摘要:

Summaryp40 is the major protein antigen in eggs and miracidia of Schistosoma mansoni. Immunization with recombinant p40 produced in bacteria and with p40 from miracidia reveals a conventional immune response gene effect in which H‐2bmice fail to produce antibody against p40. This is true when either denatured recombinant p40 and non‐denatured miracidial p40 are used as immunogens. In contrast, during infection all strains of mice produce antibodies to p40. However, non‐responder H‐2bmice produce only IgM to p40 and never any IgG. Thus, H‐2bmice appear to be producing specific IgM to p40 in the absence of MHC‐restricted T‐cell help. The mechanism revealed in these non‐responder mice might play an important role in stimulating the production of IgM ‘blocking’ antibodies to antigens from schistosomula which cross‐re

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1993.tb00573.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryInhibitory monoclonal antibody (MoAb) 8E7/55 recognizes a parasitophorous vacuole membrane (PVM) antigen in Plasmodium falciparum. Previous studies have identified the epitope, DNNLVSGP, recognized by the MoAb. A synthetic peptide containing this sequence was synthesized and coupled to diphtheria toxoid (DT) and was found capable of generating antibodies when used as an immunogen in mice which recognize the native antigen exp‐1. In this study we demonstrate the ability of the MoAb and antisera generated against the peptide construct to recognize a 54 kD PVM antigen in Plasmodium chabaudi. The P. chabaudi antigen is synthesized in trophozoites and released to the surrounding culture media outside the parasitized erythrocyte. Mice immunized with the peptide conjugate are protected when challenged with a lethal strain of P. chabaudi. Protection in the mice correlated with the antibody titre prior to challenge. If the PVM antigen from P. chabaudi is a homologue of exp‐1 from P. falciparum, then these experiments may provide a guide to the antibody titres required in human trials before antibody mediated protection could be expected. The discovery that a PVM localized antigen is secreted into the surrounding in vitro culture media provides us with a valuable model system for further investigation of protein trafficking pathways in malaria‐infected erythro

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1993.tb00574.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryThe interaction between protoscoleces of Echinococcus multilocularis and activated murine macrophages was examined in this study. Marked protoscolicidal activity was displayed by peritoneal macrophages (PM) activated with interferon‐γ (IFN‐γ), or IFN‐y plus lipopolysaccharide. Pretreatment of the parasites with heat‐inactivated specific murine infection serum, but not with normal serum rendered them more susceptible to PM killing. NG‐monomethyl‐Larginine, a competitive inhibitor of L‐arginine completely inhibited the killing activity of activated PM. while reconstitution of arginine‐free medium with L‐arginine restored the killing properties of the activated PM. The results show that activated PM have the ability to kill E. multilocularis protoscoleces in vitro and suggest that reactive nitrogen intermediates (RNl) play an important role in the mechanism. An oxygen‐mediated mechanism did not appear to play a role because scavengers of reactive oxygen species did not reduce the killing activity. The arginine‐dependent killing mechanism was enhanced by superoxide dismutase (SOD), probably because SOD might prolong the effect of nitric oxide. Secretion of RNI by activated macrophages may be capable of a significant role in preventing of the dissemination of E. multilocu

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1993.tb00575.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryImmunofluorescence on live Dictyocaulus viviparus parasites revealed a significant antibody response by vaccinated and patently infected bovine hosts to the sheath of infective larvae (L3), a structure which is generally thought to be shed from the parasite surface prior to invasion of host tissue. In contrast, surface‐exposed antigens of the adult, egg and pulmonary L1 stages were recognized only by serum antibody from calves exposed to a patent lungworm infection. Radioiodination of sheathed L3 identified a restricted set of components while a more complex pattern of labelled material was observed with adult parasites. Many more components of adult worms were labelled by the Bolton‐Hunter than by the lodogen reagent, probably reflecting the more penetrative labelling propensities of the former. Stage‐specificity of surface‐associated antigens of adult parasites was demonstrated by their immunoprecipitation by antibody from patently‐infected, but not from vaccinated, calves. There was no in vitro release of the major iodinatable surface‐associated antigens of adult parasites nor any binding of antibody raised against adult excretory‐secretory (ES) products to the surface of living adult worms, suggesting that surface components do not contribute to adult ES products in this species. Antibody responses to the surface of adults. L1 and eggs were specific to patently‐infected animals and may provide a useful indicator of exposure to p

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1993.tb00576.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummarySoluble extracts from salivarian trypanosomes (Trypanosoma brucei brucei, T. evansi and T. congolense) were shown to be capable of inducing murine tumour necrosis factor (mTNF) secretion, both in vivo and in vitro, whereas the soluble extract of an intracellular trypanosome (T. cruzi) failed to do so. Furthermore, the role of mTNF during the initial phase of experimental infections with T. brucei was studied by treating infected mice with mTNF‐inducing trypanosoma soluble extract and with neutralizing monoclonal anti‐mTNF antibodies. Treatment of the infected animals with different doses of T. brucei soluble extract resulted in a lower first parasitaemia peak (low lysate dose) and in a longer survival time or in a nearly total inhibition of parasite development (high lysate dose). Cotreatment of the infected mice with both anti‐mTNF antibodies and a high dose of soluble extract completely restored the parasite development in both trypanosusceptible C3H/He mice and trypanosubtolerant CBA/Ca mice, indicating a protective role of mTNF during the parasitaemia. Collectively these results suggest a negative influence of mTNF on T. brucei development in

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1993.tb00577.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY

摘要:

SummaryRepetitive administration of recombinant IL‐3 induced protection against Strongyloides ratti but not against Nippostrongylus brasiliensis in C57BL/6 mice. Numbers of S. ratti were negligible from day 4 to day 6 post‐infection in mice injected with IL‐3, whereas N. brasiliensis burdens were almost equal from day 4 to day 6 between mice injected with IL‐3 or with medium. Mice treated with IL‐3 and then concurrently infected with S. ratti and N. brasiliensis were protected from intestinal S. ratti but not from N. brasiliensis. The numbers of intestinal mucosal mast cells were increased by the repetitive IL‐3 treatment on one day after the final injection and was augmented by subsequent infection with bot

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1993.tb00578.x

出版商:Blackwell Publishing Ltd    

年代:1993

数据来源: WILEY