摘要:

SummaryThe effect of immune serum and complement on the in vitro phagocytosis ofBabesia rodhainiwas investigated. Infected erythrocytes and parasites released from erythrocytes by lysis were phagocylosed by mouse peritoneal macrophagesin vitrowhen the infected erythrocytes or parasites were exposed to hyperimmuneB. rodhainiserum. Complement, in the presence of immune serum, did not reproducibly enhance phagocytosis of infected erythrocytes or parasites alone. When adjusted for its effect on normal erythrocytes and normal serum, complement generally inhibited rather than enhanced phagocytosis. When coupled with other published data, our data suggest that the activation of the immune system in vivo against this species ofBabesiainvolves a series of mechanisms of which phagocytosis is but one.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1991.tb00544.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryA member of the glutathione S‐transferase family. Sm28GST has previous! demonstrated a good ability to protect rodents against experimental infection withSchistosoma mansoni.In order lo evaluate its efficacy in a model closer to man, two different protocols of immunization with recombinant Sm28GST were tested on baboons in a large‐scale trial. Three injections in the presence of aluminium hydroxide as adjuvant resulted in a significant 38% reduction in the adult worm burden together with a trend for a lower percentage of inflammatory tissue in the liver. Individual levels of protection, ranging from 0 to 80%, underlined the heterogeneity of the immune response to this purified molecule in outbred primates. On the other hand, two injections of Sm28GST in the presence of aluminium hydroxide andBordetella pertussisreduced female schistosome fecundity by 33%, with a more pronounced effect (66%) on faecal egg output; there was also a trend, in this protocol, for decrease of the mean granuloma surface in the liver. Individual anti‐Sm28GST IgG antibodies were apparently unrelated to levels of immunity, but there was partial evidence that cytophilic IgE might play a role in the immune mechanisms affecting worm viability, but not fecundity. In the mouse model, Sm28GST vaccination resulted in a lower hatching ability of tissue eggs recovered from immunized mice whereas passive transfer of specific anti‐Sm28GST T‐lymphocytes, one day before infection, significantly reduced the number of eggs in the liver of mice. We propose that different protocols of immunization with a recombinant molecule can impedeSchistosoma mansoniworm viability and fecundity, but can also affect

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1991.tb00545.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe humoral immune response to infection withTrichuris trichiurawas investigated by ELISA and immunoblotting using human sera from the Caribbean island of St Lucia. Immunoblot analysis of the degree of cross‐reactivity with the related trichuroidTrichinella spiralisand with the other commonly co‐existent nematodes.Ascaris lumbricoidesandToxocara canis, was carried out using selected sera. The IgM, IgA, IgE, and IgG subclass antibody levels were measured in ELISA using a detergent solubilized extract of adultT. trichiura.The IgG and IgE responses were highlyTrichurisspecific. Anti‐T. trichiuraIgM responses were totally cross‐reactive withA. lumbricoidesand were completely ablated by pre‐incubation of sera withAscarisantigen. The IgG response was predominantly of the IgG1 subclass with a minimal IgG3 response. Only 1 person out of 130 tested had a delectable IgG3 response. The IgG2 response appeared to be directed primarily against carbohydrate or polysaccharide antigens as pre‐treatment of the ELISA plates with poly‐L‐lysine was necessary before a response could be detected. These data are the first demonstration of human isotypic responses to infection w

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1991.tb00546.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryTwo independent vaccination trials using a hybrid synthetic poly pep‐tide containing epitopes from four proteins ofPlasmodium falciparumwere performed. In the first trial 63 and in the second 122 volunteers were vaccinated, using different immunization schedules. The analysis of the humoral response to the vaccine, measured by IgG antibody titres to the polypeptide showed a bimodal distribution in both cases suggesting genetic control of the immune response to this protein. There was a small group of low or non‐responders and a large group of good responders. HLA phenotyping of the two groups disclosed an association of the low responders to HLA‐DR4 antigens with chi‐square P value of 0.00039 when compared with the good responders group. These findings provide evidence for the genetic control of the immune response to the synthetic vaccine by the association of this response with particular alleles of the HLA class II antigens; such findings may lead to an explanation of the mechanism involved in disease susceptibility and need to be used in the design of a totally effective

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1991.tb00547.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryMice can be immunized toPiasmodium vinckeiby repealed infections followed by cure. Such immunity is dependent on CD4 T cells and an architecturally modified spleen, but has little requirement for antibody. Thus, athymic mice can be exposed toP. vinckeiand cured, but do not develop immunity. They are resistant to challenge with parasites, however, if they a re then given spleen cells from euthymic immunized animals. Such immune spleen cells, however, cannot transfer resistance to normal mice which have been exposed toBCG, Salmonella typhimurium, orvacciniavirus, and are only partially effective in transferring resistance to mice which have been previously immunized with heterologousplasmodia, P. yoelii. P. chabaudiandP. berghei.Mice exposed to varying numbers of irradiatedP. vinckei‐pRBC do not develop immunity and nor are such animals protected following adoptive transfer of immune spleen cells. Cellular immunity to malaria may not only be dependent on a population of immune CD4 T cells, but may require a specifically architecturally modified spleen which may not occur following cither exposure lo candidate vaccine vectors, heterologous plasmodia or non‐viable homologous plasmo

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1991.tb00548.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe Marseilles region is an endemic area for visceral mediterranean leishmaniasis, but although the number of dog cases, the parasite's main host, is very high, only a few people develop the disease. We looked for sensitized healthy subjects among 25 healthy individuals living in this area by studying their in vitro lymphoproliferative response toLeishmania infantumantigens and gamma interferon synthesis. We found that 65% of tested subjects were sensitized againstL. infantum.We compared their cell mediated immunity to that of 13 active Kala‐Azar patients and 13 controls from non‐endemic areas. In patients, results showed a specific cellular immuno‐deficiency in the lymphocyte response toL. infantumantigens and a global deficiency of gamma interferon production. Interestingly, the healthy individuals from the endemic area who responded toL. infantumantigens were found to produce high γ interferon levels afterL. infantumantigen stimulation. After healing, the cell mediated‐immunity of the 3 patients we followed up was similar to that of the sensitized tested healthy subjects, but the former were still producing antibodies at the time

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1991.tb00549.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummarySeven mixed‐breed dogs were challenged with either promastigotes or amastigotes ofLeishmania donovani infantumstrains recently isolated from naturally infected dogs. Different routes and numbers of parasites were utilized and each dog was monitored for at least 1 year post‐infection. Anti‐parasite specific antibody levels were measured by enzyme‐linked immunosorbence, immunofluorescence, crossed‐immune electrophoresis and Western blotting on crude antigen. Western blotting on two pure parasite proteins, dp72 and gp70‐2. was also done. Mitogenic and antigen‐specific stimulation of peripheral blood lymphocytes was monitored; and the haematological, clinical and parasitological parameters measured. Dogs challenged with amastigotes exhibited a more pronounced humoral response to leishmanial antigens. Only in one case was strong antigen‐specific proliferation detected. Clinical signs of disease, including hypergammaglobulinaemia, enlarged lymph nodes and the presence of parasites, were also more apparent in the dogs challenged with amastigotes. None of the seven dogs died. Serum antibodies to leishmanial antigens were apparent between 15 to 3 months following challenge and correlated with the appearance of enlarged lymph nodes, hypergammaglobulinaemia and the presence of parasites in tissue biopsies. Serum antibodies remained chronically high in these dogs throughout the period of the study. Only one dog (1/3) challenged intravenously with promastigotes and the dog challenged intradermally with amastigotes produced transient antibody responses to leis

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1991.tb00550.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummaryThe presence of the prophenoloxidase (proPO) system in the haemolymph ofRhodnius protixusandTriatoma infestansand the role played byTrypanosoma rangeliin the in vitro activation of proPO were tested. BothR. prolixusandT. infestanswhole blood preparations showed a very active ProPO system. The proPO cascade of the two insect species were differentially activated by microbial‐derived extracts: laminarin was a better activator ofT. infestanshaemolymph than ofR. prolixusblood, and lipopolysaccharides fromShigella flexneriorPseudomonas aeroginasacaused significant proPO activation ofT. infestanshaemolymph but not ofR. prolixuspreparations. For the two insect species, neitherT. rangelifrom culture nor parasite lysates were able to trigger proPO activation. The presence of the parasite inR. prolixushaemolymph/laminarin assays, however, significantly reduced the level of proPO activation to that of spontaneous activating controls. The immobilization ofT. rangeliin vitro in haemolymph preparations occurred in both insect species and was dependent on the proPO activation intensity Our results suggest that the susceptibility ofR. prolixustoT. rangelihaemocoel infection may be explained, at least in part, by the suppression of the insect immune defence system i.e., inhibition of proPO in the presence of this protozoan parasit

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1991.tb00551.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY

摘要:

SummarySix groups of four ovines each were injected intraperitoneally with Freund's complete adjuvant (FCA), at various limes before, during, or after infection with 10000 larvae (L3) ofHaemanchus contortusper sheep. Animals in groups A and B received FCA on days 14 and 7, respectively, before infection. Ovines in group C were treated with FCA on the same day of infection; while sheep in groups D, E. and F were injected with the adjuvant on days 7. 14. and 21, respectively, after infection. Significant reductions in adult worm numbers compared with non‐treated controls, as determined 42 days after infection, were of 30%, 34%, 45%. 52%, 56%, and 55% in groups A, B, C, D, E, and F, respectively. A significant correlation, between the time of FCA administration (referred to the day of infection) and the number of worms recovered at necropsy, was also observe

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1991.tb00552.x

出版商:Blackwell Publishing Ltd    

年代:1991

数据来源: WILEY