摘要:

SummaryThe following bovine (Bo) and human (Hu) cytokines—Bo rTNF‐a, Bo rIFN‐g, Hu IFN‐a, Hu rIL‐1, Hu rIL‐2—significantly inhibited the in vitro development of trophozoite‐infected cells of three stocks ofTheileria annulataand ofTheileria parva(Muguga). However, none of these cytokines inhibited the proliferation of establishedT. annulataorT. parvamacroschizont‐infected cell lines. Indeed, Bo rTNF‐a and Hu rIL‐2 consistently enhanced the proliferation of macroschizont‐infected cell lines of both species and the blastogenesis of uninfected lymphocytes in trophozoite‐infected cultures. These results suggest that cytokines could help in resistance to challenge infections by preventing the further development of trophozoite‐infected cells but provide no evidence that any of the above cytokines directly help to resolve primary infections by inhibiting the growth of macroschizont‐infected cells. These findings also suggest that both TNF‐a and IL‐2 could play a role in the pathogenesis ofTheileriainfections by promoting the proliferation of macroschizont‐infected cells and

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00456.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryA limiting dilution microculture system was optimized to quantify the frequency ofTheileria parva‐specific cytotoxic T lymphocyte precursors (CTLp) in peripheral blood mononuclear cells (PBMC) from immune cattle. Optimal results were obtained with responder cell input levels ranging from 2 × 104/well to 6.25 × 102/well, along with 1–5 × 103/well stimulator cells in standard supplemented RPMI 1640 medium containing 2.5–5% T cell growth factors. Thirty‐six microtitre wells were established at each responder input level. Cultures were incubated for 7 days at 38°C, at the end of which time individual wells were screened for cytotoxic activity in a 4‐h111indium oxine‐release assay. Analysis of the cytotoxicity data, by a computer‐programmed maximum likelihood estimation method indicated that they conformed to the Poisson model of single‐hit kinetics. Estimates of frequencies ranged from 1:3600 to 1:5275 CTLp in PBMC of eight cattle between 1 and 24 months after immunization withT. parva. By contrast, no CTLp were detected in six naïve animals analysed to a responder cell input of 105/well. Split‐well analysis of individual microwells showed that the CTL clones generated under limiting dilution conditions displayed exquisite specificity for parasitized cells, were genetically restricted and in some animals were pa

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00457.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryMacrophage activation and production of opsonizing antibodies were studied in mice either infected with a lethal and reticulotropicTrypanosoma cruzistrain, RA, or with a non lethal and myotropic strain, CA‐I, as well as with a clone, K98 (derived from CA‐I), similar to the parental strain. Measurement of macrophage respiratory burst by chemiluminiscence disclosed thatT. cruziinfection induced an enhancement of the respiratory burst, no matter the parasite subpopulation employed. But, while in mice surviving RA infection the respiratory burst was higher than during the acute period and parasitaemia was efficiently controlled, in mice infected with K98 enhanced respiratory burst coexisted with measurable levels of parasitaemia either at acute or chronic infection periods. Macrophage activation was also proved by enhanced trypanocidal activity in macrophages derived from mice infected with any of the parasite subpopulations. Sera from RA mice opsonized and lysedT. cruzibloodstream forms efficiently, whereas sera from CA‐I or K98 mice neither lysed nor opsonized this parasite stage. All three subpopulations assayed here showed IgG bound to their membranes in vivo and similar capping kinetics, but only antibodies bound to RA parasites invariably triggered lysis. Therefore, the role played by macrophage activation in resistance and control of Pm levels is related to some features of eachT. cruzisubpopulation, such as its capacity to invade macrophages and to elicit opsonizing antib

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00458.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryThe effect of dietary protein on the specific antibody responses (total immunoglobulins, IgGI and IgA) to the intestinal nematodeTrichuris muriswas studied in CBA/Ca mice fed isocaloric diets containing 16% or 4% protein. Mice fed the 16% diet and given a high infection dose of 650 eggs expelled almost their entire primary infection by day 21 post infection. In similarly infected animals fed the 4% protein diet, there was prolonged survival of adult worms. At a low infection dose of 10 eggs, there was no evidence of an expulsion response in either dietary group. The primary antibody response to parasite excretory/secretory (E S) antigen was time‐dependent, regardless of dietary protein or infection dose, and was predominantly an IgGI response. Within each dietary group, antibody production and antigen recognition occurred earlier and the antibody responses were more intense in mice given the higher infection dose. The principal finding was that the specific antibody response was more vigorous, both quantitatively (serum titres) and qualitatively (antigen recognition by IgGI), in mice on a low protein diet, even though worm expulsion did not occur in these hosts. This result suggests that serum antibody level or antigen recognition is not related simply to protective immunity againstT. murisin CBA/Ca mic

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00459.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryChanges in the surface antigenicity and susceptibility to eosinophil‐dependent killing duringin vitrodevelopment of schistosomula ofSchistosoma mansoni, were examined using sera from rabbits and mice immunized with antigens that are shed from the schistosomulumin vitro(shed antigen), a carbohydrate extract of shed antigen (SAg/CHO) or a periodate‐insensitive fraction of shed antigen (SAg/PEP). Anti‐SAg/CHO antisera recognised mainly carbohydrate epitopes on the parasite surface, whilst anti‐SAg/PEP antisera bound to periodate‐insensitive, putative peptide, surface epitopes. Anti‐SAg/PEP antibodies failed to recognise the surface of newly transformed schistosomula unless the parasite was first treated with sodium periodate, suggesting that these epitopes may be masked by periodate sensitive (i.e., carbohydrate) epitopes. There was an increase in anti‐SAg/PEP antibody binding to the larval surface with age of the parasite in vitro; five‐day‐old lung schistosomula were also recognised by anti‐SAg/PEP antisera. In contrast, anti‐SAg/CHO antibody binding declined with parasite age, and failed totally to recognise lung schistosomula. This change in epitope expression was reflected in eosinophil‐dependent cytotoxicity assays, with anti‐SAg/CHO antisera killing young larvae and anti‐SAg/PEP antisera only killing older larvae. Lung worms were not killed by either antisera. The difference in epitopes recognised by the antisera was also reflected in the antigens identified by immun

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00460.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryIn Spain, considerable efforts are currently being devoted to the eradication ofOrnithodoros erraticusfrom the swine farms harbouring this parasite, the European vector of African swine fever (ASF). However, to do so, a preliminary requirement is to determine on which farms it is present. Of all possible methods for discovering this, the only one feasible for large scale application is the serological detection of swine bearing anti‐O. erraticusantibodies. To apply serology it was necessary to check the specificity of extracts from the salivary glands (SGE) fromO. erraticus. For this, indirect ELISA, competitive ELISA and Western blot were used to assay the SGE fromO. erraticusand their corresponding antisera against the SGE and respective antisera from 4 ixodidae, one mange mite, one louse and a mosquito. The results obtained show that only the anti‐ixodidae sera are able to react against the SGE fromO. erraticus. The cause of this reaction are the somatic antigens present in the SGE of the argasid but not its soluble (secretory) antigens. It is proposed that the anti‐cement antibodies present in the anti‐ixodidae sera are those that react with the somatic antigens ofO. er

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00461.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryMice infected withTrichinella spiralisdeveloped significant enteropathy, comprising villus atrophy, crypt hyperplasia, goblet cell hyperplasia and a decrease in intra‐epithelial lymphocyte numbers by 10 days post‐infection, when most of the parasites had been expelled from the gut. However, worm expulsion was prevented by treatment with cyclosporin A and, despite a continued parasite burden, cyclosporin A treated animals had no villus atrophy or changes in inflammatory cell numbers. These results confirm that the expulsion ofT. spiralisfrom the mouse gut is accompanied by a significant intestinal lesion and that both of these phenomena are T‐cell med

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00462.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryAn investigation was made of the antigenic composition of oocyst isolates of Cryptosporidium parvum by immunoblotting using rabbit polyclonal or murine monoclonal antibodies (MoAbs) developed against this parasite. Using the polyclonal antibodies in blots, a common antigenic profile was obtained from a number of human oocyst isolates from AIDS patients and immunocompetent children in the UK and Portugal. Antigenic differences were observed, however, between a human isolate from Turkey and these other human isolates. The antigenic profilies of oocyst isolates from deer and cattle were similar, but the profiles of the animal and human isolates differed to some extent. Two MoAbs which, in immunofluorescence microscopy, reacted with the surface of theC. parvumsporozoite were also used in blots. A major antigen(s) from 9 of 11 human oocyst isolates recognized by these MoAbs had a molecular weight of 47 kD, but the sizes of the corresponding antigens of the remaining 2 human isolates, one from Turkey (same as above) and one from the UK, were 45–5 and 51 kD, respectively. The equivalent antigen(s) from 4 bovine and 4 ovine isolates was 48 kD. One of the MoAbs failed to react in blots with 2 of the isolates, 1 human and 1 bovin

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00463.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY

摘要:

SummaryA comparative study of lectin binding to ensheathed (EnL3) and exsheathed (ExL3) L3larvae ofNecator americanus, Ancylostoma duodenaleandAncylostoma ceylanicumrevealed a number of differences between these hookworm species. These differences could provide a novel approach to distinguish infective L3larvae in field conditions. For example, binding ofUlex europaeusagglutinin (UEA) andRicinus communisagglutinin (RCA/20) toN. americanusEnL3distinguished them from those ofA. duodenaleandA. ceylanicum. Furthermore, UEA and RCA/20negative EnL3could be separated into the twoAncylostomasps. tested, asDolichos biflorusagglutinin and Soybean agglutinin bound to EnL3ofA. ceylanicumbut not to those ofA. duodenale.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1992.tb00464.x

出版商:Blackwell Publishing Ltd    

年代:1992

数据来源: WILEY