Spirocerca lupi draft genome, vaccine and anthelmintic targets.

Spirocerca lupi is a parasitic nematode affecting predominantly domestic dogs. It causes spirocercosis, a disease that is often fatal. The assembled draft genome of S. lupi consists of 13,627 predicted protein-coding genes and is approximately 150 Mb in length. Several known anthelmintic gene targets such as for ß-Tubulin, glutamate, and GABA receptors as well as known vaccine gene targets such as cysteine protease inhibitor and cytokines were identified in S. lupi by comparing orthologs of C. elegans anthelmintic gene targets as well as orthologs to known vaccine candidates. New anthelmintic targets were predicted through an inclusion-exclusion strategy and new vaccine targets were predicted through an immunoinformatics approach. New anthelminthic targets include DNA-directed RNA polymerases, chitin synthase, polymerases, and other enzymes. New vaccine targets include cuticle collagens. These gene targets provide a starting platform for new drug identification and vaccine design.

Quantitative analysis of Northern bobwhite (Colinus virginianus) cytokines and TLR expression to eyeworm (Oxyspirura petrowi) and caecal worm (Aulonocephalus pennula) glycoproteins.

Helminth parasites have been a popular research topic due to their global prevalence and adverse effects on livestock and game species. The Northern bobwhite (Colinus virginianus), a popular game bird in the USA, is one species subject to helminth infection and has been experiencing a decline of > 4% annually over recent decades. In the Rolling Plains Ecoregion of Texas, the eyeworm (Oxyspirura petrowi) and caecal worm (Aulonocephalus pennula) helminths are found to be highly prevalent in bobwhite. While there have been increasing studies on the prevalence, pathology, and phylogeny of the eyeworm and caecal worm, there is still a need to investigate the bobwhite immune response to infection. This study utilizes previously sequenced bobwhite cytokines and toll-like receptors to develop and optimize qPCR primers and measure gene expression in bobwhite intramuscularly challenged with eyeworm and caecal worm glycoproteins. For the challenge experiments, separate treatments of eyeworm and caecal worm glycoproteins were administered to bobwhite on day 1 and day 21. Measurements of primary and secondary immune responses were taken at day 7 and day 28, respectively. Using the successfully optimized qPCR primers for TLR7, IL1ß, IL6, IFNα, IFNγ, IL10, and ß-actin, the gene expression analysis from the challenge experiments revealed that there was a measurable immune reaction in bobwhite in response to the intramuscular challenge of eyeworm and caecal worm glycoproteins.

In vitro lectin binding to the outer surface of Spirocerca lupi at different life-stages.

Spirocerca lupi is the esophageal nematode of dogs. Early, transient eosinophilia occurs in experimentally infected dogs, but is absent in advanced cases, suggesting that the nematode evades the dog's immune system. Lectins are proteins or glycoproteins of plant or animal origin, binding different saccharides, with varying specificities and avidities, used to characterize surface haptens in plant and animal parasitic helminths. This study investigated the in vitro binding of six lectins (Concanavalin A [ConA], wheat germ agglutinin [WGA], peanut agglutinin [PNA], soybean agglutinin [SBA], Dolichus biflorus agglutinin [DBA] and Ulex earopaeus agglutinin I [UEA]) to the surface of S. lupi nematodes at different life stages, the L2 and L3 larvae (dead and alive) and to dead adult worms, with negative controls, with and without addition of the six respective inhibitory sugar haptens. Con A moderately bound to surfaces of both live and frozen L3, to the stoma and excretory pores of adult worms, and to the outer surface nematode's eggs, within a female worm, but not to L2. PNA bound only to stoma and excretory pores surfaces in both frozen and live L3. WGA bound strongly to the outer surfaces of live and dead L2 and L3, which resulted in molting of live larvae. These results suggest that the nematode's surface content change during its development. Such changes may play roles in the nematode's interactions with the intermediate and definitive hosts' tissues, and in its ability to evade the immune response, its long survival within the host, and even induce neoplastic transformation.

Evaluation of hemostatic abnormalities in canine spirocercosis and its association with systemic inflammation.

BACKGROUND: Canine spirocercosis is caused by the nematode Spirocerca lupi and is characterized by esophageal fibro-inflammatory nodules that may undergo neoplastic transformation. No sensitive and specific laboratory assays other than histopathology have been reported to differentiate non-neoplastic from neoplastic disease. HYPOTHESIS/OBJECTIVES: Dogs with spirocercosis will have evidence of hypercoagulability based on thromboelastography (TEG)-derived maximal amplitude (MA); increased MA will be correlated with increased acute phase protein (APP) concentrations (C-reactive protein [CRP] and fibrinogen); increased MA and APPs will be exacerbated with neoplastic spirocercosis. ANIMALS: Thirty-nine client-owned dogs with naturally occurring spirocercosis and 15 sex-matched healthy controls. METHODS: A prospective comparative study evaluating TEG, activated partial thromboplastin time, prothrombin time, antithrombin (AT) activity, platelet count and D-dimer concentration, and APPs of dogs with non-neoplastic (n = 24) and neoplastic (n = 15) spirocercosis compared to control dogs. RESULTS: Median MA was significantly increased in the non-neoplastic group (P < .01) and neoplastic group (P < .01) compared to the controls. Both APPs were significantly increased in the neoplastic group compared to the non-neoplastic and control groups. MA was strongly correlated with fibrinogen (r = 0.85, P < .001) and CRP (r = 0.73, P < .001). An MA >76 mm provided 96% specificity and 73% sensitivity for differentiation of disease state. CONCLUSIONS AND CLINICAL IMPORTANCE: Canine spirocercosis is associated with increased TEG variables, MA and α, and decreased AT activity, which may indicate a hypercoagulable state seemingly more severe with neoplastic transformation. MA was correlated with APP in dogs with spirocercosis and can be used as an adjunctive test to support the suspicion of neoplastic transformation.

Vascular endothelial growth factor concentrations in dogs with spirocercosis.

BACKGROUND: Vascular endothelial growth factor (VEGF) is a potent proangiogenic factor associated with tumor development. Spirocerca lupi is a nematode of canids that induces an esophageal nodule that progresses to a sarcoma in 25% of cases. Determination of neoplastic transformation is challenging and usually based on endoscopy-guided biopsies under general anesthesia, an expensive procedure that often yields nondiagnostic, necrotic samples. HYPOTHESIS: Circulatory VEGF concentrations are increased in dogs with neoplastic spirocercosis and can distinguish between dogs with neoplastic and nonneoplastic disease. ANIMALS: A total of 24 client-owned dogs, 9 nonneoplastic, 9 neoplastic, and 6 controls. METHODS: Case-control study. Plasma and serum VEGF concentrations at the time of diagnosis were compared with those of healthy controls. Measurement of VEGF was performed using a canine-specific ELISA. Kruskal-Wallis and Dunn's tests were used for statistical analysis with significance set at P < .05. RESULTS: The median plasma VEGF concentrations of dogs with neoplastic spirocercosis were 629 pg/mL (range, 282-2,366) higher than both the nonneoplastic (<39.5 pg/mL; range, <39.5-716) and control dogs (<39.5 pg/mL; all values, <39.5; P = .0003). The median serum VEGF concentration of the neoplastic dogs was 69 pg/mL (range, <39.5-212) higher than the nonneoplastic (<39.5 pg/mL; range, <39.5-44.13) and control dogs (<39.5 pg/mL; all values, <39.5; P = .001). CONCLUSIONS AND CLINICAL IMPORTANCE: Both plasma and serum VEGF concentrations can be used to differentiate nonneoplastic and neoplastic spirocercosis. The role of VEGF in neoplastic transformation of S. lupi-induced nodules and the potential utility of anti-VEGF drugs in spirocercosis-induced sarcoma warrant further investigation.

Plasma IL-8 concentrations are increased in dogs with spirocercosis.

The nematode Spirocerca lupi (S. lupi) induces sarcoma in the dog oesophagus in about 25% of cases. The aim of this study was to compare the differences in the cytokine milieu between dogs with neoplastic (n=29) and non-neoplastic disease (n=49) and age- and gender-matched healthy controls (n=25). We measured IL-2, IL-4, IL-6, IL-8, IL-10, IL-18, GM-CSF and MCP-1 in a specific canine multiplex immunoassay kit. Cytokine concentrations were compared between the different groups using the Kruskal-Wallis test followed by Dunn's test. Only IL-8 and IL-18 showed significant differences in their plasma concentration among the three groups. Kruskal-Wallis test revealed a significant (p=0.001) difference in IL-8 concentration between the neoplastic group (634pg/ml), the non-neoplastic (429 pg/ml) and the control groups (150 pg/ml). Post-test analysis revealed a significance difference between the two S. lupi groups and the control group (p<0.01). The highest IL-18 concentration was found in the non-neoplastic group (53 pg/ml), followed by the control group (46 pg/ml) and finally the neoplastic group (33 pg/ml). IL-18 concentrations were significantly higher in the non-neoplastic group than in the neoplastic group (p=0.05). The increased IL-8 in the spirocercosis groups is consistent with the neutrophilic infiltrate in spirocercosis lesions and in those of other inflammatory-induced neoplasias such as Barret's oesophagus and Helicobacter gastritis. IL-18 showed negative regulatory effect in several worm infections and it is possible that it plays the same role in spirocercosis, allowing the worm to evade the host response and to induce neoplastic transformation.

Immunohistochemical characterization of lymphocyte and myeloid cell infiltrates in spirocercosis-induced oesophageal nodules.

Spirocerca lupi is a nematode that infects the dog's oesophagus and promotes the formation of an inflammatory fibroblastic nodule that progresses to sarcoma in approximately 25% of cases. Spirocercosis-associated oesophageal sarcoma is an excellent and under-utilized spontaneous model of parasite-associated malignancy. The inflammatory infiltrate of paraffin-embedded, non-neoplastic oesophageal nodules (n = 46), neoplastic nodules (n = 25) and normal oesophagus (n = 14) was examined by immunohistochemistry using MAC387 (myeloid cells), CD3 (T cells), Pax5 (B cells) and FoxP3 (T regulatory cells) antibodies. Myeloid cells predominated in 70% of nodules, in pockets around the worms' migratory tracts and in necro-ulcerative areas in neoplastic cases. T cells predominated in 23% of cases with a focal or diffuse distribution, in the nodule periphery. No significant differences were observed between neoplastic and non-neoplastic stages. FoxP3+ cells were observed in low numbers, not significantly different from the controls. The inflammation in spirocercosis is characterized by pockets of pus surrounded by organized lymphoid foci. There was no evidence of a local accumulation of FoxP3+ cells, unlike many previous studies that have reported an increase in FoxP3+ T cells in both malignancies and parasite infections. The triggering factor(s) driving the malignant transformation of the spirocercosis-associated chronic inflammatory nodule warrants further investigation.

[Antigenic recognition of rats infected with Gnathostoma hispidum: comparison of antigens derived from the advanced third stage larvae of Gnathostoma hispidum and Gnathostoma doloresi].

To increase understanding of immune response of host against G. hispidum, antigenic recognition of rodent gnathostomiasis were identified by the immunoblot method after PAGE of the advanced third stage larvae of G. hispidum and G. doloresi. The molecular weight of the major antigenic bands of G. hispidum extracts were 35 kDa and 16 kDa, and of G. doloresi were 48 kDa, 37 kDa and 35 kDa. Of these bands, the 35 kDa antigen of G. hispidum and G. doloresi was recognized with the sera of rats infected with G. hispidum 5 weeks after inoculation. Lecting staining with endoglycosidase-H or hydrolytic degradation on nitrocellulose strips revealed that the 35 kDa band of G. hispidum possessed the mannose-rich oligosaccharides. On the other hand, the band of G. doloresi had the hybrid-type glycopeptides. The larval extracts and excretory-secretory materials of G. hispidum were not antigenitically identical.

Demonstration of species-specific antigens of Gnathostoma spinigerum, a preliminary attempt.

An attempt was made to demonstrate the presence of species-specific antigens for Gnathostoma spinigerum advanced third-stage larvae (GsAL3) in a rabbit receiving weekly immunization with GsAL3 for seven weeks. The homologous and heterologous antibodies against GsAL3 and G. doloresi adult worm (Gd) antigens were initially detected by immunoelectrophoresis (IEP) and ELISA after the second immunization, and their levels were gradually increased with the number of immunizations. Though cross-reactivity between GsAL3 and Gd were shown with both tests, species-specific antibodies for the homologous antigens were demonstrated. After cross-absorption of rabbit hyperimmune serum was collected after the seventh immunization, seven 'putative' species-specific precipitin bands of GsAL3 were identified. The ELISA values of the rabbit hyperimmune serum showed 50% inhibition after absorption with 0.7 micrograms/ml of homologous GsAL3 antigens as opposed to 1.0 micrograms/ml of the heterologous Gd antigens.

Anatomical localization of Gnathostoma spinigerum larval antigens by an indirect fulorescent antibody test.

Indirect fluorescent antibody test (IFAT) was performed on sections of Gnathostoma spinigerum advanced third-stage larva with gnathostomiasis, angiostrongyliasis, trichinosis, strongyloidiasis and cysticercosis sera. Positive fluorescence was observed with the first three sera. Fluorescence was associated with the anterior part of the esophagus, surface of the cuticle and cytoplasmic granules of the intestine. Absorption of sera with gnathostome antigen did not elicit fluorescence. The results suggest that substances secreted from the esophagus and intestine constitute antigens in excretory-secretory products of the larva.

ELISA for diagnosis of gnathostomiasis using antigens from Gnathostoma doloresi and G. spinigerum.

ELISA was developed for the detection of IgG antibody in sera obtained from patients in Japan and in a foreign country. Gnathostoma doloresi adult antigen was less specific than G. spinigerum advanced third-stage larval antigen but their sensitivity were similar. Cross reactivity was observed in Toxocara canis-, Anisakis-, Paragonimus westermani- and Fasciola-infected sera when G. doloresi adult worms but not G. spinigerum advanced third-stage larvae were used as antigens.

Immunization of cattle using varying infective doses of Theileria parva lawrencei sporozoites derived from an African buffalo (Syncerus caffer) and treatment with buparvaquone.

A Theileria parva lawrencei isolate in the form of a sporozoite stabilate, derived by feeding clean Rhipicephalus appendiculatus nymphal ticks on an African buffalo (Syncerus caffer) captured in the Laikipia District, Kenya, was inoculated into groups of cattle at dilutions between 10(0) and 10(-3). Groups of 3 cattle infected with 1 ml inocula at 10(0), 10(-1) and 10(-2) dilutions were treated with 2.5 mg/kg body weight of buparvaquone on day 0 and similar groups were left untreated to act as controls. An additional group, given 10(0) dilution of the stabilate, was treated with buparvaquone on day 8 post-inoculation. It was found that all control cattle inoculated with the stabilate at dilutions between 10(0) and 10(-2) became infected, but only 2 out of 3 cattle developed patent infections at 10(-3) dilution. All 3 control cattle receiving 10(0) dilution died of theileriosis, 2 at 10(-1) and 10(-2) dilutions, and 1 at 10(-3) dilution died. Buparvaquone treatment on day 0 at 10(0) dilution resulted in the survival of 2 of 3 cattle and all the cattle at 10(-1) and 10(-2) dilutions. All the surviving cattle eventually developed a significant serological response against T. parva in the indirect fluorescent antibody test, except 1 in the 10(-3) dilution group, and were immune to homologous challenge when tested 3 months later with a lethal inoculum of stabilate, except 2 cattle in the 10(-3) dilution group. As a result of a theileriosis problem at about day 60 after inoculation in 2 cattle given 10(-2) dilution of stabilate and buparvaquone treatment on day 0, an additional 5 cattle were given 10(-2) dilution of stabilate and developed a good immunity after buparaquone treatment. None was shown to develop the carrier state. Treatment with buparvaquone on day 8 after infection with 10(0) dilution of stabilate was not successful since 2 died. The stabilate used was shown to produce reproducible infection in cattle at different dilutions.

A study on immunodiagnosis of gnathostomiasis by ELISA and double diffusion with special reference to the antigenicity of Gnathostoma doloresi.

In order to diagnose gnathostomiasis immunologically, Gnathostoma doloresi was evaluated for the antigenicity in comparison with G. hispidum which was recently reported in Japan by using micro-ELISA. The study revealed that G. doloresi can be used as the alternate source of antigen in the test. A significant increase of specific IgG antibodies was seen in 22 (73.3%) out of 30 gnathostomiasis cases. Although double diffusion was slightly less sensitive than ELISA, it was considered more specific than the latter method.

Detection of humoral immune response to Gnathostoma spinigerum in mice.

The humoral immune response to early third stage larvae (EL3) and advanced third stage larvae (AL3) of Gnathostoma spinigerum infection was studied in mice by Ouchterlony gel diffusion technique. The antibodies was detected at week 3 in mice infected with EL3 and remained up to week 10 after infection. Highest positive sample of sera were demonstrated at week 4 to week 7. Similar results were obtained from AL3 infected sera except the antibodies was found and disappeared earlier (week 2 to week 6). G. spinigerum larvae recovery from mice in both groups showed that the number of advanced third stage larvae located in muscle correlated to the peak of positive sera. No cross reaction was observed on positive sera of G. spinigerum and antigens of A. cantonensis, P. siamensis, T. spiralis, O. viverrini and A. ceylanicum. Cross reaction was shown on the G. spinigerum antigen against rat sera with angiostrongyliasis and bandicoot sera with paragonimiasis.

Enzyme-linked immunosorbent assay for detection of antibody to Gnathostoma antigen in patients with intermittent cutaneous migratory swelling.

A sensitive enzyme-linked immunosorbent assay is described for the detection of immunoglobulin G antibody to Gnathostoma antigen in the sera of patients with intermittent cutaneous migratory swelling who were suspected of being infected by the tissue nematode Gnathostoma spinigerum. The antigen used was a crude somatic aqueous extract of the third larval stage obtained from naturally infected eels. The 1:320 dilution of all sera from 46 patients gave enzyme-linked immunosorbent assay values above the mean (+2 standard deviations) of normal healthy controls, which was arbitrarily used as a cutoff point. The sera from patients suspected of being infected by another tissue nematode, Angiostrongylus cantonensis, as well as from patients with intestinal roundworm infections, also reacted weakly in the test system used in this study. Nonetheless, when the assay was carried out using both Gnathostoma and Angiostrongylus antigens simultaneously, it appeared to be a reliable laboratory test that can be used to support a clinical diagnosis of gnathostomiasis in patients with intermittent cutaneous migratory swelling.