Worm Antigen Research Articles

Serodiagnosis of urogenital schistosomiasis and profiling of immunoreactive protein(s) in Schistosoma haematobium soluble egg and adult worm antigens.

To achieve schistosomiasis eradication plan by 2030, the development of efficient diagnosis is crucial. This study focuses on assessing the immunodiagnostic potential of S. haematobium (Sh) soluble egg antigen (SEA) and worm antigen (SWA) for urogenital schistosomiasis. Urine microscopy identified 50 S. haematobium-positive and 50 negative samples from a total of 500 examined. An additional 50 samples from a non-endemic area were included, bringing the total number of samples used for the assay to 150. Indirect ELISA immunoassays using SEA and SWA as the probing antigens evaluated 50 sera samples each from Sh positive, negative endemic (NE), and non-endemic (NNE) individuals. SDS-PAGE analysis of crude protein extracts was conducted, followed by Western blot analysis using primary antibodies from pooled Sh-infected sera samples. Diagnostic performance was evaluated using the area under the receiver operating characteristic (ROC) curve (AUC), sensitivity, and specificity. The AUC values for Sh SEA and SWA were 0.75 and 0.76 in NE samples, and 0.91 and 0.89 in NNE samples, respectively. Sensitivities 90 (95% CI: 78.64 - 95.65)/ 64.71 (95% CI: 52.17 - 75.92), and specificities 50 (95% CI: 36.64 - 63.36)/ 81.25 (95% CI: 63.56 - 92.79) were recorded for SEA and SWA, respectively in NE samples. In addition, sensitivities 90 (78.64 - 95.65)/ 92 (95% CI: 80.77 - 97.78), and specificities 72 (95% CI: 58.33 - 82.53)/ 72.00 (95% CI: 57.51 - 83.77) were recorded for SEA and SWA, respectively in NNE samples. The mean antibody titer against Sh SEA in infected samples was significantly higher than in non-infected samples (P <0.0001). Eight (8) immunoreactive protein bands; 4 each of SEA and SWA were identified, indicating potential for diagnostic tool development. Sh SEA and SWA demonstrate promise for diagnosing urogenital schistosomiasis in both endemic and non-endemic regions.

Immuno-therapeutic and prophylactic potential of Trichinella spiralis antigens for inflammatory bowel diseases

Ulcerative colitis (UC), a severe chronic inflammatory disorder of the colon, is one of the inflammatory bowel diseases (IBD) that affects humans and several domestic animal species, including cats and dogs. Helminth infections and autoimmune diseases are inversely correlated, as explained by the hygiene hypothesis, which suggests that IBD is infrequent in countries where helminth infections are common but more prevalent in developed nations. This study investigated the therapeutic and prophylactic potential of Trichinella spiralis (T. spiralis) antigens in an experimental colitis model for IBD. Mice were divided into eight groups: normal model, colitis model, larval antigen prophylaxis, adult antigen prophylaxis, larval antigen therapeutic, adult antigen therapeutic, larval antigen prophylaxis and therapeutic, and adult antigen prophylaxis and therapeutic. Colitis was induced intrarectally by administering a single dose of 0.2 ml of acetic acid, except in the healthy group, which received PBS (0.2 ml). The mice were euthanized 12 days after colitis induction. The therapeutic and prophylactic potential of T. spiralis antigens were assessed through colitis severity and histopathological, immunological, and immunohistochemical examinations. The results showed a significant reduction in Disease Activity Index (DAI), an increase in goblet cells' acidic mucin levels, reduced iNOS and TNF-α expression, and decreased serum levels of IFN-γ and IL-10 cytokines in Groups IV-VIII compared to the colitis model, particularly in the group that received adult worm antigen both prophylactically and therapeutically. This study demonstrated that T. spiralis antigens, especially from adult worms, had protective and therapeutic effects on experimental colitis, with a superior effect when administered both before and after colitis induction by reducing inflammation and modulating the immune response. Thus, T. spiralis antigens may improve disease outcomes and provide a novel treatment approach for ulcerative colitis.

Comparative evaluation of plasma biomarkers of Schistosoma haematobium infection in endemic populations from Burkina Faso.

Infection with Schistosoma haematobium causes urogenital disease associated with organ disfunction, bleeding, pain, and higher susceptibility to infections and cancer. Timely and accurate diagnosis is crucial for prompt and appropriate treatment as well as surveillance efforts, and the use of plasma biomarkers offers important advantages over parasitological examination of urine, including increased sensitivity and the possibility to use the same specimen for multiple investigations. The present study aims to evaluate the diagnostic performance of different plasma biomarkers in endemic populations from Burkina Faso, West Africa. Schistosoma spp. Circulating Anodic Antigen (CAA), cell free S. haematobium DNA (cfDNA), class M and G antibodies against S. haematobium Soluble Worm Antigen Preparation (SWAP) and Soluble Egg Antigen (SEA) were measured in 406 plasma samples. Results of each biomarker test were compared to those of CAA, a Composite Reference Standard (CRS) and Latent Class Analysis (LCA). An identical proportion of positive samples (29%) was observed as a result of CAA and cfDNA testing, with a substantial agreement (84%, Cohen k = 0.62) between the results of the two tests, and a comparable agreement with the results of CRS and LCA. A higher positivity was observed, as expected, as a result of specific antibody testing (47%-72%), with IgG showing a higher agreement than IgM with the three references. Also, higher IgG levels were observed in current vs past infection, and ROC analysis identified optimal cutoff values for improved testing accuracy. This study provides compelling evidence that can inform the choice of the most appropriate diagnostic plasma biomarker for urogenital schistosomiasis in endemic areas, depending on the purpose, context, and available resources for testing. Either CAA or cfDNA testing can be used for the diagnosis of patients and for epidemiological investigations, even in absence of urine filtration microscopy, whereas anti-SWAP or anti-SEA IgG can be employed for surveillance and integrated monitoring of control interventions against poverty-associated diseases.

Enteric tuft cells coordinate timely expulsion of the tapeworm Hymenolepis diminuta from the murine host by coordinating local but not systemic immunity.

Recognizing that enteric tuft cells can signal the presence of nematode parasites, we investigated whether tuft cells are required for the expulsion of the cestode, Hymenolepis diminuta, from the non-permissive mouse host, and in concomitant anti-helminthic responses. BALB/c and C57BL/6 mice infected with H. diminuta expelled the worms by 11 days post-infection (dpi) and displayed DCLK1+ (doublecortin-like kinase 1) tuft cell hyperplasia in the small intestine (not the colon) at 11 dpi. This tuft cell hyperplasia was dependent on IL-4Rα signalling and adaptive immunity, but not the microbiota. Expulsion of H. diminuta was slowed until at least 14 dpi, but not negated, in tuft cell-deficient Pou2f3-/- mice and was accompanied by delayed goblet cell hyperplasia and slowed small bowel transit. Worm antigen and mitogen evoked production of IL-4 and IL-10 by splenocytes from wild-type and Pou2f3-/- mice was not appreciably different, suggesting similar systemic immune reactivity to infection with H. diminuta. Wild-type and Pou2f3-/- mice infected with H. diminuta displayed partial protection against subsequent infection with the nematode Heligmosomoides bakeri. We speculate that, with respect to H. diminuta, enteric tuft cells are important for local immune events driving the rapidity of H. diminuta expulsion but are not critical in initiating or sustaining systemic Th2 responses that provide concomitant immunity against secondary infection with H. bakeri.

Seroprevalence of dirofilariasis in dogs in Sukabumi Regency

Dirofilariasis is a serious zoonotic disease in dogs. This study aimed to measure the prevalence and determine the risk factors of dirofilariasis in the Sukabumi Regency. A total of 152 blood samples were collected from dogs in two sub-districts in Sukabumi which have different topographic characteristics, namely Jampang Tengan District which is a hilly area, and Cisolok District which is a coastal area. Blood serum was examined using the commercial rapid test kit CHW Ag Test Kit 2.0 ® Bionote to detect the presence of the Dirofilaria immitis adult worm antigen. The results showed that the seroprevalence of dirofilariasis in dogs in the Sukabumi Regency was 20.4%. Areas with hilly characteristics have a higher prevalence of dirofilariasis than coastal areas do. The incidence of dirofilariasis in the Sukabumi Regency was not influenced by sex, method of keeping, or age of the dog.

Evaluation of isotype-based serology for diagnosis of Schistosoma mansoni infection in individuals living in endemic areas with low parasite burden

Intestinal schistosomiasis is a chronic and debilitating disease that affects public health systems worldwide. Control interventions to reduce morbidity primarily involve the diagnosis and treatment of infected individuals. However, the recommended Kato-Katz (KK) parasitological method shows low sensitivity in individuals with low parasite loads and is not useful for monitoring elimination of parasite transmission at later stages. In the current study, we evaluated the accuracy of serum reactivity levels of different immunoglobulin isotypes in an enzyme-linked immunosorbent assay (ELISA), utilizing Schistosoma mansoni crude extracts, with the aim to improve the diagnosis of infected individuals with low parasite loads. The serum reactivity of IgM and IgG subclass antibodies (IgG1, IgG3, and IgG4) against soluble adult worm and egg antigen preparations was evaluated in residents from a schistosomiasis-endemic area in northern Minas Gerais, Brazil. The parasitological status of the study population was determined through fecal examination with multiple parasitological tests to create a consolidated reference standard (CRS) plus a fecal DNA detection test (q-PCR). Twelve months after praziquantel treatment, a second serum sample was obtained from the population for reexamination. A two-graph receiver operating characteristic curve (TG-ROC) analysis was performed using the serum reactivity of non-infected endemic controls and egg-positive individuals, and the cut-off value was established based on the intersection point of the sensibility and specificity curves in TG-ROC analyses. The diagnostic accuracy of each serological test was evaluated in relation to the parasitological CRS and to the combination of CRS plus qPCR results. The data revealed that serum reactivity of IgM and IgG3 against S. mansoni antigens did not allow identification of infected individuals from the endemic area. In contrast, serum IgG1 and IgG4-reactivity against schistosome antigens could distinguish between infected and non-infected individuals, with AUC values ranging between 0.728–0.925. The reactivity of IgG4 anti-soluble egg antigen - SEA (sensitivity 79 %, specificity 69 %, kappa = 0.49) had the best diagnostic accuracy, showing positive reactivity in more than 75 % of the infected individuals who eliminated less than 12 eggs per gram of feces. Moreover, serum IgG4 reactivity against SEA and against soluble worm antigen preparation (SWAP) was significantly reduced in the serum of infected individuals after 12 months of confirmed parasitological cure and in the absence of re-infection. These results reinforce that the described IgG4 anti-SEA ELISA assay is a sensitive alternative for the diagnosis of active intestinal schistosomiasis in individuals from endemic areas, including in those with a very low parasite load.

Comparison of a Urine Antigen Assay and Multiple Examinations with the Formalin-Ethyl Acetate Concentration Technique for Diagnosis of Opisthorchiasis.

Detection of worm antigen in urine is a sensitive diagnostic method for opisthorchiasis, particularly for light-intensity infections; however, the presence of eggs in feces is essential for validating results from the antigen assay. To address the issue of low sensitivity of fecal examination, we modified the protocol for the formalin-ethyl acetate concentration technique (FECT) and compared it against urine antigen measurements for detection of the parasite Opisthorchis viverrini. First, we optimized the FECT protocol by increasing the number of drops for examinations from the standard two drops to a maximum of eight. We were able to detect additional cases after examination of ≥ 3 drops, and the prevalence of O. viverrini saturated after examination of ≥ 5 drops. We then compared the optimized FECT protocol (examining five drops of suspension) against urine antigen detection for the diagnosis of opisthorchiasis in field-collected samples. The optimized FECT protocol detected O. viverrini eggs in 25 of 82 individuals (30.5%) who had positive urine antigen tests but were fecal egg negative by the standard FECT protocol. The optimized protocol also retrieved O. viverrini eggs in 2 of 80 antigen-negative cases (2.5%). In comparison with the composite reference standard (combined FECT and urine antigen detection), the diagnostic sensitivity of examining two and five drops of FECT and the urine assay was 58.2, 67, and 98.8%, respectively. Our results show that multiple examinations of fecal sediment increase the diagnostic sensitivity of FECT and thus provide further support for the reliability and utility of the antigen assay for diagnosis and screening of opisthorchiasis.

Pattern and repeatability of ascarid-specific antigen excretion through chicken faeces, and the diagnostic accuracy of coproantigen measurements as compared with McMaster egg counts and plasma and egg yolk antibody measurements in laying hens

BackgroundA coproantigen enzyme-linked immunosorbent assay (ELISA) has recently been proposed for detecting ascarid infections in chickens. The excretion pattern of ascarid antigens through chicken faeces and the consistency of measurements over the course of infections are currently unknown. This study evaluates the pattern and repeatability of worm antigen per gram of faeces (APG) and compares the diagnostic performance of the coproantigen ELISA with a plasma and egg yolk antibody ELISA and McMaster faecal egg counts (M-FEC) at different weeks post-infection (wpi).MethodsFaecal, blood and egg yolk samples were collected from laying hens that were orally infected with a mix of Ascaridia galli and Heterakis gallinarum eggs (N = 108) or kept as uninfected controls (N = 71). Measurements including (a) APG using a coproantigen ELISA, (b) eggs per gram of faeces (EPG) using the McMaster technique and (c) ascarid-specific IgY in plasma and in egg yolks using an ascarid-specific antibody ELISA) were performed between wpi 2 and 18.ResultsTime-dependent significant differences in APG between infected and non-infected laying hens were quantified. At wpi 2 (t(164) = 0.66, P = 1.00) and 4 (t(164) = −3.09, P = 0.094) no significant differences were observed between the groups, whereas infected hens had significantly higher levels of APG than controls by wpi 6 (t(164) = −6.74, P < 0.001). As indicated by a high overall repeatability estimate of 0.91 (CI = 0.89–0.93), APG could be measured consistently from the same individual. Compared to McMaster and antibody ELISA, coproantigen ELISA showed the highest overall diagnostic performance (area under curve, AUC = 0.93), although the differences were time-dependent. From wpi 6 to 18 coproantigen ELISA had an AUC > 0.95, while plasma IgY ELISA showed the highest diagnostic performance in wpi 2 (AUC = 0.95). M-FEC had the highest correlation with total worm burden, while APG had highest correlations with weights and lengths of A. galli.ConclusionAscarid antigen excretion through chicken faeces can be measured with high accuracy and repeatability using a coproantigen ELISA. The antigen excretion increases over time, and is associated with worm maturation, particularly with the size of A. galli. Our results suggest the necessity of complementary use of different diagnostic tools for a more accurate diagnosis of infections.Graphical

Involvement of the excretory/secretory and surface-associated antigens of Dirofilaria immitis adult worms in the angiogenic response in an in-vitro endothelial cell model

Angiogenesis is a process by which new vessels are formed from pre-existing ones when the physiological conditions of the vascular endothelium are altered. Heartworm disease, caused by Dirofilaria immitis, causes changes in the vascular endothelium of the pulmonary arteries due to obstruction, friction, and hypoxia. The aim of this study was to analyze whether the excretory/secretory and surface-associated antigens of adult worms interact and modulates the angiogenic mechanism, viable cell number and cell migration, as well as the formation of pseudo-capillaries. Cultures of human vascular endothelial cells (HUVECs) stimulated with excretory/secretory antigens (DiES), surface-associated antigens (Cut) from D. immitis adult worms, VEFG-A (Vascular Endothelial Growth Factor A), as well as DiES+VEFG-A and Cut+VEFG-A were used. The production of VEFG-A and other proangiogenic [soluble VEFGR-2 (sVEFGR-2), membrane Endoglin (mEndoglin)] and antiangiogenic [VEFGR-1/soluble Flt (sFlt), soluble Endoglin (sEndoglin)] molecules was assessed using commercial ELISA kits. Cell viability was analyzed by live cell count and cytotoxicity assays by a commercial kit. In addition, viable cell number by MTT-based assay, cell migration by wound-healing assay carrying out scratched wounds, and the capacity of pseudo-capillary formation to analyze cell connections and cell groups in Matrigel cell cultures, were evaluated. In all cases, non‑stimulated cultures were used as controls. DiES+VEFG-A and Cut+VEFG-A significantly increased the production of VEFG-A and sVEFGR-2, and only Cut+VEFG-A significantly increased the production of VEFGR-1/sFlt compared to other groups and non-stimulated cultures. Moreover, only DiES+VEFG-A produced a significant increase in viable cell number and significant decrease cell migration, as well as in the organization and number of cell connections. Excretory/secretory and surface-associated antigens of adult D. immitis activated the angiogenic mechanism by mainly stimulating the synthesis of proangiogenic factors, and only excretory/secretory antigens increased viable cell number, activated cell migration and the formation of pseudo-capillaries. These processes could lead to vascular endothelial remodeling of the infected host and favor the long-term survival of the parasite.

The Efficiency of Schistosoma mansoni Crude Antigens in Inhibition of Heat Shock Protein, Apoptosis, and Lysosomal Activity: An Immunohistochemical Study.

The adverse impact of schistosomiasis on tissues is considered in generating a schistosomal vaccine. The purpose of this study was to evaluate the effectiveness of Schistosoma mansoni crude antigens as a therapeutic and prophylactic formulation in the inhibition of heat shock protein, apoptosis, and CD3/CD20 expression in a liver and spleen mouse models using the immunohistochemistry method. A total of 65 mice were divided into five groups: (i) infected untreated group (G1), (ii) therapeutic treated group (G2) with egg soluble egg antigen (SEA), and soluble worm antigen preparation (SWAP), (iii) prophylactically treated group (G3) with cercarial antigen preparation (CAP), (iv) combined treated group with three antigens (G4), and (v) control group (G5). The results we obtained showed that CAP, SEA, and SWAP antigens mitigated the deterioration and inflammation induced by infection. Apoptosis and sinusoidal injuries were significantly reduced when treated with CAP antigen before infection. After infection, using SEA and SWAP antigens may help lighten the liver's load. A high degree of activation in T and B cells in the liver and spleen is linked to this. Our findings shed light on the immunological mechanisms that contribute to the recovery from therapy and vaccination against schistosome damage.

Praziquantel promotes protection against Schistosoma japonicum infection in mice

Praziquantel (PZQ) is the first line drug for the treatment of schistosomiasis. Several studies have confirmed that PZQ regulates host immunity, and we have recently found that pretreatment with PZQ enhances resistance against Schistosoma japonicum infection in buffaloes. We speculate that PZQ induces physiological changes in mice that prevent S. japonicum infection. To test this hypothesis and provide a practical measure to prevent S. japonicum infection, we determined the effective dose (the minimum dose), protection period and onset time of protection by comparing the worm burden, female worm burden and egg burden in PZQ-pretreated mice and blank control mice. Morphological differences between parasites were observed by measuring the total worm length, oral sucker, ventral sucker and ovary. The levels of cytokines, nitrogen monoxide (NO), 5-hydroxytryptamine (5-HT) and specific antibodies were measured using kits or soluble worm antigens. Hematological indicators on day 0 were analyzed in mice that received PZQ on days -15, -18, -19, -20, -21 and -22. The PZQ concentrations in plasma and blood cells were monitored using high performance liquid chromatography (HPLC). The effective dose was found to be two oral administrations (interval of 24 h) at 300 mg/kg body weight (BW) or one injection at 200 mg/kg BW, and the protection period of PZQ injection was 18 days. The optimal preventive effect was observed at two days post-administration, with a >92% worm reduction rate and significant worm reduction until 21 days after administration. Adult worms from PZQ-pretreated mice were runtish showing a shorter length, smaller organs and fewer eggs in the uteri of females. Detection of cytokines, NO, 5-HT and hematological indicators showed that PZQ induced immune-physiological changes, including higher levels of NO, IFN-γ and IL-2, and a lower level of TGF-β. No significant difference in the anti-S. japonicum specific antibody levels was observed. The PZQ concentrations in plasma and blood cells 8 and 15 days post-administration were lower than the detection limit. Our results confirmed that pretreatment with PZQ promotes the protection of mice against S. japonicum infection within 18 days. Although we observed some immune-physiological changes in the PZQ-pretreated mice, the exact mechanisms involved in the preventive effect require further study.

A review of serological tests available in Brazil for intestinal schistosomiasis diagnosis.

The World Health Organization (WHO) roadmap and recommendations for elimination of schistosomiasis were recently updated. With significant reductions in the prevalence and intensity of schistosomiasis infections worldwide, there is a need for more sensitive diagnostic methods. There are a few remaining transmission hotspots in Brazil, although low endemicity settings comprise most of the endemic localities. For the latter, serology may represent a tool for population screening which could help eliminate transmission of schistosomiasis. Here, we review serology tests currently available in Brazil from both public health and private laboratories: immunofluorescent antibody tests (IFATs) on adult worm sections and enzyme-linked immunosorbent assays (ELISAs) with soluble egg and adult worm antigens. Both in-house and commercially available tests have received less than adequate performance evaluations. Our review of immediate basic and operational research goals may help identify local adjustments that can be made to improve control interventions aimed at elimination of schistosomiasis as a public health problem.

Molecular Cloning and Characterization of a Fasciola gigantica Nuclear Receptor Subfamily 1 (FgNR1).

Fasciola gigantica, a giant liver fluke, causes tremendous loss to the livestock economy in several regions throughout the world. The situation of drug resistance has been emerging increasingly; therefore, novel drugs and drug targets need to be discovered. The adult F. gigantica inhabits the major bile ducts where bile salts accumulate-these are steroid-like molecules that mediate several physiological processes in organisms through interacting with their specific nuclear receptors. However, the molecular mechanism of the interaction in the parasitic organisms have not been clearly understood. In this study, putative nuclear receptor subfamily 1 of F.&amp;nbsp;gigantica (FgNR1) was identified. Nucleotide and amino acid sequences of the FgNR1 homolog were obtained from the transcriptome of F. gigantica and predicted for properties and functions using bioinformatics. The full-length cDNA was cloned and expressed in the bacterial expression system and then used for immunization. Western analysis and immunolocalization suggested that FgNR1 could be detected in the crude worm antigens and was highly expressed in the caeca and testes of the adult parasite. Moreover, the bile could significantly activate the expression of FgNR1 in cultured parasites. Our results indicated that FgNR1 has high potential for the development of a novel anthelminthic drug in the future.

Effects of adult Ascaris suum and their antigens (total and trans-cuticular excretory-secretory antigen, cuticular somatic antigen) on intestinal nutrient transport in vivo.

AbstractAscaris suumconstitutes a major problem in commercial pig farming worldwide. Lower weight gains in infected pigs probably result from impaired nutrient absorption. This study investigated intestinal nutrient transport in 4 groups of 6 pigs each, which were inoculated with 30 living adultA. suum, or antigen fractions consisting of (1) total excretory–secretory (ES) antigens of adult worms, (2) ES antigens secreted exclusively from the parasites' body surface (trans-cuticular ES) and (3) cuticular somatic antigens ofA. suum, compared to placebo-treated controls. Three days after inoculation into the gastrointestinal tract, glucose, alanine and glycyl-l-glutamine transport was measured in the duodenum, jejunum and ileum using Ussing chambers. Transcription of relevant genes [sodium glucose cotransporter 1 (SGLT1), glucose transporter 1 (GLUT1), GLUT2, hypoxia-inducible factor 1-alpha (Hif1α), interleukin-4 (IL-4), IL-13, signal transducer and activator of transcription 6 (STAT6), peptide transporter 1 (PepT1)] and expression of transport proteins [SGLT1, phosphorylated SGLT1, GLUT2, Na+/K+-ATPase, amino acid transporter A (ASCT1), PepT1] were studied. Although no significant functional changes were noted after exposure to adultA. suum, a significant downregulation of jejunal GLUT1, STAT6, Hif1αand PepT1 transcription as well as ileal GLUT2 and PepT1 expression indicates a negative impact of infection on transport physiology. Therefore, the exposure period of 3 days may have been insufficient for functional alterations to become apparent. In contrast,A. suumantigens mainly induced an upregulation of transport processes and an increase in transcription of relevant genes in the duodenum and jejunum, possibly as a compensatory reaction after a transient downregulation. In the ileum, a consistent pattern of downregulation was observed in all inoculated groups, in line with the hypothesis of impaired nutrient transport.

Reduce the Changes in Histological Features of Colon Resulting from Induced Ulcerative Colitis in Mice by Worm Antigens.

Ulcerative colitis is one of the inflammatory bowel disease (IBD) consequences characterized by chronic inflammation of the gastrointestinal (GI) tract. The current study aims to determine the changes in colon tissue caused by induced Ulcerative Colitis and reduce these changes by worms' antigen. The study included 45 adult male albino mice (Mus musculus), with ages ranging between 8-10 weeks; the average weights ranged between 18-32 g. Ulcerative colitis was induced by intracolonic administration of 100 μL of 4% after they had been starved for 18 h. The animals were dissected after one week, and routine histological sections were conducted. The results of the histological study showed that in the colon of white mice treated with 4% acetic acid occurred, many histological changes were represented by the appearance of inflammatory cells in the mucous layer around the goblet cells, and the formation of vacuoles, necrosis at epithelium and intense congestion under the surface epithelium. The marked histological sections of the colon in mice with induced ulcerative colitis treated with helminth extract at a concentration of 0.1 mg/kg for a week, were showed that the histological changes began to decrease in the colon tissue, with the presence of a few inflammatory cells as well as little mucus secretion.

A copro-antigen ELISA for the detection of ascarid infections in chickens

A reliable method of diagnosing the most prevalent helminth infections in chickens is vital for developing effective control strategies. Ascaridia galli and Heterakisgallinarum are phylogenetically close nematode species that can elicit the development of cross-reactive antibodies in chickens. Therefore, an enzyme-linked immunoassay (ELISA) based on Ascaridia galli antigens in faeces of chickens to detect and quantify infections with both A. galli and H. gallinarum was developed. The ELISA utilised polyclonal antibodies that were obtained from rabbits immunised with soluble antigens isolated from A. galli. In two separate experiments, chickens were kept as uninfected controls or were orally infected with either 100 or 1000 of embryonated eggs of A. galli or H.gallinarum. Faecal samples were collected after 28–30 weeks post-infection. The ELISA was then used to quantify the concentration of soluble worm antigens in faecal samples, i.e., the amount of antigen per gram faeces, APG. The APG from infected chickens was significantly higher than non-infected groups in both experiments (P 0.001). Both 100 and 1000 infection dose groups were not significantly different (P = 0.999) in the experiment with H. gallinarum, whereas in the experiment with A. galli, APG was significantly higher in the 1000 infection group (P 0.001). A receiver operation characteristics (ROC) analysis that evaluates the qualitative performance of diagnostics tests was used to calculate the assay parameters within each mono-infection experiment. The result showed that the assay had a high diagnostics accuracy with an area-under-curve (AUC) of 0.99 in detecting infection in A. galli infected chickens and a moderate-high accuracy (AUC = 0.89) in birds infected with H. gallinarum. The diagnostic sensitivity and specificity of the assay at the optimal cut-off point equivalent to Youden index were 93% and 100% for detecting infections in A. galli experiment and 85% and 92% in H. gallinarum experiment, respectively. The correlation between faecal antigen concentration and all worm burden parameters was positive but generally low (r < 0.33), which provided less information about infection intensities. Nonetheless, these results indicate that a reliable and accurate qualitative diagnosis of the two most prevalent intestinal nematodes in chickens can be achieved using a non-invasive copro-antigen ELISA assay.

Dynamic miRNA profile of host T cells during early hepatic stages of Schistosoma japonicum infection.

Schistosomes undergo complicated migration in final hosts during infection, associated with differential immune responses. It has been shown that CD4+ T cells play critical roles in response to Schistosoma infections and accumulated documents have indicated that miRNAs tightly regulate T cell activity. However, miRNA profiles in host T cells associated with Schistosoma infection remain poorly characterized. Therefore, we undertook the study and systematically characterized T cell miRNA profiles from the livers and blood of S. japonicum infected C57BL/6J mice at 14- and 21-days post-infection. We observed 508 and 504 miRNAs, in which 264 miRNAs were co-detected in T cells isolated from blood and livers, respectively. The comparative analysis of T cell miRNAs from uninfected and infected C57BL/6J mice blood showed that miR-486b-5p/3p expression was significantly downregulated and linked to various T cell immune responses and miR-375-5p was highly upregulated, associated with Wnt signaling and pluripotency, Delta notch signaling pathways, etc. Whereas hepatic T cells showed miR-466b-3p, miR-486b-3p, miR-1969, and miR-375 were differentially expressed compared to the uninfected control. The different expressions of some miRNAs were further corroborated in isolated T cells from mice and in vitro cultured EL-4 cells treated with S. japonicum worm antigens by RT-qPCR and similar results were found. In addition, bioinformatics analysis combined with RT-qPCR validation of selected targets associated with the immune system and parasite-caused infectious disease showed a significant increase in the expression of Ctla4, Atg5, Hgf, Vcl and Arpc4 and a decreased expression of Fermt3, Pik3r1, Myd88, Nfkbie, Ppp1r12a, Ppp3r1, Nfyb, Atg12, Ube2n, Tyrobp, Cxcr4 and Tollip. Overall, these results unveil the comprehensive repertoire of T cell miRNAs during S. japonicum infection, suggesting that the circulatory (blood) and liver systems have distinct miRNAs landscapes that may be important for regulating T cell immune response. Altogether, our findings indicated a dynamic expression pattern of T cell miRNAs during the hepatic stages of S. japonicum infection.

Immunotherapy for type 1 diabetes mellitus by adjuvant-free Schistosoma japonicum-egg tip-loaded asymmetric microneedle patch (STAMP)

BackgroundType 1 diabetes mellitus (T1DM) is an autoimmune disease mediated by autoreactive T cells and dominated by Th1 response polarization. Insulin replacement therapy faces great challenges to this autoimmune disease, requiring highly frequent daily administration. Intriguingly, the progression of T1DM has proven to be prevented or attenuated by helminth infection or worm antigens for a relatively long term. However, the inevitable problems of low safety and poor compliance arise from infection with live worms or direct injection of antigens. Microneedles would be a promising candidate for local delivery of intact antigens, thus providing an opportunity for the clinical immunotherapy of parasitic products.MethodsWe developed a Schistosoma japonicum-egg tip-loaded asymmetric microneedle patch (STAMP) system, which serves as a new strategy to combat TIDM. In order to improve retention time and reduce contamination risk, a specific imperfection was introduced on the STAMP (asymmetric structure), which allows the tip to quickly separate from the base layer, improving reaction time and patient’s comfort. After loading Schistosoma japonicum-egg as the immune regulator, the effects of STAMP on blood glucose control and pancreatic pathological progression improvement were evaluated in vivo. Meanwhile, the immunoregulatory mechanism and biosafety of STAMP were confirmed by histopathology, qRT-PCR, ELISA and Flow cytometric analysis.ResultsHere, the newly developed STAMP was able to significantly reduce blood glucose and attenuate the pancreatic injury in T1DM mice independent of the adjuvants. The isolated Schistosoma japonicum-eggs micron slowly degraded in the skin and continuously released egg antigen for at least 2 weeks, ensuring localization and safety of antigen stimulation. This phenomenon should be attributed to the shift of Th2 immune response to reduce Th1 polarization.ConclusionOur results exhibited that STAMP could significantly regulate the blood glucose level and attenuate pancreatic pathological injury in T1DM mice by balancing the Th1/Th2 immune responses, which is independent of adjuvants. This technology opens a new window for the application of parasite products in clinical immunotherapy.

Increased ShTAL1 IgE responses post-Praziquantel treatment may be associated with a reduced risk to re-infection in a Ghanaian S. haematobium-endemic community.

BackgroundEvidence from recent studies in Schistosoma mansoni-endemic areas show an age-associated immunity that is positively correlated with IgE titres to Schistosoma mansoni-specific tegumental allergen-like protein 1 (SmTAL1). The structural homology between SmTAL1 and the S. haematobium-specific TAL1 (ShTAL1) has been verified, yet it remains unclear whether similar age- and immune-associated trends characterize ShTAL1. This community-based intervention study was conducted to assess whether ShTAL1IgE responses post-treatment with praziquantel (PZQ) might be associated with a reduced risk to re-infection with S. haematobium.Methodology/Principal findingsThis study was conducted at Agona Abodom, Central Region, Ghana, and involved 114 participants aged 6 to 55 years. EDTA blood samples were collected at baseline and 7 weeks after PZQ treatment (Follow-up). Baseline and Follow-up titres of specific IgG1, IgG4, and IgE antibodies to the S. haematobium-specific adult worm antigen (ShAWA), the Sh-specific soluble egg antigen (ShSEA), and the Sh-specific tegumental-allergen-like 1 protein (ShTAL1) in plasma samples were measured using sandwich ELISA. Participants at both time points also provided stool and urine for helminth egg detection by microscopy. Prevalence of S. haematobium at baseline was 22.80%, and decreased to 3.50% at Follow-up. The egg reduction rate (ERR) was 99.87%. Overall plasma levels of ShTAL1-IgE increased 7 weeks post-PZQ treatment, and with increasing age; whiles S. haematobium infection prevalence and intensity decreased. For S. haematobium-infected participants who were egg-negative at Follow-up (N = 23), minimal median levels of ShTAL1-IgE were observed for all age groups prior to treatment, whilst median levels increased considerably among participants aged 12 years and older at Follow-up; and remained minimal among participants aged 11 years or less. In the univariate analysis, being aged 12 years or older implied an increased likelihood for ShTAL1-IgE positivity [12–14 years (cOR = 9.64, 95% CI = 2.09–44.51; p = 0.004); 15+ years (cOR = 14.26, 95% CI = 3.10–65.51; p = 0.001)], and this remained significant after adjusting for confounders [12–14 years (aOR = 22.34, 95% CI = 2.77–180.14; p = 0.004); ≥15 years (aOR = 51.82, 95% CI = 6.44–417.17; p < 0.001)]. Conversely, median ShTAL1-IgG4 titres were hardly detectible at Follow-up.Conclusions/SignificanceThese findings demonstrate that increased IgE levels to ShTAL1 7 weeks after PZQ treatment could be associated with a reduced risk to re-infection, and adds to the large body of evidence suggesting a protective role of the treatment-induced ShTAL1 antigen in schistosomiasis infections. It was also quite clear from this work that apart from being persistently S. haematobium-positive, elevated ShTAL1-IgG4 levels at Follow-up could be indicative of susceptibility to re-infection. These outcomes have important implications in vaccine development, and in shifting the paradigm in mass chemotherapy programmes from a ‘one-size-fits-all’ approach to more sub-group-/participant-specific strategies in endemic areas.

Clinical and blood count findings in dogs naturally infected with Dirofilaria immitis.

Dirofilaria immitis is a nematode that infects canids worldwide as well as other mammalian species, including humans. Worms and dogs are well adapted to one another, making dogs the best urban host for the parasite. Nevertheless, 30% of dogs do not sufficiently present microfilaremia, that is, the low larval load impairs transmission by mosquitoes and diagnosis by its detection in the blood samples. Therefore, the canine diagnosis must always include a microfilaria test and serological tests to detect adult worm antigens. To describe the clinical findings in naturally infected dogs in Rio de Janeiro, 34 dogs were included in the study. All dogs were evaluated for history, anamnesis, physical examination, complete blood count (CBC), D. immitis testing for antigens (ELISA test SNAP 4Dx Plus®), and microfilarial burden. The most frequent complaint from the owners was coughing (14.7%, 5/34). The most common CBC finding was eosinophilia (29.4%), followed by thrombocytopenia (26.5%) and neutrophilia (14.7%). Of the 34 animals, 91.2% were microfilaremic, with a mean count of 11.939 microfilaria/mL. Veterinarians working in areas endemic to D. immitis should always undergo screening tests and pulmonary auscultation, and increased expiratory sounds, even in the absence of coughing, can be considered a sign of the disease, along with eosinophilia, thrombocytopenia, and neutrophilia.