摘要:

Groups of five dogs were vaccinated against Babesia canis using soluble parasite (SPA) antigens from in vitro cultures. Although vaccination did not significantly alter peripheral parasitaemia upon challenge, protected animals had lower levels of SPA in the plasma after a challenge infection. The severity of anaemia correlated with the SPA‐load during the post‐challenge period in that high levels of SPA were associated with low haematocrit values. In addition, it was found that recovery was associated with the production of antibodies against SPA. The results suggest that SPA induce anaemia during B. canis infection, and that vaccination with SPA results in antibody production that can neutralize the effects of SPA after a challenge infect

ISSN:0141-9838    

DOI:10.1046/j.1365-3024.1996.d01-1.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Sera from rabbits infected with unattenuated Schistosoma mansoni cercariae conferred significant levels of protection against S. mansoni challenge (P < 0.001) after passive transfer to mice. Infected rabbit sera were only effective in conferring protection when transferred during the first week of infection, and were not effective when administered against liver‐stage worms. Immunoglobulins isolated from the infected rabbit sera with Protein A‐Sepharose were shown to be responsible for the transfer of protection to mice. Immunofluorescence studies demonstrated that the sera were more reactive against the surface of three hour‐old mechanically transformed schistosomula than against the surfaces of lung‐stage schistosomula. The sera from infected rabbits reacted polyspecifically against antigens in cercaria, schistosomula, and the worm and egg stages of the S. mansoni life‐cycle. The host parasite relationship of S. mansoni in the rabbit

ISSN:0141-9838    

DOI:10.1046/j.1365-3024.1996.d01-2.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Some structural, biophysical and molecular features of the tegument are shown, highlighting their changes during maturation as important adaptative mechanisms for the survival of the parasite and resistance to immune attack. On the other hand, many antigens, targets of the immune response against the schistosome, are located on the tegument. Some of the features of these molecules are presented and the possibilities of using them in the immunological control of the disease are discussed.

ISSN:0141-9838    

DOI:10.1046/j.1365-3024.1996.d01-6.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Antibodies toSchistosoma mansonisoluble egg antigens (SEA) generated in outbred rabbits from two different sources were used to study cross‐reactive idiotype/anti‐idiotype (Id/anti‐Id) interactions inS. mansoni‐infected mice in two different locations. Immunoaffinity purified rabbit polyclonal anti‐SEA antibody preparations (RabId) were predominantly Ig by SDS‐PAGE and demonstrated anti‐SEA activity by ELISA and Western blot. RabId prepared from three separate rabbits and used at 40 μg/mlin vitrostimulated lymphocyte proliferative responses of spleen cells from mice with eight week infections (Mean ± SEM [E–C]) of 3869 ± 764,18 594 ± 3046and8962 ± 1734  cpm. Spleen cells from uninfected mice exposed to the same RabId preparationsin vitrohad respective [E–C] values of206 ± 144, 494 ± 154and363 ± 180.Lymph node cells from mice infected for 8 weeks demonstrated [E–C] of123 ± 400, 5073 ± 828and2361 ± 656upon exposure to these 3 RabId preparations. Lymph node cells from uninfected mice had [E–C] of220 ± 76, 194 ± 82and143 ± 72when exposed to these RabId. Maximumin vitroproliferative response to Ig from unimmunized rabbits was761 ± 400by spleen cells from mice with eight week infections. These data indicate the presence of cross‐reactive Id on rabbit anti‐SEA antibodies from different rabbits that can s

ISSN:0141-9838    

DOI:10.1046/j.1365-3024.1996.d01-3.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

A cDNA designated MOv2 was isolated from anOnchocerca volvuluslibrary on the basis of its product's recognition by an antiserum raised against the infective stage. Immunogold electron microscopy revealed a high density of antigenic sites associated with the annulae of the L3 cuticle and with the uterine wall of the adult female: a general, low density of labell ing occurred in all developmental forms. Western blotting confirmed the presence of the antigen throughout the life cycle and the existence of an immunologically cross‐reactive homologue in the related filaria,Acanthocheilonema viteae. The antigen was shown to be secreted by infective larvae and adult females ofA. viteae. Sequence comparisons revealed two homologues of MOv2 (Ov‐20, Ov‐9) which had been selected independently by other laboratories on the basis of their specific recognition by human onchocerciasis infection sera. The IgG antibody response against MOv2 in cattle experimentally infected withO. lienalisrevealed the induction of a response during the prepatent period that was strongly boosted at the onset of patency. However, only a proportion of infected cattle responded with a detectable level of anti‐MOv2 antibodies. The appearance of MOv2 in larval cuticle and secretions prompted us to evaluate it as a candidate molecule for prophylactic immunization. Trials performed in theA. viteae/Mongolian jird model of filariasis revealed that recombinant MOv2 induced a host‐protective response, reducing worm recoveries by 36–55% following a challeng

ISSN:0141-9838    

DOI:10.1046/j.1365-3024.1996.d01-10.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Infection withTrypanosoma cruziis characterized by hyporesponsiveness of the immune system during the acute phase of infection. To better understand the immunological mechanisms affected byT. cruzi, we studied if a reduced T cell proliferative response could originate from an inability of T cells to proliferate or a functional deficiency at the level of accessory cells (AC). The inhibitory effect exerted byT. cruziwas during the induction phase of the lymphoproliferative response, suggesting the participation of AC in the hyporesponse. Then we further investigated the potential of the parasite to interfere with accessory cell‐dependent and ‐independent pathways of human T cell proliferation. Peripheral blood mononuclear cells and peripheral blood lymphocytes from healthy individuals, enriched for T cells, were analysed with regard to their proliferative capacity using: phytohaemagglutinin, immobilized anti‐CD3 monoclonal antibody (MoAb) and MoAb to the CD28 antigen, anti‐CD3 MoAb and recombinant IL‐2 and anti‐CD3 MoAb plus phorbol myristate acetate in the presence of parasites. Significant suppression of the proliferative response was caused by the parasite only when AC were present. The parasite markedly reduced the surface expression of HLA‐DR and CD11b antigens, key molecules in PHA‐induced proliferation. Addition of indomethacin to the culture failed to reverse the inhibitory effect of the parasites, suggesting that prostaglandin E2was not involved. These data suggest that AC in contact withT. cruzibecome incompetent as antigen presenting cell because they are unable to induce a normal proliferative response i

ISSN:0141-9838    

DOI:10.1046/j.1365-3024.1996.d01-5.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY

摘要:

Paramyosin, a 97 kDa myofibrillar protein, is a candidate vaccine antigen for prevention of infection with the human parasiteSchistosoma mansoni. To determine if paramyosin would also induce protection againstSchistosoma japonicum, paramyosin was biochemically purified fromS. japonicumadult worms. SDS‐PAGE demonstrated a single protein with a molecular weight of 97 kDa. In four separate experiments, vaccination of mice withS. japonicumparamyosin without adjuvant induced significant resistance(62%–86%, P < 0.001)against cercarial challenge as compared to controls. These data suggest thatS. japonicumparamyosin may represent a candidate vaccine for immunization against schistosomias

ISSN:0141-9838    

DOI:10.1046/j.1365-3024.1996.d01-4.x

出版商:Blackwell Science Ltd    

年代:1996

数据来源: WILEY