摘要:

SummaryThe protective effect of affinity purified antigen has been investigated in an experimental model for malaria which shows a well marked recrudescence of parasitaemia, a feature of the disease in man. A monoclonal antibody (MoAb) recognizing an epitope common to two genetically distinct cloned lines ofPlasmodium chabaudi(AS and CB). was used to purify a Mr250 000 polymorphic schizont antigen (PSA) from these parasites. The purified preparations were then examined for the presence of specific and cross‐reactive epitopes by immunoprecipilation with a panel of MoAb raised againstP. chabaudiAS. When tested previously on smears of parasitized blood by immunofluorescence, or against lysates of parasitized erythrocytes by immunoprecipitation, most of these MoAb had been found to be AS specific. When either AS or CB affinity purified Mr250 000 PSA was used as the target, these same MoAb immunoprecipitated both antigens, and in some cases, a number of associated polypeptides (AP) which co‐purify with the Mr250 000 PSA. Subsequently, mice were immunized with either the purified AS or CB antigens in Freund's complete adjuvant (FCA). Pre‐challenge sera were compared by indirect immunofluorescence and immunoprecipitation. Sera from mice immunized with AS antigen reacted strongly with AS and cross‐reacted with CB parasite preparations. Pre‐challenge serum from CB antigen immunized mice reacted well with CB, but only faintly with AS preparations. In mice immunized with the AS antigen and then challenged with either AS or CB parasites, the initial parasitaemias were delayed in appearance and the height of the peak parasitaemia reduced, an effect which was most pronounced after challenge with homologous parasites. Only homologous challenge of the mice immunized with CB antigen produced statistically significant modification of the initial parasitaemia. In the immunized mice challenged with homologous parasites, the delayed appearance and slightly reduced peak of the primary parasitaemia was associated with delayed resolution of the patent parasitaemia and significant enhancement of the recr

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1988.tb00199.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryA two‐site ELISA has been designed for the detection of sporozoite antigen in mosquitoes. Biotin‐labelled monoclonal antibodies against sporozoites and a streptavidin‐biotin‐peroxidase complex were used to visualize the antigen.Evaluation of the sensitivity and specificity of the procedure was carried out and background levels of reactivity on the basis of negative mosquitoes were calculated. The test has been deliberately kept as simple as possible for use in the tropics and was designed usingAnopheles stephensiinfected within vitrocultivatedPlasmodium falciparumgametocytes.A minimum of about 100‐350 sporozoites could be detected in mature salivary gland infections; in addition sporozoite antigen was detected in mosquitoes several days before the entry of sporozoites into the salivary glands. No reaction was demonstrable either with bloodstage or ookinete antigens ofP. falciparum, or with mosquitoes carrying sporozoites of other plasmodial species. The number of sporozoites in positive mosquitoes and the generating capacity of a single oocyst could be assessed by the use of a calibration curve based on dilution data of a known sporozoite suspension. It was found that a single oocyst can produce about 10 000 sporozoite eq

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1988.tb00200.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryAntibodies are known to be important in mediating malarial immunity, but the influence of the various immunoglobulin isotypes on parasite elimination is unclear. The purpose of this study was to provide basic information on the induction of isotype expression in genetically different mice during primary malaria. Parasitaemias and the serum antimalarial IgM. Igd1, IgG2, IgG3and IgA antibody titres measured in a radioimmunoassay were followed in outbred and 11 inbred strains of mice infected with 17XNLPlasmodium yoelii.Severity of infection, as judged by length of infection, peak parasitaemias and death, was found to differ between the strains. All strains developed rapid IgM responses, but only 3/11 inbred strains produced significant antimalarial IgG1levels during primary infection. All strains produced an IgG3response, which developed slightly more quickly in strains with the least severe courses of malaria. A large variation in the IgG3response was noted between strains. In general, IgG3antibodies were the first IgG‐isotype to appear in serum. They were detected as early as day 8 in strains that developed mild infections but were not present until around day 20 in strains with the most severe cases of malaria. Only one strain produced detectable antimalarial IgA antibodies. These results show that different patterns of isotype expression are induced in inbred strains of mice during primaryP. yoeliiinfectio

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1988.tb00201.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryZymosan‐activated and non‐activated human polymorphonuclear neutrophils (PMN) were added to in‐vitro cultures of the human malaria parasitePlasmodium falciparumin microtitre wells. Microscopic counting of parasites in Giemsa‐stained smears showed that at a PMN:RBC ratio of 1:150, the same as occurs in human malaria, parasites in wells with zymosan‐activatcd neutrophils were suppressed 65%. Determination of parasite nucleic acid synthesis by3H‐hypoxanthine incorporation showed that in wells with PMN:RBC ratio of 1:150 parasite viability was only 22% of control. Various oxygen scavengers were tested for ability to reverse the effects of activated neutrophils on parasite development. Superoxide dismutase (20 mg/ml) and catalase (50 mg/ml) had no effect; tryptophan protected the parasites to a moderate degree while histidine alleviated suppression of parasite development to the greatest extent. This suggests that singlet oxygen is the most effective neutrophil product in killing or suppressing the growth of parasites. We also observed that non‐activated neutrophils were activated by parasites and/or their products resulting in killing of newly‐rel

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1988.tb00202.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryThe development of a reliable model for the adoptive transfer of immunity to coccidiosis (infection withEimeria vermiformisin NIH mice) is described. More than 108of a mixture of spleen and mesenteric lymph node(MLN) cells, given either intravenously or intraperitoneally, were required to transfer a significant degree of protection. Dividing cells, present in the donors at 10 or 14 days after priming, but not at 5 or 19 days, were shown to be the effectors. When examined separately. MLN cells were found to be superior to spleen cells, and the injection of as few as 5 × 107was capable of substantially reducing the oocyst output from a challenge inoculum. The recipients of cells from primed mice had earlier, and sometimes higher, titres of specific antibodies in the serum but, overall, there was no correlation between these titres and protection. Further characterization of the cells responsible for adoptively transferring immunity to this infection should now be possible

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1988.tb00203.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryPrevious studies have shown that many strains of mice develop partial resistance toSchistosoma mansonias a result of intradermal vaccination with soluble schistosome antigens plus BCG. However, P and BALB/c mice are non‐responsive to this intradermal vaccination protocol. In this study, humoral and cellular responses to schistosome antigens in vaccinated P and BALB/c mice were compared to those in protected C57BL/6 mice to identify an immune correlate to resistance in this model. Levels of circulating IgG and IgM antibodies to soluble adult worm antigens, as measured by ELISA. were comparable between strains. Moreover, Western blot analysis revealed no qualitative differences in antibody reactivity, with sera from vaccinated animals of all three strains recognizing the antigen previously identified as Sm‐97 (paramyosin). However, vaccinated P and BALB/c mice showed specific defects in cell‐mediated immunity to schistosome antigens, including decreased production of macrophage‐activating lymphokines and an inability to produce activated macrophage effector cells in vivo at the site of antigen challenge. These observations strengthen our hypothesis that the intradermal vaccine acts through induction of T‐cell‐mediated immune resistance

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1988.tb00204.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryInfections with the nematodeNematospiroides dubiusfail to elicit mucosal mast cell (MMC) responses in the intestines of host mice, and suppress MMC responses generated by heterologous infection. LarvalN. dubiushave the capacity to prime for mastocytosis, and to elicit this response in primed mice during a challenge, but only if adult worms are prevented from developing, either by anthelmintic treatment or by irradiation of the larvae themselves. The suppressive effect of the adult stage was confirmed in experiments where such worms were implanted directly into the intestines of mice primed by exposure to irradiatedN. dubiuslarvae or concurrently infected withTrichinella spiralis.Data on the mechanisms underlying this suppressive effect were obtained from experiments involving the adoptive transfer of mastocytosis by mesenteric lymph node cells (MLNC) fromT. spiralisinfected mice. When MLNC were taken from mice infected concurrently with bothT. spiralisandN. dubiusno enhanced mastocylosis was seen in recipients after challenge withT. spiralis.Exposure of M LNC fromT. spiralisinfected donors to the presence of adultN. dubiusafter transfer did not reduce the adoptively transferred response. The response was also unaffected when MLNC from adultN. dubiusinfected mice were simultaneously transferred with MLNC fromT. spiralisdonors. It is concluded that the suppressive effect of adultN. dubiusupon the expression of mucosal mastocytosis acts upon the generation of lymphocytes capable of promoting the development of MMC from precursor cells.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1988.tb00205.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

SummaryRat eosinophils or neutrophils were purified from peritoneal washings which had been enriched cither for eosinophils by infection with the parasiteMesocestoides cortior by intravenous injection with Sephadex G200 particles, or for neutrophils by the intraperitoneal injection of glycogen. Neither eosinophils nor neutrophils attached to or damaged liveM. cortiparasitesin vitroalthough they did lyse chick erythrocytes in the presence of rat anti‐chick red blood cell antibody, with the neutrophils showing the highest level of cytotoxicity and the eosinophils from the infected rats the lowest. Neutrophils gave a specific antibody‐dependent cytotoxic response to chick erythrocytes coated with solubilizedM. cortiextract, a response not seen with eosinophils. The cytotoxicity shown by neutrophils could not be blocked by adding eosinophils or sera obtained from chronically infected rats although it was reduced by incubating the neutrophils with cell‐free supernatants obtained from the spleen cells of infected rats following stimulation with solubilized parasite extractin vitro.Eosinophils from infected rats expressed fewer membrane Fc receptors for antibody than did neutrophils or eosinophils from uninfected animals. Incubation of neutrophils and eosinophils from uninfected rats with the immune spleen cell supernatants reduced Fc receptor expression to levels similar to those seen with eosinophils from infected animals. These same supernatants had no effect on the expression of granulocyte complement receptors. It is suggested that infection of rats withM. cortican lead to the production of an antigen‐specific suppression capable of impairing the antibody‐dependent activity of granulocyte

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1988.tb00206.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1988.tb00207.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY