External Validation of Two Scoring Tools to Predict the Operative Duration and Open Conversion of Elective Laparoscopic Cholecystectomy in a Mexican Population.

INTRODUCTION: This study aimed to evaluate the use of laparoscopic cholecystectomy (LC) operative time (CholeS score) and conversion to an open procedure (CLOC score) outside their validation dataset in Mexican population. METHODS: Patients >18 years who underwent elective LC were analyzed in a single-center retrospective chart review study. Association between scores (CholeS and CLOC) with operative time and conversion to open procedures was assessed with Spearman correlation. The predictive accuracy of the CholeS score and CLOC score was evaluated by receiver operator characteristic. RESULTS: 200 patients were included in the study (33 excluded for emergency case or missing data). Spearman coefficient correlations between CholeS or CLOC score and operative time were 0.456 (p < 0.0001) and 0.356 (p < 0.0001), respectively. Area under the curve (AUC) for operative prediction time (>90 min) by CholeS score was 0.786 with a 3.5-point cutoff (80% sensitivity and 63.2% specificity). AUC for open conversion (CLOC score) was 0.78 with a 5-point cutoff (60% sensitivity and 91% specificity). The CLOC score had a 0.740 AUC (64% sensitivity and 72.8% specificity) for operative time >90 min. CONCLUSIONS: The CholeS and the CLOC scores predicted LC long operative time and risk for conversion to an open procedure, respectively, outside their original validation set.

The Extracellular Vesicles of the Helminth Pathogen, Fasciola hepatica: Biogenesis Pathways and Cargo Molecules Involved in Parasite Pathogenesis.

Extracellular vesicles (EVs) released by parasites have important roles in establishing and maintaining infection. Analysis of the soluble and vesicular secretions of adult Fasciola hepatica has established a definitive characterization of the total secretome of this zoonotic parasite. Fasciola secretes at least two subpopulations of EVs that differ according to size, cargo molecules and site of release from the parasite. The larger EVs are released from the specialized cells that line the parasite gastrodermus and contain the zymogen of the 37 kDa cathepsin L peptidase that performs a digestive function. The smaller exosome-like vesicle population originate from multivesicular bodies within the tegumental syncytium and carry many previously described immunomodulatory molecules that could be delivered into host cells. By integrating our proteomics data with recently available transcriptomic data sets we have detailed the pathways involved with EV biogenesis in F. hepatica and propose that the small exosome biogenesis occurs via ESCRT-dependent MVB formation in the tegumental syncytium before being shed from the apical plasma membrane. Furthermore, we found that the molecular "machinery" required for EV biogenesis is constitutively expressed across the intramammalian development stages of the parasite. By contrast, the cargo molecules packaged within the EVs are developmentally regulated, most likely to facilitate the parasites migration through host tissue and to counteract host immune attack.

Unraveling new players in helminth pathology: extracellular vesicles from Fasciola hepatica and Dicrocoelium dendriticum exert different effects on hepatic stellate cells and hepatocytes.

Fasciola hepatica and Dicrocoelium dendriticum are parasitic trematodes residing in the bile ducts of mammalian hosts, causing, in some cases, impairment of liver function and hepatic fibrosis. Previous studies have shown that extracellular vesicles released by F. hepatica (FhEVs) and D. dendriticum (DdEVs) induce a distinct phenotype in human macrophages, but there is limited information on the effect of parasitic EVs on liver cells, which interact directly with the worms in natural infections. In this study, we isolated FhEVs and DdEVs by size exclusion chromatography and labeled them with a lipophilic fluorescent dye to analyze their uptake by human hepatic stellate cells (HSC) and hepatocytes, important cell types in liver pathology, using synthetic liposomes as internal labeling and uptake control. We analyzed EV uptake and the proteome profiles after the treatment with EVs for both cell types. Our results reveal that EVs establish unique and specific interactions with stellate cells and hepatocytes, suggesting a different role of EVs derived from each parasite, depending on the migration route to reach their final niche. FhEVs have a cytostatic effect on HSCs, but induce the extracellular matrix secretion and elicit anti-inflammatory responses in hepatocytes. DdEVs have a more potent anti-proliferative effect than FhEVs and trigger a global inflammatory response, increasing the levels of NF-κB and other inflammatory mediators in both cell types. These interactions may have a major influence on the progression of the disease, serving to generate conditions that may favor the establishment of the helminths in the host.

[Is the morbid obesity surgery profitable in times of crisis? A cost-benefit analysis of bariatric surgery]. / ¿Es rentable operar a los obesos mórbidos en tiempos de crisis? Análisis coste-beneficio de la cirugía bariátrica.

Morbid obesity is a serious health problem whose prevalence is increasing. Expensive co-morbidities are associated to these patients, as well as a reduction in the survival. Bariatric surgery resolves the co-morbidities (type 2 diabetes mellitus, 86.6%; cardiovascular risk, 79.0%; obstructive sleep apnea syndrome, 83.6%; hypertension, 61.7%), reduces the mortality rate (among 31-40%), and increases the morbid obese patients survival over a 10-years period. It provides significant savings for the National Health System. The obese patients consume a 20% plus of health resources and 68% plus of drugs than general population. Bariatric surgery requires an initial investment (diagnosis-related group cost: 7,468 €), but it is recovered in a cost-effectiveness ratio of 2.5 years. Significant savings are obtained from the third year. To the direct economic benefits associated with reduced health expenditures it should be added an increase in tax collection (sick leave and unemployment reduction is estimated in 18%, with a productivity increase of 57% for self-employed people). Bariatric surgery is one of the most cost-effective procedures in the healthcare system.

Extracellular vesicles from the trematodes Fasciola hepatica and Dicrocoelium dendriticum trigger different responses in human THP-1 macrophages.

Extracellular vesicles (EVs) released by the helminths Dicrocoelium dendriticum and Fasciola hepatica are important modulators of the host immune response, contributing to the establishment of the infection. Monocytes and, in particular, macrophages are major regulators of the inflammatory response and are likely responsible for the phagocytosis of most of the parasite EVs. In this study, we isolated EVs from F. hepatica (FhEVs) and D. dendriticum (DdEVs) by size exclusion chromatography (SEC) and characterized them by nanoparticle tracking analysis, transmission electron microscopy and LC-MS/MS, and analyzed the cohort of proteins. The treatment of monocytes/macrophages with FhEVs, DdEVs or EV-depleted fractions from SEC, demonstrated species-specific effects of the EVs. In particular, FhEVs reduce the migratory capacity of monocytes and the analysis of the cytokine profile showed that they induce a mixed M1/M2 response, exerting anti-inflammatory properties in Lipopolysaccharide-activated macrophages. In contrast, DdEVs do not affect monocyte migration and seem to have pro-inflammatory properties. These results correlate with the differences in the life cycle of both parasites, suggesting different host immune responses. Only F. hepatica migrates to the bile duct through the liver parenchyma, driving the host immune response to heal deep erosions. Furthermore, the proteomic analysis of the macrophages upon FhEV treatment identified several proteins that might be involved in FhEV-macrophage interactions.

[Ophthalmic manifestations in patients recovered from COVID-19 in Mexico]. / Manifestaciones oftálmicas en pacientes recuperados de COVID-19 en México.

Introduction and objectives: Although the ophthalmic manifestations appear to be associated with the coronavirus disease 2019 (COVID-19), there is not enough evidence. Hence, the aim of this study was to determine the various types and frequency of ophthalmic manifestations in patients recovered from SARS-CoV-2 infection in Mexico. Material and methods: This retrospective, observational and descriptive study included all patients recovered from SARS-CoV-2 infection attending the tertiary level hospital of Mexican Social Security Institute (IMSS) from June 2020 to June 2022. During the hospital admission of patients, the demographic data such age, name, gender was recorded. Ophthalmologic examination was performed under torchlight by an ophthalmologist in the Department of Ophthalmology from IMSS. Data was compiled and statistically analyzed using Fisher's exact test and Spearman correlation. Results: A total of 3,081 SARS-CoV-2-positive patients were recorded, of which 318 (10.32%) met the inclusion criteria. Of them, 21 (6.60%) had ophthalmic manifestations and the female-to-male ratio was 1.6:1. The mean age (±SD) was 47.95 ± 15.27 years and the median (interquartile range) time from the diagnosis of COVID-19, as defined by positive SARS-CoV-2 RT-PCR testing, to detection of the ophthalmic manifestation was 31 (142) days. The most common ocular manifestation was orbital mucormycosis (23.80%). Interestingly, the presence of ophthalmic manifestations was not associated with severe COVID-19 (p = 0.665). Conclusions: The ophthalmic manifestations are infrequent in patients recovered from severe COVID-19. Nevertheless, further large sample studies are needed to confirm these findings.

Sperm concentrations do not correlate with semen parameters and hormone profiles in males recovered from COVID-19.

Background: Although the negative impact on fertility of men recovered from coronavirus disease 2019 (COVID-19) has been suggested, there is insufficient evidence, and the data are limited and contradictory. The present prospective study aimed to evaluate the sex-related hormones, semen parameters, erectile dysfunction (ED), and lower urinary tract symptoms (LUTS) in a cohort of men who recovered from COVID-19 and age-matched control men. Methods: Semen samples were collected from twenty-two men recovered from COVID-19 with a median time of 91.5 days and thirty-six control males. The semen parameters were evaluated according to the World Health Organization (WHO) laboratory manual to examine and process human semen. The blood samples were collected to assess the male hormone profile. ED and LUTS were evaluated with the International Index of Erectile Function 5 (IIEF-5) and the International Prostate Symptom Score (IPSS), respectively. Results: The follicle-stimulating hormone (FSH) (3.819±1.515 IU/L), luteinizing hormone (LH) (4.023±1.792 IU/L), prolactin (PRL) [12.60 (10.72-15.20) ng/mL], and testosterone (T) [4.345 (3.565-5.525) ng/mL] levels were at normal range in all males enrolled in the study. Levels of semen volume (control: 2.5 mL vs. COVID-19: 1.9 mL; P<0.05) and sperm concentration (control: 59×106/mL vs. COVID-19: 41.5×106/mL; P<0.005) were significantly lower in males recovered from COVID-19, but still technically well within normal regardless of WHO edition. All variables were examined through logistic regression analysis, demonstrating that only sperm concentration was an independent variable associated with men recovered from COVID-19 [odds ratio (OR) =1; 95% confidence interval (CI): 0.999-1.098; P=0.016]. According to correlation analysis, there was no correlation between sperm concentration and other semen parameters and sex-related hormone profiles. Furthermore, an absence of ED and LUTS in men who recovered from COVID-19 was evidenced using the IIEF-5 and IPSS, respectively. Conclusions: Reproductive-age males recovered from COVID-19 have normal sperm concentration. Sperm concentration did not correlate with other semen parameters, sex-related hormones, IIEF-5, and IPSS. Further studies should be performed to evaluate whether the lower sperm concentration and semen volume that were still within the normal range are a transient or prolonged downregulation resulting from the COVID-19 attack.

Ophthalmic manifestations in patients recovered from COVID-19 in Mexico.

INTRODUCTION AND OBJECTIVES: Although the ophthalmic manifestations appear to be associated with the coronavirus disease 2019 (COVID-19), there is not enough evidence. Hence, the aim of this study was to determine the various types and frequency of ophthalmic manifestations in patients recovered from SARS-CoV-2 infection in Mexico. MATERIAL AND METHODS: This retrospective, observational and descriptive study included all patients recovered from SARS-CoV-2 infection attending the tertiary level hospital of Mexican Social Security Institute (IMSS) from June 2020 to June 2022. During the hospital admission of patients, the demographic data such age, name, gender was recorded. Ophthalmologic examination was performed under torchlight by an ophthalmologist in the Department of Ophthalmology from IMSS. Data was compiled and statistically analyzed using Fisher's exact test and Spearman correlation. RESULTS: A total of 3081 SARS-CoV-2-positive patients were recorded, of which 318 (10.32%) met the inclusion criteria. Of them, 21 (6.60%) had ophthalmic manifestations and the female-to-male ratio was 1.6:1. The mean age (±SD) was 47.95±15.27 years and the median (interquartile range) time from the diagnosis of COVID-19, as defined by positive SARS-CoV-2 RT-PCR testing, to detection of the ophthalmic manifestation was 31 (142) days. The most common ocular manifestation was orbital mucormycosis (23.80%). Interestingly, the presence of ophthalmic manifestations was not associated with severe COVID-19 (p=0.665). CONCLUSIONS: The ophthalmic manifestations are infrequent in patients recovered from severe COVID-19. Nevertheless, further large sample studies are needed to confirm these findings.

Guidelines for the purification and characterization of extracellular vesicles of parasites.

Parasites are responsible for the most neglected tropical diseases, affecting over a billion people worldwide (WHO, 2015) and accounting for billions of cases a year and responsible for several millions of deaths. Research on extracellular vesicles (EVs) has increased in recent years and demonstrated that EVs shed by pathogenic parasites interact with host cells playing an important role in the parasite's survival, such as facilitation of infection, immunomodulation, parasite adaptation to the host environment and the transfer of drug resistance factors. Thus, EVs released by parasites mediate parasite-parasite and parasite-host intercellular communication. In addition, they are being explored as biomarkers of asymptomatic infections and disease prognosis after drug treatment. However, most current protocols used for the isolation, size determination, quantification and characterization of molecular cargo of EVs lack greater rigor, standardization, and adequate quality controls to certify the enrichment or purity of the ensuing bioproducts. We are now initiating major guidelines based on the evolution of collective knowledge in recent years. The main points covered in this position paper are methods for the isolation and molecular characterization of EVs obtained from parasite-infected cell cultures, experimental animals, and patients. The guideline also includes a discussion of suggested protocols and functional assays in host cells.

Proteomic Analysis of Extracellular Vesicles From Fasciola hepatica Hatching Eggs and Juveniles in Culture.

The identification of extracellular vesicles (EVs) in Fasciola hepatica has provided a new way to understand parasite-host communication. Most of the studies on EVs have focused on the adult stage of F. hepatica, but recently, the presence of EVs from different developmental stages has been reported. To better understand the potential role of EVs in the biology of the parasite and in the infection process, the protein cargo of EVs from embryonated eggs and newly-excysted juvenile (NEJs) flukes cultured up to 28 days, has been analyzed. EVs were isolated by size exclusion chromatography and evaluated by nanoparticle tracking analysis and transmission electron microscopy. LC-MS/MS proteomic analysis of EVs revealed the presence of 23 different proteins from embryonated egg-derived EVs and 29 different proteins from NEJ-derived EVs. Most of the identified proteins had been previously described in EVs from F. hepatica adults, including cytoskeletal proteins, glycolytic enzymes, stress-related proteins and tetraspanins. Nevertheless, EVs from hatching eggs and NEJs exhibited qualitative differences in composition, when compared to EVs form adults, including the absence of cathepsin cysteine peptidases. The differential content of the EVs released by the different developmental stages of the parasite reflect the intense activity of NEJs at this early stage, with several proteins involved in membrane traffic and cell physiology. This new set of identified proteins could help to understand key metabolic, biochemical and molecular mechanisms mediated by EVs that take place upon egg hatching and after parasite excystment.

Evaluation of the Immunomodulatory Effect of the Recombinant 14-3-3 and Major Antigen Proteins of Strongyloides stercoralis against an Infection by S. venezuelensis.

Strongyloidiasis, caused by Strongyloides stercoralis, is a neglected parasitic disease that represents a serious public health problem. In immunocompromised patients, this parasitosis can result in hyperinfection or disseminated disease with high levels of mortality. In previous studies, the mRNAs encoding for the 14-3-3 and major antigen proteins were found to be expressed at high levels in S. stercoralis L3 larvae, suggesting potential key roles in parasite-host interactions. We have produced them as recombinant proteins (rSs14-3-3 and rSsMA) in a bacterial protein expression system. The serum levels of anti-rSs14-3-3 and anti-rSsMA IgGs are increased upon infection with S. venezuelensis, validating the use of the mouse model since the native 14-3-3 and MA proteins induce an immune response. Each recombinant protein was formulated in the adjuvant adaptation (ADAD) vaccination system and injected twice, subcutaneously, in CD1 mice that were experimentally infected with 3000 S. venezuelensis L3 to evaluate their protective and immunomodulatory activity. Our results, including the number of parthenogenetic females, number of eggs in stool samples and the analysis of the splenic and intestinal indexes, show that the vaccines did not protect against infection. The immunization with rSs14-3-3 induced changes in the cytokine profile in mice, producing higher expression of IL-10, TGF-ß, IL-13 and TNF-α in the spleen, suggesting a Th2/Treg-type response with an increase in TNF-α levels, confirming its role as an immunomodulator.

Leukocyte glucose index as a novel biomarker for COVID-19 severity.

The severity of coronavirus disease 2019 (COVID-19) quickly progresses with unfavorable outcomes due to the host immune response and metabolism alteration. Hence, we hypothesized that leukocyte glucose index (LGI) is a biomarker for severe COVID-19. This study involved 109 patients and the usefulness of LGI was evaluated and compared with other risk factors to predict COVID 19 severity. LGI was identified as an independent risk factor (odds ratio [OR] = 1.727, 95% confidence interval [CI]: 1.026-3.048, P = 0.041), with an area under the curve (AUC) of 0.749 (95% CI: 0.642-0.857, P < 0.0001). Interestingly, LGI was a potential risk factor (OR = 2.694, 95% CI: 1.575-5.283, Pcorrected < 0.05) for severe COVID-19 in female but not in male patients. In addition, LGI proved to be a strong predictor of the severity in patients with diabetes (AUC = 0.915 (95% CI: 0.830-1), sensitivity = 0.833, and specificity = 0.931). The AUC of LGI, together with the respiratory rate (LGI + RR), showed a considerable improvement (AUC = 0.894, 95% CI: 0.835-0.954) compared to the other biochemical and respiratory parameters analyzed. Together, these findings indicate that LGI could potentially be used as a biomarker of severity in COVID-19 patients.

Overview of the interaction of helminth extracellular vesicles with the host and their potential functions and biological applications.

Helminth Extracellular Vesicles (EVs) have emerged as important mediators in host-parasite communications, participating in the parasite survival and its pathogenic effects. In the last decade, a growing amount of information reporting the isolation and characterization of EVs from different helminth species has appeared, but unfortunately, few reports have focused on functional studies of helminth EVs in different cell lines, organoids or animal models. We here review these in vitro and in vivo studies, which clearly demonstrate that helminths secrete EVs, which affect their environment. Helminth EVs are actively internalized by different cell lines, modulating cellular functions important for host-parasite communication. We discuss how these lines of investigation should provide potential new biomarkers of infection, and since helminth EVs can modulate the host immune response, we also discuss how they can provide a new landscape for the development of new vaccine tools against helminthiases as well as immunotherapy.

Cholesterol-Rich Lipid Rafts as Platforms for SARS-CoV-2 Entry.

Since its appearance, the Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2), the causal agent of Coronavirus Disease 2019 (COVID-19), represents a global problem for human health that involves the host lipid homeostasis. Regarding, lipid rafts are functional membrane microdomains with highly and tightly packed lipid molecules. These regions enriched in sphingolipids and cholesterol recruit and concentrate several receptors and molecules involved in pathogen recognition and cellular signaling. Cholesterol-rich lipid rafts have multiple functions for viral replication; however, their role in SARS-CoV-2 infection remains unclear. In this review, we discussed the novel evidence on the cholesterol-rich lipid rafts as a platform for SARS-CoV-2 entry, where receptors such as the angiotensin-converting enzyme-2 (ACE-2), heparan sulfate proteoglycans (HSPGs), human Toll-like receptors (TLRs), transmembrane serine proteases (TMPRSS), CD-147 and HDL-scavenger receptor B type 1 (SR-B1) are recruited for their interaction with the viral spike protein. FDA-approved drugs such as statins, metformin, hydroxychloroquine, and cyclodextrins (methyl-ß-cyclodextrin) can disrupt cholesterol-rich lipid rafts to regulate key molecules in the immune signaling pathways triggered by SARS-CoV-2 infection. Taken together, better knowledge on cholesterol-rich lipid rafts in the SARS-CoV-2-host interactions will provide valuable insights into pathogenesis and the identification of novel therapeutic targets.

Diversity of extracellular vesicles from different developmental stages of Fasciola hepatica.

The secretion of extracellular vesicles (EVs) in Fasciola hepatica adult worms was described by our group in 2012. Since then, EVs have been found in other helminths, thus providing a new paradigm for the complete understanding of host-parasite communication. However, information was lacking regarding the possible existence and role of EVs from other developmental stages of the parasite. In this study, we confirm the secretion of EVs by F. hepatica eggs and juvenile forms. EVs were isolated by size exclusion chromatography and characterised by nanoparticle tracking analysis and electron microscopy. We observed a large diversity in the morphologies of these EVs, suggesting specific functions for different subpopulations, as has been proposed in other model systems. The identification of these populations of morphologically diverse EVs will facilitate future studies aimed at biochemically characterising the different classes of these vesicles as a first step in deciphering their role in host-parasite communication.

Extracellular Vesicles From the Helminth Fasciola hepatica Prevent DSS-Induced Acute Ulcerative Colitis in a T-Lymphocyte Independent Mode.

The complexity of the pathogenesis of inflammatory bowel disease (ulcerative colitis and Crohn's disease) has led to the quest of empirically drug therapies, combining immunosuppressant agents, biological therapy and modulators of the microbiota. Helminth parasites have been proposed as an alternative treatment of these diseases based on the hygiene hypothesis, but ethical and medical problems arise. Recent reports have proved the utility of parasite materials, mainly excretory/secretory products as therapeutic agents. The identification of extracellular vesicles on those secreted products opens a new field of investigation, since they exert potent immunomodulating effects. To assess the effect of extracellular vesicles produced by helminth parasites to treat ulcerative colitis, we have analyzed whether extracellular vesicles produced by the parasitic helminth Fasciola hepatica can prevent colitis induced by chemical agents in a mouse model. Adult parasites were cultured in vitro and secreted extracellular vesicles were purified and used for immunizing both wild type C57BL/6 and RAG1-/- mice. Control and immunized mice groups were treated with dextran sulfate sodium 7 days after last immunization to promote experimental colitis. The severity of colitis was assessed by disease activity index and histopathological scores. Mucosal cytokine expression was evaluated by ELISA. The activation of NF-kB, COX-2, and MAPK were evaluated by immunoblotting. Administration of extracellular vesicles from F. hepatica ameliorates the pathological symptoms reducing the amount of pro-inflammatory cytokines and interfering with both MAPK and NF-kB pathways. Interestingly, the observed effects do not seem to be mediated by T-cells. Our results indicate that extracellular vesicles from parasitic helminths can modulate immune responses in dextran sulfate sodium (DSS)-induced colitis, exerting a protective effect that should be mediated by other cells distinct from B- and T-lymphocytes.

Subcutaneous injection of exosomes reduces symptom severity and mortality induced by Echinostoma caproni infection in BALB/c mice.

Recent studies have shown the importance of exosomes in the host-parasite relationship. These vesicles are an important part of the excretory/secretory pathway for proteins with the potential to alter immune responses. Therefore, in the present study, we examined the immunomodulatory role of exosomes in BALB/c mice using Echinostoma caproni as an experimental model of intestinal helminth infection. For this purpose, BALB/c mice were injected twice s.c. with purified exosomes of E. caproni, followed by experimental infection. We report a delay in the development of the parasite in mice immunised with exosomes, a concomitant reduced symptom severity and increased survival upon infection. Immunisations with exosomes evoked systemic antibody responses with high levels of IgM and IgG. IgG1, IgG2b and IgG3 are the subtypes responsible for the IgG increase. These antibodies showed specific recognition of exosomal proteins, indicating that these vesicles carry specific antigens that are involved in the humoral response. The administration of exosomes induced an increase of IFN-γ, IL-4 and TGF-ß levels in the spleen of mice prior to infection. The subsequent infection with E. caproni resulted in a further increase of IL-4 and TGF-ß, together with an abrupt overproduction of IL-10, suggesting the development of a Th2/Treg immune response. Our results show that the administration of exosomes primes the immune response in the host, which in turn can contribute to tolerance of the invader, reducing the severity of clinical signs in E. caproni infection.

Identification of enolase as a plasminogen-binding protein in excretory-secretory products of Fasciola hepatica.

We have followed a combined proteomic approach to identify proteins of Fasciola hepatica that could be involved in host-parasite interactions. Using two-dimensional gel electrophoresis, far Western immunoblot and mass spectrometry analyses, we have identified the enolase enzyme, present in the excretory/secretory materials of F. hepatica, as a human plasminogen-binding protein. This enzyme has an apparent molecular weight of 47 kDa with pI ranging from 6.2 to 7.2. These results suggest that enolase could act as a plasminogen receptor.

Surface analysis of Dicrocoelium dendriticum. The molecular characterization of exosomes reveals the presence of miRNAs.

With the aim of characterizing the molecules involved in the interaction of Dicrocoelium dendriticum adults and the host, we have performed proteomic analyses of the external surface of the parasite using the currently available datasets including the transcriptome of the related species Echinostoma caproni. We have identified 182 parasite proteins on the outermost surface of D. dendriticum. The presence of exosome-like vesicles in the ESP of D. dendriticum and their components has also been characterized. Using proteomic approaches, we have characterized 84 proteins in these vesicles. Interestingly, we have detected miRNA in D. dendriticum exosomes, thus representing the first report of miRNA in helminth exosomes. BIOLOGICAL SIGNIFICANCE: In order to identify potential targets for intervention against parasitic helminths, we have analyzed the surface of the parasitic helminth Dicrocoelium dendriticum. Along with the proteomic analyses of the outermost layer of the parasite, our work describes the molecular characterization of the exosomes of D. dendriticum. Our proteomic data confirm the improvement of protein identification from "non-model organisms" like helminths, when using different search engines against a combination of available databases. In addition, this work represents the first report of miRNAs in parasitic helminth exosomes. These vesicles can pack specific proteins and RNAs providing stability and resistance to RNAse digestion in body fluids, and provide a way to regulate host-parasite interplay. The present data should provide a solid foundation for the development of novel methods to control this non-model organism and related parasites. This article is part of a Special Issue entitled: Proteomics of non-model organisms.

The Role of Extracellular Vesicles in Modulating the Host Immune Response during Parasitic Infections.

Parasites are the cause of major diseases affecting billions of people. As the inflictions caused by these parasites affect mainly developing countries, they are considered as neglected diseases. These parasitic infections are often chronic and lead to significant immunomodulation of the host immune response by the parasite, which could benefit both the parasite and the host and are the result of millions of years of co-evolution. The description of parasite extracellular vesicles (EVs) in protozoa and helminths suggests that they may play an important role in host-parasite communication. In this review, recent studies on parasitic (protozoa and helminths) EVs are presented and their potential use as novel therapeutical approaches is discussed.