摘要:

SummaryThe antibody responses of rats to infection with the intestinal intracellular protozoan parasiteEimeria nieschulziwere examined by a sensitive radio‐immunoassay with a soluble preparation of sporulated oocysts as antigen. Specific antibodies of the IgM, IgGl, IgG2a and IgG2b isotypes were found in the blood circulation and IgA antibodies were detected in the bile and in intestinal washings. The IgM response was rapid, its peak was relatively brief and it was not recalled by the reinoculation of oocysts. There were some differences between the responses in the different subclasses of IgG but they all reached a peak between 20–30 days after the initiation of the primary infection and there was an anamnestic response to a challenge inoculation of oocysts. IgA antibodies toE. nieschulziantigen in the bile and in intestinal washings increased and decreased after both primary and secondary inocula. Antibodies of all isotypes tested were virtually absent in the blood circulation of infected athymic rats. These findings are discussed with reference to antibody responses to other parasitic infections and to the role of antibodies in immunity to coccidio

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1984.tb00777.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SummaryGroups of CBA/CaJ and B‐cell deficient CBA/N mice were infected withTrypanosoma rhodesienseEATRO 1886 strain. Survival, parasitaemia, serum Ig levels plus specific trypanosomal IgM and IgG antibodies were assayed and compared during infection. Whereas both strains of mice had similar parasitaemias during the first week of infection, CBA/N parasitaemias were lower than those observed in CBA/CaJ mice during the subsequent study period. Antibody responses, specific forT. rhodesienseantigens, peaked on day 10 after infection in CBA/CaJ mice, then rapidly declined. However, antibody responses in CBA/N mice remained elevated throughout the study. In addition, the kinetics of specific IgG and IgM varied in CBA/N mice: IgG antibody was detected on day 4, whereas specific IgM was detected on day 16. This unique relationship between the appearance of IgG and IgM antibody may explain the longer survival observed for B‐cell deficient CBA/N mice infected withT. rhodesie

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1984.tb00778.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SummaryThe surface antigens ofToxocara canisinfective larvae have been identified by radio‐iodination and compared with the excretory‐secretory (ES) products released by the larvaein vitro.Common antigens, of molecular weight 32 000 and 120 000 are found on the larval surface, in the ES material and in culture supernatant following surface iodination of livingT. canislarvae. The 120 000 antigens consist of three closely migrating bands in each of these preparations. However, one prominent ES component, of molecular weight 400 000, is not found on the larval surface. Additional molecules of 55 000 and 70 000 are present in the ES material, but while these may be discerned in surface preparations there appears to be more heterogeneity of surface molecules in this size range. Both sets of molecules are antigenic to infected patients and experimental animals. A comparison of characterized human sera show that a radio‐immunoprecipitation assay correlates with the established ELISA test (r= 0–89), and that all labelled molecules are antigenic to the infect

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1984.tb00779.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SummaryInhibitory monoclonal antibodies which bind to some isolates ofPlasmodium falciparumfrom Papua New Guinea, but not from other areas, bound to a 220 kD antigen. By immunofluorescence microscopy this antigen was shown to be located both within the schizont cytoplasm and also within the schizont infected erythrocyte, but external to the schizont itself. Even at antibody concentrations which caused>70% inhibition of parasite multiplication, accumulation of schizont stages or aggregates of merozoites were not seen, consistent with inhibition occurring at a point after the release of merozoites. While this suggests that the antigen may be present on merozoites, the quantity was below the limit of detection. It is suggested that the large amount of antigen released by rupturing schizonts may be a mechanism used by the parasite to evade immunological attack.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1984.tb00780.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SummaryTo investigate the mechanisms of cell mediated immunity to malaria, we studied different systems to measure specific activation of T lymphocytes byP. chabaudiantigens. Mice were primed by subcutaneous administration of parasite antigens followed by co‐cultivation of lymphocytes taken from the draining lymph nodes in the presence of the priming antigen. A marked proliferative response was observed which was shown to be antigen specific, T‐cell mediated and accessory cell dependent. Continuous T‐cell lines were propagated in culture by repetitive restimulation in the presence of antigen and accessory cells, followed by expansion in a conditioned medium containing T‐cell growth factors. These lines could be induced to proliferate to the priming antigen only in the presence of syngeneic accessory cells thus indicating that H‐2 restriction operates in the recognition of Plasmodium antigens by T cells. We also induced parasite specific T cells by the use of anin vitroprimary ‘education’ system. Lymphocytes from unprimed mice were sensitized on parasite‐fed macrophages and were then injected subcutaneously into each hind foot pad of syngeneic animals. This led to recruitment of antigen‐reactive cells which were assayedin vitroby the ability of lymphocytes taken from the draining popliteal lymph nodes to proliferate in response to the sensitizing antigen.In vivoimmunization with Plasmodium antigen fed macrophages also signalled antigen specific T cells that recruited reactive T cells in the dra

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1984.tb00781.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SummaryThe surface composition of three stages in the life cycle ofLitomosoides carinii, a filarial parasite of rodents, has been studied using radio‐iodination techniques. Confirmation that radiolabeled components were confined to the parasite surface was achieved using light and electron microscope autoradiography. Biochemical analysis of extracts of radiolabeled parasites by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE) revealed that one major component (mol. wt. 55000) could be solubilized with the aid of detergents. This component, which was present on male and female adult worms and on post‐parasitic third stage larvae, accounted for about one‐third of the total proteins available for surface iodination, and was antigenic in infected hosts. The remaining surface components could be solubilized only with urea and SDS under reducing conditions. The 55 000 mol. wt. surface antigens of male and female adult worms exhibited identical two‐dimensional tryptic maps, but the similar 55 000 mol.wt. antigen of post‐parasitic third stage larvae was different. There was, however, some sharing of antigenic determinants between adult and larval surface components. The principal protein present in detergent extracts of surface‐radio‐labelled blood microfilariae was hos

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1984.tb00782.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

SummaryFreeze‐thawed extracts of mature schizonts ofPlasmodium knowlesi(strain Wl) were electrophoresed in sodium dodecylsulphate (SDS) polyacryl‐amide gels, then transferred electrophoretically to diazophenylthioether paper. The transferred antigen was probed using a purified polyvalent, polyclonal immune serum pool isolated from rhesus monkeys (Macaca mulatto). This method for identifying parasite antigens was compared with immunoabsorption, using parasites which had been metabolically labelledin vitrowith35S‐methionine. The methods showed general correspondence but some antigens failed to react after transfer because of loss of antigenicity during SDS‐polyacramide gel electrophoresis (SDS‐PAGE). Some antigens were observed preferentially after the transfer procedure, possibly because of their failure to elute from the immunoabsorbant or because they may have a low methionine content. The transfer method failed to reveal the antigen reactivity of three out of four monoclonal antibodies tested, apparently because the epitopes involved were inactivated by SDS. DuringP. knowlesiinfection in the resistant kra monkey (Macaca fascicularis) the transfer method showed the presence by day 10 of antibodies against two components having an apparent molecular weight by SDS‐PAGE similar to those of putative protective antigens described in other studies using monoclonal

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1984.tb00783.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY