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1.
A model system capable of investigating immunological changes was first established in Babesia rodhaini infected mice with an aid of a drug, diminazene diaceturate (DD). Intraperitoneal (ip) inoculation with B. rodhaini resulted in acute death in euthymic (nu/+) and athymic (nu/nu) BALB/c mice. Treatment with DD at an early stage of infection saved both mice from acute death. Parasitemia recurred in some of them but resulted in death only in nu/nu mice. A re-challenge with 10(5) parasitized erythrocytes (PE) on the surviving mice on day 28 post infection revealed resistance in nu/+ but not in nu/nu mice. The results suggested a participation of the thymus in the protective mechanisms. Immunological changes were then observed on nu/+ and nu/nu mice which were inoculated ip with 10(4)PE and treated with the drug, and then challenged with 10(5)PE ip on day 28. An antibody response was measured with immediate reaction by footpad injection of a soluble antigen of B. rodhaini and by ELISA of serum antibody using the antigen and protein A, on day 10 and later, and further a pronounced response was detected after re-challenge in nu/+ mice. No response was detected by ELISA in nu/nu mice. Delayed footpad reaction was seen in nu/+ mice by day 14 and later but it was suppressed after the re-challenge.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

2.
The surface proteins of Babesia rodhaini have previously been shown to induce a high degree of protective immunity. In the present study, one of those proteins, B. rodhaini antigen p26 was expressed in Escherichia coli and in insect cells infected with a recombinant baculovirus. These proteins were recognized by immune serum from a drug-cured BALB/c mouse. While BALB/c mice immunized with both recombinant antigens and Freund's adjuvants showed 40-100% survival rate against challenge infection with B. rodhaini, saponin failed to induce protection, although significant levels of B. rodhaini-specific antibodies were produced in both immunized mice (1:1,000-2,000 by indirect immunofluorescent antibody test). The immunization of IFN-gamma-deficient mice with the recombinant proteins was not protective against B. rodhaini infection, indicating that IFN-gamma is one of the important factors for the survival against lethal B. rodhaini infection.  相似文献   

3.
The rodent babesia, Babesia rodhaini, survived equally well in basal medium containing either 10 per cent rat serum or 10 per cent bovine serum. As a result, a B rodhaini mouse assay is now performed routinely to determine the suitability of batches of bovine serum for use in a commercial Babesia bovis vaccine issued in Australia. Heat inactivation of bovine serum at 56 degrees C for two hours did not affect the survival of either B bovis or B rodhaini.  相似文献   

4.
Changes of splenic lymphocyte subpopulation after Babesia microti and Babesia rodhaini inoculation in mice were examined by flow cytometric analysis. The B. microti inoculated mice showed a longer period of time from inoculation to the onset of increase or decrease parasitaemia (%), packed cell volume, total spleen cell numbers and surface immunoglobulin positive splenic cell numbers than respective periods in B. rodhaini inoculated mice. The Thy-1 positive cell numbers in B. microti inoculated mice and B. rodhaini inoculated mice pre-immunized with homologous parasites were significantly higher than that of B. rodhaini inoculated mice. The ratio of L3T4 positive cell/Lyt-2 positive cell after inoculation with B. microti was quite similar to that in B. rodhaini mice pre-immunized. However, the ratio in B. rodhaini inoculated mice revealed a lack of an increasing phase. These results suggested that the T-cell dependent early immune response, especially suppressor activity, was closely related to the difference in the course of infection between the non-lethal B. microti and the lethal B. rodhaini infection in mice.  相似文献   

5.
In order to identify the alternative effective chemotherapeutic agents for murine babesiosis, some selected drugs were examined for their efficacy against protozoan infection in the mouse-Babesia rodhaini (B. rodhaini) model. Clindamycin was not completely effective for elimination of parasites in a dose of 50 mg or 100 mg/kg BW/day b.i.d. but effective to prolong the life span of hosts, while it completely cured B. rodhaini infections in a dose of 200 mg. On the other hand, a double therapy consisting of 2 treatments with 100 mg clindamycin and 100 mg clindamycin and with 100 mg clindamycin and 100 mg tetracycline; respectively, and a single therapy with 100 mg tetracycline or 200 mg clindamycin, had a possibility to clear away B. rodhaini organisms from hosts. However, almost all the treatment groups, had a relapse of the infection within 10 days post treatment or re-treatment. Cured mice by treatment with clindamycin and clindamycin, or clindamycin and tetracycline showed complete resistance against challenge with B. rodhaini, while mice cured by administration of clindamycin at 200 mg or tetracycline at 100 mg showed incomplete resistance to challenge infection. The present data suggest that the two former chemotherapies can induce effective protective immunity (premunization), but the latter two chemotherapies induce incomplete premunization.  相似文献   

6.
From sera of highly parasitised mice and dogs with Babesia rodhaini, B. galagolata and B. canis ectoantigens were isolated by column-chromatography and tested in the ELISA for their serological properties. Hyperimmunsera against the three Babesia species were prepared in rabbits, mice and dogs. Serologic cross-reactions occurred between the investigated Babesia species although distinct titer differences could be observed between B. canis on one hand and B. rodhaini and B. galagolata on the other hand. The ELISA appears to be suitable for serological field surveys of babesiosis.  相似文献   

7.
BALB/c mice, immunized against Babesia rodhaini by an amicarbalide controlled infection, were exposed to selective immunosuppressive treatment with corticosteroids and anti-thymocyte serum (ATS) respectively. Hydrocortisone acetate, 100 mg/kg, given i.p. six times during the three weeks after challenge inoculation caused a rising parasitaemia and high mortality (6/7). Dexamethasone in the drinking water at 20 mg/l or 10 mg/l for 22 days had a similar suppressive effect on the protection against B. rodhaini. Mortality, 100% at the dose rate of 20 mg/l and 50% at 10 mg/l, occurred both in challenged and in carrier animals after the reappearance of parasites in the bloodstream. All the ATS-treated immune mice demonstrated parasitaemia after challenge, although at a lower level than did the corticosteroid treated mice. Seven out of 9 animals died. Corticosteroid-sensitive macrophages together with T-lymphocytes are considered to play an important role in protection against B. rodhaini in specifically induced immunity in mice.  相似文献   

8.
Babesia bigemina and Babesia bovis are intra-erythrocytic protozoan parasites transmitted by ticks to cattle in which they induce babesiosis, a disease that resembles human malaria. Anemia, caused by the destruction of non-infected erythrocytes, is a critical feature of the disease. Anti-erythrocyte antibodies could be one of the explanations for such destruction. These antibodies are found in the sera of dogs and mice respectively infected with B. gibsoni and B. rodhaini. However, data concerning the presence of anti-erythrocyte antibodies in the sera of infected cattle are not conclusive. In the present study, we made an attempt to detect anti-erythrocyte antibodies from the sera of cattle naturally infected with B. bigemina. Erythrocytes from a non-infected calf were used in ELISA reaction for the detection of antibodies from samples. Results confirmed the presence of anti-erythrocytes antibodies in higher amounts in the serum of infected cattle. In order to correlate this increment with the parasite, anti-erythrocyte antibodies from the sera from infected calves were purified, coupled to a Sepharose-4B column and than used for anti-idiotypic antibodies purification. These antibodies were found to react with the parasites, suggesting a correlation between both anti-parasite and anti-erythrocyte antibodies.  相似文献   

9.
Li C  Wei X  Xu L  Li X 《Veterinary parasitology》2007,144(3-4):299-303
Recombinant galectins of female and male adult worms of Haemonchus contortus were expressed in Escherichia coli and their hemagglutinating activities to human and different animal erythrocytes were analyzed. The results showed that female and male galectins could be highly expressed in E. coli using a temperature-sensitive plasmid, with the recombinant protein being mainly appeared in inclusion bodies. Hemagglutinating activity assays showed that both of the galectins hemagglutinated human A, B, O type, dog, rabbit, chicken and mouse erythrocytes at the high concentration of 40 microg/well, but did not hemagglutinate erythrocytes of the natural host of H. contortus, the goat. Sugar inhibition assays confirmed that, out of eight sugars tested, only lactose was effective to inhibit agglutination of human type B erythrocytes by the recombinant galectins.  相似文献   

10.
Immunisation of Balb/c mice against Babesia rodhaini by an amicarbalide-controlled infection resulted in a solid immunity which lasted for 216 days. With spleen cells of immune mice protection could be transferred both to naive mice pretreated with cyclophosphamide. Treatment of naive mice with cyclophosphamide (300 mg/kg) five days before a lethal B. rodhaini inoculation resulted in over 50% survival. This protective effect of cyclophosphamide is explained by its inhibiting effect on suppressor T-cells. The protection against B. rodhaini challenge infection afforded to immune Balb/c mice was completely resistant to a sublethal irradiation of 400 rad. Since B-lymphocyte function in antibody production is suppressed by this dose, the role of antibodies in the effector phase of the immunity appears to be of minor if any importance. A considerable degree of protection was still preserved after irradiation of immune animals with 875 rad. Sensitivity to this irradiation dose of all immunocompetent cells except macrophages and a small fraction of T-lymphocytes indicates the involvement of these cell types in the effector phase of the specific immunity. Highly radioresistant macrophages are therefore considered to play the major role but T-lymphocytes are also required for complete protection.  相似文献   

11.
The glucose uptake activity in Babesia rodhaini and B. microti - infected red blood cell (IRBC) was investigated in mice using 2-deoxy-D-glucose (2DOG) and L-glucose (L-Glc), a non-metabolizable analogue of D-glucose and non-incorporative glucose to non-infected RBC (NRBC), respectively. The uptake activities of both DOG and L-Glc were higher in IRBCs than those in NRBC. The concentration dependent uptake of 2DOG and L-Glc in both IRBC revealed a linear curve, indicating non-transporter mediated uptake. In addition, B. microti IRBC showed higher 2DOG uptake than B. rodhaini IRBC, whereas no difference was observed in L-Glc uptake. These results indicated that some new glucose uptake system, at least two systems, developed in both IRBC. The new systems were sodium independent, non-competitive to L-Glc, and sensitive to temperature. One of two systems had no kinetical difference between B. rodhaini and B. microti IRBC, however another one might have higher uptake activity in B. microti IRBC compared to that in B. rodhaini IRBC.  相似文献   

12.
A series of experiments were undertaken to determine the most effective route of immunization with a mixture of killed Babesia rodhaini antigen (S antigen) and formalin-fixed Corynebacterium parvum (Propionibacterium acnes) bacterin (CPB) against challenge infection with B. rodhaini 3 weeks later. The mice pretreated with S antigen and CPB mixture intraperitoneally, but not intramuscularly, were significantly resistant to intraperitoneal (IP) or intravenous (IV) challenge with 10(6) organisms. The survival rates were 70.0 (IP challenge) and 60.0% (IV challenge) respectively. Fairly protective activities were equally produced in mice intravenously pretreated with S antigen and CPB with survival rates of 60.0% against IV challenge, but 30% against IP. These results indicated that the IP injection of S antigen and CPB mixture is desirable route for immunization against subsequent IP or IV challenge with B. rodhaini. On the other hand, lower protective effect was reconfirmed in the mice treated with S antigen and Freund's Complete adjuvant, regardless of immunization routes in the additional experiment. The survival rates were 33.3, 14.3 and 11.8% in the intraperitoneally, intramuscularly and subcutaneously-treated mice respectively against IP challenge with 10(6) organisms.  相似文献   

13.
The aggregation capacity of human erythrocytes lies between that of the non-aggregating bovine erythrocytes and the remarkably aggregating equine ones. As the ability to aggregate is attributed to cell factors and the composition of the plasma proteins, the role that plasma proteins play in the aggregation process in these three species was studied. Washed erythrocytes were suspended in phosphate-buffered saline (PBS; pH 7.4, 300 mOsm/L) plus polyvinylpyrrolidone (PVP) in a suitable concentration to obtain an average intensity of aggregation (control media). The superimposed effect of replacing 80% of the medium by either autologous plasma, serum or albumin solution was studied. The plasma proteins appeared to enhance aggregation by human and equine erythrocytes, but impaired this process in bovine erythrocytes. Some evidence was obtained supporting the existence of serum factors capable of reducing aggregation of erythrocytes in cattle and it was concluded that the non-aggregating behaviour of bovine erythrocytes may be due to the cells interacting particularly with the macromolecules in the serum.  相似文献   

14.
Babesia divergens was cultivated in sheep erythrocytes in RPMI 1640 supplemented with 10% Fetal Calf Serum (FCS) or sheep serum. In vitro cultures in sheep red blood cells were initiated with human erythrocytes infected in vitro with B. divergens Rouen 1987 or with gerbil blood infected with several isolates from bovine origin. After the first subcultures on sheep erythrocytes, a ten-fold multiplication of the parasites was obtained within 48 h. Erythrocytes from three splenectomized sheep were infected in vitro with B. divergens; when parasitaemia reached 10%, the animals were inoculated with homologous parasitized erythrocytes. All sheep expressed hyperthermia with a peak between the 6th and the 9th day post-infection (p-i) and a transitory parasitaemia 10 days p-i. In vitro primary cultures were performed on two of these sheep, demonstrating the parasite persistence at very low parasitaemia in the infected animals. Splenectomized sheep can be used as a new model for B. divergens chronic infection.  相似文献   

15.
Bartonella vinsonii subsp. berkhoffii is a recognized cause of endocarditis in dogs and human patients and has been associated with cardiac arrhythmias, myocarditis, granulomatous lymphadenitis, polyarthritis, and granulomatous rhinitis in dogs. Little is known regarding the mode of transmission or cellular localization of this bacteria following infection of a canine host. The aim of the current study was to determine whether erythrocytes may serve as a site of infection by B. vinsonii subsp. berkhoffii. In the study, we successfully demonstrate the invasion of canine erythrocytes by a B. vinsonii subsp. berkhoffii genotype III strain using an in vitro model system. Dog erythrocytes were incubated with B. vinsonii subsp. berkhoffii after which tubes were treated with gentamicin at 12, 24, and 48 h post-inoculation. After gentamicin elimination of extracellular bacteria, there was a gradual increase in intra-erythrocytic bacteria, as assessed by colony forming units per ml, at each collection time point. The largest recovery of intracellular bacteria occurred at 48 h post-infection. These results suggest that canine erythrocytes may serve in the maintenance of bacteremia due to B. vinsonii subsp. berkhoffii within an infected host.  相似文献   

16.
The heat shock protein 70 (hsp70) genes of Babesia gibsoni, B. canis canis, B. canis vogeli, and B. canis rossi isolated from infected dogs were cloned by polymerase chain reaction (PCR) and sequenced. In the nucleotide sequence and the predicted amino acid sequence of the gene, the parasites were very similar to each other. The nucleotide sequences of the hsp70 gene had more variety than those of 18S nuclear subunit ribosomal DNA (18S rDNA). A phylogenetic analysis of these sequences and comparisons with sequences from other Babesia and Theileria species revealed that all canine babesial isolates analyzed in the present study were closely related to each other and formed one cluster. Additionally, a phylogenetic analysis of Babesia and Theileria species showed that these parasites could be divided into three groups: group A including canine babesial isolates, B. divergens, B. odocoilei, B. bovis, B. caballi, and B. ovis; group B including Theileria annulata, T. orientalis, and T. cervi; and group C including B. microti and B. rodhaini. These results suggested that a phylogenetic analysis of the hsp70 gene sequence might be helpful in classifying Babesia and Theileria species, and that canine babesial isolates might be closely related to each other, indicating their evolution from the same ancestry.  相似文献   

17.
Recent in vitro-based studies using several Babesia spp. have suggested that sialic acids and/or sialoglycoproteins on host red blood cells (RBCs) play an important role in their invasion of RBCs. In the present study, we analyzed the RBC characteristics of glycophorin A (GPA)-knockout mice and studied their in vivo susceptibility to lethal infection of Babesia rodhaini for the first time. In immunoblot and lectin blot analyses, glycoproteins containing O-linked oligosaccharides terminated with alpha2-3-linked sialic acids disappeared from the RBCs of GPA homozygous ((-/-)) mice. Flow cytometric analysis showed a remarkable reduction of Maackia amurensis lectin II binding to the surface of GPA(-/-) RBCs relative to control RBCs, indicating an appreciable loss of alpha2-3-linked sialic acids on the RBC surface of GPA(-/-) mice. Importantly, while B. rodhaini caused lethal infection in wild-type mice, the infected GPA(-/-) mice showed inhibition of parasite growth and eventually survived. These results indicate that RBC sialoglycoproteins lost in GPA(-/-) mice are involved in the in vivo growth of B. rodhaini, probably functioning as essential molecule(s) for the parasite invasion of host RBCs in the blood circulation.  相似文献   

18.
Susceptibility of sheep erythrocytes to Babesia divergens was investigated in vitro and a high inter-individual variability in their ability to support parasite population development was demonstrated, with some individuals having refractory red blood cells (RBC). As neither changes in growth conditions nor the use of different B. divergens strains influenced the level of susceptibility, the main factor postulated for this variability is the erythrocyte itself. Sheep therefore represent an excellent in vitro model to study the parasite-erythrocyte interaction. In addition, the existence of refractory RBC should help in the identification of the erythrocyte components required for B. divergens development. Experimental infections were carried out on spleen-intact sheep characterized by refractory or fully susceptible erythrocyte types. These differences translated into the successful infection of only those animals with susceptible erythrocytes: infected animals showed no clinical signs, but maintained an asymptomatic persistent infection, as usually observed in the natural bovine host. Sheep therefore represent model organisms that can allow us to study interactions between B. divergens and its vertebrate host at different levels of biological organisation, from the target cell to the intact animal, and represent an experimental infection model of concomitant immunity. Only a low percentage (13%) of the sheep population tested possessed susceptible erythrocytes and the potential role of sheep as a natural host or reservoir of B. divergens is discussed.  相似文献   

19.
The virus was grown in BEK-1 cells, a stable cell line from bovine embryo kidney, and tested for hemagglutination (HA) with erythrocytes of a variety of species at 4°C, room temperature and 37°C. HA was observed at all temperatures with chicken, mouse, rat, and hamster erythrocytes but not with erthyrocytes of human (O), cattle, horses, sheep, guinea pigs, geese, ducks, pigeons and 1-day-old chicks. Chickens showed an individual variation in agglutinability of their erythrocytes, requiring selection of birds to obtain erythrocytes for HA. HA reaction was inhibited by specific antiserum. Some factors involved in HA and HA inhibition (HI) were investigated and standard HA and HI tests were worked out.  相似文献   

20.
Bovine erythrocytes parasitised with Babesia major were fused with human HeLa cells by means of Sendai virus. B major parasites entered the HeLa cell cytoplasm and in some cases underwent multiplication over a period of three days.  相似文献   

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