Immunogenic Peptides Research Articles

Abstract P389: Immunogenic Peptides Responsible for Experimental Hypertension Contribute to Systemic Lupus Erythematosus

Introduction: Hypertension and systemic lupus erythematosus (SLE) lead to modification of self-peptides by isolevuglandin (isoLG) lipid oxidation products. These self-peptides are presented by class 1 major histocompatibility complexes and drive CD8 + T cell activation. We have identified self-peptides from the sodium/glucose cotransporter2 (SGLT2); cadherin 16; Kelch domain-containing protein 7A and solute carrier family 23 that are IsoLG-adducted and cause CD8 + T cell activation in both ang II and L-NAME/high salt models of hypertension. These prime hypertension in response to low dose ang II. Hypothesis: We hypothesized that the same immunogenic peptides responsible for experimental hypertension contribute to systemic lupus erythematosus. Methods: A fluorescent probe made of recombinant IgG and the murine class 1 MHC H2-D b was loaded with either unadducted SGLT2 peptide or an isoLG-adducted SGLT2 peptide. This probe was used in flow cytometry to detect CD8 + T cells specific for this peptide antigen in 12-week-old C57Bl/6 and female B6SLE1.2.3 mice. Results: The unadducted SGLT2 probe recognized < 1% of CD8 + T cells (Figure). In contrast, ang II-infusion caused a striking increase in IsoLG-SGLT2 specific CD8 + T cells in C57Bl/6 aortas (Figure panels A and D). In C57Bl/6 very few CD8 + T cells recognizing IsoLG-SGLT2 were observed in the spleen (Panel B and E). Importantly, from 5 to 20% of CD8 + T cells in spleens of female B6SLE1.2.3 mice recognized the IsoLG-SGLT2 peptide (Figure panels C and E). Image 1. Conclusions: These findings strongly suggest that IsoLG-adducted peptides responsible for ang II-induced hypertension contribute to SLE and suggest that these conditions share similar immunogenicity.

Peptide-based immunoprotection against Rhipicephalus microplus tick

The main agents for tick control are chemical acaricides. However, when used without technical guidance, they can lead to environmental damage and the development of resistant tick strains. In this context, vaccines are alternative o be used in integrated tick management format by combining with other effective tools. We isolated RNA from ticks Rhipicephalus microplus, prepared the library, and performed next-generation sequencing; a pipeline analysis was applied to identify the hypothetical proteins having immunogenic potential and their predicted immunogenic peptides. Twelve peptides, ranging from 12 to 38 amino acid residues, containing the selected epitopes from different targets were selected and synthesized in two forms: the pure peptide; and the peptide conjugated to keyhole limpet hemocyanin (KLH) carrier. These peptides were divided into two groups of six peptides each. The antigen formulations (groups 1 and 2) were prepared with conjugated peptides containing 200 µg of each peptide per dose emulsified with Montanide ISA 61VG (SEPPIC); the control treatment had the adjuvant formulation without peptides (group 3). To evaluate the protective efficacy, 15 weaned male calves (Angus breed) aged around 6 months to one year and weighing approximately 200–250 kg were divided into three groups of five animals each; they were immunized thrice, at an interval of 28 days. After immunization, all the calves infested with 15,000 larvae of Rhipicephalus microplus. Peptide epitopes were recognized by antibodies against host-specific IgGs using indirect ELISA. The mean of the antibody level was determined for each group and compared using analysis of variance with two factors (ANOVA). F-test was used to determine the significance of differences observed between the groups. The percentage efficacy was calculated based on the number of ticks, the weight of teleoginas, and the weight and hatchability of the eggs, compared to that in the control group. The evaluation of immunoprotection indicated efficacies of 69 and 51 %, respectively in Group 1 and 2.

Immunotherapies targeting the oncogenic fusion gene CLDN18-ARHGAP in gastric cancer

The CLDN18-ARHGAP fusion gene is an oncogenic driver newly discovered in gastric cancer. It was detected in 9% (8/87) of gastric cancer patients in our center. An immunogenic peptide specifically targeting CLDN18-ARHGAP fusion gene was generated to induce neoantigen-reactive T cells, which was proved to have specific and robust anti-tumor capacity both in in vitro coculture models and in vivo xenograft gastric cancer models. Apart from the immunogenic potential, CLDN18-ARHGAP fusion gene was also found to contribute to immune suppression by inducing a regulatory T (Treg) cell-enriched microenvironment. Mechanistically, gastric cancer cells with CLDN18-ARHGAP fusion activate PI3K/AKT-mTOR-FAS signaling, which enhances free fatty acid production of gastric cancer cells to favor the survival of Treg cells. Furthermore, PI3K inhibition could effectively reverse Treg cells upregulation to enhance anti-tumor cytotoxicity of neoantigen-reactive T cells in vitro and reduce tumor growth in the xenograft gastric cancer model. Our study identified the CLDN18-ARHGAP fusion gene as a critical source of immunogenic neoepitopes, a key regulator of the tumor immune microenvironment, and immunotherapeutic applications specific to this oncogenic fusion.

Development of a gold nanoparticle-based novel diagnostic prototype for in vivo detection of Indian red scorpion (Mesobuthus tamulus) venom

Indian red scorpion Mesobuthus tamulus is responsible for substantial mortality in India and Sri Lanka; however, no specific diagnostic method is available to detect the venom of this scorpion in envenomed plasma or body fluid. Therefore, we have proposed a novel, simple, and rapid method for detecting M. tamulus venom (MTV) in the plasma of envenomed animals using polyclonal antibodies (PAb) raised against three modified custom peptides representing the antigenic epitopes of K+ (Tamapin) and Na+ (α-neurotoxin) channel toxins, the two major MTV toxins identified by proteomic analysis. The optimum PAb formulation containing PAb 1, 2, and 3 in proportion (1:1:1, w/w/w) acted synergistically, demonstrating significantly higher immunological recognition of MTV than anti-scorpion antivenom (developed against native toxins) and individual antibodies against peptide immunogens. The PAb formulation could detect MTV optimally in envenomed rat plasma (intravenous and subcutaneous routes) at 30–60 min post-injection. The acetonitrile precipitation method developed in this study to augment the MTV detection sensitivity enriched the low molecular mass peptide toxins in envenomed rat plasma, which was ascertained by mass spectrometry analysis. The gold nanoparticles conjugated PAb formulation, characterised by biophysical techniques such as Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM), demonstrated their interaction with low molecular mass MTV peptide toxins in envenomed rat plasma. This interaction results in the accumulation of the gold nanoparticles, thus leading to signal change in absorbance spectra that can be discerned within 10 min. From a standard curve of MTV spiked plasma, the quantity of MTV in envenomed rat plasma could be determined by gold nanoparticle-PAb formulation conjugate.

Dynamics of IgM and IgG Antibody Response Profile against Linear B-Cell Epitopes from Exoerythrocytic (CelTOS and TRAP) and Erythrocytic (CyRPA) Phases of Plasmodium vivax: Follow-Up Study.

Malaria is a serious health problem worldwide affecting mainly children and socially vulnerable people. The biological particularities of P. vivax, such as the ability to generate dormant liver stages, the rapid maturation of gametocytes, and the emergence of drug resistance, have contributed to difficulties in disease control. In this context, developing an effective vaccine has been considered a fundamental tool for the efficient control and/or elimination of vivax malaria. Although recombinant proteins have been the main strategy used in designing vaccine prototypes, synthetic immunogenic peptides have emerged as a viable alternative for this purpose. Considering, therefore, that in the Brazilian endemic population, little is known about the profile of the humoral immune response directed to synthetic peptides that represent different P. vivax proteins, the present work aimed to map the epitope-specific antibodies' profiles to synthetic peptides representing the linear portions of the ookinete and sporozoite cell passage protein (CelTOS), thrombospondin-related adhesive protein (TRAP), and cysteine-rich protective antigen (CyRPA) proteins in the acute (AC) and convalescent phases (Conv30 and Conv180 after infection) of vivax malaria. The results showed that the studied subjects responded to all proteins for at least six months following infection. For IgM, a few individuals (3-21%) were positive during the acute phase of the disease; the highest frequencies were observed for IgG (28-57%). Regarding the subclasses, IgG2 and IgG3 stood out as the most prevalent for all peptides. During the follow-up, the stability of IgG was observed for all peptides. Only one significant positive correlation was observed between IgM and exposure time. We conclude that for all the peptides, the immunodominant epitopes are recognized in the exposed population, with similar frequency and magnitude. However, if the antibodies detected in this study are potential protectors, this needs to be investigated.

Immunogenicity of a peptide-based vaccine for measles: a pilot evaluation in a mouse model

Although neutralizing antibody is an established correlate of protection for measles, T cell-mediated responses play at least two critical roles in immunity to measles: first, through provision of ‘help’ enabling robust humoral immune responses; and second, through clearance of measles virus-infected cells. Previously, we identified 13 measles-derived peptides that bound to human leukocyte antigen (HLA) molecules in Priess cells infected with measles virus. In this study, we evaluated the immunogenicity of these peptides in a transgenic mouse model. Our results demonstrated that these peptides induced Th1-biased immune responses at varying levels. Of the 13 peptides, the top four immunogenic peptides were further selected for a viral challenge study in mice. A vaccine based on a combination of these four peptides reduced morbidity and weight loss after viral challenge compared to placebo. Our results emphasize the potential of T cell-mediated, peptide-based vaccines against measles.

Intranasal Multiepitope PD-L1-siRNA-Based Nanovaccine: The Next-Gen COVID-19 Immunotherapy.

The first approved vaccines for human use against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are nanotechnology-based. Although they are modular, rapidly produced, and can reduce disease severity, the currently available vaccines are restricted in preventing infection, stressing the global demand for novel preventive vaccine technologies. Bearing this in mind, we set out to develop a flexible nanovaccine platform for nasal administration to induce mucosal immunity, which is fundamental for optimal protection against respiratory virus infection. The next-generation multiepitope nanovaccines co-deliver immunogenic peptides, selected by an immunoinformatic workflow, along with adjuvants and regulators of the PD-L1 expression. As a case study, we focused on SARS-CoV-2 peptides as relevant antigens to validate the approach. This platform can evoke both local and systemic cellular- and humoral-specific responses against SARS-CoV-2. This led to the secretion of immunoglobulin A (IgA), capable of neutralizing SARS-CoV-2, including variants of concern, following a heterologous immunization strategy. Considering the limitations of the required cold chain distribution for current nanotechnology-based vaccines, it is shown that the lyophilized nanovaccine is stable for long-term at room temperature and retains its in vivo efficacy upon reconstitution. This makes it particularly relevant for developing countries and offers a modular system adaptable to future viral threats.

Urinary excretion of gluten immunoreactive peptides as an indicator of gastrointestinal function after fasting and dietary provocation in healthy volunteers.

Understanding intestinal permeability is paramount for elucidating gastrointestinal health and pathology. The size and nature of the molecule traversing the intestinal barrier offer crucial insights into various acute and chronic diseases, as well as the evolution of some conditions. This study aims to assess the urinary excretion kinetics of gluten immunogenic peptides (u-GIP), a unique class of dietary peptides detectable in urine, in volunteers under controlled dietary conditions. This evaluation should be compared to established probes like lactulose, a non-digestible disaccharide indicative of paracellular permeability, and mannitol, reflecting transcellular permeability. Fifteen participants underwent simultaneous ingestion of standardized doses of gluten (10 g), lactulose (10 g), and mannitol (1 g) under fasting conditions for at least 8 hours pre-ingestion and during 6 hours post-ingestion period. Urine samples were collected over specified time intervals. Excretion patterns were analyzed, and correlations between the lactulose-to-mannitol ratio (LMR) and u-GIP parameters were assessed. The majority of u-GIP were detected within the first 12 hours post-ingestion. Analysis of the variability in cumulative excretion across two sample collection ranges demonstrated that lactulose and u-GIP exhibited similar onset and excretion dynamics, although GIP reached its maximum peak earlier than either lactulose or mannitol. Additionally, a moderate correlation was observed between the LMR and u-GIP parameters within the longest urine collection interval, indicating potential shared characteristics among permeability pathways. These findings suggest that extending urine collection beyond 6 hours may enhance data reliability. This study sheds light on the temporal dynamics of u-GIP in comparison to lactulose and mannitol, established probes for assessing intestinal permeability. The resemblance between u-GIP and lactulose excretion patterns aligns with the anticipated paracellular permeability pathway. The capacity to detect antigenic food protein fragments in urine opens novel avenues for studying protein metabolism and monitoring pathologies related to the digestive and intestinal systems.

In Silico Immunogenicity Assessment of Therapeutic Peptides.

The application of therapeutic peptides in clinical practice has significantly progressed in the past decades. However, immunogenicity remains an inevitable and crucial issue in the development of therapeutic peptides. The prediction of antigenic peptides presented by MHC class II is a critical approach to evaluating the immunogenicity of therapeutic peptides. With the continuous upgrade of algorithms and databases in recent years, the prediction accuracy has been significantly improved. This has made in silico evaluation an important component of immunogenicity assessment in therapeutic peptide development. In this review, we summarize the development of peptide-MHC-II binding prediction methods for antigenic peptides presented by MHC class II molecules and provide a systematic explanation of the most advanced ones, aiming to deepen our understanding of this field that requires particular attention.

Synthesis and Structure Optimization of Star Copolymers as Tunable Macromolecular Carriers for Minimal Immunogen Vaccine Delivery.

Minimal immunogen vaccines are being developed to focus antibody responses against otherwise challenging targets, including human immunodeficiency virus (HIV), but multimerization of the minimal peptide immunogen on a carrier platform is required for activity. Star copolymers comprising multiple hydrophilic polymer chains ("arms") radiating from a central dendrimer unit ("core") were recently reported to be an effective platform for arraying minimal immunogens for inducing antibody responses in mice and primates. However, the impact of different parameters of the star copolymer (e.g., minimal immunogen density and hydrodynamic size) on antibody responses and the optimal synthetic route for controlling those parameters remains to be fully explored. We synthesized a library of star copolymers composed of poly[N-(2-hydroxypropyl)methacrylamide] hydrophilic arms extending from poly(amidoamine) dendrimer cores with the aim of identifying the optimal composition for use as minimal immunogen vaccines. Our results show that the length of the polymer arms has a crucial impact on the star copolymer hydrodynamic size and is precisely tunable over a range of 20-50 nm diameter, while the dendrimer generation affects the maximum number of arms (and therefore minimal immunogens) that can be attached to the surface of the dendrimer. In addition, high-resolution images of selected star copolymer taken by a custom-modified environmental scanning electron microscope enabled the acquisition of high-resolution images, providing new insights into the star copolymer structure. Finally, in vivo studies assessing a star copolymer vaccine comprising an HIV minimal immunogen showed the criticality of polymer arm length in promoting antibody responses and highlighting the importance of composition tunability to yield the desired biological effect.

A hidden element governing immunogenicity in tumoral neoepitopes

The search for what characteristics define an epitope as either an immunogenic or a non-responsive target for immunotherapy has eluded researchers for years. Several studies demonstrate that certain positions in the peptide sequences, the major histocompatibility complex (MHC) anchor residues, have a preferential composition of amino acids (allelic motifs), being those epitopes more likely to display a better immunogenic response. First of all, not all MHC ligands are immunogenic, considering that unnumbered self-epitopes are continuously presented on the cell surfaces. In this work, we analyzed data to evaluate an additional element, central to our hypothesis that alterations in tumor protein sequences result in a structural change that shifts the electrostatic surface of the peptide-major histocompatibility complex (pMHC) molecules, pivotal for T-Cell receptor (TCR) recognition and the initiation of an immunogenic response. Firstly, previously neoepitope sequences presenting differential immune responses when compared with their wild-type counterparts were recovered. Even though the sequences were very similar, they triggered responses that were considerably different, and currently, there is no well-established explanation for why they conspicuously differ in immunogenic aspects from each other. The pMHCs structures harboring the epitope sequences were modeled and then used to generate images of their electrostatic surfaces, looking for qualitative differences that indicate the distinct responses. We noticed that no significant alteration occurred between immunogenic tumor peptides and their wild-type non-immunogenic counterparts when comparing their electrostatic surface. An additional comparison was made against structures of pMHCs containing immunogenic epitopes recovered from the Crosstope Database (https://crosstope.com.br/). In this sense, it was also possible to verify if immunogenic tumor epitopes were similar to viral immunogenic ones. Surprisingly, both wild-type (WT) sequences and neoepitopes shared an electrostatic surface distribution with pathogen targets, which could indicate their immunogenic predisposition. So we theorized that a “hidden element” may be responsible for the immunogenicity shift in neoepitopes.

Gluten-Free Diet Adherence Tools for Individuals with Celiac Disease: A Systematic Review and Meta-Analysis of Tools Compared to Laboratory Tests.

This systematic review aimed to find the tool that best predicts celiac individuals' adherence to a gluten-free diet (GFD). The Transparent Reporting of Multivariable Prediction Models for Individual Prognosis or Diagnosis (TRIPOD-SRMA) guideline was used for the construction and collection of data from eight scientific databases (PubMed, EMBASE, LILACS, Web of Science, LIVIVO, SCOPUS, Google Scholar, and Proquest) on 16 November 2023. The inclusion criteria were studies involving individuals with celiac disease (CD) who were over 18 years old and on a GFD for at least six months, using a questionnaire to predict adherence to a GFD, and comparing it with laboratory tests (serological tests, gluten immunogenic peptide-GIP, or biopsy). Review articles, book chapters, and studies without sufficient data were excluded. The Checklist for Critical Appraisal and Data Extraction for Systematic Reviews of Prediction Modeling Studies (CHARMS) was used for data collection from the selected primary studies, and their risk of bias and quality was assessed using the Prediction Risk of Bias Assessment Tool (PROBAST). The association between the GFD adherence determined by the tool and laboratory test was assessed using the phi contingency coefficient. The studies included in this review used four different tools to evaluate GFD adherence: BIAGI score, Coeliac Dietary Adherence Test (CDAT), self-report questions, and interviews. The comparison method most often used was biopsy (n = 19; 59.3%), followed by serology (n = 14; 43.7%) and gluten immunogenic peptides (GIPs) (n = 4; 12.5%). There were no significant differences between the interview, self-report, and BIAGI tools used to evaluate GFD adherence. These tools were better associated with GFD adherence than the CDAT. Considering their cost, application time, and prediction capacity, the self-report and BIAGI were the preferred tools for evaluating GFD adherence.

Selection and characterisation of DNA aptamer targeting immunogenic peptide sequence of high molecular weight glutenin (HMW-GS) of gluten

Selection and characterisation of DNA aptamer targeting immunogenic peptide sequence of high molecular weight glutenin (HMW-GS) of gluten

Universal peptide-based potential vaccine design against canine distemper virus (CDV) using a vaccinomic approach

Canine distemper virus (CDV) affects many domestic and wild animals. Variations among CDV genome linages could lead to vaccination failure. To date, there are several vaccine alternatives, such as a modified live virus and a recombinant vaccine; however, most of these alternatives are based on the ancestral strain Onderstepoort, which has not been circulating for years. Vaccine failures and the need to update vaccines have been widely discussed, and the development of new vaccine candidates is necessary to reduce circulation and mortality. Current vaccination alternatives cannot be used in wildlife animals due to the lack of safety data for most of the species, in addition to the insufficient immune response against circulating strains worldwide in domestic species. Computational tools, including peptide-based therapies, have become essential for developing new-generation vaccines for diverse models. In this work, a peptide-based vaccine candidate with a peptide library derived from CDV H and F protein consensus sequences was constructed employing computational tools. The molecular docking and dynamics of the selected peptides with canine MHC-I and MHC-II and with TLR-2 and TLR-4 were evaluated. In silico safety was assayed through determination of antigenicity, allergenicity, toxicity potential, and homologous canine peptides. Additionally, in vitro safety was also evaluated through cytotoxicity in cell lines and canine peripheral blood mononuclear cells (cPBMCs) and through a hemolysis potential assay using canine red blood cells. A multiepitope CDV polypeptide was constructed, synthetized, and evaluated in silico and in vitro by employing the most promising peptides for comparison with single CDV immunogenic peptides. Our findings suggest that predicting immunogenic CDV peptides derived from most antigenic CDV proteins could aid in the development of new vaccine candidates, such as multiple single CDV peptides and multiepitope CDV polypeptides, that are safe in vitro and optimized in silico. In vivo studies are being conducted to validate potential vaccines that may be effective in preventing CDV infection in domestic and wild animals.

Foetal gluten immunogenic peptides during pregnancy: a new determinant on the coeliac exposome

BackgroundThe increasing incidence of coeliac disease is leading to a growing interest in active search for associated factors, even the intrauterine and early life. The exposome approach to disease encompasses a life course perspective from conception onwards has recently been highlighted. Knowledge of early exposure to gluten immunogenic peptides (GIP) in utero could challenge the chronology of early prenatal tolerance or inflammation, rather than after the infant’s solid diet after birth.MethodsWe developed an accurate and specific immunoassay to detect GIP in amniotic fluid (AF) and studied their accumulates, excretion dynamics and foetal exposure resulting from AF swallowing. One hundred twenty-five pregnant women with different gluten diets and gestational ages were recruited.ResultsGIP were detectable in AF from at least the 16th gestational week in gluten-consuming women. Although no significant differences in GIP levels were observed during gestation, amniotic GIP late pregnancy was not altered by maternal fasting, suggesting closed-loop entailing foetal swallowing of GIP-containing AF and subsequent excretion via the foetal kidneys.ConclusionsThe study shows evidence, for the first time, of the foetal exposure to gluten immunogenic peptides and establishes a positive correlation with maternal gluten intake. The results obtained point to a novel physiological concept as they describe a plausible closed-loop circuit entailing foetal swallowing of GIP contained in AF and its subsequent excretion through the foetal kidneys. The study adds important new information to understanding the coeliac exposome.

Newly developed peptide-ELISA successfully detected anti-IgG antibodies against Maedi-Visna virus in sheep

Maedi Visna Virus (MVV) is a retrovirus that can infect sheep. There is still no effective therapy or vaccine against this virus and timely diagnosis is important to combat the complications of the disease. In this study, we aimed to develop an ELISA using peptides derived from gag protein as antigen. For this purpose, B cell epitopes of gag protein were predicted and a docking analysis with the B cell receptor was performed to select peptides to be used in ELISA. After three soluble epitopes with the highest antigenicity were produced as peptides, the immunogenicity of each peptide was determined by ELISA using sheep serum samples categorized as MVV positive (n=24) and negative (n=13). Subsequently, in house ELISA using above mentioned immunogenic peptides as antigen was used to investigate MVV seroprevalence in sheep (n=88). According to the results, among three peptides, two of them strongly reacted with MVV positive serum samples and the mean absorbance values detected among positive and negative serum samples were statistically significant, indicating that these peptides were immunogenic (P=0.016 and P=0.038). The third peptide also reacted with positive serum samples but the mean absorbance value was not statistically significant and this peptide was considered non-immunogenic (P=0.175). The immunogenic two peptides showed the same high sensitivity and specificity values of 91.60 and 92.80 according to the commercial kit. Moreover, MVV seroprevalence detected by peptide-ELISAs using CKQGSKE and CRPQGKAGHKG peptides as antigen was 3.40 % and 4.5 %, respectively. As a result, it was shown that these peptides can be successfully used for serological diagnosis of MVV.

Reverse vaccinology approach for identification of epitopes from E1 protein as peptide vaccine against HCV: A proof of concept

The development of effective vaccines against Hepatitis C Virus (HCV) remains a global health priority and challenge. In this study, we employed an integrative approach combining computational epitope prediction with experimental validation to identify immunogenic peptides targeting the E1 glycoprotein of HCV. In the present report, computational data from various epitope prediction algorithms such as IEDB and SYFPEITHI, followed by molecular dynamics (MD) simulations and immuno-informatics analysis is presented. Through computational screening, we identified potential epitope candidates, with QVRNSSGLY (P3) and QLFTFSPRH (P7) emerging as promising candidates. MD simulations revealed stable interactions between these epitopes and MHC molecule, further validated by free energy estimations using MMPBSA method. Immuno-informatics analysis supported these findings, showing high binding potential and immunogenicity scores for the selected peptides. Subsequent synthesis and characterization of epitope peptides confirmed their structural integrity and purity required for conducting immune activation assays. Experimental immunological assays carried out in this study involved epitope peptide induced activation of CD8 + and CD4 + T cells from healthy human subjects and HCV- recovered patients. Data from experimental validation revealed significant cytokine release upon exposure to epitope peptides, particularly TNF-a, IL-6, and GM-CSF, indicative of robust immune responses. Notably, peptides P3 and P7 exhibited the most pronounced cytokine induction profiles, underscoring their potential as vaccine candidates. Further investigations addressing the mechanism of action of these epitope peptides under preclinical and clinical settings may help in developing effective vaccine against HCV.

Commensal HPVs Have Evolved to Be More Immunogenic Compared with High-Risk α-HPVs.

Commensal human papillomaviruses (HPVs) are responsible for persistent asymptomatic infection in the human population by maintaining low levels of the episomal genome in the stratified epithelia. Herein, we examined the immunogenicity of cutaneotropic HPVs that are commonly found in the skin. Using an in silico platform to determine human leukocyte antigen (HLA)-peptide complex binding affinity, we observed that early genes of cutaneotropic HPV types within the same species can generate multiple conserved, homologous peptides that bind with high affinity to HLA class I alleles. Interestingly, we discovered that commensal β, γ, μ, and ν HPVs contain significantly more immunogenic peptides compared with α-HPVs, which include high-risk, oncogenic HPV types. Our findings indicate that commensal HPV proteins have evolved to generate peptides that better complement their host's HLA repertoire. Promoting higher control by host T cell immunity in this way could be a mechanism by which HPVs achieve widespread asymptomatic colonization in humans. This work supports the role of commensal HPVs as immunogenic targets within epithelial cells, which may contribute to the immune regulation of the skin and mucosa.

Aspergillus niger prolyl endopeptidase in celiac disease

We comment here on the article by Stefanolo et al entitled “Effect of Aspergillus niger prolyl endopeptidase in patients with celiac disease on a long-term gluten-free diet”, published in the World Journal of Gastroenterology . Celiac disease is a well-recognized systemic autoimmune disorder. In genetically susceptible people, the most evident damage is located in the small intestine, and is caused and worsened by the ingestion of gluten. For that reason, celiac patients adopt a gluten-free diet (GFD), but it has some limitations, and it does not prevent re-exposure to gluten. Research aims to develop adjuvant therapies, and one of the most studied alternatives is supplementation with Aspergillus niger prolyl endopeptidase protease (AN-PEP), which is able to degrade gluten in the stomach, reducing its concentration in the small intestine. The study found a high adherence to the GFD, but did not address AN-PEP as a gluten immunogenic peptide reducer, as it was only tested in patients following a GFD and not in gluten-exposing conditions. This study opens up new research perspectives in this area and shows that further study is needed to clarify the points that are still in doubt.

Development and Validation of a Tool for Assessing Adherence to Gluten-Free Diet in Patients With Celiac Disease.

Life-long adherence to gluten-free diet (GFD) and its assessment is essential for patients with celiac disease (CeD). We have developed and validated a tool for assessing adherence to GFD which can be used by both physicians and dietitians. Phase 1: Development, content validation, and assessment of reliability of tool. Phase 2: Validation of tool against standard dietary evaluation (SDE) (gold standard), immunoglobulin A - anti-tissue transglutaminase antibodies (IgA anti-tTG Ab), and gluten immunogenic peptides in urine. Overall, 380 biopsy-confirmed patients with CeD (derivation cohort: n = 100 [phase 1], n = 210 [phase 2] and independent validation cohort, n = 70) were recruited. Of an initial 90-point questionnaire, 84 items (Celiac Disease: Compliance Assessment Test [CD-CAT.v1]) were retained after content validation and pilot testing. In phase 1, upon administering CD-CAT.v1 on 100 patients, a comprehensive 35-item tool (CD-CAT.v2; α = 0.86) was obtained after removing items with low test-retest reliability and item-rest correlation values. In phase 2, upon administering CD-CAT.v2 on 210 patients, 22 items were removed having low correlation values (R < 0.4) with SDE. Finally, a 13-item tool (CD-CAT.v3; α = 0.84) was obtained with high criterion validity with SDE ( r = 0.806, P < 0.001), moderate convergent validity with celiac disease adherence test ( r = 0.602, P = 0.007), and moderate to weak correlation with urine gluten immunogenic peptides ( r = 0.46, P = 0.001) and IgA anti-tTG Ab ( r = 0.39, P = 0.008), respectively. The final 13-item tool also strongly correlated with SDE ( r = 0.78, P < 0.001) in an independent validation cohort of 70 patients with CeD. Principal component analysis identified 3 relevant subscales with a cumulative variance of 62%. The sensitivity and specificity of CD-CAT.v3 were 80% and 91%, respectively, with an area under curve of 0.905 with SDE. The obtained cutoff score of <19 from the receiver operating characteristic curve was further categorized as 13 = excellent, 14-18 = very good, 19-28 = average, and >28 = poor adherence to GFD. CD-CAT is a new and rapid tool for monitoring dietary adherence to GFD with high sensitivity and specificity, which can be administered by both physicians and dietitians.