摘要:

SummaryVideo recordings and ultrastructural studies have revealed an intricate sequence of antibody‐mediated cytotoxic activity by quokka peritoneal macrophages onBreinlia macropimicrofilariae. The microfilaricidal activity was effected by at least two types of macrophages measuring 17 μm and 8 μm in diameter respectively. The relatively large macrophages were responsible for trapping, encircling and eventually degrading the highly motile microfilariae in a sequence of events in which the participating macrophages may interdigitate. The smaller macrophages adhered transiently to a number of adjacent sites on the surface of a trapped microfilaria, resulting in a series of damaged spots. This activity of the small macrophages was interpreted as responsible for killing the microfilaria. Thus the microfilaricidal activity was interpreted to be accomplished by the co‐operative functions of the relatively large and small macrop

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb01033.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryExperimentalT. congolenseinfections in sheep resulted in a striking decrease in parameters of the alternative complement pathway (ACP), ie. factor B, C3 and haemolytic complement activity (HA) initiated via the ACP. The levels of factor B, C3 and HA declined before, during and after the first wave of parasitemia which reached a peak at day 8. Levels of 20 to 25% of normal values (factor B) and 20% (C3, HA) persisted throughout the course of the infection. After Berenil treatment, when no parasites were detected in blood, their serum levels remained low. They returned to normal values about 8 (factor B) to 20 days (C3, HA) after trypanocidal treatment. Serum concentrations of factor B were significantly elevated in some, but not all sheep 6 days after infection withT. congolense.The sheep were tested for their potential state of immuno‐modulation by immunization withBrucella abortus4 days after trypanocidal treatment. In contrast to other sheep, the sheep which had shown early elevated serum factor B levels were found to express immune enhancement. It is suggested that there might be a positive correlation between the degree of enhanced serum levels of factor B at the early stage of infection and enhanced immune responsivenes

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb01034.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryAntibodies were raised in rabbits by immunizing against fresh unfixed or cryopreserved female gametes of the human malaria pathogenPlasmodium vivax.The antibodies were shown to react with the surface of gametes by the indirect immunofluorescent test. When parasite isolates fromP. vivaxinfected individuals were fed through a membrane toAnopheles tessellatusmosquitoes in the presence of immune rabbit sera, they completely blocked the infectivity of the parasite isolates to the vector. Immunoglobulins separated from these sera also blocked infectivity to the same extent as did the immune sera indicating that antibodies were responsible for the transmission blocking effect of the sera. This study indicated thatP. vivaxlike other malaria parasites is highly susceptible to anti gamete transmission blocking immunity.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb01035.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummarySerum was obtained from CBA/Ca mice infected, reinfected or superinfected with parasites taken one or two syringe passages from cryopreserved reference stabilates derived from cloned lines of the AS or CB isolates ofP.c. chabaudi.Serum was also collected from mice superinfected with parasites derived from a cloned line ofP. bergheiKSP‐11. When injected into normal syngeneic recipients subsequently challenged with homologous or heterologous parasites, these sera mediated some or all of the following modifications to the breakthrough parasitaemias which invariably occurred (i) an extension of the pre‐patent period (ii) an extension of the time taken for the parasitaemia to reach 2% (iii) a reduction of peak parasitaemia (iv) protraction of the initial peak of parasitaemia. These modifications were particularly evident with serum from superinfected mice and to a lesser extent with serum from animals reinfected once after recovery from a primary infection. Serum taken during the course of such a primary infection produced extended pre‐2% periods, other effects being only marginal. Serum mediated modifications produced by reinfection and superinfection serum appeared largely species‐specific with a limited degree of cross‐reactivity. Intraspecific specificity was also apparent with serum fromP.c. chabaudiAS or CB reinfected or superinfected mice, although marginal cross‐immunity was again observed. When analysed by the fluorescent antibody technique on smears of methanol fixed parasitized erythrocytes, reinfection and superinfection sera were almost totally cross‐reactive both within and across species. Preliminary evidence that parasites breaking through the effects of these sera may constitute a phenotypic antigenic variant is presented and possible mechanisms for the parasitaemia modifying effects of the various s

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb01036.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryLymphoid cells from genetically‐susceptible BALB/c mice immunized against a glycoconjugate of the protozoan parasite,Leishmania major, promote chronic cutaneous disease in BALB/c nude mice. This cell population therefore differs from cells harvested from non‐immunized BALB/c mice that are known to be potent mediators of protection against cutaneous leishmaniasis in minimally‐reconstituted, syngeneic nude mice. The glycoconjugate when injected into genetically‐resistant C57BL/6 mice will increase the size and persistence of cutaneous lesions. Recent studies have established that the water soluble glycoconjugate is derived from a membrane‐bound glycolipid that is a receptor used by the parasite in the attachment to macrophages. This glycolipid can protectively immunize mice against cutaneous leishmaniasis. Identification of a vaccinating glycolipid antigen and a suppressogenic component derived from it will greatly facilitate analysis of disease‐promoting and resistance‐promoting immunity in cutaneous leishmaniasis. However, the fact that a host‐protective antigen contains a disease‐promoting component may militate against the immediate use of this molecul

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb01037.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

SummaryA histopathological and ultrastructural study was made of schistosomula and associated inflammatory reactions in the lungs of normal mice, and mice previously vaccinated with irradiated cercariae. In normal mice at day 7 postinfection all schistosomula were located in blood vessels. From day 11 onwards an increasing proportion of schistosomula were intra‐alveolar (80% from day 20). No cellular reactions were evident around intravascular parasites in normal mice but at later sampling times large compact foci were associated with alveolar parasites. Initial reactions, probably in response to non‐specific tissue damage, were approximately 50% polymorphonuclear, and 50% mononuclear. Mononuclear cells predominated at later times. In spite of inflammation, no damage to the schistosomula was observed. There was no evidence for re‐entry of schistosomula into blood vessels, and it was assumed entry into alveoli occurred accidentally as parasites attempted to traverse pulmonary blood vessels. The pattern of localization of schistosomula in vaccinated mice was similar to that in normal mice, the proportion in alveoli increasing with time (64% from day 20). The most significant difference was that intravascular schistosomula attracted foci of host leucocytes which were always 85% or more mononuclear, containing both lymphocytes and macrophages. The infiltrating cells enlarged the intersititium, separating the vascular endothelium from the alveolar epithelium. Fibrous protein was also deposited in the interstitial region. In some instances the complete blood‐air barrier was destroyed by the infiltrates. Unusual paracrystalline inclusions were observed in alveolar macrophages and giant cells. The differences in cellular responses in vaccinated and normal mice suggest that challenge schistosomula stimulated an anamnestic immune response. The resulting inflammation, by impeding movement through the vasculature, terminated migration in the lungs, and accounted for the observed resistance to reinfection. The reactions in vaccinated mice have many of the features of a delayed hypersensitivity response implying that lung phase resistance in vaccinated mice may be T‐cell rather than antibody

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb01038.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1986.tb01039.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY