Probiotic supplementation with Lactobacillus casei (Actimel) induces a Th1 response in an animal model of Antiphospholipid syndrome

Probiotic fermented milk products have the capacity to modulate many immunological mechanisms. Several attempts have been made to alter the progression of various atopic and inflammatory disorders in which the immune system plays a major role. We studied this issue in an animal model of the antiphospholipid syndrome (APS) by supplementing the animals' daily intake with a probiotic mixture. We studied the effects of nutritional supplementation of a commercial product that consists of 10(8)/ml Lactobacillus casei (Actimel) on Balb/c mice that were immunized with beta-2- glycoprotein (beta 2GPI) in order to induce a familiar murine model of APS. As controls, we used similar animals that were fed with either yogurt or sham solution as a supplement. We analyzed the effect of Actimel on the concentrations of interleukin (IL)-10 interferon gamma (IFN gamma) as well as the extent of the primary T cell response to beta 2GPI, and the levels of autoantibodies to beta 2GPI determined by ELISA. Two weeks after priming (in the hind footpad) of Balb/c mice with beta 2GPI, we analyzed the cytokine profile of the animals by measuring the concentration of IL-10 and IFN gamma in the supernatants of lymphocytes that were extracted from the popliteal lymph nodes. Following stimulation with 10 mu g/mL of beta 2GPI, we noticed significant (P < 0.05) suppression of IL-10 production by the stimulated lymphocytes in the animals fed with Actimel and yogurt in comparison to sham solution (73.42 +/- 29.4, 84.7 +/- 8, 196 +/- 41.62 pg/mL, respectively). Both dairy products enhanced the secretion of IFN gamma from 657 +/- 47.09 pg/mL to 896 +/- 78.1, and 933 +/- 76.7 (P < 0.01), respectively; similarly they also accelerated by a mild degree the level of the T cell primary response to beta 2GPI measured by [H-3]thymidine incorporation. The level of autoantibodies to beta 2GPI was suppressed in mice fed with actimel and yogurt in a significant manner (P < 0.05). Actimel as well as yogurt confer an immunological impact on Balb/c mice immunized with beta 2GPI. Actimel was able not only to enhance IFN gamma secretion but also to inhibit IL-10 production.