven immune responses.
Peluso
Ilaria
I
Dipartimento di Medicina Interna, Università Tor Vergata, Via Montpellier 1, 00133 Rome, Italy.
Fina
Daniele
D
Caruso
Roberta
R
Stolfi
Carmine
C
Caprioli
Flavio
F
Fantini
Massimo Claudio
MC
Caspani
Giorgio
G
Grossi
Enzo
E
Di Iorio
Laura
L
Paone
Francesco Maria
FM
Pallone
Francesco
F
Monteleone
Giovanni
G
D017209:Apoptosis; D001769:Blood / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000096:biosynthesis; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015212:Inflammatory Bowel Diseases / Q000276:immunology; D007413:Intestinal Mucosa / Q000276:immunology; D007778:Lactobacillus / Q000276:immunology*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation; D027501:Monocarboxylic Acid Transporters / Q000096:biosynthesis; D010581:Peyer's Patches / Q000276:immunology; D019936:Probiotics; D027981:Symporters / Q000096:biosynthesis; D000099233:Monocarboxylate Transport Protein 1
D016207:Cytokines; D051858:Forkhead Transcription Factors; D027501:Monocarboxylic Acid Transporters; D027981:Symporters; D000099233:Monocarboxylate Transport Protein 1; C418974:FOXP3 protein, human