bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological studies on the killing of schistosomula of Schistosoma mansoni by human eosinophil and neutrophil cationic proteins in vitro
Authors: McLAREN DIANE J. , McKEAN J. R. , OLSSON I. , VENGE P. , KAY A.B. 
Published: October 2007

SUMMARYPurified eosinophil and neutrophil cationic proteins isolated from the lysosomal secretion granules of human granulocytes, evoke characteristic, dose‐dependent morphological changes in young schistosomula of S. mansoni. The first sign of damage is seen within 15–30 min of incubation and involves the formation of surface microvilli and blebs. Subsequently, tegumental evaginations of varying size are developed, but these appear to explode with rapidity, so that lengths of expanded tegumental outer membrane are deposited over the severely damaged surface of the parasite. Both types of granulocyte proteins are able to effect comparable damage at equimolar concentration. Other cationic proteins such as protamine and poly‐L‐arginine also damage the parasite surface but the pathological changes differ from those induced by the granulocyte proteins and they take longer to develop. In contrast, lysozyme‐treated parasites are virtually similar to control schistosomula incubated in medium alone. These findings are discussed in relation to published data concerning the interaction of intact granulocytes with young schistosomula both in vitro and in viva.
The detection of autoantibodies to IgE in plasma of individuals infected with hookworm (Necator americanus) and the demonstration of a predominant IgG1 anti‐lgE autoantibody response
Authors: SHAKIB F. , PRITCHARD D. I. , WALSH E. A. , SMITH S. J. , POWELL‐RICHARDS A. , KUMAR S. , EDMONDS P. 
Published: October 2007

SUMMARYIn this study we have demonstrated significantly elevated levels of circulating IgG autoanti‐IgE antibody in hookworm infected individuals from Kebasob village on Karkar Island, Papua New Guinea. Although anti‐IgE activity was demonstrable in IgG1, IgG3 and IgG4, IgG1 was by far the most important subclass of IgG anti‐IgE in terms of frequency of detection (34/39; 87.2%) and magnitude of increase (P = 0.0000); with IgG3 (16/39; 41.0%) and IgG4 (15/39; 38.5%) antibodies being considerably less prevalent. Plasma levels of IgG1 anti‐IgE (P = 00019) and IgG3 anti‐IgE (P = 0.0034) showed significant correlations with total IgE concentrations, but not with IgE specific to excretory‐secretory worm products; thus suggesting that anti‐IgE synthesis is more related to polyclonal hyper IgE production than to antigen‐specific IgE stimulation. No correlation was seen between IgG subclass anti‐IgE levels and faecal egg counts or worm burden. Given that our data failed to show a negative or a positive correlation between anti‐IgE and the degree of infection with hookworm, it is tempting to speculate that the main role of autoanti‐IgE is to provide the host with protection against immune complex‐ and IgE‐mediated hypersensitivity reactions to parasitic antigens.
Reduced microbicidal and anti‐tumour activities of human monocytes after ingestion of Plasmodium falciparum‐infected red blood cells
Authors: FIORI P. L. , RAPPELLI P. , MIRKARIMI S. N. , GINSBURG H. , CAPPUCCINELLI P. , TURRINI F. 
Published: October 2007

SummaryOxidatively stressed red blood cells (RBC) and Plasmodium falciparum‐infected RBC (PRBC) are avidly phago‐cytosed by human peripheral monocytes. Following the ingestion of PRBC the monocytes’ ability to phagocytose PRBC and to generate aggressive oxidative compounds is severely impaired. In the present work the microbicidal and anti‐tumour capacities of monocytes fed with diamide‐treated RBC and PRBC harbouring mature (trophozoite) parasites have been investigated. The capacity of the latter, but not of the former, to phagocytose Escherichia coli and Staphylococcus aureus and to kill them, as well as ingested Candida albicans cells intracellularly, was found to be markedly impaired. Monocytes that have ingested PRBC had a significantly reduced cytostatic and cytolytic activities against a lymphoblastic tumour cell line. Monocytesfed with oxidatively stressed RBC had normal or sometimes even greater anti‐tumour activities. Monocytes that have ingested PRBC showed a reduced capability to produce superoxide following stimulation with phorbol ester. Such impairment in monocyte functions may explain the reduced antibacterial and anti‐tumour activities of monocytes in malaria patients, and could be consequential to their ability to resist bacterial infections and to provide means for the control of tumour development in those patients.
Chromatographic and antigenic properties of Echinococcus granulosus hydatid cyst‐derived glycolipids
Authors: DENNIS ROGER D. , BAUMEISTER STEFAN , IRMER GABRIELE , GASSER ROBIN B. , GEYER EGBERT 
Published: October 2007

SummaryThe neutral and acidic fraction glycolipids of Echinococcus granulosus metacestode tissue compartments were isolated, defined by their chromatographic and antigenic properties, and assessed as to their efficacy as antigens in the serodiagnosis of human hepatic cystic and alveolar echinococcosis, and other helminthiases. Analyses were accomplished by thin‐layer chromatography immunostaining and ELISA. The neutral glycolipid fraction's major carbohydrate epitope was the same as or very similar to that of Taenia crassiceps neutral glyco(sphingo)lipids, as represented by the ‘neogala'‐series core structure. The blood group‐active, carbohydrate epitope P1 was expressed by a number of neutral fraction glycolipid component bands. The reverse‐phase, thin‐layer chromatography‐isolated neutral fraction glycolipid component, designated Ag1, was efficient in the serological discrimination of cystic echinococcosis medium to high‐titred sera. Ag1 did not specifically discriminate low‐titred sera, i.e., other human helminthiases. The detected sialic acid residues of the acidic fraction glycolipids, on enzymatic cleavage, were identified as N‐acylneuraminic acid and terminal. The acidic fraction glycolipids exhibited the paradox of only chemically minor components being antigenic towards cystic and alveolar echinococcosis infection sera. The combined acidic fraction glycolipid components Ra and Rx were capable of serological discrimination between cystic echinococcosis, alveolar echinococcosis and other helminthiases.
Immune attrition of adult schistosomes
Authors: AGNEW A. M. , MURARE H. M. , DOENHOFF M. J. 
Published: October 2007

SummaryMouse infection models are described that demonstrate reduction in the rate of egg production in Schistosoma haematobium worms 6–10 weeks after the onset of oviposition and loss of Schistosoma bovis worms around 10 weeks after infection. Neither phenomenon has been shown in Schistosoma mansoni‐ or Schistosoma japonicum‐infected mice. The immunological basis for these anti‐adult responses was inferred by comparison with infections in T‐cell deprived mice and by transferance of the ability to reduce a S. bovis worm burden in immuno‐compromised hosts with immune serum. Vaccination with irradiation‐attenuated parasites of S. haematobium was also shown to have consequences for the adults of challenge infections of either S. haematobium or of S. bovis, but not of S. mansoni. Thus, prior vaccination resulted in an abrogation of the reduced egg production by S. haematobium and S. bovis worms and also of the adult worm elimination that occurred in non‐vaccinated S. bovis‐infected mice. These models are being used to define the targets and mechanisms involved in the attrition of adult worms of schistosomes with terminal spined eggs.
Alterations induced by Trypanosoma cruzi in activated mouse lymphocytes
Authors: LOPEZ H. MEJIA , TANNER M. K. , KIERSZENBAUM F. , SZTEIN M. B. 
Published: October 2007

SummaryAlthough a number of immunological anomalies have been shown to occur during the acute period of Trypanosoma cruzi infection, the contribution of the parasite has not been clarified. In this work, we co‐cultured activated splenic mononuclear cells (SMC) from normal oulbred (CD1) or inbred (CBA/J) mice with purified T. cruzi trypomastigotes and studied ensuing T‐ and B‐ lymphocyte alterations. In the presence of parasites, phytohaemagglutinin‐stimulated SMC from either mouse background manifested a marked reduction in both lymphoproliferative capacity (i.e., 3H‐thymidine incorporation) and cell membrane levels of interleukin‐2 receptors (H.‐2R; determined by flow cytomet.y) relative to SMC from parasite‐free cultures. Thus, substantial proportions of activated SMC either became unable to express detectable levels of IL‐2R or expressed this receptor in significantly lower numbers than control SMC. Supernatants from T. cruzi suspensions reproduced these suppressive effects on phytohaemagglutinin‐stimulated SMC from normal or chronically infected CD1 or CBA/J mice. Similar results were obtained with SMC activated with a bacterial lipopolysaccharide. Since IL‐2R expression is required for activated lymphocytes to progress through the cell cycle and multiply to mount effective immune responses, impaired IL‐2R expression by T. cruzi provides a plausible hypothesis for the wide‐ranged immunosuppression that occurs in the infected host.
Phenotypic and functional properties of Th lines and clones recognizing larval antigens of Schistosoma mansoni
Authors: PEMBERTON R. M. , COULSON P. S. , SMYTHIES L. E. , WILSON R. A. 
Published: October 2007

SummaryFive T cell clones and two lines were derived from the lymph nodes (LN) of C57BL/6 mice immunized with radiation‐attenuated lung‐stage larvae of Schistosoma mansoni. All seven clones/lines were CD4+, CD8‐ and expressed high levels of CD44 and CD45RB surface markers. After prolonged maintenance in‐vitro, with soluble antigen from 18 h schistosomula (SSP), five retained the ability to proliferate readily and release IFNg in response to conca‐navalin A (Con‐A) and to SSP and/or soluble adult worm antigen (SWAP). These Th clones/lines induced significant footpad DTH reactions when injected with SWAP, but were unable to confer protective immunity after transfer to naïve recipient mice. This result could be explained by the antigen specificity of the clones/lines, since they were not able to release IFNg when cultured in‐vitro with living lung‐stage larvae. A second possibility is that the high level of CD45RB expression, which is not seen on the surface of pulmonary CD4+ memory/effector cells isolated directly from protectively‐vaccinated mice, alters the ability of the clones/lines to release IFNg and to induce a DTH response in the lungs when they encounter antigen released from migrating schistosomula.
The inhibitory effect of ovine recombinant interferon‐gamma on intracellular replication of Toxoplasma gondii
Authors: OURA C. A. L. , INNES E. A. , WASTLING J. M. , ENTRICAN G. , PANTON W. R. M. 
Published: October 2007

SummaryA model for the in vitro infection of ovine cells with Toxoplasma gondii tachyzoites has been developed and used to investigate the effect of treatment with ovine recombinant interferon‐gamma (ov.rIFNγ) on parasite replication. Treatment of both alveolar macrophages and fibroblast cells either 24 h pre‐infection or 2 h post‐infection with ov.rIFNγ inhibited replication of T. gondii and was quantified by suppression of 3H uracil uptake by the parasite. Replication of T. gondii in the fibroblast cells was significantly inhibited by treatment with 200‐300 U/ml ov.rIFNγ, whereas concentrations as low as 1 U/ml suppressed parasite replication in the alveolar macrophages.
Studies on the immunogenicity of a recombinant ookinete surface antigen Pbs21 from Plasmodium berghei expressed in Escherichia coli
Authors: MATSUOKA HIRO , PATON MICHAEL G. , BARKER GUY C. , BLANCO A. RICHARD ALEJO , SINDEN ROBERT E. 
Published: October 2007

SUMMARY Plasmodium berghei ookinete surface antigen (Pbs21), was produced as a fusion product with maltose binding protein (MBP) in Escherichia coli and used to induce transmission‐blocking immunity in mice. Specificity of induced antibody was confirmed by Western blotting with native ookinete Pbs21, and by the indirect immunofluorescent antibody test on ookinete bloodfilms. Immunized mice were infected with P. berghei and transmission to Anopheles stephensi mosquitoes determined by both the intensity and prevalence of oocyst infections. Compared with a control group immunized with MBP alone the maximum blockade of oocyst intensity was 66% in the mice immunized with recombinant MBP‐Pbs21. Over nine experiments blockade averaged only 33%. By comparison with native Pbs21 protein, which usually induces 90% blockade, our data suggests the recombinant protein produced in this bacterial system is a less effective immunogen despite expressing epitopes recognized by known transmission‐blocking monoclonal antibodies.
Toxoplasma gondii: detection of antibodies in human saliva and serum
Authors: HAJEER A. H. , BALFOUR A. H. , MOSTRATOS ANN , CROSSE BARBARA 
Published: October 2007

SUMMARYSaliva samples from 27 patients with a recent toxoplasma infection were tested for specific IgG, IgM and IgA antibodies to Toxoplasma gondii. Thirteen of the 27 saliva samples were positive for IgG anti‐T. gondii by direct agglutination and 8 of the 27 were positive for IgM anti‐T. gondii by an immunosorbent agglutination assay. Twenty of the 27 saliva samples were positive for IgG antibody on toxoplasma immunoblots with three major immunodominant antigens; 38, 30 and 35 kDa. IgA results on toxoplasma immunoblots were positive for all three groups tested, recently infected patients, chronically infected and seronegative adults without distinguishing between them. The 35 and 43 kDa antigens were the most frequently detected proteins. IgM in saliva gave negative or very weak reactions. None of the eight seronegative or the 17 chronically infected adults gave positive results in any of the tests performed to detect IgG or IgM in saliva. Serial saliva and serum samples from a laboratory‐infected patient were collected and tested for toxoplasma‐specific IgG, IgM and IgA. IgG in saliva was detected by 27 days post infection (p.i.) and was negative by 81 days p.i.; it detected mainly the 38 and 30 kDa antigens. IgM in saliva was detected by 11 days p.i. and was negative by 81 days p.i., with no reaction on immunoblots.
Strongyloides venezuelensis infection in Syrian golden hamster, Mesocricetus auratus, with reference to the phenotype of intestinal mucosal mast cells
Authors: SHI B. ‐B. , ISHIKAWA N. , KHAN A. I. , TSUCHIYA K. , HORII Y. , NAWA Y. 
Published: October 2007

SUMMARYSyrian golden hamster, Mesocricetus auratus, was found to be a moderately susceptible host for the intestinal helminth, Strongyloides venezuelensis. After infection by subcutaneous inoculation with 3000 infective larvae(L3), about 20% of them became adult worms in the small intestine, and, after a stable infection up to day 20, adult worms were slowly and gradually expelled towards day 45. Before infection, mast cells in the jejunum were about 30/10 villus crypt units and over 80% of them were formalin‐resistant and berberine sulphate‐fluorescence positive. After infection with S. venezuelensis, the number of intestinal mast cells gradually increased with time and about a half of them were formalin‐sensitive and berberine sulphate fluorescence‐negative. Intraepithelial migration of mast cells was never seen before and after infection. Heterogeneity of mucosal mast cells in terms of granular proteoglycans was further confirmed by the determination of critical electrolyte concentration. In spite of the heterogeneity of proteoglycans, enzyme‐histochemical study revealed that practically all mucosal mast cells of Syrian golden hamsters were positive for chymase but negative for tryptase. Mast cells in the skin and tongue were also positive for chymase but negative for tryptase. Together with our previous study on mucosal mast cells of other rodents, phenotypic variances of mucosal mast cells seem to be closely related to the protective capacity against the genus Strongyloides.
Characterization of the recognition specificity of autoreactive, polyspecific monoclonal antibodies obtained from spleen cells of parasite‐infected BALB/c mice
Authors: SAITO SUSUMU , ROJEKITTIKHUN WICHIT , GAO PENG , YAMASHITA TAKAO , WATANABE TADASHI , SAKATO NOBUO , SENDO FUJIRO 
Published: October 2007

SUMMARYWe examined the specificity of four monoclonal antibodies (MoAbs) obtained from Schistosoma japonicum (1D, GAO3), Trypanosoma cruzi (TSLO), and Trichinella spiralis (TSY2) infected BALB/c mice. All four MoAbs reacted not only with autologous parasite antigens but also with various heterologous parasite antigens and normal tissues. The antigen recognition pattern seen on Western blots was almost identical in 1D and GAO3, and in TSLO and TSY2. Furthermore, certain bands were identical among all four MoAbs. The mechanisms responsible for these phenomena are discussed.
Possible role of nitric oxide in malarial immunosuppression
Authors: ROCKETT KIRK A. , AWBURN MELISSA M. , ROCKETT ELIZABETH J. , COWDEN WILLIAM B. , CLARK IAN A. 
Published: October 2007

SUMMARYWe have tested the hypothesis that nitric oxide may be responsible for the immunosuppression reported during malaria infections. We first showed that reactive nitrogen intermediates, which indicate nitric oxide generation, were increased in the plasma of Plasmodium vinckei‐infected mice. We next found that Concanavalin A‐induced proliferation of spleen cells from these mice was reduced compared with that observed in uninfected animals. The addition of NG‐methyl‐L‐arginine (L‐NMMA) for the duration of the cultures restored the malarial proliferative response to normal. We then tested the effect of oral L‐NMMA on the proliferative response of P. chabaudi‐infected mice to a human red blood cell lysate. The secondary response to this antigen, measured as spleen cell proliferation in vitro ten days after immunization and when there was no discernible parasitaemia, remained normal in L‐NMMA‐ treated P. chabaudi mice, but was decreased in the untreated infected mice. These results suggest a role for nitric oxide in malarial immunosuppression.
Roles for both CD+ and CD8+ T cells in protective immunity against Onchocerca lienalis microfilariae in the mouse
Authors: FOLKARD SHELLEY G. , BIANCO ALBERT E. 
Published: October 2007

SummaryMice inoculated with microfilariae of the filarial nematode Onchocerca lienalis clear their parasites from the skin over a period of 3 to 4 months and are highly resistant to a challenge infection. The adoptive transfer of spleen cells at various time points following primary and secondary infections of mice shows that exposures of 50 days or greater are required for the generation of lymphocytes capable of transferring protection to naive recipients. This adoptive transfer of protection with spleen cells from infection‐primed mice partitions with the T lymphocyte population. In contrast, the passive transfer of protection with spleen‐derived B cells, or sera taken at various time points following infection was not achieved. Moreover, there was no detectable synergistic effect when B and T cells were co‐administered to recipient animals. Depletion of CD4+ and CD8+ T cells with monoclonal antibodies shows that CD8 + T cells have some regulatory effect on parasite establishment early in primary infection, but this is later superseded by CD4+ T cell reactivity that is predominant both when primary infection microfilariae are cleared and also during resistance to reinfection. Measurement of cytokines in the sera of mice undergoing primary and secondary infections support a microfilariae‐induced Th2 activity, with high levels of IL‐5 that are sustained upon reinfection, and low levels oflFN‐γ that are negligible at the time when mice are most strongly immune.
Clethrionomys glareolus, but not Apodemus flavicollis, acquires resistance to lxodes ricinus L, the main European vector of Borrelia burgdorferi
Authors: DIZIJ ASTRID , KURTENBACH KLAUS 
Published: October 2007

SummaryThe European rodents Clethrionomys glareolus (bank vole) and Apodemus flavicollis (yellow‐necked‐mouse) are important hosts of the tick species Ixodes ricinus, the main European vector of Borrelia burgdorferi. We have addressed the question whether or not these tick hosts develop resistance to I. ricinus larvae. C. glareolus and A. flavicollis were exposed to 40 I. ricinus larvae for five consecutive times at two week intervals. Resistance was tested by the following parameters: percentage of ticks fully engorged, time of attachment, engorgement index, percentage of recovered ticks and proportion of larvae moulting to nymphs. Repeated infestation ofC. glareolus resulted in progressive and significant reductions in the percentage of fully engorged ticks, the time of attachment of partially engorged ticks, the scutal index of partially engorged ticks and the moulting success. In contrast, repeatedly infested A. flavicollis did not acquire resistance to larval I. ricinus. Effects of resistance in C glareolus could be partially disrupted by treatment with the immunosuppressive agent, cyclosporin A (CsA), indicating that T helper cells participate in the immune responses to tick bites. The data suggest that acquired immunity to I. ricinus larvae in C. glareolus is a density‐dependent factor regulating natural tick burdens and that it may have an impact on the transmission cycle of B. burgdorferi in Central Europe.
Strain variation limits protective activity of vaccines based on soluble Babesia canis antigens
Authors: SCHETTERS TH. , KLEUSKENS J. , SCHOLTES N. , BOS H. J. 
Published: October 2007

SummaryGroups of five dogs were immunized with vaccines containing soluble parasite antigens (SPA) derived from in vitro culture of Babesis canis parasites, either obtained commercially (Pirodog®) or produced at laboratory scale. Both vaccines generated antibodies that reacted with parasitised erythrocytes (PE). Upon challenge infection with homologous parasites, protection was evident from less severe decreases of haematocrit values, and reduced morbidity. Vaccinated animals, however, were not protected against challenge infection with heterologous B. canis parasites. Recovery from challenge infection coincided with the production of antibodies against parasitized erythrocytes. The results suggest that SPA from B. canis carry strain‐specific determinants that are crucial for inducing protection in dogs against challenge infection, and explain vaccination failures in the field.
Plasmodium vivax: detection of blood parasites using fluorochrome labelled monoclonal antibodies
Authors: PEREZ HILDA A. , WIDE ALBINA , BRACHO CARMEN , la ROSA MERCEDES 
Published: October 2007

SummaryA monoclonal antibody (MoAb) 2C6111 specific for Plasmodium vivax erythrocytic stages was shown to detect parasitized erythrocytes in blood samples collected in the field. This MoAb binds to the mature trophozoite, schizont and gametes of P. vivax and upon examination of 43 wild isolates no evidence of polymorphism was found. To search for P. vivax parasites in human blood a MoAb immunofluorescent test (MoAb‐IFT) was developed. The assay is based on the ability of fluorescein isothiocyanate labelled MoAb 2C6111 to combine with parasitized erythrocytes on thin blood smears. A preliminary field trial was carried out in Venezuela to determine the usefulness of MoAb‐IFT for the specific diagnosis of P. vivax malaria. Blood samples collected from malarious and non‐malarious individuals were examined both by standard microscopy of Giemsa stained thick blood smears (G‐TS) and MoAb‐IFT. The latter was specific and gave a 100% correlation with G‐TS. Sensitivity was close to that usually achieved with Giemsa stained blood films.,