bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trypanosoma cruzi infection in mice enhances the membrane expression of low‐affinity Fc receptors for IgG and the release of their soluble forms
Authors: JORGE TANIA ARAUJO , BOUHDIDI AYACHI EL , RIVERA MARIA‐TERESA , DAËRON MARC , CARLIER YVES 
Published: October 2007

SummaryThe membrane expression of low‐affinity Fc receptors for IgG (FcγRII/III) on cells and the number of FcγRII/III(+) cells were studied by flow cytometry, using the 2‐4G2 MoAb, in mice infected by Trypanosoma cruzi. Cells from spleen, mesenteric lymph nodes and peritoneum were collected on days 10, 20, 30 and 40 post infection (p.i.). The in vivo serum level of soluble FcγRII/III, as well as its in vitro release by cells from infected mice were studied. Parasitaemia and IgG1, IgG2a and IgG2b T. cruzi‐specific antibody titres were also recorded. Both the expression of FcγR on cell membrane and the absolute number of FcγR(+) cells increased in spleen and in mesenteric lymph nodes, but not in peritoneum. The modifications in spleen occurred in the early and late parasitaemic phase of infection, i.e., before and after detection of T. cruzi‐specific antibodies (from day 10 to 40 p.i.). In mesenteric lymph nodes, the variations were observed only in the early acute infection, when antibodies were not yet detectable at significant levels (on days 10 and 20 p.i.). Higher levels of soluble FcγR were detected in sera and in culture supernatants of spleen and lymph node cells from day 20 to 40 p.i. These results show that T. cruzi infection in mice upregulates the expression and the release of FcγRII/III, in the acute phase of infection, before as well as after the rise of antibody response.
Induction of protective immunity against murine secondary hydatidosis
Authors: HERNÁNDEZ ANA , NIETO ALBERTO 
Published: October 2007

SUMMARYSignificant protective immunity against secondary hydatidosis in mice was achieved by immunization with a preparation of surface molecules of E. granulosus protoscoleces with Freund's incomplete adjuvant (PSEx‐IFA). Study of PSEx‐IFA immunogenicity demonstrates that glucidic epitopes evoke mainly IgM responses while peptidic epitopes evoke mainly IgG responses; however both types of epitopes elicit both types of responses. Analysis of the possible association between susceptibility or resistance to infection and antibody responses after challenge was also performed. Cyst fluid antigen (CFAg) specific antibody titres on month eight after challenge correlated with number and size of cysts. On the other hand no correlation was observed between protection and PSEx specific IgG titres either on the day of challenge or one month later. Nonetheless, immunoblot analysis revealed that some PSEx molecules were recognized on day 30 after challenge only by sera from immunized mice.
Litomosoides carinii: macrofilariae‐derived glycolipids—chromatography, serology and potential in the evaluation of anthelminthic efficacy
Authors: BAUMEISTER S. , DENNIS R. D. , KLÜNDER R. , SCHARES G. , ZAHNER H. , GEYER E. 
Published: October 2007

SUMMARYA preliminary characterization of the glycolipids of Litomosoides carinii macrofilariae, resolved according to their chromatographic, chemical and serological properties, has been performed. Emphasis has been placed on the neutral fraction glycolipids. These are separable on thinlayer chromatography into two groups of fast and slow migrating band components, that differ in their migration, differential chemical staining and serological traits, respectively. Serological analyses have been accomplished by thin‐layer chromatography immunostaining and ELISA. Only components of the slow migrating band group react with infection serum from Litomosoides carinii‐infected Mastomys coucha. Cross‐reactivity experiments with homologous and heterologous infection sera of various helminthiases indicate that, epitopes bound to the neutral glycolipid fraction show structural similarity within the Nematoda, but not to the Cestoda or Trematoda. The dynamic development of specific Ig‐, IgG‐ and IgM‐anti‐neutral glycolipid fraction antibody levels were correlated with the different progression of L. carinii and Brugia malayi infections in the multimammate rat, Mastomys coucha. The reduction in the dynamics of IgG‐ and IgM‐antibody levels on chemotherapeutic treatment with the filaricides flubendazole and CGP 20376 has been related to their macrofilaricide‐activity.
Identification of Babesia bigemina infected erythrocyte surface antigens containing epitopes conserved among strains
Authors: SHOMPOLE SANKALE , McELWAIN TERRY F. , JASMER DOUGLAS P. , HINES STEPHEN A. , KATENDE JOSEPH , MUSOKE ANTHONY J. , RURANGIRWA FRED R. , McGUIRE TRAVIS C. 
Published: October 2007

SUMMARYThe presence of previously uncharacterized antigens (new antigens) on the surface of intact erythrocytes infected with three strains of Babesia bigemina from Kenya and one each from Puerto Rico, Mexico, St. Croix, and Texcoco‐Mexico was demonstrated by indirect immunofluorescent antibody (IFA) reactions. These antigens were not strain specific because antibodies in bovine immune serum to either the Mexico or Kenya isolates reacted with all seven strains tested. Homologous and heterologous immune serum antibodies bound a maximum of 83% and 55%, respectively, of intact erythrocytes infected with the Kenya‐Ngong strain but not uninfected erythrocytes. Both sera caused agglutination of only infected erythrocytes. Antibodies eluted from the surface of glutaraldehyde (0.25%) fixed infected erythrocytes had IFA reaction patterns among strains similar to those of immune sera before elation. Eluted antibodies were used to determine if these antigens were protein and encoded by B. bigemina. Eluted antibodies bound seven parasite‐encoded proteins of 240, 220, 66, 62, 58, 52 and 38 kDa in an erythrocyte surfacespecific immunoprecipitation reaction of 35‐methionine labelled proteins. It was concluded that the surface of B. bigemina infected erythrocytes had parasite‐encoded proteins and that these proteins had surface exposed epitopes that were conserved among the seven strains examined which were from two continents.
Expulsion of Hymenolepis nana from mice with congenital deficiencies of IgE production or of mast cell development
Authors: WATANABE NAOHIRO , NAWA YUKIFUMI , OKAMOTO KENICHI , KOBAYASHI AKIO 
Published: October 2007

SUMMARYThe roles of IgE and mast cells on expulsion of adult Hymenolepis nana from the intestine were examined in mice. IgE‐dependency was determined by comparing congenitally IgE‐deficient SJA/9 and IgE‐producing SJL/J mice infected with 50 H. nana eggs. Anti‐H. nana IgE antibody was detected at three weeks post infection (p.i.) in SJL but not in SJA mice. The number of adult worms in the intestines of SJA and of SJL mice were similar at two weeks, but significantly more were found in SJA mice at three weeks p.i. Treatment of mice with anti‐ɛ antibody also resulted in an increased worm burden at three weeks, suggesting participation of IgE in expulsion of H. nana. Intestinal mastocytosis was induced by infection regardless of the IgE status of the mice. Mast cell‐dependency was tested in mast cell‐deficient W/Wu and in normal littermate +/+ mice infected with 100 H. nana eggs. Anti‐H. nana antibody was detected in both groups of mice at three weeks p.i. Worm expulsion seemed to be mast cell dependent because expulsion was less complete in W/Wu mice at three weeks p.i. Peripheral blood eosinophilia was comparable at three weeks p.i. in both IgE and mast cell sufficient and deficient mice. These results suggest that IgE and mast cells participate in the expulsion of H. nana adults from intestine in mice.
Detection of antibodies in sera from Chagas' disease patients using a Trypanosoma cruzi immunodominant recombinant antigen
Authors: PARANHOS‐BACALLA GLAUCIA S. , SANTOS MARCIA R. M. , COTRIM PAULO C. , RASSI ANIS , JOLIVET MICHEL , E.CAMARGO MARIO , DA SILVEIRA JOSÉ FRANCO 
Published: October 2007

SUMMARYA Trypanosoma cruzi DNA fragment encoding an immunodominant repetitive antigen (H49) was subcloned into a protein purification and expressed system. Purified H49 peptide reacted specifically in an enzyme‐linked immunosorbent assay (ELISA) with sera from T. cruzi‐infected patients, but not with sera from patients with other parasitic diseases such as leishmaniasis and T. rangeli‐infection. The H49 recombinant ELISA was able to detect specific antibodies in 84% of chronic chagasic serum samples tested. One of the major advantage of the recombinant ELISA for serodiagnosis of chronic Chagas’disease resides in its high specificity (100%). Our data suggest that recombinant peptides could provide a practical basis for specific diagnosis tests for Chagas’disease.
Production and characterization of genus and species specific monoclonal antibodies against surface tegumental antigens of Schistosoma mekongi
Authors: VIYANANT V. , SOBHON P. , UPATHAM E. S. 
Published: October 2007

SUMMARYA panel of monoclonal antibodies (MoAbs) against freeze thaw surface tegumental antigens of Schistosoma mekongi were produced from naturally infected BALB/c mice. In this study, we have characterized two MoAbs which have different antigenic specificity for S. mekongi, S. japonicum and S. mansoni. The target epitopes of these two hybridoma antibodies are contained in the Mr 38 kDa (designated Sme 38) and Mr 97 kDa (designated Sme 97) proteins of adult worms as analysed by immunoblotting. The Sme 38 epitope was genus‐specific, since it is also detectable in S. japonicum and S. mansoni. The Sme 97 was not detected in S. japonicum and S. mansoni. therefore it is considered as species‐specific epitope. Immunocytochemical analysis revealed the presence of Sme 38 epitope in the surface tegument, the tegumental cells lying underneath the muscle layer and gut surface. The Sme 97 epitope was detectable only in the surface tegumental area.
Protection studies with integral membrane fractions ofHaemonchus contortus
Authors: SMITH W. D. , SMITH S. K. , MURRAY J. M. 
Published: October 2007

SUMMARYTechniques for targetting glycoproteins integral to the luminal membrane of the intestinal cells ofHaemonchus contortuswere used to isolate fractions of whole parasites with protective antigen potential. Sheep immunization trials with various candidate fractions revealed one which selectively bound to lectins with specificity for N‐acetylgalactosamine and which reduced mean challenge worm burdens by up to 72% and mean faecal egg counts by up to 93%. The luminal surface of the intestines of theHaemonchusrecovered from sheep immunized with this antigen were coated with host immunoglobulin, suggesting that the protective effect was due to antibodies interfering with the function of the gut. Further biochemical characterization of this fraction, which has been termedHaemonchusgalactose‐containing glycoprotein complex (H‐gal‐GP complex), showed that it could be distinguished from previously described protective antigens of this parasite and that it was only detectable in detergent extracts of the worms.
Possible protective immunity in human opisthorchiasis
Authors: AKAI PETER S. , PUNGPAK SWANGJAI , KITIKOON VIROJ , BUNNAG DANAI , BEFUS A. DEAN 
Published: October 2007

SUMMARYChronic infections with the liver flukes Opisthorchis viverrini and Clonorchis sinensis affect over 30 million people in southeastern Asia. With ongoing exposure, reinfection readily occurs following curative treatment and cumulative infections result in significant morbidity and a predisposition to cholangiocarcinoma. Though protective immunity has never been described in human opisthorchiasis, heterogeneity in worm burden occurs and a small number of exposed residents of endemic areas remain apparently uninfected. To explore the nature of this heterogeneity, we compared levels of serum antibody (Ab) to O. viverrini measured by an enzyme‐linked immunosor‐bent assay in 83 stool egg‐positive and 49 stool egg‐negative residents of an O. viverrini‐endemic area in Thailand. Compared to the egg‐positive residents, the egg‐negative group had significantly higher levels of immunoglobulin (Ig)G, IgA and IgM to adult worm homogenate (AWH) and total Ab to metacercaria homogenate (MH). Furthermore, immunoblot analyses revealed that a significantly higher proportion of sera from the egg‐negative residents had IgA reactivity against a 38‐k Da AWH antigen and IgM reactivity against carbohydrate epitopes of a 42‐k Da AWH glycoprotein antigen. These findings support a hypothesis that the egg‐negative group includes individuals who may be immunologically resistant to this usually chronic infection.
Human monocytes cultured with and without interferon‐gamma inhibit Plasmodium falciparum parasite growth in vitro via secretion of reactive nitrogen intermediates
Authors: GYAN BEN , TROYE‐BLOMBERG MARITA , PERLMANN PETER , BJÖRKMAN ANDERS 
Published: October 2007

SUMMARYAdherent cells from human peripheral blood were studied for their interaction with asexual blood forms of Plasmodium falciparum in vitro. Freshly isolated monocytes only showed weak anti‐parasitic effects. However, an enhancement of this anti‐parasitic activity was apparent when monocytes were allowed to mature in vitro. Monocytes activated with IFN‐γ for two or three days had an enhanced anti‐parasitic effect. In contrast, the inhibition mediated by cells incubated for five days was the same with or without IFN‐γ treatment. There was no evidence of toxicity when IFN‐γ at high concentrations was added directly to P. falciparum cultures. The anti‐parasitic activity of the activated cells seemed to be due to nitric oxide since incubation of macrophages with L‐NMMA reduced the level of inhibition. However, inhibition was only partial suggesting that other factors also were involved in inhibition of parasite growth.
Cytokine mRNA expression in skin in response to ectoparasite infection
Authors: J. ELHAY MARTIN , F. HANRAHAN CATHERINE , M. BOWLES VERN , SEOW HENG‐FONG , E. ANDREWS ARNA , D. NASH ANDREW 
Published: October 2007

SUMMARYCellular infiltration and local cytokine mRNA levels were examined during the first 48 h of infection of skin by larvae of the sheep blowfly Lucilia cuprina. At the cellular level the response involved a dramatic influx of leucocytes (CD45+ cells). Among these infiltrating cells were large numbers of granulocytes, including neutrophils and eosinophils, as well as macrophage‐like cells and lymphocytes. Many of the lymphocytes expressed cell surface markers characteristic of T cells including CD4, CD8 and the γδ TCR. The numbers of each of these cell types increased progressively as infection continued so that by 48 h the lesions were densely populated. Expression of mRNA for IL‐6 could be detected by Northern blot analysis while mRNA for other inflammatory cytokines including IL‐1α, IL‐1β, IL‐8 and TNFα was detected using the polymerase chain reaction. Coincident with the influx of granulocytes and other cells there was an increase in the level of mRNA for the cytokines IL‐lα, IL‐1β, IL‐6 and IL‐8. In the skin of the sheep there appeared to be constitutive expression of message for the cytokines IL‐1β, IL‐6 and TNFα, with the level of the latter not found to increase during the 48 h of infection examined. In situ hybridization was used to determine the location of IL‐6 and TNFα mRNA within resting and infected skin. During infection, fibroblasts, macrophage‐like cells and endothelium appeared to produce high levels of IL‐6 mRNA. Expression of the T cell dependent cytokines IL‐2 and IFN‐γ but not IL‐4, increased in expression as time progressed and the population of infiltrating cells, including T cells, expanded.
Immunization with irradiated Plasmodium berghei sporozoites induces IL‐2 and IFNγ but not IL‐4
Authors: L. WHITE KATHERINE , L. JARBOE DANIEL , KRZYCH URSZULA 
Published: October 2007

SUMMARYProtective immunity against Plasmodium induced by immunization with irradiated sporozoites (SPZ) depends on both humoral and cellular responses. Although circumsporozoite protein (CSP)‐specific cytolytic T lymphocyte responses have been established as an effector system, other cell types are required for protection. We have previously demonstrated that although protective immunity and T cell proliferative reactivity to SPZ are mouse strain‐ and SPZ dose‐dependent, no correlation between the two responses could be found. Since protective immunity involves functionally diverse T cell subsets, we asked whether the discordance between proliferative responses to SPZ and protective immunity might have resulted from selective activation of either the Th1 or Th2 cell subset. Protective immunity, in vitro proliferative responses, and lymphokine production were tested in BALB/c, C57Bl/6, and C3H/HeN mice immunized according to different SPZ regimens. The levels of IL‐2 paralleled the proliferative reactivities in each mouse strain examined. Although IFNγ levels were present in the unprimed lymphocyte cultures, they increased following each SPZ immunization, in C57Bl/6, moderate in C3H/ HeN, and lowest in BALB/c splenic cultures. Surprisingly. no IL‐4 was detected in splenic cultures from any mouse strain during proliferative activity or protective immunity. In contrast, elevated IL‐6 production was noted after each immunization, regardless of the protective status and it correlated with anti‐CSP IgG serum levels. These data establish that lymphokine profiles corresponding primarily to the Th1 cells were induced by immunization with P. berghei SPZ and that IL‐4 secreting T cells were not induced by the SPZ‐stage berghei antigens.
Theileria annulata sporozoite targets
Authors: CAMPBELL J. D. , BROWN D. J. , GLASS E. J. , HALL F. R. , SPOONER R. L. 
Published: October 2007

SUMMARYBovine peripheral blood mononuclear cells (PBM) infected in vitro with Theileria annulata sporozoites have previously been characterized as MHC class II+ mature macrophages. The ability of T. annulata sporozoites to infect different subpopulations of MHC class II+ bovine monocytes was investigated. Cells were labelled with monocyte specific monoclonal antibodies (MoAb) and isolated using magnetic cell sorting (MACS). Sporozoites infected both immature and mature monocytes, but more readily infected the mature population. A potential ligand for sporozoite entry is the elastin receptor which is expressed mainly on the immature population of monocytes and not on B cells or T cells. T. annulata sporozoites infected elastin receptor positive and negative cell populations equally well. Infected immature cells lost the expresstion of elastin receptors and the immature marker, subsequently expressing the mature marker. All monocytes lost the expression of CD14 (the LPS receptor) upon infection with sporozoites. The infection of specific populations and subsequent alterations in phenotype may alter the function of these cells and play an important role in disease pathogenesis.
Differential effects of Trypanosoma cruzi on the transcription of the p55IL‐2R, c‐fos, c‐myc and CD69 genes in activated human lymphocytes
Authors: KIERSZENBAUM F. , MAJUMDER S. , LOPEZ H. MEJIA , SZTEIN M. B. 
Published: October 2007

SummaryMitogen‐activated lymphocytes co‐cultured with either purified Trypanosoma cruzi trypomastigotes or the filtrate of trypomastigote suspensions in culture medium manifest a significant decrease in their capacities to express p55 interleukin‐2 receptor molecules (p55IL‐2R) on their membrane and proliferate. In this study we found that the cytoplasmic levels of p55IL‐2R are also markedly reduced under these conditions. This inhibition appeared to result from altered gene transcription since the levels of p55IL‐2R mRNA in phytohaemagglutinin (PHA)‐stimulated human peripheral blood mononuclear cells (PBMC) dropped substantially in the presence of parasite suspension filtrate. The rates of decay for p55IL‐2R mRNA determined in cultures lacking and containing the parasite filtrate after addition of actinomycin D to inhibit further RNA synthesis were comparable. These results indicated that decreased p55IL‐2R mRNA was not due to decreased stability of this mRNA under our conditions and pointed to a transcriptional or pre‐transcriptional modification as the likely mechanism by which T. cruzi affects activated lymphocytes. The parasite filtrate did not appear to affect transcription of c‐fos or c‐myc (known to occur in the very early stages of lymphocyte activation) or that of CD69 (which is concomitant with p55IL‐2R transcription). Thus, decreased p55IL‐2R gene transcription appears to be a somewhat selective effect of a T. cruzi‐derived molecule(s) rather than the consequence of an overall shutdown of gene transcription.
Immunoepidemiology of human necatoriasis: correlations between antibody responses and parasite burdens
Authors: QUINNELL R.J. , WOOLHOUSE M.E.J. , WALSH E.A. , PRITCHARD D.I. 
Published: October 2007

SummaryIn this paper we describe the relationship between antibodies to Necator americanus stage‐specific antigens and parasite burden in an endemically‐infected population in Papua New Guinea. Using an age‐structured analysis, we show that the correlation coefficient between levels of IgG against adult worm excretory‐secretory (ES) antigen and parasite burden declined significantly with host age from positive in younger hosts to significantly negative in older hosts. A trend towards similar patterns was present for anti‐larval IgG both pretreatment and after reinfection, and for anti‐ES IgM and anti‐ES IgE pretreatment. These patterns are consistent with a role for these isotypes in a protective immune response, although parasite‐induced immunosuppression may provide an alternate explanation. This is another demonstration of possibly protective responses to N. americanus infection.,
Heat shock proteins of Toxoplasma gondii
Authors: LYONS R.E. , JOHNSON A.M. 
Published: October 2007

SummaryWe have investigated heat shock protein (HSP) expression in mouse‐virulent and ‐avirulent strains of Toxoplasma gondii by performing Western blot analysis using a monoclonal antibody against HSP65 of Mycobacterium bovis and a polyclonal antiserum against HSP70 o/Plasmodium falciparum as primary antibodies. We initially observed that murine macrophages express HSP65 when infected with either virulent or avirulent strains, a result which contradicts previous reports. Differential HSP expression consistent with virulence was observed between strains, with high levels of a 70kDa HSP (HSP70) only detected in virulent strains in vivo. This protein was not observed in virulent strains in the immunocompromised mouse or in vitro, suggesting induction by immunological stresses. This protein was only poorly expressed in avirulent strains. A 65 kDa protein was observed in all strains in vivo and in vitro, suggesting a shared epitope with HSP70. These results are consistent with the hypothesis that the induced expression of HSP70 in virulent strains of T. gondii by immunological stresses may provide protection for these strains against cell damage associated with invasion of the host, allowing the virulent strains to persist as tachyzoites without the requirement for the encystation observed in avirulent strains.