摘要:

Glossinainfected with African trypanosomes infest 107Km2of intertropical Africa. Ten thousand cases of human sleeping sickness are officially recorded each year and 35 times 106human beings are at risk. Animal trypanosomiasis impedes the use of 7times 106Km2of land adequate for cattle raising and constitutes a major constraint to increasing protein production in Africa.Several approaches are used to combat trypanosomiasis (a) vector eradication has been successful in certain denned situations but cannot be realistically extended to the whole area at risk, (b) prophylactic drugs, which are too toxic for humans, are widely used to protect cattle. This practice has led to field resistance to many drugs used in the past (reviewed in Holmes&Scott 1982) and the appearance of resistance to the last available prophylactic drug, isometamidium, is being reported (Bourn&Scott 1978, Kiipper&Wolters 1983, Pinder&Authie 1984), (c) the hope for a vaccine has been largely abandoned, in the present state of knowledge, due to the considerable extent of antigenic diversity in trypanosomes (reviewed in Doyle 1977, Turner 1982, Roelants&Pinder 1984), (d) consequently, the possible use of certain West African breeds of cattle, which appear resistant to trypanosomiasis, has been emphasized as a solution to this problem in domestic animals. The analysis of this natural resistance is the subject of the present essay.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb00828.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryThis study demonstrates the involvement of a large number of salivary proteins in the acquisition of resistance toHyalomma anatolicum anatolicum.Using immunoblotting, sera from hypersensitized rabbits were shown to react with nine proteins in the saliva and 17 in salivary gland extracts (SGE) from 96 h fed female ticks. The salivary antigens had molecular weights in the range of 14 400 to 130000. All the antigens identified in the saliva and 12 of the SGE antigens were glycoprotein in nature and a majority of them appeared to be common to different stages of feeding. In addition antigen I (molecular weight 130000) showed acid phosphatase and antigen III (molecular weight 96000) showed both non‐specific esterase and aminopeptidase activity. Three high molecular weight proteins isolated from saliva (antigen I, antigen II–molecular weight 103 000 and antigen III), gave immediate hypersensitivity reactions in intradermal inoculation into rabbits which had previously been exposed to ticks. Antigens II and III also elicited a strong delayed hypersensitivity reaction. These results may help to explain the nature of the immune mechanisms which effect resistance againstH. a. anatoli

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb00829.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb00830.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryMale B10–129 (10M) ScSn mice were relatively resistant to cutaneous leishmanisis, while females frequently developed non‐healing expanding ulcers, leading to loss of infected extremities, metastasis to distal skin sites, and in some animals, death. Anti‐leishmanial antibody titers were higher, and delayed‐type hypersensitivity responses to parasite antigens, lower, in infected females than in males. Sex differences in response to cutaneous infection were not marked in BALB/cJ mice, a highly susceptible strain, and both males and females ultimately lost infected extremities, developed metastases, a

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb00831.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryRing‐stage asexual parasites ofP. falciparumwere collected from six Gambian children and the S‐antigens radiolabeled by3H‐glycine uptake duringin vitroculture up to rupture of infected cells and merozoite release. Ouchterlony double diffusion of boiled culture supernatants against a panel of adult Gambian sera identified one S‐antigen precipitin arc for five isolates and two precipitin arcs for one isolate. Five of the six isolates were serologically distinct. Analysis of S‐antigens by comparison of SDS‐polyacrylamide gel electrophoresis patterns of heat‐treated soluble proteins revealed a more complex pattern of3H‐labelled S‐antigens that was different for each isolate. There were between two and six different3H‐labelled bands for each isolate in the size range of molecular weight 137 000 to 285 000. This result confirms the large size range of S‐antigens identified with culture adaptedP. falciparum.Several bands were relatively weakly labelled with3H‐glycine, suggesting that natural isolates contain one or two predominant S‐antigen phenotypes and several other S‐antigen phenotypes expressed by minor parasite subpopulations. Immunoprecipitation was performed using a panel of sera from Gambian adults, or, acute and 3 week convalescent sera from the same patients used for S‐antigen radiolabelling. Adult sera generally immunoprecipitated some of the S‐antigens in each isolate, including antigens that must represent extremely minor parasite subpopulations since they could not be seen in the patterns of non‐immunoprecipitated heat‐stable proteins. Sera from convalescent children were generally negative on immunoprecipitation, even with the homologous isolate. In one case we observed the acquisition of specific immuoprecipitating antibody to one of the homologous S‐antigens during the convalescent period. The antigenic and structural complexity of S‐antigens in natural isolates that have not been submitted to the selection pressure of adaptation forin vitroculture is clearly greater

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb00832.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryA panel of monoclonal antibodies has been shown previously to identify both serologically diverse and serologically conserved epitopes on a major polymorphic surface protein ofP. faliparumschizonts from culture‐adapted isolates. The molecular nature of the antigen recognized by eight of these monoclonal antibodies was studied with three isolates analyzed directly from patients in The Gambia. Malarial (glyco) proteins were labelled by biosynthetic uptake of3H‐glucosamine or3H‐leucine during culture of ring‐stage parasites from infected blood to the late‐trophozoite/early‐schizont stage (26–30 h). Those monoclonal antibodies which reacted positively with an isolate by indirect immunofluorescence also immunoprecipitated a single3H‐leucine or3H‐glucos‐amine labelled antigen of mol. wt ˜200 000 from Triton X‐100 extracts of the same isolate. Monoclonal antibodies which did not react by indirect immunofluorescence failed to immunoprecipitate this antigen. Although each of the three isolates studied in detail was very similar serologically with the panel of monoclonal antibodies specific for this mol. wt ˜200 000 antigen, this protein could be distinguished with each isolate on the basis of its apparent size on SDS‐polyacrylamide gel electrophoresis. The specifically immunoprecipitated antigen had a mol. wt of 204 000, 197 000 or 202 000, depending on the isolate. Size diversity of this malarial glycoprotein was also detected with seven other GambianP. falciparumisolates. We conclude that natural isolates ofP. falciparumexpress a major3H‐glucosamine labelled glycoprotein of mol. wt Mr˜200 000 which exhibits size diversity and expresses antigenically conserved as well as diverse epitopes as defined by the pa

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb00833.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryThe protozoan parasiteTheileria annulatacauses a severe disease of cattle in tropical countries; one stage in the parasite life cycle involves the transformation of bovine lymphocytes leading to rapid lymphoproliferation. Immunity to this disease is largely cell mediated and directed against the infected lymphocyte. In this paper we report the identification of three classes of infection specific antigen (using monoclonal antibodies) one of which is found on the surface of the lymphocyte. Such antigens can be used in parasite strain typing, in providing an understanding of the molecules involved in immunity and in providing the basis for a vaccine.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb00834.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryAntibody and lectin binding characteristics ofSchistosoma mansonischistosomula maturingin vivoandin vitrowere quantitatively assessed and compared in order to investigate the basis of the reduced surface antigenicity of host derived larval schistosomes. Quantitative indirect immunofluorescence assays showed that schistosomula recovered from mice at 24 h and 5–10 days post infection bound low or insignificant amounts of a variety of anti‐schistosome antibodies including those from chronically infected and radiation attenuated cercariae‐vaccinated mice, a vaccinated rabbit and rabbits hyper‐immunized with non‐living larval and adult schistosome antigen preparations. In contrast, parasites maturingin vitrocontinued to bind highly significant levels of each of these antibody preparations until at least 10 days post transformation. To investigate the basis of the decreased surface antigenicity of parasites maturingin vivo, 6‐day‐cultured parasites were injected intravenously into mice and recovered from the lungs at various times thereafter and examined for their ability to bind both anti‐parasite and anti‐host antibodies. After 30 minin vivo, cultured schistosomula exhibited a significantly decreased capacity to bind anti‐parasite antibodies and concanavalin A (Con A), and by 16 h had lost their binding sites for fucose binding protein (FBP) as well. That this reduction in antigenicity was due to shedding of surface antigens was suggested by the observation that the reduced ability of these parasites to bind anti‐parasite antibodies coincided closely with the loss of125I‐labelled surface proteins. Furthermore unlike 6 day schistosomula which had developed whollyin vivo, 6‐day‐cultured parasites recovered after 30 minin vivofailed to bind anti‐host antibodies suggesting that in these organisms parasite antigens were not masked by host molecules. These data argue that surface antigen shedding may explain the reduced surface antigenicity of schistosomula developingin vivo.While this surface modulation apparently independently of host antigen uptake, it is dependent upon an as

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb00835.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryTwo monoclonal antibodies against the surface ofS. mansonischistosomula were found to confer significant passive protection to mice (M7B3A, range 28–70%; M22H12C, range 14–58%). No additive effect was observed when both were transferred together. Neither McAb bound to the cercarial surface but both bound to the surface ofin vitroderived schistosomula and schistosomula recovered from mouse skin up to 3 days after infection. The McAbs were species specific, but notS. mansonistrain specific. M22H12C immunoprecipitated an125I‐labelled surface antigen of relative molecular weight (mol. wt) 32 000. In Western blotting of an NP40 schistosomular extract, M7B3A recognized an antigen smear of 13000–18000 with a dominant band at 16000. This 16000 antigen was recognized by serum from demonstrably immune mice and rats vaccinated with highly irradiated carcariae but not by sera from mice with chronic single sex or bisexual inf

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb00836.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY