Cry1Ac protoxin has potent mucosal and systemic adjuvant effects on antibody responses to proteins or polysaccharides. In this work, we examined whether Cry1Ac increased protective immunity against fatalNaegleria fowleriinfection in mice, which resembles human primary amoebic meningoencephalitis. Higher immunoglobulin G (IgG) than IgA anti-N. fowleriresponses were elicited in the serum and tracheopulmonary fluids of mice immunized by the intranasal or intraperitoneal route withN. fowlerilysates either alone or with Cry1Ac or cholera toxin. Superior protection against a lethal challenge with 5 × 10⁴liveN. fowleritrophozoites was achieved for immunization by the intranasal route. Intranasal immunization ofN. fowlerilysates coadministered with Cry1Ac increased survival to 100%; interestingly, immunization with Cry1Ac alone conferred similar protection to that achieved with amoebal lysates alone (60%). When mice intranasally immunized with Cry1Ac plus lysates were challenged with amoebae, both IgG and IgA mucosal responses were rapidly increased, but only the increased IgG response persisted until day 60 in surviving mice. The brief rise in the level of specific mucosal IgA does not exclude the role that this isotype may play in the early defense against this parasite, since higher IgA responses were detected in nasal fluids of mice intranasally immunized with lysates plus either Cry1Ac or cholera toxin, which, indeed, were the treatments that provided the major protection levels. In contrast, serum antibody responses do not seem to be related to the protection level achieved. Both acquired and innate immune systems seem to play a role in host defense againstN. fowleriinfection, but further studies are required to elucidate the mechanisms involved in protective effects conferred by Cry1Ac, which may be a valuable tool to improve mucosal vaccines.

Background. The consumption of sweeteners has increased in recent years, being used to control body weight and blood glucose. However, they can cause increased appetite, modification of immune function, and secretion of hormones in the GALT.Objective. To assess the effect of chronic sweetener consumption on glycaemia, cytokines, hormones, and GALT lymphocytes in CD1 mice.Material and Methods. 72 CD1 mice divided into 3 groups were used: (a) baseline, (b) middle, and (c) final. Groups (b) and (c) were divided into 4 subgroups: (i) Control, (ii) Sucrose, (iii) Sucralose, and (iv) Stevia. The following were determined: body weight, hormones (GIP, insulin, and leptin), lymphocytes CD3⁺T cells and CD19⁺B cells, IgA⁺plasma cells, and cytokines (IL-4, IL-5, IFN-γ, and TNF-α).Results. Sucralose reduces secretion of GIP and glycaemia but does not modify insulin concentration, increases body weight, and reduces food intake. Stevia increases the secretion of GIP, insulin, leptin, body weight, and glycaemia but keeps food consumption normal. Sucralose and Stevia showed a higher percentage of CD3⁺T cells, CD19⁺B cells, and IgA⁺plasma cells in Peyer’s patches, but only Stevia in lamina propria.Conclusion. Sweeteners modulate the hormonal response of cytokines and the proliferation of lymphocytes in the intestinal mucosa.

Introduction: Boron-containing compounds induce effects on immune responses. Such effects are interesting to the biomedical field for the development of therapeutic tools to modulate the immune system. Areas covered: The scope of BCC use to modify immune responses is expanding, mainly with regard to inflammatory diseases. The information was organized to demonstrate the breadth of reported effects. BCCs act as modulators of innate and adaptive immunity, with the former including regulation of cluster differentiation and cytokine production. In addition, BCCs exert effects on inflammation induced by infectious and noninfectious agents, and there are also reports regarding their effects on mechanisms involving hypersensitivity and transplants. Finally, the authors discuss the beneficial effects of BCCs on pathologies involving various targets and mechanisms. Expert opinion: Some BCCs are currently used as drugs in humans. The mechanisms by which these BCCs modulate immune responses, as well as the required structure–activity relationship for each observed mechanism of action, should be clarified. The former will allow for the development of improved immunomodulatory drugs with extensive applications in medicine. Patenting trends involve claims concerning the synthesis and actions of identified molecules with a defined profile regarding cytokines, cell differentiation, proliferation, and antibody production.