bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased CD4+ T cell‐dependent anti‐erythrocyte antibody levels following the onset of parasite egg production in Schistosoma mansoni infected mice
Authors: HUMPHRIES DEBBIE , T. VELLA ANTHONY , J. PEARCE EDWARD 
Published: October 2007

SUMMARYAnaemia has been reported to be a symptom of schistosomiasis mansoni. In other chronic infectious diseases, antired blood cell (RBC) antibodies have been suggested or shown to play a role in anaemia by participating in either complement or macrophage‐dependent RBC elimination. To examine whether such a situation could be contributing to the anaemia of schistosomiasis, we examined RBC taken from infected mice for surface‐bound antibodies. Our data show that prior to the onset of egg production infected mice have plasma haemoglobin levels that are indistinguishable from age matched controls (AMC). However, consistent with previous reports, following the initiation of egg laying, infected mice have significantly lower haemoglobin levels than AMC. Surface‐bound IgM, IgG1 and IgG3 on RBC from infected mice increased markedly after egg laying began. Levels of RBC‐associated IgG2b were similar on RBC from infected and normal mice. Antibody production against RBC was Th cell‐dependent since it did not occur in mice depleted of CD4+ cells. Antibodies eluted from RBC of infected mice bound to isolated membranes of RBC from AMC and to a soluble extract of schistosome eggs. Furthermore, antibodies in serum from mice carrying patent infections bound to the membranes of RBC from normal mice. Taken together, these data suggest that schistosome eggs induce an antibody response which may cross react with a RBC surface antigen.
Interferon‐gamma and the induction of protective lgG2a antibodies in non‐lethal Plasmodium berghei infections of mice
Authors: WAKI S. , UEHARA S. , KANBE K. , NARIUCH H. , SUZUKI M. 
Published: October 2007

SummaryMice treated with anti‐IFN‐gamma monoclonal antibodies were unable to recover from infection with an attenuated variant of P. berghei (Pb XAT) which causes non‐lethal malaria in normal mice. On the other hand, treatment with anti‐lL‐4 monoclonal antibodies had no effect on the course of infection. IFN‐gamma was produced by spleen cells in vitro during the early phase of the infection. Treatment with anti‐IFN‐gamma suppressed development of an anti‐plasmodial IgG2a immunoglobulin isotype in the serum of infected mice whereas anti‐IL‐4 interfered with the IgGl response. An lgG2a fraction of immune serum collected from mice that had recovered from Pb XA T transferred immunity to naive mice but the IgGl fraction did not. When glutaraldehyde fixed parasitized erythrocytes were incubated with immune serum in suspension, specific IgG2a antibodies were detected by fluorescein staining on the membranes of cells infected with mature stages of parasites. These results indicate that IFN‐gamma is a key to inducing B cells to produce the protective anti‐plasmodial IgG2a immunoglobulin isotype. Antibody‐dependent cell‐mediated parasite killing seems to be involved in the mechanism of recovery from infection with Pb XAT.
Detection and characterization by immunoblot analysis of potentially diagnostic Leishmania infantum polypeptides in human visceral leishmaniasis
Authors: CARDENOSA N. , RIERA C. , CORTES P. , MARCH F. , MUNOZ C. , PORTUS M. , PRATS G. 
Published: October 2007

SummaryHumoral immune responses were studied in 53 sera from 18 patients with visceral leishmaniasis by immunoblot analysis. Sera from visceral leishmaniasis patients recognized antigens with molecular weights ranging from < 14kDa to more than 100 kDa. Bands ranging between 49 and < 14 kDa were the most specific. The 40, 33 and 17kDa antigens were recognized by 90%, 79% and 79% of the patients sera, respectively. Sera from one patient with Chagas' disease identified 8 of 11 antigens of the specific region. Treatment with periodate eliminated the cross‐reaction in three of these antigens (40, 29, 26 kDa). The study of serial sera collected from the different patients showed a decrease in intensity or dissappearance in some of the diagnostic bands, particularly the 17 kDa band. The band of 17 kDa seems to be useful to study the clinical evolution, for post‐treatment control and also for epidemiologic purposes. (It has been identified in 7% of control sera from endemic areas.) Immunoblot could be a valuable tool in the diagnosis of visceral leishmaniasis, being more sensitive and specific than other serologic tests.
Humoral immune response of children with chronic schistosomiasis. Isotype recognition of adult worm antigens
Authors: NOYA O. , FERMÍN Z. , NOYA B. ALARCÓN DE , LOSADA S. , COLMENARES C. , HERMOSO T. 
Published: October 2007

SummaryIn areas of low transmission of schistosomiasis, the evaluation of the success of control depends on reliable diagnostic tests. Under such conditions, some of the serological tests better estimate the real prevalence of this parasitosis than the classical stool examinations. On the search of highly sensitive and specific antigenic fractions for use in serological tests, an immunoblot technique with a luminescent substrate was used in order to evaluate, under dissociating and reducing conditions, the Schistosoma mansoni adult worm antigen (A WA). The sera of 30 infected Venezuelan children were assayed for specific recognition of A WA by IgG, IgM, IgE, IgA, and the four IgG subclasses. Eight highly specific polypeptide molecules from the parasite of 118,114,105, 74, 71,45,36, and 30 kDa were recognizedby total IgG. Additionally, IgGl and IgG2 recognized a molecule of 100 kDa and IgM one of 77 kDa. The present data suggests that certain molecules from the adult worm, specially the 36 kDa, might be relevant in the specific immunodiagnosis of this parasitic disease. The fact that the children antibodies were able to recognize the primary structure of these antigens, will allow us to chemically synthesize the relevant linear epitopes.,
Isotype‐specific characterization of antibody responses to Onchocerca volvulus in putatively immune individuals
Authors: STEWART GRAHAM R. , ELSON LYNNE , ARAUJO EDMUNDO , GUDERIAN RONALD , NUTMAN THOMAS B. , BRADLEY JANETTE E. 
Published: October 2007

SummaryIsotypejsubclass‐specific antibody responses to adult Onchocerca volvulus extract (OvAg) were assessed by both ELISA and immunoblotting for a group of putatively immune individuals (PIs, n = 29) from a hyperendemic area in Ecuador and for a group of infected individuals (INFs, n = 47) from the same region. As a group, the Pis have been previously shown to possess lower levels of OvAg specific IgG1, IgG2, IgG3 and IgG4 than INFs but semiquantitative analysis revealed that the relative proportions of these subclasses differs between the two groups. The IgG of the PI group contained a higher proportion of IgG3 and a lower proportion of IgG4 than the INF group. The frequency distribution of IgG3 responses was similar for the PI and INF groups. The frequency distributions for IgG1, IgG4 and IgE were significantly different between the PI and INF groups. A subgroup of the Pis were identified from frequency distributions and multivariate plots of individual isotype responses as having antibody responses (mainly IgG4) possibly indicative of cryptic infection. High IgE responses were exclusive to INF individuals, and a rare response type of high IgG3 with negligible levels of other isotypes/subclasses was seen only in the PI group. However, the majority of the Pis had negligible responses for all antibody classes. Immunoblots demonstrated no obvious differences in qualitative recognition between the PIs and INFs.
NK and LAK functions in human chronic Chagas disease
Authors: STRACIERI A.B.P.L. , VOLTARELLI J.C. 
Published: October 2007

SummaryNatural killer (NK) and lymphokine activated killer (LAK) functions were measured in 40 patients with chronic Chagas disease divided into asymptomatic/indeterminate (18) and symptomatic forms (22) and in 24 healthy controls. A chromium release assay was used employing K562 or P815 cell lines as targets. There was no difference in either NK or LAK activity between the three groups. A small number of patients in each group showed results above or below the normal range for controls. However, there was no correlation between NK and LAK values in the same individual. In conclusion, NK and LAK functions do not seem to be involved in the immunosuppression associated with human chronic Chagas disease.
Temporal changes in the humoral immune response of cattle during experimental infections with Onchocerca lienalis
Authors: KUO YIEN‐MING , BIANCO ALBERT E. 
Published: October 2007

SummaryIn order to gain insights into the immune response in onchocerciasis during early infection, laboratory‐reared calves were infected with 1000 Onchocerca lienalis infective larvae and examined serologically over a period of 508 days. Levels of serum antibodies measured by ELISA against adult worm extract revealed a multiphasic response, characterized by a broadly similar profile of peaks in individual animals arising at 15–30, 79 and >266 days after infection. Timings of these changes in responsiveness closely mirrored parasite development, coinciding with larval moults and with the onset of a patent infection. The levels of individual antibody isotypes directed against parasite antigens was strongly skewed. The dominant response was of IgG1, although limited reactivities were also found for IgG2 and IgM: No parasite‐specific IgA antibodies were detected. Immuno‐blots of adult worms extracts revealed a pattern of antigen recognition over time that matched the results obtained by ELISA. Again, the IgGl response was strongest, although certain lgG2 and IgM specificities were well represented. In general, there was a steady increase in the number of individual antigens recognized as the infection progressed, with a striking expansion of antibody specificities from day 79 following the fourth larval moult. Antibodies to a 16kDa component were a prominent feature of the response following development of a patent infection. These data reveal the strong influence of parasite biology on the development of the immune response in onchocerciasis.
Cellular and humoral immune responses to recombinant antigens in sheep infected with Toxoplasma gondii
Authors: COUGHLAN S. N. , SAMAN E. , JACOBS D. , MERCIER C. , CESBRON‐DELAUW M. F. , TREES A. J. 
Published: October 2007

SummaryImmune responses to recombinant fragments of the Toxoplasma gondii antigens ROP2 and GRA2 were investigated in sheep naturally and experimentally infected with T. gondii oocysts. Specific serum antibodies to C‐terminal fragments were detected by ELISA. Cell‐mediated responses in peripheral blood mononuclear cells were demonstrated by proliferation and interferon‐gamma production following in vitro stimulation with the ROP2 fragment. This data indicates the presence of epitopes for sheep B cells in the recombinant GRA2 fragment and for both B and T cells in the ROP2 fragment.
Protective immunity against malaria: cellular changes in the liver vary according to the method of immunization
Authors: FAURE PATRICK , HULIER ELISABETH , MILTGEN FRANCOIS , RENIA LAURENT , MAZIER DOMINIQUE 
Published: October 2007

SummaryCharacterization of cells present in the extravascular compartment of murine liver was performed after different immunization procedures against the malaria parasite Plasmodium yoelii. Mice were immunized with live or irradiated sporozoites or with parasitized erythrocytes. Whatever the immunization protocol used, the mice were protected against a sporozoite challenge but each immunization procedure induced a specific profile of cell types. Immunization with irradiated sporozoite induce a significant increase in CD8+ lymphocytes, parasitized erythrocytes stimulates production of monocytes/macrophages and CD8+ lymphocytes while, after live sporozoites immunization, polymorphonuclear cells, macrophages/ monocytes, B cells and a range of T cell subsets were increased in number.
Cytotoxicity in human mucosal and cutaneous leishmaniasis
Authors: BARRAL‐NETTO M. , BARRAL ALDINA , BRODSKYN CLAUDIA , CARVALHO E. M. , REED S. G. 
Published: October 2007

SummaryCD8+ T cells and lysis of parasitized macrophages seem to be important in the resistance to murine leishmaniasis. In the present study, we evaluated peripheral blood mononuclear cell (PBMC) from patients with either cutaneous (CL) or mucosal (ML) leishmaniasis in cell lysis assays using 51‐Cr‐labeled Daudi or K562 cells, or autologous antigen‐pulsed macrophages as targets. Results are reported as lytic units (number of cells required for 30% lysis) per million PBMC. Exposure of patient PBMC (n= 12) to lysate from Leishmania amazonensis promastigotes led to an increase in cytotoxic activity compared to unstimulated patient cells against Daudi (81.8 ± 14.9 vs 13.6 ± 5 lytic units (LU) per million PBMC; mean ± SEM) and K562 (65.7 ± 8.4 vs 13.1 ± 5 LU/106 PBMC). ML had higher responses than CL in both targets (80–4 ± 11.0 vs 46.4 ± 11.6 LU/106 PBMC for K562, and 104.3 ± 23.8 vs 59.3 ± 14.3 LU/106 PBMC for Daudi). Normal control PBMC, stimulated with L. amazonensis antigen had 6.32 ± 3.72 LU/106 PBMC against Daudi cells and 9.06 ± 2.78 LU/106 PBMC against K562. The cell responsible for lysis of the K562 cells was characterized as NK, by means of cell separation employing magnetic beads coupled to antibodies. Addition of recombinant TGF‐β or recombinant human IL‐10 reduced L. amazonensis‐mdwcec? cytotoxicity by 90% and 70%, respectively. Cytotoxicity of antigen‐stimulated PBMC was also demonstrated against autologous L. amazonensis antigen‐pulsed macrophages in the range of 6.7 to 41.7LU/106 PBMC. In this system TGF‐β and IL‐10 also decreased the antigen‐induced cytotoxic response.
Immunohistochemical localization of excretory/secretory antigens in adult Ancylostoma caninum using monoclonal antibodies and infected human sera
Authors: SAWANGJAROEN N. , OPDEBEECK J. P. , PROCIV P. 
Published: October 2007

SummaryHuman eosinophilic enteritis (EE) may result from hypersensitivity to the excretory I secretory (ES) antigens of adult Ancylostoma caninum. The origin of several antigens were identified by probing adult A. caninum with mouse monoclonal antibodies (MoAbs), sera from mice vaccinated with ES antigens and sera from human EE patients. Six MoAbs (AC/ES1–6) were produced against ES antigens, two being IgG3 and four IgM. Western blots demonstrated four different antigen specificities: MoAb AC/ES 1 bound strongly to an ES product at about 30kDa; AC/ES 2 recognized a broad band ranging from 50–200kDa; AC/ES 3, AC/ES 5 and AC/ES 6 reacted at about 68 kDa, and AC/ES 4 at about 97kDa. Sections of formalin‐fixed, paraffin embedded adult A. caninum were then incubated with these MoAbs and immunostained by the peroxidase‐anti‐peroxidase (PAP) technique. The target epitope of MoAb AC/ES 1 was found mainly in the oesophageal, amphidial and excretory glands; AC/ES 2 reacted weakly with many structures in the sections; AC/ES 3, AC/ES 5 and AC/ES 6 were specific for excretory glands only, and AC/ES 4 bound to amphidial glands. Sera from immunized mice reacted with all three (especially the excretory) glands and the cuticle. In an indirect assay, worm sections probes with three human EE patient sera demonstrated maximal staining in the amphidial glands. Our findings confirm that ES products of A. caninum include immunogenic glandular secretions which may be involved in the pathogenesis of human EE.
Immunological studies on an Onchocerca volvulus intermediate‐filament protein
Authors: ZHANG DAN , MILLER DAVID J. 
Published: October 2007

SummaryWe report the complete sequence of the cDNA encoding an intermediate filament (IF) protein from Onchocerca volvulus. The OVIF cDNA encodes a protein of 613 amino acid residues, which has a predicted molecular weight of approximately 70 kD. The size of the protein encoded by the O VIF cDNA corresponds well with estimates obtained in Western blotting experiments, but these same experiments suggest that Onchocerca sp. may contain at least two IF proteins. To identify the domain(s) of the O VIF protein responsible for immunogenicity in human filariasis patients, fragments of the OVIF cDNA were subcloned into the appropriate pGEX vector and Western blots of the corresponding fusion proteins probed with human sera. Pooled sera from general onchocerciasis or Bancroftian filariasis patients reacted only with the C‐terminal region of the OVIF protein, whereas sowda onchocerciasis sera reacted 1–2 orders of magnitude more strongly and with a number of other epitopes. Immunolocalization experiments implied that the OVIF protein is associated with both muscle and a number of specific membrane layers. These studies provide the basis for evaluation of the protective potential of the OVIF protein.
Immunity to a challenge infection ofStrongyloides stercoralisthird‐stage larvae in the jird
Authors: NOLAN THOMAS J. , ROTMAN HARRIS L. , BHOPALE VEENA M. , SCHAD GERHARD A. , ABRAHAM DAVID 
Published: October 2007

SUMMARYJirds support the entire life‐cycle of Strongyloides stercoralis. We therefore used this host as a model to define the mechanism of the immune response to a challenge infection, as well as the parasite stage effected by the response. Jirds given a primary infection of S. stercoralis are resistant to re‐infection. The use of implanted diffusion chambers containing larvae showed that the immune response killed the third‐stage larvae, and this was confirmed by subcutaneous infections. The larvae of a challenge infection are killed within 48 h, a time period too short to allow for the development of L4 and adult worms. The immune response is dependent on both a serum factor and cells, suggestive of an ADCC type response.
The specificity of the human IgE response to Necator americanus
Authors: PRITCHARD D. I. , WALSH E. A. 
Published: October 2007

SUMMARYHuman IgE responses to helminth infections have been described as both problematic and beneficial, in that type 1 hypersensitivity to parasite infections can reputedly cause pathology and/or parasite expulsion, (Pritchard, Quinnell & Walsh 1995). In the present communication, we can report that the IgE response to helminth infections may be beneficial in a diagnostic sense, in that antibodies of this isotype showed minimal cross‐reactivity against antigens from the parasites tested. This information may be of benefit to workers attempting to establish ELISA assays for the specific diagnosis of zoonotic hookworm infections, for example, Ancylostoma caninum (Croese 1988), particularly in regions where human hookworm infection is endemic.
B cell mitogenic activity of Toxocara canis adult worm antigen
Authors: WANG MEI QI , JIANG HONG JIE , INOUE HIROKO , MYOZAKI MITSURU , YAMASHITA UKI 
Published: October 2007

SUMMARYThe effect of Toxocara (T.) canis antigen (TcAg) on lymphocytes was studied in vitro using normal murine spleen cells and human peripheral blood lymphocytes. TcAg prepared from adult worms stimulated murine spleen cells to proliferate at concentrations of 1–125 μg/ ml. The responder cells for TcAg are B cells, because the response was depleted by the treatment of spleen cells with anti‐immunoglobulin (Ig) antibody and complement and after separation on a nylon wool column. This response was not due to the contamination of lipopolysaccharide (LPS), because TcAg could stimulate C3 HI He J spleen cells which are low responders to LPS. Not only the proliferative response but also polyclonal IgG and IgE production were stimulated with TcAg. TcAg also stimulated macrophages to produce interleukin‐1 and could stimulate human B cells. These results suggest that TcAg is a potent B cell mitogen and this activity may be relevant to the alteration of immunological functions in hosts infected with T. canis.
Immunogenicity of recombinant Plasmodium falciparum rhoptry associated proteins 1 and 2
Authors: STOWERS ANTHONY , PRESCOTT NICOLE , COOPER JUAN , TAKACS BELA , STUEBER DIETRICH , KENNEDY PETER , SAUL ALLAN 
Published: October 2007

SUMMARYMice and rabbits immunized with recombinant forms of malaria vaccine candidate antigens rhoptry‐associated proteins 1 and 2 (RAP‐1, RAP‐2 and rRAP‐l, rRAP‐2) produce antibodies at litres equivalent to monoclonal antibody ascites fluid raised against the native proteins. Sera from animals immunized with rRAP‐l contain antibodies which recognize the native protein by indirect immunofluorescence and immunoblotting, partially inhibit erythrocyte invasion in vitro and are long lasting. Epitope mapping shows these antibodies predominantly recognize epitopes in the N‐terminal third of rRAP‐l, some of which coincide with the targets of inhibitory monoclonal antibodies. By contrast, sera from animals immunized with rRAP‐2 contain antibodies which recognize the recombinant but not the native protein
Influence of humoral immunity on leukotriene B4 production by neutrophils in response to Trichomonas vaginalis stimulation
Authors: SHAIO MEN‐FANG , LIN PEY‐RU 
Published: October 2007

SUMMARYNeutrophils are the predominant inflammatory cells found in vaginal discharges from patients with Trichomonas vaginalis infection. In this study, we investigated the effect of humoral immunity on leukotriene B4 (LTB4) generation by neutrophils in the inflammatory response of vaginal trichomoniasis. As quantitated by a radioimmunoassay, no release of LTB4 was detected from neutrophils (5 x l06/ml) interacted with trichomonads (1 times 106/ml). However, specific immunoglobulin G(IgG) but not F(ab1)2, at a titre of 1:256 directed against T. vaginalis, augmented LTB4 production (1·4 ± 0·4 ng/ml, n= 5) by neutrophils, suggesting that this enhancement is Fey receptor‐mediated. Moreover, addition of the specific IgG (1 mglml) to C2‐deficient serum or Factor B‐deficient serum, but not C5‐deficient serum, significantly increased LTB4 production by neutrophils in response to trichomonad stimulation. This indicates that the complement common pathway activation is crucial for the amplification of host defence mechanisms against T. vaginalis. An LTB4 receptor antagonist, SC‐41930, completely abolished neutrophil chemotactic activity induced by LTB4. Taken together, these results indicate that humoral immunity could promote the interaction of neutrophils with T. vaginalis and augment the inflammatory response through the amplification of LTB4 production.
Malaria: toxins, cytokines and disease
Authors: JAKOBSEN P. H. , BATE C. A. W. , TAVERNE J. , PLAYFAIR J. H. L. 
Published: October 2007

SUMMARYIn this review the old concept of severe malaria as a toxic disease is re‐examined in the light of recent discoveries in the field of cytokines. Animal studies suggest that the induction of TNF by parasite‐derived molecules may be partly responsible for cerebral malaria and anaemia, while hypoglycaemia may be due to direct effects of similar molecules on glucose metabolism. These molecules appear to be phospholipids and we suggest that when fully characterized they might form the basis of antitoxic therapy for malaria.,
Epitopes in the 19kDa fragment of the Plasmodium falciparum major merozoite surface protein‐1 (PfMSP‐119) recognized by human antibodies
Authors: SHAI SHAFRIRA , BLACKMAN MICHAEL J. , HOLDER ANTHONY A. 
Published: October 2007

SUMMARYThe antibody response to two different epitopes located in the C‐terminal 19 kDa fragment of the Plasmodium falciparum merozoite surface protein‐1 (MSP‐119) has been studied using a competitive ELISA based on the inhibition of monoclonal antibody (MoAb) binding by serum samples. Sera from children aged three to eight years who suffered clinical symptoms of malaria, or were partially immune with an asymptomatic infection, and from adults all living in The Gambia, West Africa were tested. The results suggest that the antibody response to MSP‐1 iQ has a role in naturally‐acquired immunity in Gambian individuals.,