bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of the Plasmodium berghei ookinete protein Pbs21 in a baculovirus‐insect cell system produces an efficient transmission blocking immunogen
Authors: MARGOS GABRIELE , KURTENBACH KLAUS , POSNETT ELSA , BARKER GUY C. , MATSUOKA HIROYUKI , PATON MICHAEL G. , SINDEN ROBERT E. 
Published: October 2007

SummaryA surface protein of Plasmodium berghei ookinetes, Pbs21, was expressed in a baculovirus‐insect cell system in cell culture and in Heliothis virescens larvae. Groups of BALB/c mice received two intraperitoneal inoculations of either i) Tris‐buffer or homogenized H. virescens larvae infected with wild‐type baculovirus; ii) enriched, homogenized ookinetes, or Hi) homogenizedH. virescens larvae expressing recombinant Pbs21 (rPbs21). All animals immunized with ookinetes or with rPbs21 had high litres of antibodies (IgG isotype) that bound to native Pbs21. The large majority of antibodies in immune sera of both groups recognized the antigen under non‐reducing but not under reducing conditions. The predominant IgG‐sub‐classes in mice immunized with ookinetes was IgGl and in mice immunized with rPbs21, the subclasses were IgGl and IgG2a. Immunization with rPbs21 reduced the infec‐tivity of P. berghei to mosquitoes by 91% compared to a 99% reduction following immunization with ookinetes. This preliminary data indicate that rPbs21 expressed in this eukaryotic system induces a transmission‐blocking immunity which is more effective than that achieved using rPbsll expressed in Escherichia coli (Matsuoka et al. 1994).
Trypanosoma cruz/‐induced decrease in the level of interferon‐7 receptor expression by resting and activated human blood lymphocytes
Authors: KIERSZENBAUM F. , LOPEZ H. MEJIA , TANNER M. K. , SZTEIN M. B. 
Published: October 2007

SummaryA substantial proportion of human peripheral blood mononuclear cells (PBMC) manifested a decreased capacity to express membrane interferon‐γ receptors (IFN‐γR) when co‐cultured with Trypanosoma cruzi. Among the lymphocytes, B cells accounted for the bulk of this effect, evidenced by a marked drop in the proportion of CD19+ or CD20+ cells expressing IFN‐γR. Decreased IFN‐γR expression by B lymphocytes was seen as early as 3 h after co‐culture with T. cruzi and persisted for at least 24 h. The parasite had no detectable effect on CD19, CD20 or DR antigen expression by B lymphocytes. Neither the proportion ofB cells expressing these markers nor the membrane density of these molecules varied significantly in the presence of T. cruzi. In PBMC cultures stimulated with Staphlyococcus aureus Cowan I (SACI), T. cruzi decreased the percentages of both IFN‐γR+ and IFN‐R +bnght (cells expressing above‐normal levels of surface IFN‐γR) B lymphocytes. Cell‐free filtrates of T. cruzi suspensions reproduced the suppressive effects of living parasites on IFN‐γR expression by B cells. When T. cruzi was present, the intracellular levels of IFN‐γR molecules in resting or SACI‐activated B lymphocytes, represented by fluorescence intensity, were well below control values, suggesting that decreased surface expression resulted from suppressed IFN‐γR synthesis. Among T (CD3+) cells, 10–8% to 39–6% (7 donors) expressed surface IFN‐γR and did so at a very low level. These percentages were also reduced by T. cruzi. If occurring in the host, downregulated expression of IFN‐γR could curtail the utilization of IFN‐γ, known to play a critical role in host defence against T. cruzi infection.
Lack of an association between hydatid disease and autoimmunity
Authors: COLEBROOK AMANDA L. , LIGHTOWLERS MARSHALL W. 
Published: October 2007

SummaryThe prolonged survival of Echinococcus granulosus within the human host indicates that some mechanism is operating to permit parasite evasion of the host immune response. Several publications have described autoimmune phenomena in patients infected with hydatid cysts. The aim of this study was to test the postulate that there is a higher prevalence of autoantibodies in serum from patients with hydatid disease than in control samples, and this may provide some evidence of an association between autoimmunity andE. granulosus infection. Sera from 70 patients with hydatid disease and 45 control subjects were assayed for the presence of antinuclear antibodies (ANA), tissue specific autoantibodies and rheumatoid factor. All patients were aged between 20 and 80 years of age with no known history of autoimmune disease. Hydatid patients were surgically confirmed cases. Control subjects were chosen on the basis that they were age and sex matched to the test sera and had no known illness at the time blood samples were obtained. On the basis of an ANA autoantibody litre of > 1:40 being regarded as positive, 19 (27%) of the hydatid patients, 13 (28%) of the controls were positive. Low levels of tissue specific autoantibodies and rheumatoid factor were detected in sera from 5 (7%) and 2 (11%) hydatid patients and 4 (8%) and 3 (16%) of control subjects respectively. No significant differences (P > 0–05) were found between autoantibody levels in the hydatid patient sera and the controls. These findings suggest that there is no association between hydatid infection and the level of autoantibodies to a broad range of self antigens.
Immunoprophylactic potential of a 120 kDa Brugia malayi adult antigen fraction, BmA‐2, in lymphatic filariasis
Authors: CHENTHAMARAKSHAN V. , REDDY M.V.R. , HARINATH B.C. 
Published: October 2007

SummaryA 120 kDa antigen containing SDS‐PAGE fraction BmA‐2 isolated from Brugia malayi adult parasite was highly reactive with normal sera from filarial endemic area. BmA‐2 was analysed for its propylactic potential in in vitro and in vivo. Sera collected from BmA‐2 immunized jirds induced a significant level (80 to 90%) of protection against infective larvae and microfilariae in in vitro ADCC assay as well as in in situ micropore chamber implantation studies. Mastomys natalensis immunized with BmA‐2 showed a significant level of protective response against circulating microfilariae by clearing 90% of them from circulation by fifth day after challenge infection. Immunization of jirds with BmA‐2 resulted in an enhanced level of antibody response against BmA‐2 and 88% reduction in the development of the parasites to the adult stage. Passive transfer of immunesera from jirds immunized with BmA‐2 to naive jirds resulted in 71% reduction in adult worm recovery as observed 90 days after challenge infection with B. malayi. On the other hand the passive transfer of nonadherent spleen cells from immune jirds did not show any significant effect on the development of parasite. Administration of jirds anti BmA‐2 serum to microfilaraemic jirds showed a temporary decrease in micrqfilarial count which was increased to pretherapeutic level within 100 days and there was no effect on the adult worms. This implies that the immune protective effect of BmA‐2 is mainly antibody dependent and active immunization with BmA‐2 is effective against filarial infection.,
Further characterization of the 38 kDa antigen from Echinococcus granulosus (hydatid disease) cyst fluid: evidence for antigenic heterogeneity and reactivity with anti‐P1 antibodies
Authors: ZHANG LI‐HUA , LEGGATT G.R. , McMANUS D.P. 
Published: October 2007

SummaryA panel of 5 IgM and 6 IgG1 monoclonal antibodies (MoAbs) was produced against a band, eluted from a reducing SDS‐PAGEgel, containing the 38 kDa subunit of antigen 5 (Ag5) from Echinococcus granulosus cyst fluid; seven of the MoAbs were shown subsequently to bind epitopes on Ag5 but none recognizedphosphorylcho‐line or periodate‐sensitive carbohydrate epitopes. Differences in the fine specificity of the MoAbs were apparent and, upon reduction, heterogeneity in 38 kDa components from hydatid cyst fluids of different intermediate host origin was revealed by peptide fingerprinting and immuno‐blotting using the MoAbs. One of the IgGl MoAbs (ED9) was able to distinguish a reduced 38 kDa molecule in cyst fluids from two distinct genotypes–the horse/dog and sheep/dog strains–of E. granulosus and this may have implications for hydatid serology, immunoepidemiology and strain typing. Furthermore, epitopes on this 38 kDa component or on a different molecule with the same or similar Mr are reactive with anti‐P1 blood group antigen antibodies and this could result in false‐positive reactions where sera from P2 patients with suspected hydatid disease are tested by immunoblot or immunoprecipitation analysis.,
The effects of H2 and non‐H2 genes on the survival of Onchocerca lienalis microfilariae in the mouse
Authors: FOLKARD SHELLEY G. , BIANCO ALBERT E. 
Published: October 2007

SummaryThe effect of H2 and non‐H2 genes in a mouse model of protective immunity against Onchocerca lienalis microfilariae have been investigated. Non‐H2 effects were determined using CBA, BALB/c, B10, SJL and TO strains. All were permissive for establishment of a primary infection with microfilariae, although significant differences in parasite recoveries were evident amongst the various strains. The effect of H2 genes upon a primary infection was investigated using H2 congenic B10 and BALB strains, B10, B10.S, B10.BR, B10.D2/n, BALB/c, BALB.B, and BALB.K. Significant H2 effects were seen among the relatively weak responder B10 strains, but were not present among the relatively strong responder BALB strains. These results support a dominant effect of non‐H2 genes following primary exposure to microfilariae, and a ‘fine tuning’ effect of H2 genes that is apparent only in weaker responding strains. Upon reinfection of all the strains investigated, a gradation of protection was detected that appeared to be exclusively dependent upon H2.,
Vaccination of patas monkeys experimentally infected with Schistosoma haematobium using a recombinant glutathione S‐transferase cloned from S. mansoni
Authors: BOULANGER D. , WARTER A. , TROTTEIN F. , MAUNY F. , BREMOND P. , AUDIBERT F. , COURET D. , KADRI S. , GODIN C. , SELLIN E. , PIERCE R.J. , LECOCQ J.P. , SELLIN B. , CAPRON A. 
Published: October 2007

SummaryThe capacity of a recombinant glutathione S‐transferase from Schistosoma mansoni (rSm28GST) to vaccinate primates fErythrocebus patas,) against a heterologous infection with Schistosoma haematobium has been tested. Two injections of the purified molecule with Muramyl‐Di‐Peptide (MDP) as adjuvant resulted in a high level antibody response in the five immunized animals and in a significant reduction in worm fecundity compared to the controls which received adjuvant alone. Mean levels of daily egg excretion in urine and faeces were reduced by respectively 55% and 74% although perfusion revealed that worm burdens were similar in both groups. The protective effect was long lasting since it was maintained up to the end of the experiment, 42 weeks after infection. Hatching rates and the numbers of intra‐uterine eggs were also significantly affected by the vaccination. Tissue eggs were also drastically diminished in the urogenital system (–80%) but the reduction was not statistically significant. One animal was not protected by the immunization. There was a good correlation between parasitological data and the intensity of bladder lesions assessed by microscopic examination. Polypoid formations together with an intense exudation of the lamina propria were frequently seen in the controls but rarely in the vaccinated group where formation of scar tissue was predominant. These results underline the vaccine potential of the recombinant Sm28GST as a possible valuable prophylactic tool for the control of egg‐induced pathology and transmission of African schistosomes.
Immunoregulation in human lymphatic filariasis: the role of interleukin 10
Authors: MAHANTY SIDDHARTHA , NUTMAN THOMAS B. 
Published: October 2007

SummaryIn humans with lymphatic filariasis microfilaremia is associated with a parasite antigen‐specific hyporesponsive‐ness when assessed by cell proliferation and secretion of interleukin‐2 and interferon‐γ. Hyporesponsiveness in these individuals is not only parasite antigen‐specific but appears to be limited to Th1‐type responses. Th2 mediated responses such as IL‐5 secretion and IgE antibody production to parasite antigens are generally strong and usually no different than those seen in immunologically more reactive amicrofilaremic individuals with chronic lymphatic pathology. The mechanisms by which Th1 responses are inhibited have not yet been elucidated, but some studies suggest that down‐regulatory cytokines such as IL‐10 may be involved in this process. Mononuclear cells from microfilaremic individuals have been found to secrete greater quantities of IL‐10 spontaneously and in response to parasite antigens. In this review, mechanisms by which IL‐10 may be induced by the parasite and the mode by which IL‐10 may regulate parasite antigen‐specific Th1 responses in these individuals are discussed.
Reduced amount of intestinal mucus by treatment with anti‐CD4 antibody interferes with the spontaneous cure of Nippostrongylus brasiliensis‐infection in mice
Authors: KHAN W. I. , ABE T. , ISHIKAWA N. , NAWA Y. , YOSHIMURA K. 
Published: October 2007

SummaryMechanism of spontaneous cure was studied in mice infected with mouse‐nonadaptive Nippostrongylus brasiliensis. Adult BALB/c mice were cured spontaneously of infection with this strain of N. brasiliensis by Day 7 post‐infection. Expulsion of intestinal worms was delayed dose‐dependently by a treatment with anti‐CD4 antibody. However, the treatment had no significant effect on larval recovery from the lungs. Treatment of mice with anti‐IL‐5 antibody suppressed intestinal tissue eosinophilia induced by the infection, but did not affect intestinal worm recovery. Antigen specific IgE antibody was not detected in the sera obtained from Days 5 to 15. Therefore, IL‐5 and specific IgE antibody are probably not important in the spontaneous cure. Treatment of mice with anti‐CD4 antibody had no significant effect on number of intestinal goblet cells or on expression of terminal sugars of goblet cell mucins. However, histological and quantitative analyses revealed that significantly less intestinal mucus was released in anti‐CD4 antibody treated mice than in control mice. These results suggest that CD4+ lymphocytes control the amount of intestinal mucus and consequently the reduced mucus interferes with the spontaneous cure. Quantity of mucus released in the intestinal lumen may have an essential role in the spontaneous cure ofN. brasiliensis‐in/fcfio/i of mice.
Human immune recognition of recombinant proteins representing discrete domains of the Plasmodium falciparum gamete surface protein, Pfs230
Authors: RILEY ELEANOR M. , WILLIAMSON KIM C. , GREENWOOD BRIAN M. , KASLOW DAVID C. 
Published: October 2007

SummaryThe 230 kD gamelocyte/gamete‐specific surface protein of Plasmodium falciparum, Pfs230, is a target of antibodies which inhibit the development of the parasite inside the mosquito vector. A transmission blocking vaccine based on Pfs230 may be a powerful tool for malaria control. As a first step, Pfs230 has been expressed in E. coli as a series of recombinant proteins, fused to maltose binding protein. We have used the fusion proteins to assess cellular and humoral immune responses to Pfs230 in malaria‐immune adult Gambian blood donors; responses to the fusion proteins have been compared with responses to native Pfs230. The tetrapeptide repeat region of the molecule appears to be immunodominant for both antibody‐producing cells and peripheral blood T cells. We postulate that this may represent a mechanism for immune evasion since the N‐terminal repeat region of the molecule is cleaved from the mature protein and shed into the plasma. Responses to fusion proteins representing the seven‐cysteine motifs were correlated within individual donors, suggesting that cross‐reactive epitopes occur within the motifs. Antibody responses to recombinant proteins were poorly correlated with responses to native Pfs230 suggesting that dominant epitopes of the native protein are not adequately represented in the recombinant proteins. Although prokaryotic expression products may be suitable for induction of cellular immune responses to Pfs230, alternative expression systems may be needed for creation of appropriate B cell epitopes.
Cellular responses during liver fluke infection in sheep and its evasion by the parasite
Authors: MEEUSEN E. , LEE C. S. , RICKARD M. D. , BRANDON M. R. 
Published: October 2007

SummaryThe cellular immune response in sheep to an acute and chronic primary and an acute secondary liver fluke infection were examined by immunohistology of liver tissue and flowcytometry of lymphocytes from the draining hepatic lymph nodes. Ten days after primary infection, portal tract areas surrounding migratory tunnels were infiltrated with CD4+ and CD8+ lymphocytes with fewer B cells and T19+ T cells. Micro abscesses were distributed sporadically in the liver parenchyma and young flukes could be easily observed in the liver tissue free from inflammatory cells. More intensive infiltration of the portal tract areas was observed during a secondary liver fluke infection characterized by a pronounced increase in eosinophils, B cells and CD4+ T cells. In addition, there was an increase in MHC class II+ fibroblastic‐like cells surrounding the migratory tracts. In contrast to the primary infection, no young flukes were observed in the same tissue areas during the secondary infection. Chronic primary infections were characterized by perilobular fibrosis and a predominance of CD8+ and γδ‐TCR+ T19‐ T cells distributed within fibrotic strands. Distinct B cell follicles were observed in the fibrotic strands and near major bile ducts and necrotic patches. Pronounced lymphocyte infiltration could occasionally be observed surrounding liver fluke eggs lodged in liver tissue. A progressive increase in lymph node weight, cell number and CD4/CD8 ratio was observed in the acute and chronic primary infections. The role of the infiltrating cell populations and possible mechanisms of immune evasion by the parasite are discussed.
Immune cytotoxic activity of human eosinophils againstTrichinella spiralisnewborn larvae
Authors: VENTURIELLO S. M. , GIAMBARTOLOMEI G. H. , COSTANTINO S. N. 
Published: October 2007

SUMMARYThe ability of human eosinophils to kill the newborn larvae (NBL) of Trichinella spiralis of different maturation status, in the presence of antibody, was studied. A cytotoxic in vitro test was performed using NBL less than 2h of age (NBL2) or NBL maintained in culture at 37°C for 20 h (NBL20), peripheral blood eosinophils, anti‐Trichinella serum and human fresh serum as source of complement. Under these experimental conditions eosinophils from normal individuals attached to NBL2as well as to NBL2o but only the latter were killed. On the other hand, eosinophils from volunteers with eosinophilia killed NBL regardless of larval age. Neither adherence nor significant mortality was observed in the absence of immune serum. These results indicate that NBL maturation and eosinophil activation status are crucial for antibody‐dependent cellular cytotoxic reaction (ADCC).
The cachexia associated with Trypanosoma cruzi acute infection in mice is attenuated by anti‐TNF‐a, but not by anti‐IL‐6 or anti‐IFN‐7 antibodies
Authors: TRUYENS CARINE , TORRICO FAUSTINO , ANGELO‐BARRIOS ALCIRA , LUCAS RALF , HEREMANS HUBERTINE , BAETSELIER PATRICK DE , CARLIER YVES 
Published: October 2007

SUMMARYBALB/c male mice acutely infected with Trypanosoma cruzi underwent a severe weight loss (around 20%, from day 18 to 31 post‐infection), when compared to age‐matched uninfected animals. Though mice regained weight later, when blood parasites were hardly detectable, wasting extended over the chronic phase of infection. The onset and the magnitude of weight loss were related to the mouse susceptibility to infection, since they were respectively earlier and higher in male mice which will die than in surviving ones, in males than in females, and in BALB/c than in B6D2 [(C57B1/6 × DBA/2)F1], a mouse strain more resistant to infection. Fat weight of infected mice (male BALB/c) was reduced by 60 to 80%, whereas lean mass was unaffected and water content rose by 6 to 10% in acute and chronic infection. Haematocrit was also decreased by 15–16% in acute infection. Animals failed to compensate their energetic loss since their food intake remained similar to that of uninfected animals. Injections of neutralizing anti‐TNF‐α monoclonal antibody into infected male mice, during the first two weeks but not later in infection, significantly attenuated the weight loss. Early administration of anti‐IL‐6 or anti‐IFN‐γ MoAbs did not improve the mouse wasting. Taken together, these data show that TNFis a key agent of cachexia occurring in the acute T. cruzi infection in mice.
Stem cell factor dependent hyperplasia of mucosal‐type mast cells but not eosinophils in Schistosoma mansoni‐infected rats
Authors: NEWLANDS G. F. J. , COULSON P. S. , WILSON R. A. 
Published: October 2007

SUMMARYStem cell factor (SCF) is a growth factor with multiple activities which acts on numerous cell types including primordial germ cells, haemopoietic stem cells, melanocytes and mast cells. SCF is critical for the development of the mast cell hyperplasia associated with infection with the intestinal parasites Nippostrongylus brasiliensis and Trichinella spiralis. In the present study we have assessed the role of SCF in the mast cell and eosinophil responses to Schistosoma mansoni in the rat by blocking its effects in vivo with polyclonal antibody to SCF. Rats treated with sheep anti‐SCF antibody on days 21, 24, 27 and 30 of infection with S. mansoni showed a rapid decrease in serum concentrations of the mucosal mast cell‐associated protease rat mast cell protease II (RMCP II) by day 24, compared with normal sheep IgG‐treated controls. Similarly, the number of mucosal mast cells and RMCP II levels in both small intestine and liver were also significantly reduced by day 32 of infection. In contrast with the depeletion of mast cells and mast cell proteases, eosinophil numbers in liver or intestine did not change significantly after anti‐SCF treatment compared with controls. These results confirm that mast cell survival and hyperplasia are dependent on the presence of SCF whilst demonstrating that the eosinophil recruitment to liver and intestine associated with S. mansoni infection is SCF‐independent.
Immunoglobulin and cytokine profile in murine secondary hydatidosis
Authors: HARALABIDIS S. , ARAGOUNI E. K. , FRYDAS S. , DOTSIKA E. 
Published: October 2007

SUMMARYWe have investigated specific immune responses in BALB/c mice with experimentally induced secondary hydatidosis. Following intraperitoneal inoculation of brood capsules containing Echinococcus granulosus‐protoscoleces, the course of the infection was followed for 513 days. The sera of the mice were screened for the presence of a number of cytokines, and for specific antibodies. During the first 129 days of infection, high levels of cytokines TNFα, IL‐α, IFNγ, IL‐6, andIL‐10 and specific IgGl andIgG3 isotypes were detected, as compared to uninfected controls. The levels oflgM and IgG2a were slightly increased following infection, and remained elevated throughout the period of observation. The levels of IL‐lα and specific immunoglobulin of all isotypes except IgM and IgG2α, were significantly decreased 103 days post infection fp.i.), whereas TNFα was sharply decreased 129 days p.i. During the period of 129 to 209 days of infection there was an increase in secreted IL‐10, and a slow decrease in the levels of IL‐6 andlFN‐γ. Levels of IgM, IgG, IgGl, and IgG2a plateaud during this period, whereas IgG3 and TNFα showed a peak at day 190 p.i. These data suggest the induction of Th2 antibody‐mediated immunity with a parallel expansion of Thl‐mediated inflammatory responses as important mechanism of host defence against the metacestode.