摘要:

SummaryAntibody responses in mice with up to 64 weeks of secondaryEchinococcus granulosushydatidosis were examined by ELISA using hydatid protoscolex antigen (Px), Antigen 5 (Ag5) and Antigen B (AgB), and by immunoelectrophoresis (IEP) using sheep hydatid cyst fluid (SHCF). Anti‐Px IgG antibodies, evident from 3–5 days post infection (p.i.), increased steadily until 16 weeks and maintained a high level afterwards. Anti‐Ag5 IgG antibodies were negligible up to two weeks, but they showed a small increase around 2–3 weeks which was followed by a big increase around 16 weeks p.i. The high level of anti‐Ag5 IgG antibodies persisted to the end of experiment. The level of anti‐AgB IgG antibodies remained relatively low throughout infection. Anti‐Px IgM antibodies appeared in the early period of infection, but became insignificant as the infection proceeded. Specific IgM antibodies to Ag5 and AgB showed two waves of increase, one between 3 days to 4 weeks p.i. and the other between 16 weeks to 46 weeks p.i. The level of IgA antibodies to Ag5 and AgB was low and only a moderate amount of anti‐Px IgA antibodies was detected. Generally, a higher level of serum antibodies are associated with a larger number of mature cysts. Serum samples from 5 of 8 mice harbouring hydatid cysts formed 1–3 bands with SHCF in IEP, including Arc 5, but a precipitation arc with AgB was not observed. Analysis of hydatid cyst fluid from the infected mice (MHCF) in IEP also failed to demonstrate AgB. Despite the high levels of antihydatid antibodies generated in the infected mice, protoscoleces appeared to be unhindered in their growt

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00465.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryImmune responses to surface antigens of infective larvae ofOstertagia circumcinctawere studied in 5‐month old Finn‐Dorset male lambs. The sheep were vaccinated subcutaneously with 2 doses of 25 μg/kg body weight of infective larvae surface or somatic extracts and Freund's or beryllium hydroxide adjuvants. It was found that only in lambs vaccinated with L3 surface extracts and beryllium hydroxide as an adjuvant did worm burdens differ significantly (P<0.01) from those of challenge controls (71.7% protection). Sheep vaccinated with the same antigenic preparation but administered with Freund's adjuvant or with beryllium adjuvant and somatic extracts demonstrated rather poor protection (32.4 and 30.5% respectively). All the vaccinated sheep showed a high IgG response to L3 surface antigens while significant levels of serum and bile IgA reacting with the surface extracts were only detected in those lambs vaccinated with L3 surface extracts and beryllium hydroxide. In immunofluorescence tests serum IgA of this group reacted with the whole surface of exsheathed larvae or with the site of opening of excretory pore while IgG antibodies reacted strongly with the anterior and posterior parts of the infective larvae. Both IgA and IgG responses to surface antigens were stage spec

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00466.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryThe investigation of MHC restricted antibody responses to an 86 kDa antigen (p86) during chronicSchistosoma mansoniinfection has been extended to immunization with this antigen. In the absence of adjuvant, a similar pattern of responsiveness by mice expressing H‐2k and H‐2d but not H‐2bwas observed following immunization with unpurified adult worm homogenate. Adjuvant selectively abrogated the capacity of H‐2dmice to respond and this was also the case when purified p86 with adjuvant was injected. Immunization with purified subfragments of p86 again demonstrated MHC restriction in the capacity to immunoprecipitate p86in vitrotranslation product, the pattern varying according to the fragment used. Western blot analysis showed that in some, but not all instances of apparent ‘non‐responsiveness’ characterized by immunoprecipitation, antibody specificities capable of recognizing p86 epitopes on the nitrocellulose bound p86 were, indeed, present. Thus the fine specificity as well as the absolute capacity to respond is influenced by both the MHC haplotype of the host and the nature of the immun

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00467.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryThe role of T‐helper (TH) lymphocytes in activating peritoneal macrophages (PM) to kill larvae of the helminthSchistosoma mansoni(schistosomula) was investigated with the use of egg antigen‐specific CD4 positive TH clones of both the TH1 and TH2 types. Results showed that stimulated TH1 clones, in exceedingly small numbers, or supernatants thereof, conferred on PM the ability to kill schistosomula. The molecule responsible for PM activation was found to be interferon‐γ (IFN‐γ). IFN–γ‐induced PM larvicidal activity was dependent on live cells, energy, as well as protein synthesis, and appeared to be mediated by toxic nitrogen metabolites. In contrast, egg antigen‐specific TH2 clones, or their supernatants, failed to induce PM larval killing, as they did not secrete IFN‐γ, or any equivalent macrophage activating factor. We postulate a mechanism by which egg antigen‐specific TH1 clones may be capable of playing a critical role in the resistance to schistosomal reinfection through IFN‐γ‐mediated activation of ma

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00468.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryGroups of five dogs were vaccinated with differentBabesia canisvaccine formulations. It appeared that partial protection against challenge infection was obtained when using parasite antigens from in vitro culture in combination with saponin. Protection was evident as a decrease in parasitaemia after challenge and was associated with the presence of serum antibodies against Babesia parasites. In addition, parasite antigen derived from in vitro culture supernatant exhibited more protective activity than somatic parasite antigen, in that a less marked fall of haematocrit values was found after challenge infection. The fall of haematocrit value observed in the animals immunized with somatic parasite antigen was not different from that observed in the adjuvant control group.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00469.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryTestosterone (Te) is known to suppress immunity and to increase host susceptibility to many parasites. This study investigates the action of Te on immunity acquired against blood‐stages of the malaria parasitePlasmodium chabaudiin female mice of the inbred strain C57BL/10. Our data show: (i) About 90% of mice infected with 106P. chabaudi‐infected erythrocytes are able to develop protective immune mechanisms which become evident in self‐healing the infection. The capability of self‐healing is lost when mice are pretreated with Te for 3 weeks. (ii) Mice which have self‐healed infections acquire immunity to homologous rechallenge. Concomitantly, mice become Te‐unresponsive in that their acquired immunity is not suppressible by Te‐treatment. (iii) Flow cytometry reveals that Te‐pretreatment entails an increase of CD8+ cells and a decrease of Ig+ cells by about 4% in spleens of non‐immune mice. In immune mice, however, there is a Te‐unresponsiveness of the percental distribution of splenic cell populations. (iv) Adoptive transfer experiments indicate that immunity is conferred by spleen cells, presumably non‐T‐cells. These cells are Te‐unresponsive, since they exert their effect in Te‐pretreated mice in the presence of Te. (v) Teunresponsive immunity can be also transferred by serum, especially the IgG‐fraction, obtained from immune mice. Our data demonstrate that Te prevents the development of protective immunity againstP. chabaudiinfections. However, when once established, protective immunity becomes unresponsive to Te. Our data suggest that the effector mechanisms of protective immunity involve Teunresponsive B cells secret

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00470.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryWe have investigated the pattern of acquired immune responses to the major surface protein ofPlasmodium falciparummerozoites (gp 190, Pf MSP1) in a malaria endemic population in West Africa. A prospective longitudinal study in 3‐ to 8‐year‐old children was conducted to examine the relationship between naturally acquired immune responses to Pf MSP1 and subsequent susceptibility to malaria infection and clinical disease. A population cross‐sectional survey was performed to investigate changes in immune response with age. The prevalence and concentration of antibodies to all regions of the molecule increased with age with the highest prevalence of antibodies being detected against regions of the molecule which are highly conserved between parasite isolates. In vitro lymphoproliferation and interferon‐gamma production in response to recombinant proteins representing polymorphic regions of the molecule also increased with age. Interestingly, proliferative responses to some regions of the molecule, including some highly conserved sequences, were highest in young children and decreased markedly with increasing age. Significant associations were observed between antibody and lymphoproliferative responses to proteins from the C terminus of the molecule and resistance to episodes of fever associated with high parasitaemia in partially immune children. In addition, high concentrations of antibodies to a conserved region close to the N terminus of Pf MSP1 were also significantly associated with p

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00471.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryCats given a single inoculation ofBrugia pahangiinfective larvae (L3) were retrospectively allocated into three groups according to parasitological outcome of infection. Recognition of somatic and surface antigens ofB. pahangiby sera from each group was compared by ELISA, immunoelectroblotting, and immunoprecipitation techniques.In cats that never became microfilaraemic mean serum IgG antibody levels against somatic extracts from adult male worms. L3, and microfilariae (mf) were higher than levels in cats that initially became microfilaraemic (mf+ve) then spontaneously became nonmicrofilaraemic (mf‐ve). The lowest levels of antibody against each stage were found in cats that remained persistently mf+ve.Antigenic components of 18 kD and 22 kD in somatic extracts of adult worms and L3 were recognized by sera from cats that never became mf+ve and by spontaneously mf‐ve cats, but not by sera of persistently mf+ve cats.When radioiodinated surface antigens of mixed adult worms and microfilariae were immunoprecipitated by sera from cats in the three groups, no correlation was observed between recognition of individual antigen components and parasitological outcome of infect

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00472.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00473.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY