摘要:

SummaryTwo mouse strains maintained in this laboratory (WEHI) are variably resistant to infection withSchistosoma japonicumandS. mansoniin that worms cannot be found in the liver and portal system in a high proportion (WEHI 129/J mice) or low proportion (C57BL/6 mice) some weeks after exposure to cercariae. Resistance can be as high as 100% in WEHI 129/J mice and is usually around 20% in C57BL/6 mice. The proportion of resistant mice closely parallels the proportion of mice that demonstrate a shunting of microbeads, injected into a mesenteric vein, from liver to lungs. This applies to F1x WEHI 129/J backcross mice in which the data suggest oligogenic genetic effects although no evidence for a participation of MHC‐linked genes in the phenomenon has emerged. 129/J mice derived from the Jackson Laboratory do not show a shunting of beads from the portal system to the lungs but their progeny bred at WEHI do. Germ‐free WEHI 129/J mice resemble conventionally‐maintained, SPF‐derived WEHI 129/J mice in their variable resistance to schistosome infection. No satisfactory explanation for hepato‐portal system peculiarities in WEHI 129/J and C57BL/6 mice can be advanced as yet and a possibility raised in this paper is a contribution from nutritional factors such as hypervitaminosis A superimposed on a genetic predisposition in these two related mous

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00988.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryAs with 20 krad‐irradiated infections in mice, the present study shows that the immunity induced by Ro11‐3128 termination of unattenuated infections at the skin stage is species specific, not operating againstS. japonicum.Treatment with the drug Ro15‐5458, also effective at the skin stage, however, resulted in significantly lower levels of resistance than Ro11‐3128. Sera from mice immunized by infection plus Ro11‐3128 treatment on days 1 or 2 (Ro11S) coprecipitated essentially the same pattern ofl25I‐labelled surface antigens as the 20 krad vaccine serum (VMS), viz. Mr38000, 32000, 23000 and 15000. However, recognition by Ro11S was markedly stronger. Sera from the infected and Ro15‐5458‐treated mice (Ro15S) failed to recognize the Mr23000 antigen and produced a weaker response than RollS or VMS against the Mr38000 or 32000 antigens but a comparable response to VMS against the Mr15000 antigen. Ro11S and VMS also recognized the Mr16000 surface antigen seen by Western blotting but its recognition by Ro15S was weaker. Compared with sera from animals treated at the skin stage, sera from animals treated at the lung stage (day + 6) showed weaker recognition of the Mr32 000 and 15 000 antigens and no recognition of the Mr23 000 antigen. In contrast, sera from mice treated at 15 days recognized both the Mr32 000 and 23 000 antigens but not the Mr15 000 antigen. Mice treated at these times show progressively less immunity than at the skin stage. Infected but untreated animals only showed significant recognition of the Mr32 000 antigen. Thus compared with infections treated with Ro11‐3128 on days 1 or 2, treatment at later times or with the drug Ro15‐5458 resulted in selective and differential absence or diminution of response against either the Mr38 000, 32000, 23000, 16000 or 15000 antigens.In vitro, Ro11‐3128, in contrast to Ro15‐5458, caused multiple vesicle formation at the surface of skin stage schistosomula but this was progressively less pronounced with lung and liver stage worms. The vesicles were shown to express surface membrane antigens but wer

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00989.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryWe have studied the properties of epitopes onPlasmodium falciparumgamete surface protein Pfs 48/45, a target antigen of malaria transmission blocking antibodies. Using a two site immunoradiometric assay we have defined three spacially separate, non‐repeated, epitope regions on the peptides representing this antigen. Epitope region I is a target of monoclonal antibodies (MoAbs) which strongly suppress infectivity of gametocytes ofP. falciparumto mosquitoes; the effect is complement independent and is mediated as effectively by the monovalent Fab fragments as by intact MoAb. Epitope region II consists of two spacially close subregions, Ha and lib; variant forms of epitopes Ha and lib occurred in different isolates ofP. falciparum.Epitope region III also showed slight structural modification between isolates. MoAbs against regions II or III were relatively ineffective in suppressing gametocyte infectivity compared to MoAbs against region I. However, certain combinations of MoAbs against regions II and III together acted synergistically to suppress infectivity to mosquitoes. All these epitopes failed to react with MoAb when the antigen was presented in reduced form. A fourth epitope, however, was identified which reacted strongly with MoAb when the antigen was presented in reduced form. The MoAb against this epitope had no effect on the infectivity of gametocytes ofP. falciparumto mosquitoe

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00990.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryClonal analysis of the murine B‐cell repertoire has been used to investigate the possible role of tandem repeat sequence epitopes ofPlasmodium falciparumin immune evasion. A limiting dilution culture system was used whereby murine spleen cells were stimulated with the B‐cell mitogen Iipopolysac‐charide (LPS) in the presence of 3T3 fibroblast filler cells. One in three B cells were shown to produce clones secreting immunoglobulin measurable by an ELISA. The frequency of antibody forming cell precursors (AFCp) specific for the 3′ repeat epitopes of the ring injected erythrocyte surface antigen (RESA) was estimated in non‐primed mice and found to be low. However, an accurate frequency determination was not possible using this method since the detection of the few positive cultures was found to depend on the presence of more than one AFCp or its products. Limiting dilution analysis was used to assess the frequency and repertoire of splenic AFCp at various times after immunization with a synthetic peptide of the RESA 3′ repeat epitope (8 times 4‐mer), presented in various ways. There was no marked increase in LPS‐responsive AFCp specific for this antigen at the level of either IgM or IgG secretion. This was in marked contrast to the antibody responsein vivo, where moderate IgG antibody titres, normally indicative of a secondary response, were seen in the serum of the same mice used for AFCp assay. This discrepancy between serum titre and AFCp frequency following immunization was not apparent with a non‐malarial antigen, keyhole limpet haemocyanin (KLH). It was concluded that the LPS‐stimulated limiting dilution culture system was not registering RESA‐specific memory AFCp. These results raise the possibility that the malarial antigens are deficient in memory B‐cell generation, or that secondary responses to these determinants may arise from a distinct B‐cell progenitor which is non

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00991.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryFree radical generation by peritoneal leukocytes from BALB/c and C57BL/6 mice was monitored for 18 days following infection withEimeria vermiformis.Free radical generation occurred earlier and was quantitatively much greater in resistant BALB/c mice than in susceptible C57BL/6 mice, resistance being indicated by a much lower oocyst production and a shorter patent period ofE. vermiformis.Plasma greatly enhanced free radical generation in response to a soluble antigen prepared from sporulated oocysts indicating the presence of plasma‐borne factor(s) which enhance free radical generation in response toE. vermiformi

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00992.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryLectin‐binding surface receptors on haemocytes from host oysters were compared with those on plasmodial stages of the ascetosporan parasiteHaplosporidium nelsoni(MSX). Haemocytes were agglutinated, in descending order of strength, by WGA, HPA, LPA, ConA, and CFA. GMA, PHA, and RMA lectins failed to agglutinate at 100 μg/ml, the highest concentration tested. These results indicate that haemocytes contain surface receptors resemblingN‐acetyl‐D‐glucosamine and α‐methylmannopyranoside. Fluorescent (FITC) labelled ConA and WGA also bound toH. nelsoniplasmodia, but parasites were commonly excluded from clumps of agglutinated haemocytes, except for those that were apparently trapped passively in large aggregates. Although seasonal variations existed, agglutination titres for all reacting lectins were 2‐ to 8‐fold higher for cells from systemically infected oysters compared to control oysters not manifesting systemic infections. Preincubation of lectins in serum from control animals reduced agglutination titres 6‐ to 9‐fold, whereas incubation in serum from systemically infected oysters reduced titres only 4‐ to 6‐fold. The loss of lectin‐like molecules from the serum of systemically infected animals, and the concurrent increase of lectin receptors in the haemocyte population, is probably related to known changes in haemocyte composition and the loss of serum glycoproteins in diseased animals. Antigenic similarities were detected between surface receptors on oyster haemocytes and those onH. nelsoniplasmodia, which may help explain the failure of oyster haemocytes to

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00993.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryMononuclear cell subpopulations in local skin reactions (chancres) in sheep infected with metacyclic forms ofTrypanosoma congolensewere studied by indirect immunoperoxidase staining using a panel of monoclonal antibodies (MoAbs) specific for ovine leucocyte subsets. Morphometric analysis revealed significant increases in numbers of cells expressing CD5, CD4, CD8, CD45R (mainly B cells), major histocompatibility complex (MHC) class II antigens, Fc receptors (FcR) on macrophages (VPM32) and FcR on B cells and macrophages (VPM33) from five days post‐infection. B cells which also expressed MHC class II were found mainly in dense aggregates. The CD4/CD8 ratios were raised over pre‐infection levels at 5–7 days post‐infection. In sheep which had been infected, treated with trypanocidal drugs and then challenged with an heterologous serodeme ofT congolense, changes in cellular phenotype kinetics were similar to those seen in the skin in primary infections. Sheep superinfected with either an homologous or an heterologous,T. congolenseserodeme showed only mild cellular infiltration and slight increases in various cellular phenotypes at the sites of inoc

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00994.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryNeonatal mice (CR:NIH:S) were infected with a cloned human isolate ofGiardia lamblia(GS/M‐83‐H7) and the surface antigens of the intestinal trophozoites, as well as the cellular and humoral immune responses, were analysed during the course of infection. Infections in mice peaked 2–3 weeks after inoculation and were self‐cured by day 42 post‐infection (p.i.). The proportion of trophozoites expressing the Mr72 000 surface antigen of the initial inoculum had decreased by day 12 and approached zero by day 22 p.i., similar to infections in humans. The predominant parasite‐specific humoral response was an IgM‐ and IgG‐isotype directed to the original Mr72 000 surface antigen as well as other antigens. T‐lymphocytes (predominantly LY4(CD4)+) isolated from Peyer's patches 12 days p.i. and later showed a significant proliferative response toGiardia lambliaantigens. Spleen and lymph node cells showed no lymphoproliferative response. T‐cell blot analysis revealed the presence of dominant T‐cell epitopes in the areas of Mr200 000–75 000 and<50 000 polypeptides. No response was demonstrated in the Mr72 000 region (migration site of the major surface antigen), suggesting T‐cell dependent mechanisms are most likely not responsible for the surface antigen switch which occurred during the course of infection. This model infection can be used to study the role of immunological mechanisms inGiardia lambliavariant antigen switching and in

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00995.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryLevels of intestinal mast cell protease (IMCP) were quantified in serum, gut tissue and in intestinal fluids taken from mice infected withTrichinella spiralisduring primary and secondary infections. The ability to generate a mast cell response was dependent on the response phenotype of the mouse strain used. The mast cell response in rapid responder mice (NIH) occurred sooner and was more pronounced than in either intermediate (SWR) and low responder (BIO) mice. This pattern was also reflected in the concentration of IMCP found in various tissues examined. The correlations between IMCP concentrations in blood, and worm expulsion, are discussed.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00996.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

SummaryVaccination of mice with an antigen extract fromTaenia soliumcysticerci induced protection against challenge withT. crassicepscysticerci as successfully as did antigen extracts fromT. crassiceps.Vaccination was more effective in male than in female mice and in the resistant strain (BALB/B) more so than in the susceptible strain (BALB/c). While only the resistant strain was completely protected by vaccination, the parasite load of the susceptible strain was significantly reduced by vaccination. Cross immunity between the human and murine parasites establishes murineT. crassicepscysticercosis as a convenient laboratory model in which to test promisingT. soliumantigens aimed at vaccine development againstT. soliumcysticercosis. Further, results point to strong interactions of the immune system with sexual and histocompatibility factors in the host's dealing with cysticercosis.

ISSN:0141-9838    

DOI:10.1111/j.1365-3024.1990.tb00997.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY