Schistosoma mansoni Venom Allergen Like Proteins Present Differential Allergic Responses in a Murine Model of Airway Inflammation

The Schistosoma mansoni Venom Allergen Like proteins (SmVALs) have been identified in the Transcriptome and Post-Genomic studies as targets for immune interventions. Two secreted members of the family were obtained as recombinant proteins in the native conformation. Antibodies produced against them showed that SmVAL4 was present mostly in cercarial secretions and SmVAL26 in egg secretions and that only the native SmVAL4 contained carbohydrate moieties. Due to concerns with potential allergic characteristics of this class of molecules, we have explored the mouse model of airway inflammation in order to investigate these properties in a more confined system. Sensitization and challenge with rSmVAL4, but not rSmVAL26, induced extensive migration of cells to the lungs, mostly eosinophils and macrophages; moreover, immunological parameters were also characteristic of an allergic inflammatory response. Our results showed that the allergic potential of this class of proteins can be variable and that the vaccine candidates should be characterized; the mouse model of airway inflammation can be useful to evaluate these properties

Evaluation of rSmVALs induction of airway inflammation and lung histopathology.

<p>(A) BAL total and differential cell counts for animals immunized with rSmVAL4 or rSmVAL4-Pro (rSmVAL4 protein after treatment with Pronase) and (B) rSmVAL26. Control group received only the intranasal challenge with rSmVAL and naïve mice received only PBS. Results are expressed as means ± SEM for groups of four mice and are representative of two experiments. *Significant differences (p<0.05) when compared to Control (mice that were only challenged with the respective proteins). (C) Lung sections of mice that were only challenged. (D) Representative lung sections of rSmVAL4-induced allergic airway inflammation in BALB/c mice, revealing the marked infiltration of inflammatory cells in the peribronchiolar space. (E) Lung sections of mice that received rSmVAL4-Pro, showing patterns similar to the control group; pictures at 10× of magnification.</p

Immunoblotting of protein extracts from <i>S. mansoni</i> stages and tegument fraction using anti-rSmVALs polyclonal antibodies.

<p>(A) Anti-rSmVAL4, and (B) anti-rSmVAL26. CER, cercariae; EGG, eggs; MIR, miracidia; AD, adult worms (female and male); SCH, 7-day old schistosomula; TEG, tegument; (C) Immunoblotting of Cercariae extracts before (−) and after (+) treatment with PNGase F using anti-rSmVAL4; and (D) Immunoblot of Egg extracts before (−) and after (+) treatment with PNGase F using anti-rSmVAL26 (20 µg of protein was loaded in each lane); P, positive control rSmVALs (50 ng). Positions of molecular mass standards (kDa) are indicated inside or on the side the autoradiogram film.</p

Molecular weight and isoeletric point of SmVALs investigated in this study.

a<p>Exp Mw = Expected Molecular weight.</p>b<p>Obs Mw = Approximate Observed Molecular weight.</p

Immunoblotting of released proteins using anti-rSmVALs polyclonal antibodies.

<p>(A) Released proteins by newly transformed schistosomulum (RP) cultured 0–6 h or correspondent parasite extract (PE) hybridized with anti-rSmVAL4 (RP - total released proteins by 1000 parasites was loaded in each lane, PE - 10 µg of protein extract was loaded in each lane). (B) EGG, eggs; MIR, miracidia; Hf, hatched fluid containing released proteins by hatching eggs, hybridized with anti-rSmVAL26; (C) ESP, secreted proteins by 72 h cultured viable mature eggs, hybridized with anti-rSmVAL26, (20 µg of protein was loaded in each lane); P, positive control rSmVALs (50 ng).</p

rSmVALs specific antibody production.

<p>BALB/c were sensitized s.c. with rSmVALs/Alum, rSmVAL4-Pro/Alum or PBS/Alum (Control) and then challenged i.n. with the proteins. The experiments were performed 24 h after the last challenge. (A) rSmVALs-specific IgG1 and (B) rSmVALs-specific IgE were determined in the sera by sandwich ELISA. Results are expressed as means ± SEM for groups of four mice and are representative of two experiments. a, b or #, significant differences (p<0.05) when compared to Control group (mice that were challenged with protein only).</p

Scientific Evidence about the Risks of Micro and Nanoplastics (MNPLs) to Human Health and Their Exposure Routes through the Environment

Nowadays, a large amount and variety of plastic is being produced and consumed by human beings on an enormous scale. Microplastics and nanoplastics (MNPLs) have become ubiquitous since they can be found in many ecosystem components. Plastic particles can be found in soil, water, and air. The routes of human exposure are numerous, mainly involving ingestion and inhalation. Once ingested, these particles interact with the gastrointestinal tract and digestive fluids. They can adsorb substances such as additives, heavy metals, proteins, or even microorganisms on their surface, which can cause toxicity. During inhalation, they can be inhaled according to their respective sizes. Studies have reported that exposure to MNPLs can cause damage to the respiratory tract, creating problems such as bronchitis, asthma, fibrosis, and pneumothorax. The reports of boards and committees indicate that there is little data published and available on the toxicity of MNPLs as well as the exposure levels in humans. Despite the well-established concept of MNPLs, their characteristics, and presence in the environment, little is known about their real effects on human health and the environment