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G V Hillyer

Publications and source records attributed to G V Hillyer.

At least 73 records · Page 4Linked to original sources
PubMed1987

Failure of anti-Fasciola antisera to induce antibody-dependent, eosinophil-mediated killing of Schistosoma mansoni schistosomula.

Sera from rabbits or humans infected with Fasciola hepatica were tested for their ability to kill Schistosoma mansoni schistosomula in an antibody-dependent, eosinophil-mediated in vitro assay. In addition, anti-F. hepatica antisera raised in rabbits or calves, including one to a Fasciola/Schistosoma cross-reactive, cross-protective defined immunity antigen, were also tested for their killing ability. None of these antisera induced damage to S. mansoni schistosomula in vitro, even when enhanced with mononuclear cell supernatants containing eosinophil-activating factor. Serum from humans with S. mansoni did induce schistosomulum killing in vitro when tested under these same conditions. These results suggest that the mechanism of immunity to schistosomes induced by Fasciola antigens at the level of the schistosomula is mediated by factors other than eosinophils.

Animals↗
PubMed1987

Acquired resistance to Fasciola hepatica in cattle using a purified adult worm antigen.

Calves were immunized twice in 4 weeks with a Fasciola/Schistosoma cross-reactive, cross-protective defined immunity antigen (denoted FhSmIII(M)) isolated from F. hepatica adult worm extracts by antibody affinity chromatography and challenged 7 weeks later with F. hepatica metacercariae. Flukes were recovered at 16 weeks of infection at which time the immunized calves had 55% less F. hepatica than the controls. All of the immunized calves developed high antibody levels of FhSmIII(M), detectable in the ELISA, by 4 weeks after a single immunization. By 9 weeks of infection with F. hepatica the immunized calves had lower sorbitol dehydrogenase levels than the unimmunized, F. hepatica-infected control calves, indicating less liver damage in the vaccinated group. These studies demonstrate that subcellular F. hepatica macromolecules cross-reactive and cross-protective against S. mansoni also have the potential to serve as vaccines in cattle exposed to this parasitic disease.

Animals↗
PubMed1986

Resistance to fascioliasis--a review.

Attempts to actively stimulate or passively transfer resistance to Fasciola hepatica or F. gigantica in various laboratory and farm animals including mice, rats, rabbits, sheep, goats and cattle have been reviewed. These attempts comprised sensitization by primary homologous or heterologous normal or irradiated infections per os, sensitization by subcutaneous, intramuscular or intraperitoneal implantation with the various fluke stages, sensitization by somatic extracts or metabolic products of mature or immature flukes and passive transfer of resistance by immune serum or sensitized lymphocytes.

Animals↗
PubMed1986

Fractionation of Fasciola hepatica tegument antigens and their application to the serodiagnosis of experimental fascioliasis by the enzyme-linked immunosorbent assay.

A Fasciola hepatica tegument antigen preparation was obtained from intact adult worms by solubilization with a non-ionic detergent, Nonidet P-40. This antigen preparation contains antigens useful for the serodiagnosis of infection with this parasite. However, the antigen preparation is inadequate for use in the enzyme-linked immunosorbent assay (ELISA). The present work demonstrates that fractionation by demulsification of this antigen preparation with ammonium sulphate results in a soluble aqueous phase which contains F. hepatica serodiagnostic antigens which can then be applied to the ELISA. This F. hepatica tegument antigen preparation when used in the ELISA can detect rabbit fascioliasis two weeks after infection, with antibody levels peaking by 10 to 12 weeks of infection.

Animals↗
PubMed1986

Identification of a genus-specific Schistosoma mansoni soluble egg antigen reactive with the serum of infected patients.

The ability of serum samples obtained from humans with schistosomiasis mansoni to recognize Schistosoma mansoni soluble egg antigens (SmSEA) was assessed by the enzyme-linked immunotransfer blot (EITB) method. The sera from 15 infected patients before and 2 years after treatment with oxamniquine (n = 30) recognized bands ranging in molecular weight from 9 to 200 Kd. A 31 Kd component of SmSEA was recognized by all infection sera, but not by normal human serum. The sera from 2 humans infected with S. haematobium and 2 with S. japonicum also recognized the 31 Kd band present in SmSEA, whereas those from 2 humans infected with Fasciola hepatica did not. The 31 Kd antigen was isolated by electrophoresing SmSEA through a 15% SDS-acrylamide gel, followed by excision and electroelution of the 31 Kd band. The purified 31 Kd was used in conjunction with ELISA at a concentration of 1 microgram/ml to confirm the apparent genus specificity of this protein. Thus, the sera of patients infected with S. mansoni, S. haematobium, or S. japonicum were clearly reactive in ELISA, whereas normal human serum or sera from patients with F. hepatica were negative. In conclusion, the 31 Kd protein appears to be a good candidate for developing a screening assay for the immunodiagnosis of schistosomiasis.

Antigens, Helminth↗
PubMed1986

Isolation of potential serodiagnostic Fasciola hepatica antigens by electroelution from polyacrylamide gels.

In the present study a partially purified antigen preparation enriched in Fasciola-specific antigens (designated p3 and 4) was used in the enzyme-linked immunoelectrotransfer blot (EITB) to identify polypeptides which induce antibody formation in acute fascioliasis. The pattern of antigens recognized by the sera of infected rabbits, humans, and cows was also compared. Similar but not identical patterns of recognition were obtained for the different models tested; the main antigenic polypeptides recognized were in clusters within 27-38, 18-23, and 11-14 Kd molecular weight (Mr) ranges. An antigen of 31-33 Kd was one of the most prominently recognized by all of the acute infection sera tested. This antigen, as well as those in the 18-23 Kd range, appear to have good specificity, as they are not recognized by antibodies to S. mansoni or P. westermani adult worm extracts. To further characterize and evaluate these low Mr antigens, we have isolated polypeptides by electrophoresing p3 and 4 F. hepatica antigens in 10%-15% gradient gels, identifying the desired Mr range with prestained markers, cutting individual gel strips, and then isolating them by electroelution. Antigen fractions of 19-23 and 31-33 Kd were isolated in this manner, re-electrophoresed, transferred to nitrocellulose and found to be reactive with the sera from a rabbit with acute fascioliasis. At least one of these antigens, of 20 Kd Mr, has been obtained by this means with a high degree of purity. This, as well as other antigen fractions isolated, showed high absorbance values in ELISA when reacted with the serum from a rabbit with an 8-week-old F. hepatica infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Identification of functional Fasciola hepatica antigens in experimental infections in rabbits.

Studies done comparing the reactivity of serum from an infected rabbit at different intervals of infection with a Fasciola hepatica crude tegument extract, F. hepatica excretory-secretory (ES) products and Fh arc 2 by ELISA show that the first 2 antigen preparations offer a better sensitivity for detecting acute infection, especially in its early stages (3 weeks). The ES proteins from F. hepatica adult worms were identified by the enzyme-linked immunotransfer blot (EITB) in order to define the antigens recognized by the sera from rabbits with experimental fascioliasis. A group of 7 polypeptides with molecular weights of 23-28 Kd were the major antigens recognized. Reactivity to these antigens is maximum at 8-10 weeks of infection by EITB. As the infection progresses, reactivity to the 23-28 Kd antigens decreases but does persist through 52 weeks of infection. At least 5 other polypeptides of 120, 84, 58, 52, 39 and 33 Kd were recognized by the sera of infected rabbits from 6 to 52 weeks of infection. A different pattern was observed in parallel studies done with these same sera by immunoprecipitation of ES antigens. In addition to a 33 Kd antigen, which was detected by both techniques, a 62 Kd antigen was detected early in infection (5 weeks) and 3 major antigens of 38, 40 and 44 Kd were prominent by immunoprecipitation from 9 weeks onward. This implies the presence of multiple Fasciola antigens with serodiagnostic potential. The expression of these antigens during development and their possible role in immunity is discussed.

Animals↗
PubMed1986

Isolation and characterization of Schistosoma haematobium egg antigens.

Schistosoma haematobium soluble egg antigen (ShSEA) was prepared from eggs isolated from the livers of hamsters or mice infected for at least 3 months. Immunoaffinity purified S. haematobium egg antigens (ShSh) were isolated by first passing ShSEA through a column containing anti-S. mansoni hamster IgG coupled to CNBr-activated Sepharose 4B, and recycling the unbound fraction until no more bound material could be eluted with an acid wash. The unbound fraction was then filtered through a second antibody affinity column containing anti-S. haematobium hamster IgG, and in the acid eluate the ShSh antigens were obtained. This antigenic preparation was shown by PAGE to contain at least 6 distinct bands ranging in molecular weight (Mr) from 116 to less than 31 Kd. A 40 Kd polypeptide was identified by both silver staining and EITB as specific for S. haematobium eggs. In addition, a 55 Kd worm-egg shared antigen was identified as a prominent band in EITB expressed during a primary S. haematobium hamster infection. The sera from hamsters harboring patent S. haematobium or S. mansoni infections were reacted by ELISA with ShSh antigens. The anti-Sh sera showed significantly higher absorbance values than the anti-Sm sera, demonstrating that only a minor population of S. mansoni cross-reactive egg antigens is still present in the ShSh antigens. Sera collected weekly for 13 weeks from hamsters with a primary infection of S. haematobium were then tested by ELISA against ShSh, ShSEA and SmSEA antigens. Antibody levels against both ShSEA and SmSEA were shown to increase early in infection (2 weeks). Moreover, antibody levels to ShSh did not increase until week 5 post-infection. These findings suggest that the purification procedure utilized results in the elimination of most of the S. mansoni worm antigens cross-reactive with S. haematobium eggs. The ShSh antigens had shown a high degree of sensitivity and stage-species specificity also suggesting their potential as antigens for the immunodiagnosis of schistosomiasis haematobia.

Animals↗
PubMed1985

Induction of immunity in mice to Fasciola hepatica with a Fasciola/Schistosoma cross-reactive defined immunity antigen.

The paradox of schistosomiasis is that infection confers immunity to its host, yet immunization with subcellular antigens of the parasite does not, in general, induce protective immunity. Infection or immunization with subcellular antigens of Fasciola hepatica confers high levels of immunity to a challenge infection with another trematode, Schistosoma mansoni. We have isolated by antibody affinity chromatography a Fasciola hepatica/Schistoma mansoni cross-reactive antigen, designated FhSmIII(M), and also have shown that this antigen confers immunity in mice to a challenge infection with S. mansoni. This antigen was compared with a crude F. hepatica worm extract (FhWWE) as to its ability to induce an IgG antibody response in mice, and to determine whether it had a protective effect in mice to a challenge infection with F. hepatica metacercariae. Mice immunized with FhSmIII(M) or FhWWE, and subsequently infected with F. hepatica, developed higher IgG antibody levels to FhSmIII(M), as measured by ELISA, than F. hepatica-infected controls. Mice immunized with FhWWE did not develop significant levels of resistance to challenge with F. hepatica metacercariae. Mice immunized with FhSmIII(M) and infected with F. hepatica metacercariae developed 69%-78% less worms than controls. An F. hepatica/S. mansoni cross-reactive, cross-protective defined immunity antigen confers in mice significant levels of protection to a challenge infection with F. hepatica.

Animals↗
PubMed1985

Isolation and partial characterization of an antigen shared between Schistosoma mansoni, Fasciola hepatica, and Biomphalaria glabrata.

An antigen was isolated and partially characterized from adult Schistosoma mansoni which immunologically cross-reacted with Fasciola hepatica and Biomphalaria glabrata, a schistosome intermediate snail host. The antigen was isolated from a solubilized freeze-thaw preparation containing 0.5% Triton X-100 by passage through a CNBr-activated Sepharose 4B column coupled with rabbit IgG prepared against a homogenate of B. glabrata hepatopancreas. The eluted antigen (designated as SMw-53P) stained with Coomassie Brilliant Blue R250, but not with Nile Blue A or periodic acid-Schiff's stains. The antigen did not bind to a Concanavalin A affinity column. SMw-53P was determined to have a molecular weight of 53,000 daltons by SDS-polyacrylamide gel electrophoresis. Western blotting, using sera from mice infected with S. mansoni, revealed the presence of the antigen in whole worm preparations of both S. mansoni and F. hepatica. The serodiagnostic potential of the antigen was evaluated by ELISA utilizing sera from S. mansoni-infected mice, or rabbits injected with homogenates of F. hepatica or S. mansoni whole worm, or B. glabrata hepatopancreas. SMw-53P was shown to strongly react with all antisera, but not normal mouse or rabbit sera. These data suggest a limited value for the antigen for the specific immunodiagnosis of schistosomiasis mansoni, but do suggest a possible potential as a general screening tool for detecting trematode infections. Further studies regarding the antigen's potential as a vaccine are indicated.

Animals↗
PubMed1985

Immunodiagnosis of bovine fascioliasis by enzyme-linked immunosorbent assay and immunoprecipitation methods.

Calves were infected with 1,000 Fasciola hepatica metacercariae and the antibodies which developed were monitored by gel diffusion, counterelectrophoresis (CEP) and the enzyme-linked immunosorbent assay (ELISA) using crude or tegument antigen preparations of the adult fluke. Serologic diagnosis was positive as early as 2-4 wk of infection by gel diffusion, by 4 wk by CEP, and by 6-8 wk by ELISA, whereas parasitologic diagnosis via the detection of fluke eggs in the feces was possible only after 8-10 wk of infection. In general, both gel diffusion and ELISA were superior to CEP in detecting active infection.

Animals↗
PubMed1985

Isolation and partial characterization of shared antigens of Biomphalaria glabrata and Schistosoma mansoni and their evaluation by the ELISA and the EITB.

Serum from humans infected with Schistosoma mansoni, when reacted with a Biomphalaria glabrata soluble hepatopancreas antigen extract (BgSHA) yields 2 lines of precipitation by gel diffusion and 1 by immunoelectrophoresis. The IgG from the serum of a human infected with S. mansoni was coupled to CNBr-activated Sepharose 4B. BgSHA (8.0 mg) was then filtered through the gel and the bound antigens, denoted BgSm, eluted with HCl-glycine, pH 2.6. These bound antigens comprised 2.8% of the total BgSHA. BgSm was then applied to an anti-Fasciola hepatica column as above. The drop through in PBS (38% yield) and containing the BgSm antigens depleted of cross-reactivity with F. hepatica was then tested by the ELISA to evaluate its serodiagnostic potential. These antigens detected a primary S. mansoni infection by 4 wk but were less sensitive than SmSEA in the detection of a primary infection with S. mansoni. However, the BgSm-specific antigens were more specific than SmSEA and showed less cross-reactivity with the serum of mice infected with F. hepatica. At least 16 peptides were seen by silver staining following SDS-PAGE with 5-20% gradient gels. The 2 more prominent bands obtained were estimated to have molecular weights of 62 and 66 kd. Nitrocellulose strips blotted with BgSHA were incubated with the serum of mice infected with S. mansoni for 12 wk and developed 6 bands with molecular weights of 66, 57, 55, 50, 48 and 32 kd.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Fasciola hepatica and Schistosoma mansoni: immunofluorescent antigen localization and cross-reactivity.

In an attempt to identify the tissue sources of biochemically purified antigenic fractions of Fasciola hepatica and Schistosoma mansoni, antisera were tested against plastic-embedded sections of worms of various ages by an indirect fluorescent-antibody-labeling technique. Antibodies prepared against antigens purified by chromatography of F. hepatica whole worm extract through concanavalin A-Sepharose 4B labeled the parenchyma and tegument of adult F. hepatica strongly while antibodies developed against antigens purified by antibody-affinity chromatography against antibodies of S. mansoni labeled only the parenchyma. Antigens common to these two groups clearly originated from F. hepatica parenchyma. Certain of these common antigens are known to provide significant protection in mice to challenge with S. mansoni cercariae, and in the present study antisera against F. hepatica extracts cross-labeled S. mansoni adult male parenchyma. Reciprocal cross-reactions between antisera against S. mansoni and the parenchyma of adult F. hepatica were also noted. FhFIIb, an extract of F. hepatica which Tailliez described as not cross-reacting with S. mansoni, was found to contain no F. hepatica parenchymal antigens. Antigenic fractions of F. hepatica and S. mansoni collected from the surface of worms after incubation in nonionic detergent were unexpectedly found to contain much parenchymal antigen, suggesting leakage of internal components into the supernatant during preparation. Antisera to F. hepatica developed during a natural infection in rabbits labeled tegumental components and gut strongly but did not react with parenchymal tissue. Antisera against extracts of adult schistosomes labeled the parenchyma of male worms and the glycocalyx of the cercarial tegument, indicating the presence of common antigens in the adult and the cercarial stage. Reciprocal reactions between anticercarial sera and adult sections provided further evidence of shared antigenicity. Antisera against S. mansoni egg antigens strongly labeled sections of eggs in liver tissue and cross-reacted with cercarial glycocalyx, indicating the existence of common antigens between these two stages. The antisera also cross-reacted with what appeared to be non-membrane-bound protein in the tegument of F. hepatica. The soluble egg antigen extract shared antigenicity with the parenchyma of both S. mansoni and F. hepatica but circumoval precipitin had no cross-reactivity with this tissue. Thus S. mansoni eggs contain nondiffusable components sharing antigenic specificity with adult parenchymal tissue.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Immunity of schistosomes using heterologous trematode antigens--a review.

This review summarizes the field of cross-protection in schistosomiasis due to other parasitic infections and with subcellular fractions of the parasite trematodes. Regarding parasitic infections, the clearest evidence of cross-protection to Schistosoma mansoni was found with the trematodes, particularly with Fasciola hepatica. Evidence was also presented which demonstrated that the protective F. hepatica worm antigens were those which bound to antibodies to S. mansoni, and that as antigen purification proceeded, smaller amounts were required to obtain significantly high levels of protection. These 2 factors, cross-reactivity and improved protection with increasing antigen purity (and possibly improved immunogenicity), are both supportive of an immunological basis for protection against S. mansoni. A Fasciola/Schistosoma-defined immunity cross-reactive antigen from F. hepatica worms was isolated and designated as FhSmIII(M). An antiserum to this antigen was developed and used as a probe to detect the presence of this antigen (or its determinants) in different extracts of parasitic trematodes. In this manner, it was possible to demonstrate that FhSmIII(M) (or at least some of its determinants) were found on (or in) S. mansoni, S. bovis and Paragonimus westermani. Since mice immunized with P. westermani worm extracts acquire resistance to challenge with S. mansoni cercariae, a common link of cross-protection to the parasitic trematodes is suggested; i.e., FhSmIII(M). Although immunity to schistosomes is undoubtedly multifactorial, the demonstration of a common protective antigen (or determinant) will provide a handle for the evaluation of additional candidate protective antigens.

Animals↗