摘要:

SUMMARYNewly excysted juvenileFasciola hepaticawere injected intraperitoneally into previously sensitized rats. They were recovered at various intervals post‐injection and examined by light and electron microscopy. The challenge flukes were rapidly coated with peritoneal cells which, in the early stages, were mainly eosinophils. The eosinophils adhered closely to the flukes and degranulated on to their surface releasing cytochemically detectable peroxidase. Vacuoles formed in the tegument of the flukes beneath the adherent eosinophils and these increased in size until they spanned the width of the tegument, thus destroying its continuity. From 4 h post‐injection some of the flukes had lost their teguments and were surrounded by phagocytic cells, particularly neutrophils; at this stage they were judged to be dead. During the first five minutes post‐injection degranulating mast cells were associated with the challenge flukes. Their role in eosinophil chemotaxis is discussed as are the possible mechanisms of eosinophil adherence and degranulation.Using an anti‐C3fluorescein conjugate, it was demonstrated that C3was not bound to the surface of challenge flukes eitherin vitroor invitroin immun

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00387.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYCattle were infected with two different clones ofTrypanosoma hrurei(MITat 1.2 and ILTat 1.3) and antibody response was followed by radioimmunoassay. In four of the seven animals there were at least two peaks of antibody activity to the infecting clones, with the second peak much higher than the first. Specific antibodies (IgG1 and IgM but not IgG2) were eluted from the immunoabsorbent columns on which the variant surface glycoproteins (VSGs) were coupled. By neutralization of infectivity tests, IgM antibodies from the first peak of antibody activity were more efficient in neutralizing trypanosomes than IgGl but the reverse was true of the antibodies isolated from the second peak. By absorption with multiple variable antigen types isolated during the course of infection, all the IgM and IgG1 in the first 3 weeks of infection were shown to be specific. It is suggested that polyclonal B cell stimulation leading to dysfunction in the control of IgM and IgG production may not be responsible for the high levels of these immunoglobulins in bovine trypanosomiasis.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00388.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryThe capacity of rat peritoneal neutrophils to adhere to and kill schistosomula ofSchistosoma mansoni in vitrohas been investigated. Neutrophils adhere readily to schistosomula in the presence of antibody plus complement (C) (fresh immune rat serum), antibody alone (heat‐inactivated immune rat serum) and C alone (fresh normal rat serum), but not with heat‐inactivated normal rat serum. However, schistosomular killing is only achieved with neutrophils and fIRS or MRS. In the presence of hiIRS the cells detach after 6 h without producing a significant level of parasite death. The system involving neutrophils plus fIRS is the most efficient in terms of serum dilution and the rate of schistosomular killing. The complement‐dependent antibody involved in this system belongs to the class IgG and occurs in rat serum at peak titres, 6–8 wk after a primary schistosome infection. Neutrophil adherence in the presence of MRS depends upon the generation of C3b molecules at the parasite surface via the alternative pathway of C activation. Studies on the antibody alone system indicate that the lack of significant schistosomular killing might result from the absence of factors which stimulate cell migration, since if a chemokinetic agent is introduced into the assay a 30% increase in mortality is recorded. The possible participation of neutrophils in the destruction of a primary and/or challenge infectionin vivois di

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00389.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYAgglutinating and vibriocidal antibodies appear in the bile of rats within a few days of intravenous or intraintestinal injection of liveVibrio cholerae.Whereas the presence of IgM and IgG antibodies are accounted for by passive exudation from serum, those of the IgA class are selectively (actively) transferred from serum to bile. Bile duct ligation causes a 10‐fold increase in serum IgA levels over a 48‐h period; a similar increase in agglutinating antibody titre occurs only in rats injected intraintestinally, thus providing further evidence for the predominance of IgA‐antibody formation when antigen is taken up from the intestinal lumen. Biliary antibodies do not appear to augment the antibody levels in mucus secretions that adhere to the small intestine surfaces. However, when the bile flow is interrupted by bile duct occlusion or cannulation, the antibody levels in these secretions increase in parenterally‐immunized animals. It is unlikely, therefore, that bile duct ligation will provide a satisfactory approach to determining the protective function of biliaryV. choleraea

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00390.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYTwo models of intraperitoneal infection withE. granulosus equinusby protoscolices and by cyst passage in BALB/c mice were used to provide mesenteric lymph node cells for adoptive cell transfer into syngeneic recipient normal responder mice. The cell transfer inocula were shown to have depleted Thy‐1 cells, but to be highly suppressive to the normal sheep erythrocyte response of the recipients. The nature of the depletion and non‐specific suppression, and the infectious nature of the latter, are discussed in relation to other examples of mitogenic stimulation resulting in non‐specific T cell suppressor activity. The functions of Ly‐2,3+cells, not only as suppressor, but as alloreactive cytotoxic cells, are discussed as a possible, autoimmune explanation for the longevity of the parasite within the mouse model, in contradistinction to the predictable early rejection of analogous xen

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00391.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYFerrets were exposed to two successive inoculations with 30 third‐stage larvae of the canine heartwormDirofilaria immitis, the inoculations being approximately 5 months apart. Each infection was terminated by ivermectin therapy approximately 2 months after inoculation. The ferrets were challenged with 30 larvae 3 weeks after the termination of the second infection, and were necropsied approximately 6 months after challenge. Of the four ferrets that survived this protracted experimentation, two were entirely free of heartworm while the other two had only a single female worm each. In contrast, 14 control ferrets that had not been immunized (four of which had been given ivermectin doses) were all infected at necropsy, yielding a mean of 6.6 worms per ferre

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00392.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYInfective larvae ofNematospiroides dubiusattenuated by cobalt 60 irradiation are extremely effective at stimulating immunity. Previously, such levels of protection could only be obtained with multiple immunizations of normal larvae. The critical factor underlying this protective response appears to be the dose of irradiation given to the immunizing infection. Various doses of irradiation have been tested and the most effective of these range between 10 and 30 krad. The experiments show that provided this level of irradiation is used, the number of immunizing infections is relatively unimportant. Such use of irradiated larvae will be of value in attempting to analyse the immune mechanisms which operate againstN. dubius.The possible mechanisms of immunity toN. dubiusare discussed.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00393.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYFactors governing the sensitization or desensitization of basophils and mast cells are discussed. Mathematical models are proposed which illustrate the effects of rising or falling specific or non‐specific IgE titres on the tendency of these cells to degranulate. The models presented are consistent with the hypothesis that fine‐tuning of the degranulatory event is achieved by one or more of the following mechanisms: alteration of the number of IgE receptors on the mast cell membrane; displacement of specific anti‐schistosomal IgE by anti‐other‐IgE molecules; clipping or otherwise inactivating mast cell‐fixed specific IgE receptor sites so as to render these incapable of binding antigen. Mechanisms proposed may explain how a mast cell population may evolve from highly sensitive to non‐reactive allergic states during early and/or chronic periods of schistosomiasis, only to revert to highly sensitive states once again, after the disease has

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00394.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SUMMARYThe association of severe strongyloidiasis and hypogammaglobulinaemia in one patient is described. Severe strongyloidiasis was observed twice (March 1971 and June 1974), and theStrongyloides stercoralisinfestation probably lasted for at least 58 months (from March 1971 to December 1975), in spite of successive thiabendazole courses of treatment. Immunological studies performed disclosed severe, steady hypogammaglobulinaemia but no abnormality in cell‐mediated immunity. The respiratory infections also seen during the follow‐up were ascribable more to humoral immunity impairment than to cell‐mediated immunity impairment. This is the first report of the association of hypogammaglobulinaemia and severe strongyloidiasis, and it suggests that humoral immunity plays a relevant role in the human defences againstS. stercoralisinfest

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00395.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY

摘要:

SummaryPrevious infection of rats withNippostrongylus brasiliensiswas shown to result in protection against an oral challenge withFusciola hepaticametacercariae but not against an intraperitoneal challenge with newly excysted juvenile (NEJ) flukes. The timing of the challenge was important and a double infection with the nematode gave more consistent results than a single. Resistance appeared to be associated with a prior induction of intestinal eosinophilia. Sera from these resistant rats, however, failed to induce eosinophil adherence to NEJ flukesin vitro.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1981.tb00396.x

出版商:Blackwell Publishing Ltd    

年代:1981

数据来源: WILEY