Perinatal and postweaning exposure to galactooligosaccharides/inulin prebiotics induced biomarkers linked to tolerance mechanism in a mouse model of strong allergic sensitization.

Food allergies are increasing, and no treatment exists, thus enhancing interest in prebiotic strategies. This study aimed to analyze the preventive effects of prebiotic feeding during perinatal and postweaning periods in a mouse model of allergy by studying biomarkers related to tolerance (IgG2a, IgA, IFN-γ, TGF-ß, and IL-10), to allergy (IgE, IgG1, IL-4, IL-17, symptoms), and to microbiota (propionate and MyD88). Balb/c mice, both dams and their pups, were fed a diet supplemented with (+Prb) or without (-Prb) GOS/inulin prebiotics. Mice were then sensitized with allergens. Regardless of diet, sensitized mice exhibited similar levels of IgE, IgG1, CD-23, IL-4, IL-17, and symptoms. However, in comparison to -Prb-sensitized mice, +Prb-sensitized mice displayed higher concentrations of total IgG2a (6669 ± 1788 vs 3696 ± 1326 fluorescence units, p < 0.005), specific IgA (285 ± 26 vs 156 ± 9 fluorescence units, p < 0.01), IFN-γ (3194 ± 424 vs 1853 ± 434 pg/mL, p < 0.01), IL-10 (777 ± 87 vs 95 ± 136 pg/mL, p < 0.005), TGF-ß (4853 ± 1959 vs 243 ± 444 pg/mL, p < 0.01), MyD88 (0.033 ± 0.019 vs 0.009 ± 0.004 relative expression, p < 0.01), and propionate (4.15 ± 0.8 vs 2.9 ± 1.15 µmol, p < 0.05). In a mouse model of allergy, prebiotic exposure during perinatal and postweaning periods induced the highest expression of biomarkers related to tolerance without affecting biomarkers related to allergy.

Exposure to a galactooligosaccharides/inulin prebiotic mix at different developmental time points differentially modulates immune responses in mice.

Prebiotics constitute emerging tools to alleviate immune pathologies. This study aimed to evaluate the effect of prebiotic exposure during perinatal and postweaning periods on immune and gut regulations. Mice were fed either a galactooligosaccharides/inulin prebiotic mix-enriched diet or a control diet during the perinatal and/or postweaning periods. Biomarkers related to gut barrier function (SCFA, heat shock proteins, zonula occludens protein-1, and mucin-2) and immune mechanisms (IgA, IgE, IgG1, IgG2a, IL-10, TGF-ß, IL-4, IL-17A, and IFN-γ) were analyzed. The milk of dams fed the prebiotic diet was more concentrated in both IgA and TGF-ß when prebiotics were introduced during both the perinatal and postweaning periods; IL-10, IgA, and IgG2a were increased in pups; and expression of intestinal markers was more pronounced. Postweaning exposure to prebiotics alone induced higher INF-γ and TGF-ß levels, whereas IgA levels fell. Combined exposure periods (perinatal/postweaning) to prebiotics increased tolerance-related immunoglobulins in pups and reinforced gut barrier functions.

Enhanced immune system activation and arterial inflammation accelerates atherosclerosis in lupus-prone mice.

OBJECTIVE: Premature atherosclerosis is a characteristic feature of systemic lupus erythematosus, a prototypic autoimmune disease. The principle cellular and molecular mechanisms which underlie such accelerated atherosclerosis are indeterminate. METHODS AND RESULTS: The pathophysiology of lupus-mediated atherogenesis was evaluated in a novel animal model involving transplantation of bone marrow cells from the lupus prone strain gld into Ldl-r(-/-) mice. Diet-induced atherogenesis in lethally-irradiated Ldl-r(-/-) mice transplanted with gld bone marrow cells resulted in accelerated atherosclerosis (+65%) as compared with control mice transplanted with wild-type marrow cells. Enhanced atherogenesis was associated with enhanced activation of both B and T lymphocytes and with arterial inflammation involving endothelial cell activation, monocyte recruitment, and accumulation of apoptotic debris, macrophages, and CD4 T cells, but was independent of plasma lipid levels and renal function. CONCLUSIONS: Our data support the contention that despite the absence of both disturbed cholesterol homeostasis and renal dysfunction in autoimmune gld-->Ldl-r(-/-) mice, lupus disease induces enhanced activation of the immune system and acts locally on the vasculature to induce inflammation, together with accumulation of apoptotic debris, macrophages, and CD4 T cells, thereby accelerating plaque progression.

Deciphering cellular states of innate tumor drug responses.

BACKGROUND: The molecular mechanisms underlying innate tumor drug resistance, a major obstacle to successful cancer therapy, remain poorly understood. In colorectal cancer (CRC), molecular studies have focused on drug-selected tumor cell lines or individual candidate genes using samples derived from patients already treated with drugs, so that very little data are available prior to drug treatment. RESULTS: Transcriptional profiles of clinical samples collected from CRC patients prior to their exposure to a combined chemotherapy of folinic acid, 5-fluorouracil and irinotecan were established using microarrays. Vigilant experimental design, power simulations and robust statistics were used to restrain the rates of false negative and false positive hybridizations, allowing successful discrimination between drug resistance and sensitivity states with restricted sampling. A list of 679 genes was established that intrinsically differentiates, for the first time prior to drug exposure, subsequently diagnosed chemo-sensitive and resistant patients. Independent biological validation performed through quantitative PCR confirmed the expression pattern on two additional patients. Careful annotation of interconnected functional networks provided a unique representation of the cellular states underlying drug responses. CONCLUSION: Molecular interaction networks are described that provide a solid foundation on which to anchor working hypotheses about mechanisms underlying in vivo innate tumor drug responses. These broad-spectrum cellular signatures represent a starting point from which by-pass chemotherapy schemes, targeting simultaneously several of the molecular mechanisms involved, may be developed for critical therapeutic intervention in CRC patients. The demonstrated power of this research strategy makes it generally applicable to other physiological and pathological situations.