An Exaggerated Immune Response in Female BALB/c Mice Controls Initial Toxoplasma gondii Multiplication but Increases Mortality and Morbidity Relative to Male Mice

Helicobacter pylori-Toxoplasma gondii interplay with a possible role of IL-10

Parasites are known for their modulatory effects on the immune response. The impact of toxoplasmosis on the immune response towards H. pylori is being studied in terms of IL-10 levels. This study included 110 patients suffering from persistent dyspepsia and 50 apparently healthy controls. Stool samples were collected and tested for H. pylori using colloidal gold one step test. Sera were examined for anti-Toxoplasma IgM and IgG using ELISA. IL-10 was also tested in the sera using ELISA. We found that Toxoplasma IgM and IgG tested positive in 1.8 % and 40 % of H. pylori positive patients, respectively. H. pylori-infected patients displayed higher IL-10 levels than the healthy controls (84 versus 0.59 pg/ml, respectively, P < 0.001). Classification of H. pylori positive patients according to Toxoplasma IgG titers yielded three groups: negative (58, 52.7 %), equivocal (8, 7.3 %), and positive (44, 40 %) groups, with the highest IL-10 levels detected in the double positive than the negative and the equivocal group (215 pg/ml versus 43 and 112.5 pg/ml, respectively, P < 0.001). There was strong positive correlation between Toxoplasma IgG titers and IL-10 levels (rs = 0.82, P < 0.001). Toxoplasma enhances IL-10 production in response to H. pylori infection. This could ameliorate the inflammatory response in the gastric mucosa, and subsequently more colonization with the H. pylori is achieved, resulting in persistent infection.

Nanosphere pharmacodynamics improves safety of immunostimulatory cytokine therapy

Systemic administration of interleukin (IL)-12 induces potent anti-tumor immune responses in preclinical cancer models through the systemic activation of effector immune cells and release of proinflammatory cytokines. IL-12-loaded PLGA nanospheres (IL12ns) are hypothesized to improve therapeutic efficacy and thwart unwanted side effects observed in previous human clinical trials. Through the investigation of peripheral blood and local tissue immune responses in healthy BALB/c mice, the immune-protective pharmacodynamics of IL12ns were suggested. Nanospheres increased pro-inflammatory plasma cytokines/chemokines (IFN-γ, IL-6, TNF-α, and CXCL10) without inducing maladaptive transcriptomic signatures in circulating peripheral immune cells. Gene expression profiling revealed activation of pro-inflammatory signaling pathways in systemic tissues, the likely source of these effector cytokines. These data support that nanosphere pharmacodynamics, including shielding IL-12 from circulating immune cells, depositing peripherally in systemic immune tissues, and then slowly eluting bioactive cytokine, thereafter, are essential to safe immunostimulatory therapy.