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1.
An effect of replication of certain viruses in murine monocytic macrophages was manifested by depletion of cells through degenerative and necrotizing changes in thymus-dependent areas of lymphoid structures. In mice infected with murine hepatitis virus (MHV-3) or lactate dehydrogenase virus, these changes were transient in mice killed on postinoculation day (PID) 2. To study these morphologic changes due to viral replication, adult Swiss specific-pathogen-free homozygous nude mice (nu/nu) and their heterozygous haired littermates (nu/+) were inoculated with 10(5) LD50 of MHV-3, euthanatized, and necropsied on PID 1, 2, 4, 6, 8, and 10 along with noninoculated controls. The nu/+ and nu/nu mice killed on PID 2 had lymphocytic karyorrhexis and depletion of cells in the thymus-dependent area. In the heterozygote, these characteristic lesions were transient; whereas in the homozygote, lesions persisted and were present in survivors euthanatized and necropsied on PID 16. Although the intensity of lesions due to MHV-3 varied between nu/+ and nu/nu mice, virus titers determined on liver homogenates were similar for the homozygote and heterozygote during acute disease. Nude and nonnude mice given lactate dehydrogenase virus and killed on PID 2 had a transient depletion of lymphocytes; whereas mice given lymphocytic choriomeningitis virus and killed on PID 4 had a similar lesion. Lesions neither occurred when mice were treated with silica before inoculation, indicating that functional monocytic macrophages were required, nor occurred when another virus, herpes simplex virus type 1, was given.  相似文献   

2.
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   

3.
Theileria parva-infected bovine lymphoid cells, grown in culture, were inoculated by different routes into neonatal and adult Swiss mice immunosuppressed by irradiation, thymectomy or inoculation of anti-lymphocyte serum. Tumour-like masses, composed of parasitized bovine lymphoid cells, formed at the site of subcutaneous inoculation in immunosuppressed neonatal and adult mice, but consistent establishment of cells following intra-peritoneal inoculation occurred only in neonatal mice. In all cases the degree of cellular establishment was proportional to the degree of immunosuppression. The best “take” was in irradiated neonatally thymectomized mice.Cells underwent short-term multiplication in mice but, as immune competence returned, the cells were rejected. There was no evidence that cells, on passage, became more adapted to grow in mice, nor that mouse cells became parasitized.Culture-derived cells were also inoculated subcutaneously into irradiated and non-irradiated nu/nu, nu/+ and Swiss mice. Tumour-like masses, composed of parasitized bovine lymphoid cells, developed at the site of inoculation in all irradiated mice. In nu/+ and Swiss mice these masses regressed after 2–3 weeks, but in the athymic nu/nu mice there was generally no rejection or cellular degeneration and parasitized cells became widely disseminated in the host's tissues and organs, in some cases causing death.T. parva-infected cells could not be established in non-irradiated nu/nu mice, nor when irradiated nu/nu mice were inoculated by the intra-peritoneal route. “Take” in irradiated neonatal nu/nu mice was also poor.Cells were passaged three times in irradiated nu/nu mice inoculated subcutaneously and it seems probable that indefinite passage of T. parva in mice can now be achieved.  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.
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   

6.
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   

7.
The enhancing effect of cross-linked ricin (CL-ricin) on the cell-mediated and humoral immune response of mice to non-viable Mycoplasma pulmonis was studied. The cell-mediated immune response was evaluated by means of the delayed-type footpad swelling, and the humoral immune response by means of the indirect hemagglutination test. Mice pre-treated subcutaneously with non-viable M. pulmonis and CL-ricin showed significantly increased delayed-type footpad swelling when they were injected in the footpad with the same antigen 7 days later. Delayed-type footpad swelling was not detected in mice pre-treated only with non-viable M. pulmonis or CL-ricin followed by footpad injection with non-viable M. pulmonis. Injection of non-viable M. pulmonis in the footpad on Days 3, 7, 14, 21, 28, 35 and 42 after pre-treatment with non-viable M. pulmonis and CL-ricin resulted in significant footpad swelling. Delayed-type footpad swelling was transferred by intravenous injection of spleen cells from mice which had been pre-treated 7 days previously with non-viable M. pulmonis and CL-ricin into non-treated recipient mice. Intravenous injection of anti-mouse thymus cell serum into mice previously pre-treated with non-viable M. pulmonis and CL-ricin reduced the delayed-type footpad swelling significantly. Mice pre-treated subcutaneously with non-viable M. pulmonis and CL-ricin showed a marked increase in serum antibody titers compared with those that received non-viable M. pulmonis alone.  相似文献   

8.
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   

9.
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   

10.
To investigate the pathogenesis of respiratory lesions caused by the facultative intracellular pathogen, Rhodococcus equi, pulmonary clearance was compared in four groups of genetically defined mice, chosen for their specific deficits in immune and inflammatory responses. Complement-deficient A/J, immunodeficient nu/nu (nude), scid/scid.bg/bg (SCID/beige), C57BI/6J.bg/bg (beige) and normal Swiss mice (SW) received approximately 10(7) R. equi intranasally on day 0. Bacterial clearance was assessed in lung, liver and spleen on days 1, 4, 7 and 14. Pulmonary clearance was not significantly different between SW and A/J mice. Beige mice cleared R. equi more rapidly and completely than A/J and SW, indicating that deficits in phagocytic and NK cell function associated with the bg/bg gene did not compromise clearance. Pulmonary clearance in immunodeficient SCID/beige mice paralleled that of the SW and A/J mice initially but bacterial proliferation produced significant differences from SW mice at day 14. Nude mice were unable to clear R. equi from day 1, resulting in the death of two nude mice at day 11. Both SCID/beige and nude mice developed severe pyogranulomatous bronchopneumonia, whereas A/J and SW mice developed transient pulmonary lesions. Beige mice developed minimal lung lesions. Significant systemic bacterial proliferation occurred only in nude and SCID/beige mice. We conclude that deficiencies in complement components, phagocytic and NK cells do not impair the pulmonary clearance of R. equi but that a competent cellular immune system is required to prevent pneumonia and death. The difference in early phase pulmonary clearance in nude and SCID/beige mice indicates two phases are important for clearance. An acapsular mutant of R. equi was completely cleared from the lungs of SCID/beige mice suggesting an important role for the capsule in virulence for mice.  相似文献   

11.
In serum, tracheal wash fluid, and bile from chickens that were inoculated with live or inactivated Newcastle disease virus (NDV), the kinetics and immunoglobulin (Ig) class distribution of an antibody response were demonstrated. The Ig classes (IgM, IgG, and IgA) were captured using monoclonal antibodies (MAbs) in enzyme-linked immunosorbent assays (Ig-capture ELISA). The antibody specificity of the captured Ig was confirmed by binding of NDV. After inoculation with live virus, antibodies of the IgG and IgM classes were mainly found in serum. IgM was produced early from day 4 postexposure (PE) onward, IgG was detected later from day 7 PE onward, and in the tracheal wash fluid and bile, all three Ig classes were demonstrated. After inoculation of inactivated virus, a delayed response of all three classes was observed in serum, and only IgM and IgG were recognized in the tracheal fluid and bile. The type of vaccine and the mute of antigen entrance may have determined the immunoglobulin class produced. The Ig-capture ELISA assay developed in this study can be useful for evaluating various strategies to improve the efficacy of Newcastle disease vaccines and to study the evoked immune mechanisms.  相似文献   

12.
The adverse effects from using currently available drugs for the treatment of leishmaniasis have motivated the search for new therapeutical agents. The aim of this work was to evaluate the effect of imidocarb and levamisole on the treatment of BALB/c mice experimentally infected by Leishmania (Leishmania) amazonensis. BALB/c mice were infected with 10(6) promastigotes of L. (L.) amazonensis (IFLA/BR/67/PH8) and, starting on day 51, mice were treated subcutaneously with imidocarb (IMD, 34 mg/kg), imidocarb plus levamisole (IMD+LVS, 34 and 12 mg/kg, respectively), only levamisole (LVS, 12 mg/kg) or without treatment (control). Lesion size and swelling were weekly monitored for 10 weeks after the beginning of the treatment. On day 121 post-infection, serum levels of specific IgG from infected mice were evaluated, as well as histopathological and morphometric alterations in the footpad, lymph nodes and spleen of these animals. The data obtained in this study demonstrated that, when compared to controls, mice treated with IMD had lower levels of IgG anti-L. (L.) amazonensis (34.45%), smaller vacuolar area in macrophages (3.75%), lower number of megakaryocytes in spleen (63.19%) and lower parasite burden in the footpad (30.2%). Thus, the evaluated parameters suggest the use of imidocarb as a potential drug in the treatment of tegumentary leishmaniasis.  相似文献   

13.
Nu/nu, nu/+, splenectomised nu/nu and Lasat mice were inoculated with freshly collected bovine blood infected with Babesia divergens and B major. There was no evidence that either parasite became established in mice but B divergens persisted in mice up to 10 days whereas B major lasted only one day. B divergens infection generally persisted longer in splenectomised mice but absence of thymus made no apparent difference to persistence of infection. B divergens underwent morphological changes in mice to vacuolated and ring forms.  相似文献   

14.
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   

15.
Infection of canine footpads with canine distemper virus (CDV) can result in so-called hard pad disease characterized by footpad epidermal proliferation and hyperkeratosis. Cultured canine footpad keratinocytes (CFK) were inoculated with a virulent canine distemper virus strain (A75/17-CDV) to study the effects of CDV-infection on keratinocyte proliferation. Infection was analyzed by immunohistochemistry and in situ hybridization for CDV nucleoprotein (N-protein) antigen and mRNA. CDV caused a persistent, non-cytocidal infection with spread from single cells to infection of the confluent cell layer 7 days post infection (p.i.). Absolute cell numbers were significantly higher in infected cultures compared to control cultures from day 4 until day 6 p.i. Infected cultures contained significantly more total DNA on day 5 p.i. compared to controls. Immunohistochemical investigation of proliferation markers Ki67 and BrdU demonstrated a nearly two-fold increase in numbers of positive cells on day 5 p.i. compared to controls. These findings demonstrate that canine distemper virus infection of canine footpad keratinocytes in vitro was associated with proliferation.  相似文献   

16.
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   

17.
A Silim  J Thorsen 《Avian diseases》1981,25(2):444-453
Turkeys poults were inoculated intraperitoneally with hemorrhagic enteritis virus (HEV) at 4-1/2 weeks of age. Antibody response and sequential development of viral antigen in various tissues were monitored. An enzyme-linked immunosorbent assay (ELISA) was developed to study antibody production, and immunoperoxidase staining was used to determined sites of localization of the viral antigens in tissues. Results of ELISA and immunodiffusion tests were compared. ELISA detected antibody from day 3 post-infection (p.i.), and gel diffusion detected antibody from day 5 p.i. Peak ELISA antibody titer appeared from day 14 p.i. HEV antigen was detected from 2-6 days p.i. in the spleen, liver, intestine, kidney, and bone marrow; peak titers in the spleen were on day 3 p.i. Virus was not detected after day 6 p.i.  相似文献   

18.
旋毛虫感染小鼠对p46 000重组抗原的抗体应答   总被引：1，自引：0，他引：1  
分别以旋毛虫肌幼虫ES抗原和p46000重组蛋白作为抗原，对小鼠人工感染旋毛虫后的抗体应答进行了ELISA检测。结果表明，以肌幼虫200条／只经口感染小鼠后，肌幼虫ES抗原在感染后9d可检出抗体，并于感染后35～42d达到最高水平；应用重组抗原检测时，感染后10d可检出抗体，抗体水平略低于用ES抗原，但是其消长规律基本一致．而且与阴性血清相比差异明显；抗体在117d后仍维持于较高水平。  相似文献   

19.
Zinc (Zn) is an essential trace element for DNA synthesis and for cell growth and differentiation. The deficiency induces a wide range of disorders including immunodeficiency. In this study, the influence of Zn deficiency to the mice infected with Babesia microti was examined, and was compared with the influence in the rats infected with B. rodhaini previously reported. Experiments of B. microti infection were conducted using Zn-deficient (ZD; allowed to eat ad libitum on the ZD diet), Zn-adequate (ZA; allowed to eat ad libitum on the ZA diet), and diet-restricted (DR; supplied 2 g/day on the ZA diet) mice. It was suggested that the Zn deficiency exacerbated the infection dynamics of the mice with B. microti by the growth retardation, the reduction of immunity and the decrease in PCV. The results in the mice supported the consequences in the rats previously reported.  相似文献   

20.
A murine model was used to study the mechanisms involved in the prolonged immune response to live and inactivated foot-and-mouth disease virus (FMDV). The antibody response elicited by the infection persisted throughout the entire life of the animal, while immunization with inactivated virus induced a transient response. The administration of inactivated virus in a water-in-oil emulsion increased antibody titres to values as high as those obtained by infection. There was a high correlation between neutralizing antibody titre and transfer of immunity with primed cells, and the protection afforded against challenge with infectious virus. It appears that the mechanism involved in the induction of prolonged immune memory in infected animals is not due to viral persistence. Nude mice infected with FMDV also evidenced a prolonged immune response, showing marked differences in antibody levels but equal effectiveness against challenge when nu/nu and nu/+ animals were compared. Furthermore, athymic and euthymic littermates were efficient in conferring protection when cells were transferred to irradiated animals. It is concluded that there is an effective, T-cell-independent, prolonged immune memory against FMDV in this murine model, and that the difference in the immune responses to live and inactivated virus is due mainly to differential antigenic processing rather than to a difference in the degree of sensitization of effector cells.  相似文献   

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