A major challenge in vaccine formulations is the stimulation of both the humoral and cellular immune response for well-defined antigens with high efficacy and safety. Adjuvant research has focused on developing particulate carriers to model the sizes, shapes and compositions of microbes or diseased cells, but not antigen fluidity and pliability. Here, we develop Pickering emulsions-that is, particle-stabilized emulsions that retain the force-dependent deformability and lateral mobility of presented antigens while displaying high biosafety and antigen-loading capabilities. Compared with solid particles and conventional surfactant-stabilized emulsions, the optimized Pickering emulsions enhance the recruitment, antigen uptake and activation of antigen-presenting cells, potently stimulating both humoral and cellular adaptive responses, and thus increasing the survival of mice upon lethal challenge. The pliability and lateral mobility of antigen-loaded Pickering emulsions may provide a facile, effective, safe and broadly applicable strategy to enhance adaptive immunity against infections and diseases.

Multidrug-resistant tuberculosis (MDR-TB) has become a lethal global threat. Insights into the immune regulation of MDR-TB are urgently needed for the development of new treatments; however, the T cell response to an MDR-TB infection in human remains unclear. In the present study, the proportion of Th1 and Th2 cell subsets and the level of related T cell subset cytokines in peripheral blood were investigated. We detected that an MDR-TB infection resulted in suppressed Th1 and Th2 cell activation, which was more remarkable in patients with MDR-TB than that in drug-sensitive tuberculosis (DS-TB) sufferers when compared to healthy controls (HCs). In addition, MDR-TB infection down-regulated the expression of IFN-γ, IL-2, and IL-10, and up-regulated IL-4, IL-6, and TNF-α expression. Our data suggest that the disturbance between protective and pathogenic effects induced by the immunosuppression of Th1- and Th2-type responses is a substantial characteristic of MDR-TB infections.

As peripheral lymphocytes are typically excluded from the gastrointestinal lymph tissues, current parenteral vaccinations fail to simultaneously induce systemic and mucosal responses. To break the natural barrier, "immunoticket" capsules are developed and heralded, which are designed with positive charged shells and oily core to spatiotemporally deliver antigens and all-trans retinoic acid (RA). After intramuscular vaccinations, these capsules function as an immunoticket to cultivate peripheral dendritic cells (DCs) with gut-homing receptors (CCR9). By hitchhiking on the concentration gradient of the CC-motif chemokine ligand 25 (CCL25), the primed DCs would home to the gut associated lymphoid tissues (GALTs) and induce antigen-specific IgA secretion and T cell engagements. Compared with the currently employed RA-involving formulations, the immunoticket capsules stimulate enhanced RA-mediated gut-tropism by mounting the inflammatory innate immunity. Through controlling the RA payload, the potential regulatory T cell engagement is circumvented. In ovalbumin (OVA) and EV71 vaccinations, the immunoticket capsules induce potent serum IgG titer and antigen-specific cytotoxic T cells in the peripheral lymph tissues, as well as robust IgA secretion and T cell engagements on gastrointestinal sites. The data suggest the potential of the immunotickets to serve as a facile, effective, and safe strategy to provide comprehensive immune responses against gastrointestinal infections and diseases.

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