title: Suppression of T-cell activation by Lactobacillus rhamnosus GG-degraded bovine casein.
abstract: Earlier data indicate that Lactobacillus rhomnosus GG ATCC 53103 (L. GG), a commensal intestinal bacterial strain, promotes the degradation of proteins in the gut in vivo, and bovine casein hydrolysed with L. GG-derived proteases suppresses lymphocyte proliferation in vitro. The present study aimed to evaluate the effect of L. GG-degraded bovine casein on T-cell activation, i.e. IL-2 mRNA expression and protein kinase C (PKC) translocation. To this end, Northern blot analyses for IL-2 mRNA expression and PKC assays with and without L. GG-degraded casein were carried out on T cells isolated from 11 healthy adults. Cell cultures in 8-11 experiments contained 1 mg ml(-1) bovine casein in degraded or undegraded form in the presence of a mitogen, i.e. phorbol 12,13-dibutyrate plus calcium ionophore (PBDu + A23187) or anti-CD3. Also IL-2, IL-4 and IFN-gamma syntheses were determined in 24-h culture supernatants. IL-2 mRNA expression was reduced in experiments with L. GG-degraded casein. In parallel, the IL-2 concentration in PBDu + A23187-stimulated culture supernatants, expressed as geometric means (95% confidence interval), decreased from 15,892 (7174-35,203) pg ml(-1) to 4744 (2095-10,742) pg ml(-1) when containing L. GG-degraded casein. L. GG-degraded casein inhibited PKC translocation, the action resembling that of PKC inhibitor, RO31-8220. These results extend previous data on L. GG-degraded casein, showing in vitro the suppression of T-cell activation.
authors.affiliation: Department of Paediatrics, University of Turku, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Pessi
authors.forename: E
authors.initials: E
authors.lastname: Isolauri
authors.forename: Y
authors.initials: Y
authors.lastname: Sütas
authors.forename: H
authors.initials: H
authors.lastname: Kankaanranta
authors.forename: E
authors.initials: E
authors.lastname: Moilanen
authors.forename: M
authors.initials: M
authors.lastname: Hurme
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002364:Caseins / Q000378:metabolism / Q000494:pharmacology*; D002417:Cattle; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007371:Interferon-gamma / Q000096:biosynthesis; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics; D015847:Interleukin-4 / Q000096:biosynthesis; D007778:Lactobacillus / Q000502:physiology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D011493:Protein Kinase C / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology
chemical_list: D002364:Caseins; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D012333:RNA, Messenger; D015847:Interleukin-4; D007371:Interferon-gamma; D011493:Protein Kinase C; D002118:Calcium