Implantable Patch of Oxidized Nanofibrillated Cellulose and Lysozyme Amyloid Nanofibrils for the Regeneration of Infarcted Myocardium Tissue and Local Delivery of RNA-Loaded Nanoparticles.

Biopolymeric implantable patches are popular scaffolds for myocardial regeneration applications. Besides being biocompatible, they can be tailored to have required properties and functionalities for this application. Recently, fibrillar biobased nanostructures prove to be valuable in the development of functional biomaterials for tissue regeneration applications. Here, periodate-oxidized nanofibrillated cellulose (OxNFC) is blended with lysozyme amyloid nanofibrils (LNFs) to prepare a self-crosslinkable patch for myocardial implantation. The OxNFC:LNFs patch shows superior wet mechanical properties (60 MPa for Young's modulus and 1.5 MPa for tensile stress at tensile strength), antioxidant activity (70% scavenging activity under 24 h), and bioresorbability ratio (80% under 91 days), when compared to the patches composed solely of NFC or OxNFC. These improvements are achieved while preserving the morphology, required thermal stability for sterilization, and biocompatibility toward rat cardiomyoblast cells. Additionally, both OxNFC and OxNFC:LNFs patches reveal the ability to act as efficient vehicles to deliver spermine modified acetalated dextran nanoparticles, loaded with small interfering RNA, with 80% of delivery after 5 days. This study highlights the value of simply blending OxNFC and LNFs, synergistically combining their key properties and functionalities, resulting in a biopolymeric patch that comprises valuable characteristics for myocardial regeneration applications.

Racial discrimination is associated with food insecurity, stress, and worse physical health among college students.

BACKGROUND: Students of color disproportionately experience racial discrimination and food insecurity, which both lead to poor academic and health outcomes. This study explores the extent to which the location of racial discrimination experienced is associated with food insecurity, stress, physical health and grade point average among college students METHODS: A cross sectional study design was implemented to survey 143 students from a racially diverse public university. Logistic regression models assessed if discrimination at various locations was associated with food insecurity and linear models assessed how racial discrimination was associated with physical health, stress and grade point average RESULTS: Student's experiencing food security had an average discrimination score of 2.3 (1.23, 3.37), while those experiencing food insecurity had a statistically significant (P < 0.001) higher average discrimination score 7.3 (5.4, 9.21). Experiencing any racial discrimination was associated with increased odds of experiencing food insecurity when experienced from the police (OR 11.76, 95% CI: 1.41, 97.86), in the housing process (OR 7.9, 95% CI: 1.93, 32.34) and in the hiring process (OR 6.81, 95% CI: 1.98, 23.48) compared to those experiencing no racial discrimination after adjusting for race, gender, age and income. CONCLUSION: The location in which a student experienced racial discrimination impacted the extent to which the racial discrimination was associated with food security status. Further research is needed to explore potential mechanisms for how racial discrimination may lead to food insecurity.

Effects and Mechanisms of Action of Preussin, a Marine Fungal Metabolite, against the Triple-Negative Breast Cancer Cell Line, MDA-MB-231, in 2D and 3D Cultures.

Triple-negative breast cancer (TNBC) represents an aggressive subtype of breast cancer (BC) with a typically poorer prognosis than other subtypes of BC and limited therapeutic options. Therefore, new drugs would be particularly welcome to help treat TNBC. Preussin, isolated from the marine sponge-associated fungus, Aspergillus candidus, has shown the potential to reduce cell viability and proliferation as well as to induce cell death and cell cycle arrest in 2D cell culture models. However, studies that better mimic the tumors in vivo, such as 3D cell cultures, are needed. Here, we studied the effects of preussin in the MDA-MB-231 cell line, comparing 2D and 3D cell cultures, using ultrastructural analysis and the MTT, BrdU, annexin V-PI, comet (alkaline and FPG modified versions), and wound healing assays. Preussin was found to decrease cell viability, both in 2D and 3D cell cultures, in a dose-dependent manner, impair cell proliferation, and induce cell death, therefore excluding the hypothesis of genotoxic properties. The cellular impacts were reflected by ultrastructural alterations in both cell culture models. Preussin also significantly inhibited the migration of MDA-MB-231 cells. The new data expanded the knowledge on preussin actions while supporting other studies, highlighting its potential as a molecule or scaffold for the development of new anticancer drugs against TNBC.

Water-Soluble Saccharina latissima Polysaccharides and Relation of Their Structural Characteristics with In Vitro Immunostimulatory and Hypocholesterolemic Activities.

Brown macroalgae are an important source of polysaccharides, mainly fucose-containing sulphated polysaccharides (FCSPs), associated with several biological activities. However, the structural diversity and structure-function relationships for their bioactivities are still undisclosed. Thus, the aim of this work was to characterize the chemical structure of water-soluble Saccharina latissima polysaccharides and evaluate their immunostimulatory and hypocholesterolemic activities, helping to pinpoint a structure-activity relationship. Alginate, laminarans (F1, neutral glucose-rich polysaccharides), and two fractions (F2 and F3) of FCSPs (negatively charged) were studied. Whereas F2 is rich in uronic acids (45 mol%) and fucose (29 mol%), F3 is rich in fucose (59 mol%) and galactose (21 mol%). These two fractions of FCSPs showed immunostimulatory activity on B lymphocytes, which could be associated with the presence of sulphate groups. Only F2 exhibited a significant effect in reductions in in vitro cholesterol's bioaccessibility attributed to the sequestration of bile salts. Therefore, S. latissima FCSPs were shown to have potential as immunostimulatory and hypocholesterolemic functional ingredients, where their content in uronic acids and sulphation seem to be relevant for the bioactive and healthy properties.

A live auxotrophic vaccine confers mucosal immunity and protection against lethal pneumonia caused by Pseudomonas aeruginosa.

Pseudomonas aeruginosa is one of the leading causes of nosocomial pneumonia and its associated mortality. Moreover, extensively drug-resistant high-risk clones are globally widespread, presenting a major challenge to the healthcare systems. Despite this, no vaccine is available against this high-concerning pathogen. Here we tested immunogenicity and protective efficacy of an experimental live vaccine against P. aeruginosa pneumonia, consisting of an auxotrophic strain which lacks the key enzyme involved in D-glutamate biosynthesis, a structural component of the bacterial cell wall. As the amounts of free D-glutamate in vivo are trace substances in most cases, blockage of the cell wall synthesis occurs, compromising the growth of this strain, but not its immunogenic properties. Indeed, when delivered intranasally, this vaccine stimulated production of systemic and mucosal antibodies, induced effector memory, central memory and IL-17A-producing CD4+ T cells, and recruited neutrophils and mononuclear phagocytes into the airway mucosa. A significant improvement in mice survival after lung infection caused by ExoU-producing PAO1 and PA14 strains was observed. Nearly one third of the mice infected with the XDR high-risk clone ST235 were also protected. These findings highlight the potential of this vaccine for the control of acute pneumonia caused by this bacterial pathogen.

Inhibiting Phase Transfer of Protein Nanoparticles by Surface Camouflage-A Versatile and Efficient Protein Encapsulation Strategy.

Engineering a system with a high mass fraction of active ingredients, especially water-soluble proteins, is still an ongoing challenge. In this work, we developed a versatile surface camouflage strategy that can engineer systems with an ultrahigh mass fraction of proteins. By formulating protein molecules into nanoparticles, the demand of molecular modification was transformed into a surface camouflage of protein nanoparticles. Thanks to electrostatic attractions and van der Waals interactions, we camouflaged the surface of protein nanoparticles through the adsorption of carrier materials. The adsorption of carrier materials successfully inhibited the phase transfer of insulin, albumin, ß-lactoglobulin, and ovalbumin nanoparticles. As a result, the obtained microcomposites featured with a record of protein encapsulation efficiencies near 100% and a record of protein mass fraction of 77%. After the encapsulation in microcomposites, the insulin revealed a hypoglycemic effect for at least 14 d with one single injection, while that of insulin solution was only ∼4 h.

Metabolic control of T cell immune response through glycans in inflammatory bowel disease.

Mucosal T lymphocytes from patients with ulcerative colitis (UC) were previously shown to display a deficiency in branched N-glycosylation associated with disease severity. However, whether this glycosylation pathway shapes the course of the T cell response constituting a targeted-specific mechanism in UC remains largely unknown. In this study, we demonstrated that metabolic supplementation of ex vivo mucosal T cells from patients with active UC with N-acetylglucosamine (GlcNAc) resulted in enhancement of branched N-glycosylation in the T cell receptor (TCR), leading to suppression of T cell growth, inhibition of the T helper 1 (Th1)/Th17 immune response, and controlled T cell activity. We further demonstrated that mouse models displaying a deficiency in the branched N-glycosylation pathway (MGAT5-/-, MGAT5+/-) exhibited increased susceptibility to severe forms of colitis and early-onset disease. Importantly, the treatment of these mice with GlcNAc reduced disease severity and suppressed disease progression due to a controlled T cell-mediated immune response at the intestinal mucosa. In conclusion, our human ex vivo and preclinical results demonstrate the targeted-specific immunomodulatory properties of this simple glycan, proposing a therapeutic approach for patients with UC.

Preparation and Characterization of Dentin Phosphophoryn-Derived Peptide-Functionalized Lignin Nanoparticles for Enhanced Cellular Uptake.

The surface modification of nanoparticles (NPs) using different ligands is a common strategy to increase NP-cell interactions. Here, dentin phosphophoryn-derived peptide (DSS) lignin nanoparticles (LNPs) are prepared and characterized, the cellular internalization of the DSS-functionalized LNPs (LNPs-DSS) into three different cancer cell lines is evaluated, and their efficacy with the widely used iRGD peptide is compared. It is shown that controlled extent of carboxylation of lignin improves the stability at physiological conditions of LNPs formed upon solvent exchange. Functionalization with DSS and iRGD peptides maintains the spherical morphology and moderate polydispersity of LNPs. The LNPs exhibit good cytocompatibility when cultured with PC3-MM2, MDA-MB-231, and A549 in the conventional 2D model and in the 3D cell spheroid morphology. Importantly, the 3D cell models reveal augmented internalization of peptide-functionalized LNPs and improve antiproliferative effects when the LNPs are loaded with a cytotoxic compound. Overall, LNPs-DSS show equal or even superior cellular internalization than the LNPs-iRGD, suggesting that DSS can also be used to enhance the cellular uptake of NPs into different types of cells, and release different cargos intracellularly.

Radiolabeled Molecular Imaging Probes for the In Vivo Evaluation of Cellulose Nanocrystals for Biomedical Applications.

Cellulose nanocrystals (CNCs) have remarkable potential to improve the delivery of diagnostic and therapeutic agents to tumors; however, the in vivo studies on CNC biodistribution are still limited. We developed CNC-based imaging probes for the in vitro and in vivo evaluation using two labeling strategies: site-specific hydrazone linkage to the terminal aldehyde of the CNC and nonsite-specific activation using 1,1'-carbonyldiimidazole (CDI). The in vivo behavior of unmodified CNC, DOTA-CNC (ald.), and DOTA-CNC (OH) was investigated in healthy and 4T1 breast cancer mouse models. They displayed good biocompatibility in cell models. Moreover, the biodistribution profile and SPECT/CT imaging confirmed that the accumulation of 111In-labeled DOTA-CNC (ald.) and 111In-DOTA-CNC (OH) was primarily in hepatic, splenic, and pulmonary ducts in accordance with the clearance of nontargeted nanoparticles. The developed CNC imaging probes can be used to obtain information with noninvasive imaging on the behavior in vivo to guide structural optimization for targeted delivery.

Engineered Multifunctional Albumin-Decorated Porous Silicon Nanoparticles for FcRn Translocation of Insulin.

The last decade has seen remarkable advances in the development of drug delivery systems as alternative to parenteral injection-based delivery of insulin. Neonatal Fc receptor (FcRn)-mediated transcytosis has been recently proposed as a strategy to increase the transport of drugs across the intestinal epithelium. FcRn-targeted nanoparticles (NPs) could hijack the FcRn transcytotic pathway and cross the epithelial cell layer. In this study, a novel nanoparticulate system for insulin delivery based on porous silicon NPs is proposed. After surface conjugation with albumin and loading with insulin, the NPs are encapsulated into a pH-responsive polymeric particle by nanoprecipitation. The developed NP formulation shows controlled size and homogeneous size distribution. Transmission electron microscopy (TEM) images show successful encapsulation of the NPs into pH-sensitive polymeric particles. No insulin release is detected at acidic conditions, but a controlled release profile is observed at intestinal pH. Toxicity studies show high compatibility of the NPs with intestinal cells. In vitro insulin permeation across the intestinal epithelium shows approximately fivefold increase when insulin is loaded into FcRn-targeted NPs. Overall, these FcRn-targeted NPs offer a toolbox in the development of targeted therapies for oral delivery of insulin.

Drug-Loaded Multifunctional Nanoparticles Targeted to the Endocardial Layer of the Injured Heart Modulate Hypertrophic Signaling.

Ischemic heart disease is the leading cause of death globally. Severe myocardial ischemia results in a massive loss of myocytes and acute myocardial infarction, the endocardium being the most vulnerable region. At present, current therapeutic lines only ameliorate modestly the quality of life of these patients. Here, an engineered nanocarrier is reported for targeted drug delivery into the endocardial layer of the left ventricle for cardiac repair. Biodegradable porous silicon (PSi) nanoparticles are functionalized with atrial natriuretic peptide (ANP), which is known to be expressed predominantly in the endocardium of the failing heart. The ANP-PSi nanoparticles exhibit improved colloidal stability and enhanced cellular interactions with cardiomyocytes and non-myocytes with minimal toxicity. After confirmation of good retention of the radioisotope 111-Indium in relevant physiological buffers over 4 h, in vivo single-photon emission computed tomography (SPECT/CT) imaging and autoradiography demonstrate increased accumulation of ANP-PSi nanoparticles in the ischemic heart, particularly in the endocardial layer of the left ventricle. Moreover, ANP-PSi nanoparticles loaded with a novel cardioprotective small molecule attenuate hypertrophic signaling in the endocardium, demonstrating cardioprotective potential. These results provide unique insights into the development of nanotherapies targeted to the injured region of the myocardium.

Preparation and biological evaluation of ethionamide-mesoporous silicon nanoparticles against Mycobacterium tuberculosis.

Ethionamide (ETH) is an important second-line antituberculosis drug used for the treatment of patients infected with multidrug-resistant Mycobacterium tuberculosis. Recently, we reported that the loading of ETH into thermally carbonized-porous silicon (TCPSi) nanoparticles enhanced the solubility and permeability of ETH at different pH-values and also increased its metabolization process. Based on these results, we synthesized carboxylic acid functionalized thermally hydrocarbonized porous silicon nanoparticles (UnTHCPSi NPs) conjugated with ETH and its antimicrobial effect was evaluated against Mycobacterium tuberculosis strain H37Rv. The activity of the conjugate was increased when compared to free-ETH, which suggests that the nature of the synergy between the NPs and ETH is likely due to the weakening of the bacterial cell wall that improves conjugate-penetration. These ETH-conjugated NPs have great potential in reducing dosing frequency of ETH in the treatment of multidrug-resistant tuberculosis (MDR-TB).

Poly-N-Acetylglucosamine Production by Staphylococcus epidermidis Cells Increases Their In Vivo Proinflammatory Effect.

Poly-N-acetylglucosamine (PNAG) is a major component of the Staphylococcus epidermidis biofilm extracellular matrix. However, it is not yet clear how this polysaccharide impacts the host immune response and infection-associated pathology. Faster neutrophil recruitment and bacterial clearance were observed in mice challenged intraperitoneally with S. epidermidis biofilm cells of the PNAG-producing 9142 strain than in mice similarly challenged with the isogenic PNAG-defective M10 mutant. Moreover, intraperitoneal priming with 9142 cells exacerbated liver inflammatory pathology induced by a subsequent intravenous S. epidermidis challenge, compared to priming with M10 cells. The 9142-primed mice had elevated splenic CD4(+) T cells producing gamma interferon and interleukin-17A, indicating that PNAG promoted cell-mediated immunity. Curiously, despite having more marked liver tissue pathology, 9142-primed mice also had splenic T regulatory cells with greater suppressive activity than those of their M10-primed counterparts. By showing that PNAG production by S. epidermidis biofilm cells exacerbates host inflammatory pathology, these results together suggest that this polysaccharide contributes to the clinical features associated with biofilm-derived infections.

Influence of Surface Chemistry on Ibuprofen Adsorption and Confinement in Mesoporous Silicon Microparticles.

The effect of adsorption and confinement on ibuprofen was studied by immersion loading the molecules into porous silicon (PSi) microparticles. The PSi microparticles were modified into thermally oxidized PSi (TOPSi) and thermally hydrocarbonized PSi (THCPSi) to evaluate the effects of the loading solvent and the surface chemistry on the obtainable drug payloads. The payloads, location, and the molecular state of the adsorbed drug were evaluated using thermal analysis. The results showed that after the adsorption of ∼800 mg/cm3 (wdrug/vpores) of drug into the mesopores, depending on the solvent used in the immersion, the drug began to rapidly recrystallize on the external surface of the particles. Moderate concentrations, however, enabled payloads of 800-850 mg/cm3 without excessive surface crystallization, and thus, there was no need for rinsing the samples to remove the externally crystallized portion. The results showed that the confined ibuprofen forms nanocrystals inside of the mesopores after approximately 200 mg/cm3 payloads were obtained, accounting for half of the adsorbed drug amount. The presence of both crystalline and noncrystalline phases was further characterized using variable temperature solid-state nuclear magnetic resonance (NMR) measurements. The interactions between the drug molecules and the pore walls of TOPSi and THCPSi were observed using Fourier transform infrared and 1H NMR spectroscopies, and the hydrogen bonding between the silanol groups of TOPSi and the adsorbed ibuprofen was confirmed, but having only limited effect on the overall state of the confined drug. In vitro drug permeation studies in Caco-2 and Caco-2/HT29 cocultures showed that the adsorption onto hydrophilic or hydrophobic PSi microparticles had no significant effects on the ibuprofen permeation, whether the drug was partially nanocrystalline or completely in a liquidlike state.

Immune response in the adipose tissue of lean mice infected with the protozoan parasite Neospora caninum.

The adipose tissue can make important contributions to immune function. Nevertheless, only a limited number of reports have investigated in lean hosts the immune response elicited in this tissue upon infection. Previous studies suggested that the intracellular protozoan Neospora caninum might affect adipose tissue physiology. Therefore, we investigated in mice challenged with this protozoan if immune cell populations within adipose tissue of different anatomical locations could be differently affected. Early in infection, parasites were detected in the adipose tissue and by 7 days of infection increased numbers of macrophages, regulatory T (Treg) cells and T-bet(+) cells were observed in gonadal, mesenteric, omental and subcutaneous adipose tissue. Increased expression of interferon-γ was also detected in gonadal adipose tissue of infected mice. Two months after infection, parasite DNA was no longer detected in these tissues, but T helper type 1 (Th1) cell numbers remained above control levels in the infected mice. Moreover, the Th1/Treg cell ratio was higher than that of controls in the mesenteric and subcutaneous adipose tissue. Interestingly, chronically infected mice presented a marked increase of serum leptin, a molecule that plays a role in energy balance regulation as well as in promoting Th1-type immune responses. Altogether, we show that an apicomplexa parasitic infection influences immune cellular composition of adipose tissue throughout the body as well as adipokine production, still noticed at a chronic phase of infection when parasites were already cleared from that particular tissue. This strengthens the emerging view that infections can have long-term consequences for the physiology of adipose tissue.

Controlled Dissolution of Griseofulvin Solid Dispersions from Electrosprayed Enteric Polymer Micromatrix Particles: Physicochemical Characterization and in Vitro Evaluation.

The oral bioavailability of a poorly water-soluble drug is often inadequate for the desired therapeutic effect. The bioavailability can be improved by enhancing the physicochemical properties of the drug (e.g., dissolution rate, permeation across the gastrointestinal tract). Other approach include shielding the drug from the gastric metabolism and targeted drug release to obtain optimal drug absorption. In this study, a poorly water-soluble model drug, griseofulvin, was encapsulated as disordered solid dispersions into Eudragit L 100-55 enteric polymer micromatrix particles, which were produced by electrospraying. Similar micromatrix particles were also produced with griseofulvin-loaded thermally oxidized mesoporous silicon (TOPSi) nanoparticles dispersed to the polymer micromatrices. The in vitro drug dissolution at pH 1.2 and 6.8, and permeation at pH 7.4 across Caco-2/HT29 cell monolayers from the micromatrix particles, were investigated. The micromatrix particles were found to be gastro-resistant, while at pH 6.8 the griseofulvin was released very rapidly in a fast-dissolving form. Compared to free griseofulvin, the permeability of encapsulated griseofulvin across the intestinal cell monolayers was greatly improved, particularly for the TOPSi-doped micromatrix particles. The griseofulvin solid dispersions were stable during storage for 6 months at accelerated conditions. Overall, the method developed here could prove to be a useful oral drug delivery solution for improving the bioavailability of poorly water-soluble or otherwise problematic drugs.

siRNA Inhibition of Endocytic Pathways to Characterize the Cellular Uptake Mechanisms of Folate-Functionalized Glycol Chitosan Nanogels.

Glycol chitosan nanogels have been widely used in gene, drug, and contrast agent delivery in an effort to improve disease diagnosis and treatment. Herein, we evaluate the internalization mechanisms and intracellular fate of previously described glycol chitosan nanogels decorated with folate to target the folate receptor. Uptake of the folate-decorated nanogel was impaired by free folate, suggesting competitive inhibition and shared internalization mechanisms via the folate receptor. Nanogel uptake was shown to occur mainly through flotillin-1 and Cdc42-dependent endocytosis. This was determined by inhibition of uptake reduction observed upon siRNA depletion of these two proteins and the pathways that they regulate. The data also suggest the involvement of the actin cytoskeleton in nanogel uptake via macropinocytosis. After 7 h of incubation with HeLa cells, approximately half of the nanogel population was localized in endolysosomal compartments, whereas the remaining 50% of the material was in undefined regions of the cytoplasm. Glycol chitosan nanogels may thus have potential as drug delivery vectors for targeting different intracellular compartments.

Deficits in endogenous adenosine formation by ecto-5'-nucleotidase/CD73 impair neuromuscular transmission and immune competence in experimental autoimmune myasthenia gravis.

AMP dephosphorylation via ecto-5'-nucleotidase/CD73 is the rate limiting step to generate extracellular adenosine (ADO) from released adenine nucleotides. ADO, via A2A receptors (A2ARs), is a potent modulator of neuromuscular and immunological responses. The pivotal role of ecto-5'-nucleotidase/CD73, in controlling extracellular ADO formation, prompted us to investigate its role in a rat model of experimental autoimmune myasthenia gravis (EAMG). Results show that CD4(+)CD25(+)FoxP3(+) regulatory T cells express lower amounts of ecto-5'-nucleotidase/CD73 as compared to controls. Reduction of endogenous ADO formation might explain why proliferation of CD4(+) T cells failed upon blocking A2A receptors activation with ZM241385 or adenosine deaminase in EAMG animals. Deficits in ADO also contribute to neuromuscular transmission failure in EAMG rats. Rehabilitation of A2AR-mediated immune suppression and facilitation of transmitter release were observed by incubating the cells with the nucleoside precursor, AMP. These findings, together with the characteristic increase in serum adenosine deaminase activity of MG patients, strengthen our hypothesis that the adenosinergic pathway may be dysfunctional in EAMG. Given that endogenous ADO formation is balanced by ecto-5'-nucleotidase/CD73 activity and that A2ARs exert a dual role to restore use-dependent neurocompetence and immune suppression in myasthenics, we hypothesize that stimulation of the two mechanisms may have therapeutic potential in MG.

Protective effect of intranasal immunization with Neospora caninum membrane antigens against murine neosporosis established through the gastrointestinal tract.

Neospora caninum is an Apicomplexa parasite that in the last two decades was acknowledged as the main pathogenic agent responsible for economic losses in the cattle industry. In the present study, the effectiveness of intranasal immunization with N. caninum membrane antigens plus CpG adjuvant was assessed in a murine model of intragastrically established neosporosis. Immunized mice presented a lower parasitic burden in the brain on infection with 5 × 10(7) tachyzoites, showing that significant protection was achieved by this immunization strategy. Intestinal IgA antibodies raised by immunization markedly agglutinated live N. caninum tachyzoites whereas previous opsonization with IgG antibodies purified from immunized mice sera reduced parasite survival within macrophage cells. Although an IgG1 : IgG2a ratio < 1 was detected in the immunized mice before and after infection, indicative of a predominant T helper type 1 immune response, no increased production of interferon-γ was detected in the spleen or mesenteric lymph nodes of the immunized mice. Altogether, these results show that mucosal immunization with N. caninum membrane proteins plus CpG adjuvant protect against intragastrically established neosporosis and indicate that parasite-specific mucosal and circulating antibodies have a protective role against this parasitic infection.