Universitat de Barcelona

Helminth coinfections mitigate clinical, parasitological, and immune outcomes in Mozambican children with malaria.

Clearance of Plasmodium falciparum infection requires a T1 immune response with production of pro-inflammatory cytokines, IgG1, and IgG3 responses. In contrast, infections with helminths are dominated by T2/T immune responses characterized by production of anti-inflammatory cytokines, IgE, and IgG4, which could potentially interfere with malaria outcomes and immune responses. We recruited 441 malaria-symptomatic children aged 2-10 years attending two hospitals in the Manhiça District (Mozambique) and assessed infection by rapid antigen diagnostic test, microscopy, and/or quantitative PCR. Using Luminex, we measured concentrations of 30 cytokines and IgA, IgM, IgE, IgG, and IgG1-4 levels against 12 P. falciparum antigens and total IgE. Among 74 children diagnosed with malaria, 22% (16) were coinfected with STH, and 78% (58) had only P. falciparum. Soil-transmitted helminths (STH) coinfection associated with lower P. falciparum density (P = 0.005) and fever (P = 0.047). Coinfected children also had lower concentrations of plasma pro-inflammatory (IL-8, TNF, IFNα, IP-10, MCP1, MIG, MIP1β, and GM-CSF) and anti-inflammatory cytokines (IL-5, IL-10) (P < 0.05). Furthermore, antibody responses to a set of P. falciparum antigens, including SSP2 (IgG1, IgG4, IgG), PTRAMP (IgG3), MSP3 (IgG), RH5 (IgG1), and α-gal (IgG1), as well as total IgE, were elevated in STH coinfected children (P < 0.05). STH infections were associated with decreased P. falciparum parasitemia, downregulation of inflammatory cytokines, and enhanced antibody responses, potentially resulting in milder malaria episodes, suggesting enhanced protective immunity.

Editorial: Animal models of allergic diseases: from basic to preclinical research.

Purification of Glycosylphosphatidylinositol-Anchored Mucins from Trypanosoma cruzi Trypomastigotes and Synthesis of α-Gal-Containing Neoglycoproteins: Application as Biomarkers for Reliable Diagnosis and Early Assessment of Chemotherapeutic Outcomes of Chagas Disease.

Chagas disease (ChD), caused by the protozoan parasite Trypanosoma cruzi, affects millions of people worldwide. Chemotherapy is restricted to two drugs, which are partially effective and may cause severe side effects, leading to cessation of treatment in a significant number of patients. Currently, there are no biomarkers to assess therapeutic efficacy of these drugs in the chronic stage. Moreover, no preventive or therapeutic vaccines are available. In this chapter, we describe the purification of Trypanosoma cruzi trypomastigote-derived glycosylphosphatidylinositol (GPI)-anchored mucins (tGPI-mucins) for their use as antigens for the reliable primary or confirmatory diagnosis and as prognostic biomarkers for early assessment of cure following ChD chemotherapy. We also describe, as an example, the synthesis of a potential tGPI-mucin-derived α-Gal-terminating glycan and its coupling to a carrier protein for use as diagnostic and prognostic biomarker in ChD.

Antibody responses to α-Gal in African children vary with age and site and are associated with malaria protection.

Naturally-acquired antibody responses to malaria parasites are not only directed to protein antigens but also to carbohydrates on the surface of Plasmodium protozoa. Immunoglobulin M responses to α-galactose (α-Gal) (Galα1-3Galβ1-4GlcNAc-R)-containing glycoconjugates have been associated with protection from P. falciparum infection and, as a result, these molecules are under consideration as vaccine targets; however there are limited field studies in endemic populations. We assessed a wide breadth of isotype and subclass antibody response to α-Gal in children from Mozambique (South East Africa) and Ghana (West Africa) by quantitative suspension array technology. We showed that anti-α-Gal IgM, IgG and IgG levels vary mainly depending on the age of the child, and also differ in magnitude in the two sites. At an individual level, the intensity of malaria exposure to P. falciparum and maternally-transferred antibodies affected the magnitude of α-Gal responses. There was evidence for a possible protective role of anti-α-Gal IgG3 and IgG4 antibodies. However, the most consistent findings were that the magnitude of IgM responses to α-Gal was associated with protection against clinical malaria over a one-year follow up period, especially in the first months of life, while IgG levels correlated with malaria risk.

pH-responsive polysaccharide-based polyelectrolyte complexes as nanocarriers for lysosomal delivery of therapeutic proteins.

Nanopharmaceutics composed of a carrier and a protein have the potential to improve the activity of therapeutical proteins. Therapy for lysosomal diseases is limited by the lack of effective protein delivery systems that allow the controlled release of specific proteins to the lysosomes. Here we address this problem by developing functional polyelectrolyte-based nanoparticles able to promote acidic pH-triggered release of the loaded protein. Trimethyl chitosan (TMC) was synthesized and allowed to form polyelectrolyte complexes (PECs) with the lysosomal enzyme α-GAL through self-assembly and ionotropic gelation, with average particle size <200 nm, polydispersity index (PDI) <0.2, ζ potential of ∼ 20 mV, and a protein loading efficiency close to 65%. These polyelectrolyte nanoparticles were stable and active under physiological conditions and able to release the enzyme at acidic pH, as demonstrated by in situ atomic force microscopy (AFM). These nanoparticles were further functionalized with Atto 647N for single-particle characterization and tracking their cellular uptake and fate using high-resolution fluorescence microscopy. In contrast with their precursor, TMC, PECs were efficiently internalized by human endothelial cells and mostly accumulated in lysosomal compartments. The superior physicochemical characteristics of the TMC/α-GAL PECs together with their excellent cellular uptake properties indicate their enormous potential as advanced protein delivery systems for the treatment of lysosomal storage diseases.