摘要:

SummaryWe have expressed two cDNA sequences encoding 121 and 230 amino acids of the C‐terminus of theSchistosoma mansoniHsp70 inEscherichia coli.The products were synthesized as polypeptides fused to the RNA polymerase of bacteriophage MS2, and their reactivities were tested in ELISAs, using sera from human and murine infections. Anti‐Hsp70 antibodies were detected in a significant number of individuals suffering from chronic schistosomiasis mansoni, but not in patients with known recent infections. This, together with the finding that antibodies directed atS. manoni‐specific Hsp70 determinants during the course of infection of experimental mice were not detectable until 5–6 weeks postinfection, suggests that the protein may be a useful marker for distinguishing late and early infections. The diagnostic specificity of Hsp70 was evaluated with sera from humans infected with different schistosome species and other parasitic diseases. While some subjects infected with 5.haematobiumproduced antibodies which recognized theS. mansoniHsp70, no such antibodies were generated in 5.japonicuminfected individuals. However, cross‐reactive antibodies were elicited in donors with other parasitic diseases such as filariasis and malaria. The absence of antibodies in early infection and the observed cross‐reactivities led us to conclude that Hsp70 will be of limited value in the diagnosis of schi

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00973.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryPhenotypic changes in murine alveolar macrophages have been described in response to vaccination with irradiated cercariae and to a subsequent challenge with normal parasites. Flow cytometric analysis was used to quantify the proportions of cells strongly positive for a number of macrophage surface markers, detected by a panel of monoclonal primary antibodies and fluorescent secondary antibodies. The proportion of Ia+macrophages sampled by bronchoalveolar lavage increased 5‐fold over days 14 to 28 post‐vaccination. This upregulation of Ia was accompanied by a sharp decrease in F4/80 expression between days 14 and 21. The low percentage of F4/80* cells persisted for several weeks after vaccination, and no further change was stimulated by challenge parasites. These altered characteristics are consistent with the ‘activation phenotype’ induced by other infectious agents. After challenge of immune mice, further changes in macrophage phenotype were slight compared to the responses elicited by vaccination, or to those induced in the challenge control group; la expression increased to about three times normal levels. The phenotypic changes correspond both in magnitude and timing with the pattern of alveolar macrophage activation determined in a previous study. The limited changes in phenotype of alveolar macrophages from immunized mice after challenge could indicate that these cells become refractory to reactivation. Overall, the altered macrophage phenotype after vaccination and challenge provides circumstantial evidence for the action of cytokines, particularly interferon‐gamma, in lung‐phase immunity to s

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00974.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryNaive CBA mice and mice vaccinated 4 weeks previously with gamma‐irradiated cercariae of 5.mansoniwere challenged percutaneously with normal cercariae and then treated with 500 mg/kg body weight of Praziquantel (Pzq). The drug was administered intradermally on day 1 or intramuscularly on day 6, thus targeting against skin stage or lung stage challenge larvae respectively. The skin site of challenge and/or the lungs were removed at various time points to provide samples for histological examination. As reported elsewhere (Flisser, Delgado&McLaren 1989) the efficacy of Pzq was significantly enhanced in vaccinated mice and was influenced by the treatment regime. Histological analysis revealed that when Pzq was administered I/D on day 1 to vaccinated mice, the inflammatory response to challenge differed in extent but not nature from that seen in vaccinated but untreated cohorts. This correlates with worm recovery data showing no (this study), or only marginal synergy between drug treatment and immunity using this regimen of drug treatment (Flisseret al.1989). Following the day 6 protocol of drug delivery, however, lungs from treated vaccinated mice exhibited many large inflammatory reactions containing trapped challenge larvae. In contrast, lungs from untreated vaccinated mice had only few foci which were small and rarely contained trapped larvae. These data again correlate well with worm recovery data showing that there is a highly significant synergy between vaccination and drug treatment administered at this time (Flisseret al.1989; this study). It would seem, therefore, that Pzq exacerbates lung phase immunity in the NIMR vaccine mouse model where skin phase immunity predominates and pulmonary attrition is normally minimal. The results are discussed in the light of published data concerning the effector mechanisms thought to characterize skin and lung phase vaccine resistance in the murine mode

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00975.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryMonospecific rabbit antibodies were utilized to localize the 28 kDa serine protease which is released from transforming schistosomula ofSchistosoma mansoniin cercariae and freshly transformed schistosomula. This protease exerts two postulated activities, degradation of connective tissue proteins thus promoting skin penetration and release of the cercarial glycocalyx leading to accelerated schistosomular transformation. Upon immunogold labelling of cercarial cryosections, the 28 kDa protease was found stored in both the preacetabular and postacetabular glands. This enzyme was also detected in the cercarial glycocalyx by immunogold and immunofluorescence labelling and by its proteolytic activity. Following transformation and shedding of the glycocalyx, the same 28 kDa protease was found on the surface membrane of transformed schistosomula which are resistant to immune damage. It is suggested that the 28 kDa membrane protease which cleavesin vitrothe complement proteins C3, C3b and C9, may promotein vivoimmunoresistance ofS. mansoni.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00976.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryImmune reactions to cysticercosis have been extensively studied in mice. The lack of significant lymphocyte infiltration into the livers of infected mice and the obvious role of antibodies in rejection has led to the general conclusion that cellular reactions do not play a role in protection against this disease. In contrast, the present study examining the immune response to cestode infections in a large animal model (sheep) revealed the presence of a massive and highly organized cellular infiltration in the livers after a secondaryTaenia hydatigenainfection. The majority of the infiltrating lymphocytes were of the CD4+phenotype with much fewer CD8+cells present. While most γδ‐TCR+cells in peripheral blood are SBU‐T19+, the majority of γδ ‐TCR+lymphocytes in the liver lesions are SBU‐T19‐ suggesting selective migration of these cells into the lesions. In contrast to the diffuse distribution of T cells in the lesions, B cells were present as distinct aggregates.In primaryT. hydatigenainfections, host class I and class II MHC antigens were shown, for the first time in cestode infections, to be absorbed onto the surface of the metacestode bladderwall indicating their possible involvement in parasite survival. No immune reactions were observed close to the parasite although lymphocytes and eosinophils were infiltrating the adjacent portal tract areas. Most lymphocytes in both primary and secondary infections were positive for MHC class II antigens suggesting selective recruitment of activated cells to the site of infection.Significant changes in relative and absolute numbers of lymphocyte subpopulations were also observed in the draining hepatic lymph nodes dominated by a massive increase of B cells. In contrast, at the peak of local cellular infiltration, no changes in lymphocyte subpopulations were observed in peripheral blood showing the limited usefulness of this compartment in studying cellular changes in localized infections.The vigorous cellular response observed in the livers of sheep contrasts sharply with the lack of lymphocyte infiltration reported in mice indicating that small animal models may not be appropriate to study cellular responses to cysticercosis in large an

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00977.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryPurified piroplasms ofTheileria mutanswere used to immunize BALB/c mice to generate monoclonal antibodies (MoAbs). The MoAbs recognized an antigen of a relative molecular mass of 32 kDa in Western blots. This antigen was also recognized by sera from cattle which had recovered naturally from experimental tick‐transmission or infections induced by the blood stages ofT. mutans.The MoAbs did not react, in indirect immunofluorescence or enzyme‐linked immunosorbent assays (ELISA), with the common haemoparasites of cattle, namely,T. parva, T. annulata, Babesia bigemina, B. bovis, Anaplasma marginale, Trypanosoma congolense, T. vivaxorT. brucei.An antigen capture ELISA was established with two of the MoAbs which recognized different epitopes on the 32 kDa molecule. Using this test it was possible to detect circulating antigens or immune complexes in sera collected from cattle during the acute or chronic phases of infection. When the purified 32 kDa protein was used as antigen in a micro‐ELISA to detect circulating antibodies in both experimental and field cattle sera, it was found that the titres of antibodies ranged between 1:20 and 1:10 240. Results of this study indicate that the antigen and immune complex capture assays and the antibody detection ELISA can be complementary in the immunodiagnosis of acute and chronicT. mutansinfections. Moreover, the tests are useful in the differential diagnosis of the disease and for epidemiological st

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00978.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryTwo‐site and competitive ELISA have been developed against a surface antigen of zygotes‐ookinetesof Plasmodium bergheiusing monoclonal antibodies (MoAbs) which block transmission of the parasite to the mosquito. Three such MoAbs have been studied, each of which recognized a protein of an Mr21 kD (Pbs21) using immunoblot techniques. The assays showed that there are at least 3 single B‐cell epitopes expressed in Pbs21. One epitope recognized by MoAb 17.9 is conformation dependent and antibodies bound to it interfered with other MoAbs (12.1 and 13.1) each recognizing a different, apparently linear epitope. Glycosylation might not be relevant to the binding of any of the antibodies tested to their respective epi

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00979.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryThirty serum samples collected from adult patients attending the Hospital for Tropical Diseases, London, withP. falciparummalaria, were studied. Sera were screened by indirect immunofluorescence for anti‐gametocyte antibodies. Twelve of the serum samples taken from 14 patients with primary infections were found to have both IgM and IgG antibodies to gametocyte antigens and total Ig titres comparable with those of patients who had had previous malaria attacks. Sera of individuals from hyperendemic areas have been found to immunoprecipitate the 230 and 48/45 kD gametocyte surface antigens which are known targets of transmission blocking antibodies. To investigate the epitope specificity of the serum samples from our adult patients, competitive ELISAs with 3 monoclonal antibodies (MAbs) that block transmission and recognize different epitopes on the 48/45 Kd antigen, were carried out. Specific antibodies for these epitopes were found in 60% of the sera while nearly a third were able to inhibit the binding of at least two MAb

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00980.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryAn IgM monoclonal antibody that reacts with the merozoite membrane and internal merozoite antigens was shown to recognize several previously characterized asexual blood stage antigens ofPlasmodium falciparumas well as new antigens. Among the reactive antigens identified were FIRA, GYMSSA, RESA and the S‐antigen. Analysis of the cross‐reactions between FIRA and GYMSSA by epitope scanning was performed. The most reactive peptides in GYMSSA had the common sequence STNS. The cross‐reactive epitopes in FIRA could, in many cases, be explained by the results of a replacement net analysis performed on the STNS epitope. It is proposed that the cross‐reactive epitopes, which in several cases have no obvious linear homology but possess high S, T and N content, may be present as loops or coils on the surface of the mo

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00981.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryVaccines currently being evaluated against malaria are based on proteins derived from the blood, sporozoite and sexual stages. Antigens from the liver stage, which is now recognized as the major target of protective sporozoite induced immunity, have received comparatively little attention. This paper describes the generation of a monoclonal antibody (MoAb), which recognizes an antigen specific to the liver stage of the rodent malariaPlasmodium berghei.The antigen is expressed throughout liver stage development and appears to be localized to the parasitophorous vacuole membrane. The MoAb did not affect the growth of liver stages culturedin vitronor could protection be demonstratedin vivofollowing passive transfer of the antibody.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00982.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY