ARTICLE | doi:10.20944/preprints201910.0335.v1
Subject: Life Sciences, Microbiology Keywords: lipopolysaccharides; mucin; ileum; MUC2; mucosal barrier; mouse
Online: 29 October 2019 (10:50:10 CET)
The small intestinal villus is covered with a thick layer of mucus that is secreted by goblet cells and functions primarily to first barrier from damage by toxic substance. Recent studies showed that goblet cells and mucins involved in complex immune function. Lipopolysaccharide (LPS) is widespread in the housing of livestock, which can induce bacterial infection symptoms and immunological stress within a short of time. Therefore, we aimed to study the effects of long-term exposure to different doses of LPS on intestinal mucus layer and immune barrier. The result showed that mucus layer thickness and goblet cell functions were significantly increased after low doses of LPS. The intestinal mucosal barrier can block the bacteria of the lumen, but LPS can penetrate this barrier into the blood, putting the body in a state of chronic low-grade inflammation and reducing the body’s immune function. However, after long-term exposure to high doses of LPS, a large number of lysosomes in goblet cells caused loss of function, and mucus layer thickness was significantly decreased. A large amount of LPS stuck to the mucus, leading to normal LPS and inflammatory cytokines level of plasma. The intestinal tissue morphology was damaged, and a number of immune cells were necrosis in the intestine. Collectively, long-term exposure to low doses of LPS lead to chronic low-grade inflammation in the body. Long-term exposure to high doses of LPS can be directly linked to the severity of the immunosuppression in the body.
ARTICLE | doi:10.20944/preprints202208.0144.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: mucosal immunization; mucosal vaccine; vaccine delivery; administration volume; targeted vaccines; M cell targeting; dendritic cell targeting; C5aR1; C5a1R; CD88; EP54; EP67
Online: 8 August 2022 (10:17:30 CEST)
Generating long-lived mucosal and systemic antibodies through respiratory immunization with protective antigens encapsulated in nanoscale biodegradable particles could potentially decrease or eliminate the incidence of many infectious diseases but requires incorporation of a suitable mucosal immunostimulant. We previously found that respiratory immunization with a model protein antigen (LPS-free OVA) encapsulated in PLGA 50:50 nanoparticles (~380 nm diameter) surface modified with complement peptide-derived immunostimulant 02 (CPDI-02; formerly EP67) through 2kDa PEG linkers increases mucosal and systemic OVA-specific memory T-cells with long-lived surface phenotypes in young, naïve female C57BL/6 mice. Here, we determined if respiratory immunization with LPS-free OVA encapsulated in similar PLGA 50:50 microparticles (~1 μm diameter) surface modified with CPDI-02 (CPDI-02-MP) increases long-term OVA-specific mucosal and systemic antibodies. We found that, compared to MP surface modified with inactive, scrambled scCPDI-02 (scCPDI-02-MP), intranasal administration of CPDI-02-MP in 50 μL sterile PBS greatly increased titers of short-term (14 days post-immunization) and long-term (90 days post-immunization) antibodies against encapsulated LPS-free OVA in nasal lavage fluids, bronchoalveolar lavage fluids, and sera of young, naïve female C57BL/6 mice. Thus, surface modification of biodegradable microparticles with CPDI-02 is likely to increase long-term mucosal and systemic antibodies against encapsulated protein antigen after respiratory and possibly other routes of mucosal immunization.
ARTICLE | doi:10.20944/preprints202106.0431.v1
Subject: Life Sciences, Immunology Keywords: cell-penetrating peptides; nasal vaccination; mucosal; immune enhancer; adjuvant
Online: 16 June 2021 (10:19:31 CEST)
Cell-penetrating peptides (CPPs) have been evaluated as enhancers in drug delivery, their addition in medical formulations favors absorption allowing obtaining the pharmacological effect with lower drug doses. In vaccine formulations their inclusion has been also explored with interesting results. Currently mucosal vaccination constitutes a promising alternative with the main advantage of inducing both systemic and mucosal immune responses, which are crucial for control tumors and infections at mucosal tissues. The known CPP Penetratin was recently evaluated in vaccine formulations designed for nasal administration. The authors demonstrated that this non-covalent linked CPP could improve the antigen-specific systemic and mucosal antibody responses. In the present work we evaluate in Balb/C mice the nasal immune-enhancing effect of four CPPs. Animals were intranasally immunized with CPP and the recombinant hepatitis B surface protein (HBsAg) as model antigen. The IgG antibody response in sera and the mucosal IgA response were measured by ELISA. The IFN-g secretion response at spleen was also evaluated by ELISPOT and ELISA. Among the CPPs studied one novel peptide stand out by its ability to potentiate the humoral and cellular immune response against the co-administered antigen. Considering that the use of mucosal routes is a promising strategy in vaccination against infectious diseases and cancer, which are gaining special relevance nowadays in the development of novel candidates against SARS-CoV-2 and other potential emerging respiratory virus, the searching and development of safe mucosal adjuvants constitute a current need.
Subject: Medicine & Pharmacology, Allergology Keywords: Crohn’s Disease, Inflammatory Bowel Disease, Exclusive Enteral Nutrition, Mucosal Healing
Online: 16 February 2021 (15:58:08 CET)
Crohn’s disease is an inflammatory bowel disease whose prevalence is increasing worldwide. Among medical strategies, the dietary therapy with exclusive enteral nutrition is recommended as first line option, at least for children, because it induces clinical remission and mucosal healing. Modulen®, a polymeric TGF-β2 enriched formula, has a good palatability and is widely used. For the first time in the literature, this review outlines and discusses the clinical outcomes obtained with this therapy, as well as the potential mechanisms of action of its compounds. It can be explained by its TGF-β2 content but also by its protein and lipid composition. Further well-designed studies are required to improve our knowledge and to optimize therapeutic strategies.
Subject: Life Sciences, Genetics Keywords: mucosal melanoma; dogs; transcriptome sequencing; long non-coding RNAs (lncRNAs)
Online: 3 May 2019 (13:59:22 CEST)
Mucosal melanomas (MM) are rare aggressive cancers in humans and one of the most common forms of oral cancers in dogs. Similar biological and histological features are shared between MM in both species making dogs a powerful model for comparative oncology studies of melanomas. Although exome sequencing recently identified recurrent coding mutations in canine MM, little is known about changes in non-coding gene expression and more particularly in canine long non-coding RNAs (lncRNAs), which are commonly dysregulated in human cancers. Here, we sampled a large cohort (n= 52) of canine normal/tumor oral MM from three predisposed breeds (poodles, Labrador retrievers and golden retrievers) and used deep transcriptome sequencing to identify more than 400 differentially expressed (DE) lncRNAs. We further prioritized candidate lncRNAs by comparative genomic analysis to pinpoint 26 dog-human conserved DE lncRNAs, including SOX21-AS, ZEB2-AS and CASC15 lncRNAs. Using unsupervised co-expression networks analysis with coding genes, we inferred potential functions of DE lncRNAs suggesting associations with cancer-related genes, cell cycle and carbohydrate metabolism GO terms. Finally, we exploited our multi-breed design to identify DE lncRNAs per breed. This study provides a unique transcriptomic resource for studying oral melanoma in dogs and highlights lncRNAs that may potentially be diagnostic or therapeutic targets for human and veterinary medicine.
REVIEW | doi:10.20944/preprints202012.0378.v1
Subject: Life Sciences, Biochemistry Keywords: gastrointestinal tract; dietary antigens; metabolites; microbiota; macronutrients; gastrointestinal immunity; mucosal immune regulation
Online: 15 December 2020 (12:20:48 CET)
The gastrointestinal tract contains multiple types of immune cells that maintain the balance between tolerance and activation at the first line of host defense facing non-self antigens, including dietary antigens, commensal bacteria, and sometimes unexpected pathogens. Maintaining homeostasis at the gastrointestinal tract requires stringent regulation of the immune responses against various environmental conditions. Diet can be converted into gut metabolites which have unique functional activities through host as well as microbial enzymatic activities. Accumulating evidences demonstrate that gastrointestinal metabolites have significant impacts on the regulation of intestinal immunity and further integrate immune response of distal mucosal tissue. Metabolites, especially derived from microbiota, regulate immune cell functions by various ways including recognition and activation of cell surface receptors, controlling of gene expression by epigenetic regulation and integration of cellular metabolism. These mucosal immune regulations are key to understand underlying mechanism for the development of gastrointestinal disorders. Here, we review the recent advancement of our understanding on the role of gut metabolites in the regulation of gastrointestinal immunity with highlighting the cellular and molecular regulatory mechanisms by macronutrients-derived metabolites.
Subject: Medicine & Pharmacology, Other Keywords: constipation; obstructed defecation syndrome; rectocele; defecography; rectal mucosal prolapse; transanal repair; TRREMS
Online: 10 July 2019 (08:12:26 CEST)
Background The aim of this literature review was to make future guidelines for clinical tretment and next study about preoperative and postoperative clinical and functional evaluation of symptoms after transanal repair of rectocele and rectal mucosectomy with a single circular stapler(TRREMS procedure),used for treatment of obstructed defecation syndrome (ODS) caused by rectocele and rectal mucosal prolpase (RMP). Since anorectocele is usually associated with mucosa prolapse and/or rectal intussusceptions, it was developed a stapled surgical technique using one circular stapler. Methods An organized search of Medline/PubMed and medical Database of Clinical Trials was performed, from 1996 to 2016 using the key words „rectal prolapse”,”rectocele”, „ODS”,”Defecography”,”STARR”, „TRREMS”.Results The results of clinical studies are good for improving the quality of life of patients who underwent transanal repair of rectocele and rectal mucosectomy with a single circular stapler(TRREMS). The method can be considered as safe. Clearly to be implemented in our practice, for specific indications.
REVIEW | doi:10.20944/preprints202202.0271.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: oral microbiome; systemic disease; gingival sulcus; junctional epithelium; mucosal barrier; biofilm; leaky gut; leaky gum
Online: 22 February 2022 (11:18:15 CET)
The oral cavity is the gateway for microorganisms into your body where they disseminate not only to the directly connected respiratory and digestive tracts, but also to the many remote organs. Oral microbiota, traveling to the end of the intestine and circulating our body through blood vessels, not only affect a gut microbiome profile, but also many systemic diseases. By gathering information accumulated from the era of focal infection theory to the age of revolution in microbiome research, we propose a pivotal role of “leaky gum”, as an analogy of “leaky gut”, to underscore the importance of the oral cavity in systemic health. The oral cavity has unique structures, the gingival sulcus (GS) and the junctional epithelium (JE) below the GS, which are rarely found anywhere else in our body. The JE is attached to the tooth enamel and cementum by hemidesmosome (HD), which is structurally weaker than desmosome and is thus vulnerable to microbial infiltration. In the GS, microbial biofilms can build up for life, unlike the biofilms on the skin and intestinal mucosa that fall off by natural process. Thus, we emphasize that the GS and the JE are the weakest leaky point for microbes to invade human body, making the leaky gum just as important as, or even more important than, the leaky gut.
ARTICLE | doi:10.20944/preprints202202.0211.v2
Subject: Biology, Animal Sciences & Zoology Keywords: pIgR; gene structure; cold environment; gene expression; teleost immunity; adaptive evolution; mucosal tissues; genome alteration; Notothenioidei; IgV domains.
Online: 27 June 2022 (08:41:00 CEST)
The IgM and IgT classes were previously identified and characterized in the Antarctic teleost Trematomus bernacchii, a species belonging to the Perciform suborder Notothenoidei. Herein we characterized the gene encoding the polymeric immunoglobulin receptor (pIgR) in the same species and compared it to pIgR of multiple teleost species belonging to five perciform sub-orders, including 11 Antarctic and one non-Antarctic (Cottoperca gobio) notothenioid species, the latter living in less cold periantarctic sea. Antarctic pIgR genes displayed particularly long in-trons marked by sites of transposable elements and transcription factors. Furthermore, analysis of T. bernacchii pIgR cDNA unveiled multiple amino acid substitutions unique to Antarctic species, all introducing adaptive features, including N-glycosylation sequons. Interestingly, C. gobio shared most features with the other perciforms rather than with the cold adapted relatives. T. bernacchii pIgR transcripts were predominantly expressed in mucosal tissues, as indicated by q-PCR and in situ hybridization analysis. These results suggest that in cold adapted species pIgR preserved its fundamental role in mucosal immune defense, although remarkable gene structure modifications occurred.
ARTICLE | doi:10.20944/preprints201804.0245.v1
Subject: Materials Science, Polymers & Plastics Keywords: Chitosan-g-PMMA amphiphilic nanoparticles; thiolated polymers; mucoadhesion; mucosal drug delivery; Caco2 and HT29-MTX cell lines; apparent permeability in vitro.
Online: 18 April 2018 (16:28:21 CEST)
Engineering of drug nanocarriers combining fine-tuned mucoadhesive/mucopenetrating properties is currently being investigated to ensure more efficient mucosal drug delivery. Aiming to improve the transmucosal delivery of hydrophobic drugs, we designed a novel kind nanogel produced by the self-assembly of amphiphilic chitosan graft copolymers ionotropically crosslinked with sodium tripolyphosphate. In this work, we synthesized for the first time chitosan-g-poly(methyl methacrylate) nanoparticles thiolated by the conjugation of N-acetyl cysteine. First, we confirmed that both non-crosslinked and crosslinked nanoparticles in the 0.05-0.1% w/v concentration range display very good cell compatibility in two cell lines that are relevant to oral delivery, Caco2 cells that mimic the intestinal epithelium and HT29-MTX cells that produce mucin. Then, we evaluated the effect of crosslinking, nanoparticle concentration and thiolation on the permeability in vitro utilizing monolayers of (i) Caco2 and (ii) Caco2:HT29-MTX cells (9:1 cell number ratio). Results confirmed that the ability of the nanoparticles to cross Caco2 monolayer was affected by the crosslinking. In addition, thiolated nanoparticles interact more strongly with mucin, resulting in a decrease of the apparent permeability coefficient (Papp) compared to the pristine nanoparticles. Moreover, for all the nanoparticles, higher concentration resulted in lower Papp suggesting indicating that the transport pathways could undergo saturation.