IgE responses in the serum and gastric lymph of sheep infected with Teladorsagia circumcincta

The IgE response of naive or previously infected sheep to 50 000 infective larvae of Teladorsagia circumcincta was monitored in serum and gastric lymph using a monoclonal antibody generated to recombinant ovine IgE in a dot blot assay. In 4/5 naive sheep, lymph and serum IgE concentrations increased from days 8 and 14 after infection, respectively. In most previously infected sheep, the IgE response to challenge was more rapid, although not necessarily greater than that following a primary infection. IgE concentrations in lymph were some 4-fold higher than in serum indicating that its source was the mucosa or draining nodes.     

Parasite loss and inhibited development of Teladorsagia circumcincta in relation to the kinetics of the local IgA response in sheep

Groups of yearling sheep, which had been trickle infected with Teladorsagia circumcincta for 8 weeks and then drenched, were challenged with 50 000 T. circumcincta larvae together with groups of worm-free controls. Fewer parasites and a greater proportion of early fourth stage larvae were recovered from previously infected sheep compared to controls. Worm loss and arrested development were evident by 5 days after challenge whereas growth retardation of developing worms was observed by day 10. In the previously infected sheep a secondary IgA response was observed in the efferent gastric lymph from 5 days post-infection. Western blot analysis showed the lymph IgA to be predominantly dimeric and nonsecretory in nature and that the somatic antigens recognized were predominantly in the 100-250 kDa range. The concentration of IgA in lymph was always higher than in blood and in the previously infected sheep increased fivefold 8 days post-challenge in contrast to blood where IgA levels were unchanged. The timing of the response suggested that it occurred too late to have been the cause of worm loss or arrested development, though it may have retarded the growth of developing parasites.     

Structural and molecular specificity of antibody responses in mice immune to third stage larvae of Onchocerca volvulus

Immunization of mice with irradiated Onchocerca volvulus infective stage larvae (L3) has been demonstrated to confer protection against challenge infections with these larvae. Additionally, cytokine level measurements and cytokine depletion studies have shown that both IL-4 and IL-5 are important in generating a protective immune response against O. volvulus challenge infections, thus suggesting a dependency of protective immunity on IgG1, IgE and/or eosinophils. In the present study, we examined the humoral responses of immunized mice to O. volvulus L3 antigens. ELISA measurements of total serum antibody levels indicated that IgE was the only antibody isotype elevated in mice immunized with O. volvulus L3. IgM from immunized mice was the only isotype that recognized surface antigens on intact O. volvulus L3. IgG1, IgG3, IgE and IgA recognized internal parasite antigens on O. volvulus L3 frozen sections. Western blot analysis of L3 proteins showed that in serum from mice immunized with O. volvulus L3 IgG1, IgG2a/2b, IgA, and IgE, as well as IgM, recognized unique L3 proteins. Antibodies in serum from L3 immunized mice were able to detect O. volvulus adult antigens in a pattern similar to the recognition found in O. volvulus L3. Some L3 antigens were shared by adults, while other antigens were L3 specific. The ELISA, immunohistochemistry and Western blot findings thus demonstrate a complex pattern of antigen recognition of parasite antigens by antibodies found in mice immune to the L3 of O. volvulus     

Elimination of a primary schistosome infection from rats coincides with elevated IgE titres and mast cell degranulation

Schistosomes are eliminated from laboratory rats around 28 days post-infection, whilst they are still resident within the hepatic portal distributaries of the liver. We have previously shown that their presence in this location is accompanied by an intense mastocytosis. We have investigated the potential relationships between IgE responses, the allergenicity of schistosome antigens, mast cell responsiveness, and worm elimination. Total and specific IgE were measured using an ELISA and a functional assay based on ³H serotonin release from activated rat basophilic leukemia cells (RBL-SRA), respectively. Both assays revealed that infected rats produced elevated IgE titres relative to naive animals. At days 28 and 35, mixed-sex infections stimulated a higher total IgE than male-only infections. IgE was affinity purified from rat infection serum and used to probe a fractionated soluble worm antigen preparation (SWAP) by Western blotting. Two allergenic products were detected of M _r 67 and 36–38 kDa, the former having the same molecular weight as a previously identified secretory protein. IgE from mixed-sex schistosome infections bound strongly to the 36–38 kDa molecule, compared to the relatively weak binding exhibited by IgE from male-only infection serum. Since eggs were not recovered from the infected rats, this reactivity was attributed to the greater release of allergens from female worms. Results from the RBL-SRA showed that female SWAP was a more effective trigger of mast cell degranulation in vitro , for equal amounts of protein. This enhanced allergenicity was ascribed to the relative abundance of carbohydrate moieties. Our results support a role for IgE, and mast cell degranulation in the elimination of a primary schistosome burden from rats.     

Identification of an antigen from the sheep scab mite,Psoroptes ovis,homologous with house dust mite group I allergens

Infestation of sheep with the ectoparasitic mite Psoroptes ovis, results in a severe allergic dermatitis. Currently, little is known about the allergens/antigens that stimulate the allergic response. We have isolated an 836‐bp cDNA from a P. ovis cDNA library which displays strong homology to cysteine proteases and, in particular, to the group I house dust mite allergens Der p 1, Der f 1 and Eur m 1. The cDNA was expressed in Escherchia coli, fused to a hexahistidine tag and the recombinant protein (Pso o 1) purified using a nickel‐affinity column. The recombinant Pso o 1 was tested for recognition by immunoglobulin (Ig)G and IgE in serum from P. ovis naïve and P. ovis infested sheep. Using Western blots, both classes of antibody to Pso o 1 were detected in postinfestation serum. In enzyme‐linked immunosorbent assays, a pronounced IgG‐antibody response to Pso o 1 was detected in five of five sheep 3 weeks postinfestation. The IgE‐antibody response to whole mite extract was poor in four of five animals. However, a marked IgE response occurred in the fifth animal, and IgE anti Pso o 1 was detected in the serum.     

Stage-specific surface antigens of the cattle lungworm Dictyocaulus viviparus

Immunofluorescence on live Dictyocaulus viviparus parasites revealed a significant antibody response by vaccinated and patently infected bovine hosts to the sheath of infective larvae (L3), a structure which is generally thought to be shed from the parasite surface prior to invasion of host tissue. In contrast, surface-exposed antigens of the adult, egg and pulmonary L1 stages were recognized only by serum antibody from calves exposed to a patent lungworm infection. Radioiodination of sheathed L3 identified a restricted set of components while a more complex pattern of labelled material was observed with adult parasites. Many more components of adult worms were labelled by the Bolton-Hunter than by the lodogen reagent, probably reflecting the more penetrative labelling propensities of the former. Stage-specificity of surface-associated antigens of adult parasites was demonstrated by their immunoprecipitation by antibody from patently-infected, but not from vaccinated, calves. There was no in vitro release of the major iodinatable surface-associated antigens of adult parasites nor any binding of antibody raised against adult excretory-secretory (ES) products to the surface of living adult worms, suggesting that surface components do not contribute to adult ES products in this species. Antibody responses to the surface of adults. L1 and eggs were specific to patently-infected animals and may provide a useful indicator of exposure to patent infection.     

Serum antibody response following parenteral immunization with hydatid cyst fluid in sheep infected with Echinococcus granulosus

Production of specific serum antibodies following immunization with hydatid cyst fluid antigens was investigated in sheep with Echinococcus granulosus infection and in noninfected controls. Six of 10 infected animals responded to intramuscular injection of antigen by rapid production of antibodies detected in indirect hemagglutination assays. Similar responses did not occur in any of 10 noninfected controls. It is suggested that differences in the rate of response to immunization with cyst fluid antigens between groups of sheep could be exploited in serodiagnosis of E. granulosus infection in sheep. The results also suggest that low levels of antibody found in the serum of sheep infected with E. granulosus are not the result of immunosuppression or immunological tolerance, but are due to sequestration of antigen from the immune system of the host.     

Kinetics of the local cellular response in the gastric lymph of immune and susceptible sheep to infection with Teladorsagia circumcincta

Groups of yearling sheep were trickle infected with Teladorsagia circumcincta for 8 weeks, then the infection cleared with anthelmintic and both these animals and a group of parasite naïve sheep were challenged with 50 000 infective T. circumcincta larvae. The previously infected sheep demonstrated acquired immunity to the parasite, manifested by reduced worm burdens which were evident as early as 2 days after challenge. Cannulation of the common efferent gastric lymph duct allowed the kinetics of their local cell traffic to be monitored, and the phenotype of these lymphocytes was analysed. A blast cell response, consisting of both T and B lymphocytes, was observed in both groups of sheep, however this occurred more rapidly in the previously infected, immune animals. CD4⁺, CD8⁺ and CD25⁺ blast cell output peaked at day 3 in the previously infected animals, whereas CD21⁺ blast cell output peaked slightly later at day 5. In the control group the peak output of all phenotypes of blast cells occurred more slowly, peaking 10 days after infection.     

Serum immunoglobulin E response in calves infected with the lungworm Dictyocaulus viviparus and its correlation with protection

Protection of a primary Dictyocaulus viviparus infection was measured against a homologueous challenge infection in two independent experiments and this was correlated with serum immunoglobulin IgE responses. A primary infection of 30 third stage larvae (L3) of D. viviparus on day 0 protects calves for 70% against a challenge infection of 2000 L3 on day 35 compared to calves with no primary infection. The variation in post mortem worm counts within this group (n = 6) was very large with mean worm counts of 145 (range 3-446) lungworms. Parasite specific IgA, IgE, IgG1 and IgG2 and total IgE levels in serum were measured by ELISA. Parasite specific IgA, IgG1 and IgG2 were elevated after infection, but correlation with protection was only found with IgG1 levels on day 42 and with IgG2 levels on day 70. IgE was measured in a sandwich ELISA using antisheep IgE that cross-reacts with cattle IgE. No parasite specific IgE could be detected. However, total serum IgE was elevated after infection and total serum IgE levels before and on the day of challenge correlated with protection (P < 0.05). Total serum IgE also correlates with peripheral eosinophil counts between days 14 and 28 after primary infection. Western blots with three different parasite antigen preparations, L1, excretory/secretory products and crude worm adult antigens, were used to detect parasite specific IgE in sera depleted of IgG and IgM. These depleted sera from protected calves contained parasite specific IgE, while sera from nonprotected calves were negative. A band of approximately 100 kDa was recognized in all three antigens. In a second experiment, primary doses of 30, 60, 120, 240, 480 and 960 L3 of D. viviparus were used and necropsy was 11 days after challenge. This experiment confirmed the correlation between protection and total IgE levels before and on the day of challenge. The rapid and strong IgE responses in protected animals after such a low infection might be caused by the specific characteristics of the lungworm antigens or by the somatic migration of the worm and might be involved in the rapid development of protection against lungworm reinfections in cattle.     

The analysis of the humoral response of the BALB/c mouse immunized with radiation attenuated third stage larvae of Brugia pahangi

BALB/c mice immunized with L3 of Brugia pahangi, irradiated at 45kRad from a ¹³⁷Caesium source, are strongly immune to challenge infection (75–100% reduction in the recovery of challenge infection larvae on day 6 post-challenge). The target of immunity appears to be the post-infective L3, as challenge infection larvae are killed within 5–6 days of infection. By immunoblot analysis, serum from immune animals recognizes a limited set of somatic antigens, the majority of which are shared between different life cycle stages. Serum from immune mice also strongly recognizes larval surface antigens by immunofluorescence, some of which may be stage specific. The larval surface determinants do not appear to be protein or glycoprotein by standard immunochemical analysis. A proportion of the antibody response of the BALB/c mouse is directed towards phosphorylcholine epitopes on filarial antigens, but the limited antigen recognition cannot be explained on the basis of the mouse strain used, as CBA/Ca mice recognize a similar limited set of antigens.     

Variability of the intestinal immunoglobulin E response of rats to infection with Trichinella spiralis, Heligmosomoides polygyrus or Nippostrongylus brasiliensis

Total intestinal IgE level increased in rats infected with Trichinella spiralis or Heligmosomoides polygyrus (peak levels of 2.6 microg and 3.7 microg, respectively), but not in rats infected with Nippostrongylus brasiliensis. Intestinal implantation of young adult N. brasiliensis did not stimulate an intestinal immunoglobulin (Ig)E response, suggesting that mucosal penetration may be required for local intestinal IgE responses in rats. During a T. spiralis infection, total IgE levels in the intestinal lumen were consistently higher in LEWIS and LOU rats (rat strains that eliminate T. spiralis worms earlier in the infection) than in PVG, AO and WKA/H strain rats. There was no correlation in either the total level of serum IgE and IgA, or of intestinal IgA with differences between strains in the rate of worm elimination from the gut. Furthermore, the intestinal IgE immunoprecipitated from LEWIS rats 12 days after infection reacted with T. spiralis adult worm metabolic antigens, while intestinal IgE from PVG rats only became reactive with adult worm metabolic antigens from 14 days after infection. These data emphasize the significance of the intestinal IgE response and its unique features by comparison with serum IgE and IgA or intestinal IgA.     

Antibody responses to Lucilia cuprina in sheep selected for resistance or susceptibility to L. cuprina

Sheep bred for resistance (R) or susceptibility (S) to fleece rot and myiasis (blowfly strike) have been shown to differ in inflammatory response to intradermal administration of blowfly ( Lucilia cuprina ) antigens and artificial challenge. The current paper describes analysis of antibody responses to L. cuprina antigens in the R and S animals. Serum antibody titres and specificities to larval antigens were examined and the specificity of wound exudate antibodies was also investigated in animals artificially challenged with L. cuprina . Titres of L. cuprina specific serum IgA, IgM, IgG₂ and IgG₁ were measured by ELISA, while specificities were examined on two-dimensional immunoblots of larval homogenates. Exposure to L. cuprina stimulated the production of specific antibody in both R and S animals, however antibody titres did not differ between the R and S animals. There was large variation in antibody specificity between individual animals and some L. cuprina proteins appear to be more frequently recognized by sera from either resistant or susceptible animals, however the recognition of a specific protein could not be solely attributed to the resistance status of the animal. It appears that resistance in these animals may be independent of serum antibody and is likely to be an innate response. Despite high levels of IgG in wound exudates, this antibody recognized few antigens in comparison with serum from the same animal, suggesting that exudate contains little functional antibody in comparison to serum .     

Detection, quantitation, and specificity of antiparasite IgE antibodies in human schistosomiasis mansoni

Sera from 15 patients with acute or chronic Schistosoma mansoni infection were evaluated for IgE antibodies directed against soluble cercarial, adult worm, and egg antigens. Both the antigen-induced release of histamine from passively sensitized human basophils and specific radioimmunoassays were used to detect these IgE antibodies, and determination of serum IgE levels before and after specific immunosorption permitted their quantification. While chronically infected patients made IgE antibodies to all three stages of the parasite, only egg antigens induced an appreciable IgE antibody response in acutely infected individuals. Despite the fact that patients with chronic infection had significantly greater levels of total serum IgE than patients with acute disease, the percentage of this IgE that was parasite specific was similar for both groups, ranging between 4% and 28%. An ancillary observation was the fact that soluble egg antigen can trigger basophil histamine release through IgE-dependent reactions and through "nonimmunologic" mechanisms that require further characterization.     

Immune response in goats vaccinated with thiol‐binding proteins from Haemonchus contortus

The experimental protocol of immunization tested here confirms its protective effect against Haemonchus contortus in goats. This protection translated into a 65.5% mean reduction in adult worm burden after a homologous challenge, and a significant decrease (73.2%) in cumulative faecal egg counts (FECs). These parasitological findings were consistent with the levels of some biopathological parameters. Thus, the reduction in adult worms and FEC observed in immunized animals were associated with increased levels of packed cell volume as well as plasma proteins. This response seems to be related to an important increase in specific antibodies (in serum and gastric mucus) and eosinophilia in response to challenge. At the local level, a cellular response was also observed in which CD4⁺ lymphocytes and globule leucocytes played a predominant role. Finally, it should be noted that the study of immunolocalization of proteins used in the vaccination trial suggests that these antigens have an internal location (at intestinal and reproductive tissues) in the adult worm. This observation, in conjunction with the kinetics of specific antibody levels after the challenge, suggests that these antigens may be part of excretory/secretory (E/S) products.     

棘球蚴感染绵羊并诱发休克期间特异性IgG、IgE抗体对特异性抗原的识别

目的 探讨细粒棘球蚴(E.g.)囊液粗制抗原和B抗原(EgB)识别绵羊感染E.g.后及诱发过敏性休克期间特异性IgG和IgE抗体的特异性反应,并对抗原特性及分子量进行描述。 方法 制备E.g.囊液粗制抗原及EgB,应用免疫印迹技术检测经剖杀证实感染E.g.并诱发过敏性休克的20只绵羊血清特异性IgG和IgE抗体对两种抗原的抗体反应性,并对抗原特性和分子量进行描述。 结果 特异性IgE抗体与耐热、低分子量的EgB(8、12和16 kDa)抗原未见明显的反应条带,而与E.g.囊液粗制抗原在43 kDa处可见明显的反应条带。IgG抗体与E.g.囊液粗制抗原未见明显的反应条带,但与EgB抗原反应后在31、43和66.2 kDa处可见较为明显的反应条带。 结论 EgB可能不是特异性IgE抗体的特异性抗原,而是IgG抗体的特异性抗原。E.g.粗制囊液抗原中含有特异性IgE抗体的特异性抗原组分,其分子量大于43 kDa,可能是导致棘球蚴病患者过敏性休克的主要致敏原。     

Differences in immune parameters are associated with resistance to Haemonchus contortus in Caribbean hair sheep

Caribbean hair sheep are more resistant to gastrointestinal nematodes than conventional wool breeds, but mechanisms that confer resistance are not fully understood. This study compared immune effector cell populations and antibody concentrations in 12 hair and 12 wool lambs infected with the abomasal parasite Haemonchus contortus and sacrificed at 3 or 27 days post‐infection (p.i.) and 14 uninfected animals of each breed. Faecal egg counts were over 2·5‐fold higher (P = 0·12) and packed cell volumes approximately 8% lower (P < 0·10) in infected wool lambs. Abomasal lymph nodes were heavier in infected animals (P < 0·05) and infected hair sheep had larger lymph nodes than infected wool sheep (P < 0·05). Tissue eosinophil concentrations were likewise larger (P = 0·07) in hair compared with wool sheep at 3 days p.i. Circulating levels of IgE and IgA in uninfected lambs were higher in hair sheep (P < 0·05) and during infection, hair sheep had higher serum IgA than wool sheep at 3, 5, and 21 days p.i. (P < 0·05). Serum IgE in infected lambs did not differ between breeds, but concentrations of IgE in lymph nodes were higher (P < 0·01) at 27 days p.i. in infected hair sheep.     

Antibody responses in schistosomiasis haematobium in Somalia. Relation to age and infection intensity

Antibody responses in schistosomiasis haematobium were studied in relation to age and infection intensity in Somalia. The area is highly endemic for Schistosoma haematobium but free of S. mansoni. Antibodies of the IgG class against particulate antigens of S. mansoni adult worms were investigated by immunofluorescence (gut and somatic associated antigens) and against soluble egg and adult worm antigens by ELISA. Total IgE levels were examined by Pharmacia IgE RIA, and specific IgE against soluble adult worm antigen by enzyme immunoassay. The IgG antibody response showed a characteristic pattern with highest reactivity against both gut associated and soluble egg antigens in the age group 10-14 years, when both prevalence and intensity of the infection were highest. Reactivity against somatic associated antigen was also high in this age group, but it increased slightly and remained at high level in the older ages. It is thought that such antigen is exposed mainly after the death of the parasite and that the antigenic stimulation may remain throughout most of the life of infected individuals. On the other hand, the IgG antibody reactivity against soluble adult worm antigen was low during childhood, but it increased significantly with age. It is suggested that repeated booster effects are needed for more potent response against these antigenic components. The finding of high levels of total IgE already in the youngest age groups, together with low specific IgE response, indicates that mainly other antigens are involved in the IgE production. The specific IgE response against soluble adult worm antigen was low but increased significantly with age.     

后尾蚴抗原免疫荧光技术检测华支睾吸虫病血清抗体的研究

本研究以华支睾吸虫后尾蚴为抗原,用华支睾吸虫病人和实验动物血清及滤纸于血滴进行IFA,并与以成虫石蜡切片为抗原的IFA检测做了比较,同时还就实验大鼠不同时间血清抗体的变化进行了动态观察。     

感染细粒棘球蚴绵羊诱发过敏性休克期间IgG、IgG1和IgE水平的探讨

目的　测定感染细粒棘球蚴(E.g)绵羊诱发过敏性休克期间特异性IgG、IgG1和IgE抗体水平。了解抗原B对人工感染E.g绵羊IgG抗体的反应性。　方法　从绵羊E.g囊液中制备抗原B和E.g囊液粗制抗原,ELISA测定感染E.g绵羊诱发休克期间特异性IgG、IgG1和IgE抗体的动态变化。　结果　感染E.g绵羊6个月,特异性IgG、IgG1和IgE抗体水平较正常绵羊显著升高;诱发休克后特异性IgE抗体水平显著下降,尤其因休克致死的绵羊下降更为明显;IgG及IgG1抗体的衰减时间不同,趋势各不相同;抗原B和E.g囊液粗制抗原与血清IgG抗体反应阳性率分别为91%、32%。　结论　特异性IgE是导致棘球蚴病所致过敏性休克的主要抗体,而IgG和IgG1抗体也起着重要作用。抗原B与感染E.g绵羊IgG抗体的血清反应性较好,可作为一种血清免疫学诊断方法监测绵羊感染E.g的状况。     

Temporal changes in the humoral immune response of cattle during experimental infections with Onchocerca lienalis

In order to gain insights into the immune response in onchocerciasis during early infection, laboratory-reared calves were infected with 1000 Onchocerca lienalis infective larvae and examined serologically over a period of 508 days. Levels of serum antibodies measured by ELISA against adult worm extract revealed a multiphasic response, characterized by a broadly similar profile of peaks in individual animals arising at 15–30, 79 and >266 days after infection. Timings of these changes in responsiveness closely mirrored parasite development, coinciding with larval moults and with the onset of a patent infection. The levels of individual antibody isotypes directed against parasite antigens was strongly skewed. The dominant response was of IgG1, although limited reactivities were also found for IgG2 and IgM: No parasite-specific IgA antibodies were detected. Immuno-blots of adult worms extracts revealed a pattern of antigen recognition over time that matched the results obtained by ELISA. Again, the IgGl response was strongest, although certain lgG2 and IgM specificities were well represented. In general, there was a steady increase in the number of individual antigens recognized as the infection progressed, with a striking expansion of antibody specificities from day 79 following the fourth larval moult. Antibodies to a 16kDa component were a prominent feature of the response following development of a patent infection. These data reveal the strong influence of parasite biology on the development of the immune response in onchocerciasis.