Modulatory actions of Echinococcus granulosus antigen B on macrophage inflammatory activation.

Cestodes use own lipid-binding proteins to capture and transport hydrophobic ligands, including lipids that they cannot synthesise as fatty acids and cholesterol. In E. granulosus s.l., one of these lipoproteins is antigen B (EgAgB), codified by a multigenic and polymorphic family that gives rise to five gene products (EgAgB8/1-5 subunits) assembled as a 230 kDa macromolecule. EgAgB has a diagnostic value for cystic echinococcosis, but its putative role in the immunobiology of this infection is still poorly understood. Accumulating research suggests that EgAgB has immunomodulatory properties, but previous studies employed denatured antigen preparations that might exert different effects than the native form, thereby limiting data interpretation. This work analysed the modulatory actions on macrophages of native EgAgB (nEgAgB) and the recombinant form of EgAg8/1, which is the most abundant subunit in the larva and was expressed in insect S2 cells (rEgAgB8/1). Both EgAgB preparations were purified to homogeneity by immunoaffinity chromatography using a novel nanobody anti-EgAgB8/1. nEgAgB and rEgAgB8/1 exhibited differences in size and lipid composition. The rEgAgB8/1 generates mildly larger lipoproteins with a less diverse lipid composition than nEgAgB. Assays using human and murine macrophages showed that both nEgAgB and rEgAgB8/1 interfered with in vitro LPS-driven macrophage activation, decreasing cytokine (IL-1ß, IL-6, IL-12p40, IFN-ß) secretion and ·NO generation. Furthermore, nEgAgB and rEgAgB8/1 modulated in vivo LPS-induced cytokine production (IL-6, IL-10) and activation of large (measured as MHC-II level) and small (measured as CD86 and CD40 levels) macrophages in the peritoneum, although rEgAgB8/1 effects were less robust. Overall, this work reinforced the notion that EgAgB is an immunomodulatory component of E. granulosus s.l. Although nEgAgB lipid's effects cannot be ruled out, our data suggest that the EgAgB8/1 subunit contributes to EgAgB´s ability to regulate the inflammatory activation of macrophages.

Docetaxel in chitosan-based nanocapsules conjugated with an anti-Tn antigen mouse/human chimeric antibody as a promising targeting strategy of lung tumors.

The aim of this work was to evaluate the physicochemical and biological properties of docetaxel (DCX) loaded chitosan nanocapsules (CS Nc) functionalized with the monoclonal antibody Chi-Tn (CS-PEG-ChiTn mAb Nc) as a potential improvement treatment for cancer therapy. The Tn antigen is highly specific for carcinomas, and this is the first time that such structure is targeted for drug delivery. The nanocapsules (Ncs), formed as a polymeric shell around an oily core, allowed a 99.9% encapsulation efficiency of DCX with a monodispersity particle size in the range of 200 nm and a high positive surface charge that provide substantial stability to the nanosystems. Release profile of DCX from Ncs showed a sustained and pH dependent behavior with a faster release at acidic pH, which could be favorable in the intracellular drug delivery. We have designed PEGylated CS Nc modified with a monoclonal antibody which recognize Tn antigen, one of the most specific tumor associated antigen. A biotin-avidin approach achieved the successful attachment of the antibody to the nanocapsules. Uptake studies and viability assay conducted in A549 human lung cancer cell line in vitro demonstrate that ChiTn mAb enhance nanoparticles internalization and cell viability reduction. Consequently, these ChiTn functionalized nanocapsules are promising carriers for the active targeting of DCX to Tn expressing carcinomas.