摘要:

SummaryPrevious studies have shown that the recrudescence parasitaemias seen in mice infected withPlasmodium chabaudiAS strain are antigenically different from the infecting parent population. Antigenic differences between recrudescent and parent populations were demonstrated in a passive transfer assay. In the present study, using the same assay system, it has been shown that in some mice, variant parasites (i.e. different from the parent population) can be detected at a time when the primary parasitaemia is still patent but in remission. This is the first report inPlasmodiumof variant parasites being detected during the course of a patent primary parasitaemic episode of an infection initiated with a cloned line.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00939.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryWe have previously reported that Fab fragments of a monoclonal antibody to the 66 kD‐related antigens ofPlasmodium knowlesiinhibit merozoite invasion of erythrocytes, strongly suggesting a role for these antigens as merozoite receptors for red cells. In this paper we have examined the distribution of these antigens on the surface of free merozoites. Rapid immunofluorescence microscopy on free, unfixed cells demonstrated a preferential association of antigen with a polar region of merozoites. This was confirmed, and localized essentially to the apical region, by immunoelectron microscopy under a variety of fixation regimes. Metabolic inhibitors did not affect the distribution, suggesting that apical localization is not due to capping induced by cross‐linking antibodies. These observations suggest that 66 kD‐related antigens may play a role in the orientation of the apical prominence of merozoites towards the red cell, and/or in the junction formation that occurs subsequent to orient

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00940.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummarySera from 32 adult men residing in a malaria holoendemic area of Liberia were investigated for seroreactivities to different asexual blood‐stage malaria antigens on five consecutive occasions from 1984 to 1986. The seroreactivities to crude parasitic antigens and to Pf 155/RESA (EMIF) were determined by immunofluorescence and to repetitive sequences of Pf 155/RESA by enzyme‐linked immunosorbent assay (ELISA). All sera were highly reactive against the crude parasitic antigens with reciprocal titres varying from 5000 to 100000. The EMIF titres showed a wider variation from negative (<10) to 25000, and when the same individuals were re‐examined on subsequent surveys similar EMIF titres were found. The ELISA seroreactivities to three different repetitive sequences of Pf 155/RESA also showed different individual profiles which were rather consistent on consecutive surveys. High EMIF titres appeared to be correlated mainly to one of the peptide sequences, namely (EENV)2. The consistent individual profiles of the seroreactivities to Pf 155 and its repetitive sequences suggest genetic restriction of the humoral immune response. Although no significant correlation was found between EMIF titres and parasitic densities in the adult hyperimmune men the specific peptides, however, offer new possibilities of further investigating protective capacities of different immune responses to specific epitopes of the malaria par

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00941.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryBy 6 days after infection of susceptible C3H/He and resistant C57BL/6 mice withTrypanosoma brucei bruceiGUTat 3.1, splenic plasma cell responses of both strains of mice were similar in terms of plasma cell number, intracellular Ig, Ig secretion, Ig class and Ig specificity for surface‐accessible variant surface glycoprotein (VSG) epitopes on the infecting organisms, despite higher parasitae‐mia in the C3H/He mice. By 7 days after infection, however, although splenic plasma cells from both strains of mice had greatly amplified their Ig responses, those from C57BL/6 mice (which cleared parasites from their bloodstream between 6 and 7 days after infection) contained and secreted 3–5 times more Ig specific for exposed VSG epitopes on the infecting organisms than those from C3H/He mice which did not clear parasites from their bloodstream.In vitro, trypanosomes can absorb significant amounts of VSG‐specific antibody produced by splenic plasma cells. However, differences in the detection of VSG‐specific antibodies present in, and secreted by, splenic plasma cells of 7‐day infected C3H/ He and C57BL/6 mice were shown not to result from the presence of parasites in the cultures of C3H/He spleen cells. It is argued that between 6 and 7 days after infection, the C3H/He mice selectively lose the capacity to support development of plasma cells specific for exposed VSG epitopes on the infecting organisms and that this is a consequence rather than a cause of differences in the peak levels of first wave p

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00942.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryVaccination of cattle with midgut membrane (GM) antigen derived from the cattle tick,Boophilus microplus, injected with the adjuvant Quil A, resulted in significant increases in total immunoglobulins, mainly in the IgG1 and IgG2 fractions of the serum. Analysis of the anti‐GM antibody levels of vaccinated cattle showed that the levels of IgG, IgGl and complement‐fixing antibodies were significantly correlated to protection against infestation with cattle ticks. Anti‐GM antibodies of the IgG2 and IgM isotype were not correlated to protection against infestation with cattle ticks. Anti‐GM antibodies fixed complement (C′) in the presence of GM, larval membrane antigen and live, midgut cells, but not in the presence of live, larval cells. Anti‐GM antibodies were able to fix C′ equally well in the presence of GM antigen and live, midgut cells. None of the antigens tested activated the alternate pathway of complement under the conditions tested. Levels of anti‐GM IgG1 antibodies were used to develop a regression model for predicting levels of protection against infestation with cattle ticks in va

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00943.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryThe course ofTaenia taeniaeformisinfection in mice previously vaccinated with antigens prepared from either oncosphere (TtO) or metacestode (TtM) was followed by histological examination of livers from mice killed at various times post‐infection (p.i.). Distinctly different immune responses occurred in the two groups. Very few cysts were seen at any stage of infection in TtO‐vaccinated mice and most of those which were present appeared histologically similar to cysts in control mice. In TtM‐vaccinated mice many cysts were present from early in infection but histologically it was apparent that most were dying from 15 days p.i. because the tegument had lost its integrity, and degranulated polymorphonuclear leucocytes were present inside the parasites. These findings support earlier suggestions that stage‐specific antigens are expressed in oncospheres and metacestodes. Parasites developing normally were surrounded by a halo of alcian blue staining amorphous acellular material. This material appeared to act as a barrier to attack by host inflammatory cells, and disappearance of this layer signalled death of the parasite. The possibility that the gut acted as a barrier to delay migration of oncospheres to the liver in vaccinated mice was investigated, but no evidence for this could b

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00944.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryA gene fragment (II/3–10) from the cestodeEchinococcus multiloculariscoding for a species‐specific antigen was expressed in the live attenuatedSalmonella typhimuriumvaccine strain LT2 M1C. The recombinant vaccine (S. typhimurium+ pVM II/3–10) was assessed for its potential to induce both a humoral and cell‐mediated immune response in mice and dogs. Both subcutaneous and peroral administration of the vaccine resulted in antibody synthesis and lymphocyte priming of C57BL/6J mice againstS. typhimuriumantigens as well as against the recombinantE. multilocularisantigen. Two vaccinated (subcutaneous and peroral) dogs showed a strong humoral immune response toS. typhimuriumantigens and to the recombinantE. multilocularisantigen, but proliferation of peripheral blood lymphocytes was not detectable against the bacterialS. typhimuriumantigens. Regarding the recombinantE. multilocularisantigen, borderline lymphocyte proliferation was demonstrated following subcutaneous and none following peroral administration of the recombinant vaccine

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00945.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryInfective larvae ofToxocara canisare well suited for studies of nematode antigen expressionin vitro.Larvae were labelled with3H‐glucosamine, an approach permitting dual analysis of antigen quantity and composition. Their excretory/secretory (E/S) glycoproteins were efficiently labelled and antigen identity confirmed by immunoprecipitation, SDS‐PAGE and fluorography. Compartmental analysis revealed that common components ofMr100–120 kD were present in somatic, surface and soluble material. The application of biosynthetic labelling and compartmental analysis of parasite responsesin vitroto antibody, complement and neutrophils was tested. Results indicated that test larvaein vitrorespond by quantitative rather than qualitative changes in antigen production. Specifically, human serum was shown to raise, and neutrophils depress, the rate of antigen release. The implications of these findings for establishing an in‐vitro model for analysis of host/parasite reciprocal adaptive responses are di

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00946.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryAntibodies to the alkaline phosphatase (AP) ofSchistosoma mansoniin infected human and mice sera were evaluated by a direct solid‐phase AP immunoadsorption assay (APIA) and by Western blot and immunostaining. APIA consisted of (a) solid‐phase capture of immunoglobulins from infected human or mice, (b) immunoadsorption of the enzyme antigen by the antibodies, and (c) detection of the enzymatic activity. By this procedure the appearance of the anti‐AP response in mice was detected around 50 days post‐infection; this response was not specific for an AP of a given schistosome strain and it was not induced by an autoimmunity phenomenon. Fourteen out of 15 sera from infected people tested by APIA showed a clear antibody response against this enzyme. Immunoblots in non‐reducing conditions supported APIA results indicating that the parasite AP was specifically recognized by the antibodies present in infected human and mice sera. These results suggest the possible usefulness of the schistosome AP as a marker forS. mansoni

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00947.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryA family of monoclonal antibodies (MoAb) was derived from the somatic cell fusion of P3NS1 myeloma cells and lymphoid cells from naturally infected mice or hyperimmunized mice. C57BL/6 mice were naturally infected withSchistosoma japonicum, and BALB/c mice were hyperimmunized with preparations ofS. japonicumsoluble egg antigens (SEA). The MoAbs which reflected the immune repertoire of naturally infected animals versus hyperimmune animals were characterized with regard to antibody isotype, antigen binding specificity, in‐vitro immunosuppression of antigen‐induced cell‐mediated immune responses and the expression of SJ‐CRIM, a major cross‐reactive idiotype which appears on polyclonal anti‐SEA antibodies generated during murineS. japonicuminfection. The data indicate that for MoAbs of the IgG isotype which bound SEA by ELISA, the most immunosuppressive anti‐SEA MoAbs identified expressed SJ‐CRIM and were derived from naturally infected mice. All anti‐SEA MoAbs expressing SJ‐CRIM showed an identical banding pattern on immunoblot analysis which was abrogated by weak periodate treatment. The generation of expression of SJ‐CRIM on MoAbs using differing methodologies across an allotype barrier indicates that the expression of SJ‐CRIMis encoded by a germline gene. These data indicate an association between expression of this germline interstrain cross‐reactive idiotype and immunosuppressive capacity. In addition, the immunoregulatory network which develops during immuneS. japonicuminfection is initiated by a carbohydrate epitope(s) found on various SEA. These data have profound implications in the use of the cross‐reactive idiotype as a serodiagnos

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00948.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY