Kinetics of IL-23 and IL-12 Secretion in Response to Toxoplasma gondii Antigens from THP-1 Monocytic Cells

IL-23 and IL-12 are structurally similar and critical for the generation of efficient cellular immune responses. Toxoplasma gondii induces a strong cell-mediated immune response. However, little is known about IL-23 secretion profiles in T. gondii-infected immune cells in connection with IL-12. We compared the patterns of IL-23 and IL-12 production by THP-1 human monocytic cells in response to stimulation with live or heat-killed T. gondii tachyzoites, or with equivalent quantities of either T. gondii excretory/secretory proteins (ESP) or soluble tachyzoite antigen (STAg). IL-23 and IL-12 were significantly increased from 6 hr after stimulation with T. gondii antigens, and their secretions were increased with parasite dose-dependent manner. IL-23 concentrations were significantly higher than those of IL-12 at the same multiplicity of infection. IL-23 secretion induced by live parasites was significantly higher than that by heat-killed parasites, ESP, or STAg, whereas IL-12 secretion by live parasite was similar to those of ESP or STAg. However, the lowest levels of both cytokines were at stimulation with heat-killed parasites. These data indicate that IL-23 secretion patterns by stimulation with various kinds of T. gondii antigens at THP-1 monocytic cells are similar to those of IL-12, even though the levels of IL-23 induction were significantly higher than those of IL-12. The detailed kinetics induced by each T. gondii antigen were different from each other.

study of Helicobacter pylori duodenal ulcer promoting gene [cfupA] polymorphisms in Iraq and Turkey and their role in IL-12 secretion

The duodenal ulcer promoting gene [dupA] has been identified recently and was found to associate with duodenal ulceration in some populations and gastric cancer in others. It was also found that this gene is polymorphic and dupAl [but not dupAZ] substantially increased H. pylori-induced IL-12 production from mononuclear cells. The aims of this paper were to determine the prevalence ofdupA polymorphisms in Iraq and Turkey and their effect on major cytokine secretion from peripheral blood mononuclear cells [PBMCs]. We studied a total of 85 H. pylon strains: 42 [non-ulcer disease [MUD]: 26; duodenal ulcer [DU]: 13; gastric ulcer [GU]: 3; gastric cancer [GC]: 0] which were isolated from Iraq and 43 [NUD: 28; DU: 12; GU: 2; GC: 1] from Turkey. dupA was PCR amplified then polymorphisms were studied by sequencing 10 and 9 dupA+ Iraqi and Turkish strains, respectively. It was found that none of the Iraqi strains and [22%] of Turkish strains typed as dupA1. Finally, 2 dupA1, 4 dupA2 and 2 dupA-negative strains were assessed for their ability to induce IL-12, IL-10 and IL-8 in PBMCs. The IL-12 response of PBMCs cultured for 48 hours with wild-type strains carrying the dupAl was significantly higher [strain: mean +/- sd pg/ml, WTD1A:416 +/- 22.8; WTD1B:405.9 +/- 22.4] than those induced by wild-type H. pylori carrying the dupA2 [WTD2A:290.7 +/- 16.3; WTD2B:252.5 +/- 5; WTD2C:262.1 +/- 14; WTD2D:279.5 +/- 17; p<0.02 for all] and than those typed dupA-negative [WTD-veA:258.5 +/- 12; WTD-veB:225.6 +/- 32; p<0.02 for all] . Regarding IL-8 and IL-10, we found no significant differences between dupAl and others. These data suggested that dupAl is rare in these two countries and dupAl plays an important role in IL-12 secretion from PBMCs. More research is needed to determine the functionality ofdupA and its relationship with disease

Transfected human mesenchymal stem cells do not lose their surface markers and differentiation properties

In this study, we evaluated the biological properties of human mesenchymal stem cells transfected (hMSC) with a plasmid vector expressing human cytokine interleukin-12 (IL-12). Surface markers were analysed by immunophenotyping using flow cytometry. Differentiation capability was evaluated towards adipogenesis and osteogenesis. We demonstrated that successfully transfected hMSC retained their surface immunophenotypes and differentiation potential into adipocytes and osteocytes. These results indicate that hMSC may be a suitable vehicle for gene transduction.

The Effects of Treponema pallidum on Human Dendritic Cells

Cell mediated immune responses play a prominent role in syphilis, which is caused by Treponema pallidum. The role of dendritic cells (DC) in the syphilitic infection is not well understood in human. In the present study, we studied interaction of T. pallidum with DC, generated from human peripheral blood mononuclear cells with GM-CSF and IL-4. After adding T. pallidum for 16 hours to immature DC at culture day 7, the change of surface antigens on DC was monitored by flow cytometry, the amount of IL-12 in culture supernatant of DC was measured by ELISA and T cell stimulatory capacity of DC was checked in mixed lymphocyte reaction (MLR). We have observed an efficient phagocytosis of T. pallidum by electron microscopy as early as 2 hours after addition of T. pallidum to DC. Interaction of DC with T. pallidum resulted in increased surface expression of CD83 which was proportionally increased according to the number of T. pallidum. Expressions of CD80, CD86 and HLA-DR on DC were slightly increased. The amount of IL-12 in the culture supernatant of DC was increased (1, 099pg/ml) after the addition of T. pallidum. T. pallidum-infected DC also displayed enhanced T cell stimulatory capacity in MLR. As seen from the above, we observed phagocytosis of T. pallidum by DC as early as 2 hours after addition of T. pallidum to DC and found that T. pallidum can stimulate DC maturation which mean that DC modulate an protective immune response during T. pallidum infection.