bluuebunny/crossref_metadata_2025 huggingface dataset:
Trypanosoma cruzi upregulates nitric oxide release by IFN‐γ‐preactivated macrophages, limiting cell infection independently of the respiratory burst
Authors: METZ GAËTANE , CARLIER YVES , VRAY BERNARD
Published: October 2007

The relationship between nitric oxide (N = O) produced by mouse peritoneal macrophages (MPM) and Trypanosoma cruzi infection is still poorly understood. The conditions of MPM activation by gamma‐interferon (IFN‐γ) to trigger a N = O‐dependent trypanocidal activity, as well as the effect of parasite infection or of reactive oxygen species (ROS) inhibitors on the N = O release were studied. T. cruzi infection occurring after a previous 24 h MPM activation induced an enhancement of nitrite levels (the stable degradation product of N = O) in cell supernatants; both the percentage of infected MPM and the number of amastigotes per infected cell were decreased in comparison to infected but non‐activated MPM. Addition of superoxide dismutase or catalase to non‐infected but activated MPM increased the nitrite levels; these were not detectable when L‐arginine inhibitors were added together with ROS inhibitors. The latter had no effect on infection nor on nitrite levels when infection occurred after pre‐activation, and induced only a weak nitrite release when infection took place before MPM activation. Altogether, these results support the involvement of N = O in the inhibition of T. cruzi infection by IFN‐γ‐preactivated macrophages, together with the upregulation of N = O release by T. cruzi infection independently of the respiratory burst.
The 35/50 kDa surface antigen of Trypanosoma cruzi metacyclic trypomastigotes, an adhesion molecule involved in host cell invasion
Authors: RUIZ RITA DE CASSIA , RIGONI VERA LUCIA , GONZALEZ JORGE , YOSHIDA NOBUKO
Published: October 2007

We have previously shown that monoclonal antibodies directed to the 90 kDa glycoprotein and the 35/50 kDa glycoconjugate, present on the surface of Trypansoma cruzi metacyclic trypomastigotes, inhibited host cell invasion. Here we investigated whether these molecules could be the ligands for the target cell receptor. Binding assays were performed by incubating Vero cells with sonicated parasite extract. Detection of bound parasite components was carried out by using monoclonal antibodies (MoAbs) 1G7 and 10D8, which recognize the 90 kDa and the 35/50 kDa antigens respectively. These experiments revealed that the 35/50 kDa glycoconjugate of metacyclic forms, but not the 1G7‐reactive antigen, binds to Vero cells. The purified 35/50 kDa antigen bound to Vero cells and inhibited the entry of metacyclic forms in a dose‐dependent manner. Although to a lesser extent, an immunologically related 35/50 kDa antigen of non‐infective epimastigotes also bound to Vero cells but it was unable to inhibit parasite penetration at a concentration (100 μg/ml) in which metacyclic antigen exhibited more than 60% inhibition. All these data suggest that the metacyclic 35/50 kDa surface glycoconjugate is a ligand to the host cell in the process ofT. cruzi invasion.
Identifying polymorphic regions of the p190 protein from different Plasmodium falciparum strains by using specific T cells
Authors: SÜSS G. , MATILE H. , MELOEN R. H. , TAKACS B. , PINK J. R. L.
Published: October 2007

The p190 protein (also called MSA1 or MSP1) of the asexual blood stage forms of Plasmodium falciparum, a human malaria vaccine candidate, shows polymorphism between different isolates. Mice were immunized with p190–3, a recombinant protein which contains mostly conserved sequences derived from the p190 protein of the K1 parasite isolate. Proliferative T‐cell responses of lymph node cells from immunized mice were assessed by stimulation in vitro with p190–3 or preparations of parasitized red blood cells (PRBC) containing the native protein. The p190–3‐specific T cells from C57BL/6 mice consistently responded to some P. falciparum isolates, representing either the K1 or MAD20 serotype of p190, but not to other P. falciparum strains or to rodent malaria parasite‐infected red blood cells. p190–3‐specific T‐cell responses from other mouse strains (BALB/c, C3H/He) did not distinguish between P. falciparum isolates. The polymorphic epitopes which were preferentially recognized by T cells from C57BL/6 mice were identified.
The analysis of the humoral response of the BALB/c mouse immunized with radiation attenuated third stage larvae of Brugia pahangi
Authors: BANCROFT ALLISON , DEVANEY EILEEN
Published: October 2007

BALB/c mice immunized with L3 of Brugia pahangi, irradiated at 45kRad from a 137Caesium source, are strongly immune to challenge infection (75–100% reduction in the recovery of challenge infection larvae on day 6 post‐challenge). The target of immunity appears to be the post‐infective L3, as challenge infection larvae are killed within 5–6 days of infection. By immunoblot analysis, serum from immune animals recognizes a limited set of somatic antigens, the majority of which are shared between different life cycle stages. Serum from immune mice also strongly recognizes larval surface antigens by immunofluorescence, some of which may be stage specific. The larval surface determinants do not appear to be protein or glycoprotein by standard immunochemical analysis. A proportion of the antibody response of the BALB/c mouse is directed towards phosphorylcholine epitopes on filarial antigens, but the limited antigen recognition cannot be explained on the basis of the mouse strain used, as CBA/Ca mice recognize a similar limited set of antigens.
Characterization of excretory‐secretory products of adult Dictyocaulus viviparus and the antibody response to them in infection and vaccination
Authors: BRITTON COLLETTE , CANTO GERMINAL J. , URQUHART GEORGE M. , KENNEDY MALCOLM W.
Published: October 2007

In vitro released products of the adult stage of the bovine lungworm, Dictyocaulus viviparus, were characterized according to their SDS‐PAGE profile, glycosylation pattern, in vitro synthesis and antigenicity in the context of infection and vaccination with irradiated larvae. Biosynthetic labelling experiments with 35S‐methionine indicated active synthesis of ES throughout this time. There was, however, little incorporation of 3H‐glucosamine into ES products, and lectin affinity chromatography and glycopeptidase F digestion identified only one glycosylated component. Immunoprecipitation of 125l‐labelled ES products with sera from calves patently infected with D. viviparus demonstrated that all of these, with the exception of two components, are antigenic to the bovine host. One of those not immunoprecipitated was shown to be host serum albumin carried over into culture. A limited degree of cross‐reactivity between nematode species was observed, with a D. viviparus female‐specific antigen of 290 kDa being recognized by serum antibody from calves infected with the gastrointestinal nematodes Cooperia oncophora and Ostertagia ostertagi. Calves vaccinated with irradiated larvae of D. viviparus, despite not being exposed to the adult stage of the parasite, also showed some recognition of adult ES products. This might suggest that vaccination with irradiated larvae operates against both pre‐pulmonary and pulmonary stages of the infection.
‘Original antigenic sin’, T cell memory, and malaria sporozoite immunity: an hypothesis for immune evasion
Authors: GOOD MICHAEL F. , ZEVERING YINKA , CURRIER JEFF , BILSBOROUGH JANINE
Published: October 2007

Prior to any exposure to malaria, most adults have T cells specific for malaria parasites and various malaria proteins. The protein for which this has been shown more than any other is the circumsporozoite protein (CSP) of Plasmo‐dium falciparum. These T cells can be present in high frequency and appear to have arisen through exposure to other (non‐malaria) organisms. Although T cells are thought to provide protection against sporozoites, these T cells specific for cross‐reactive organisms are clearly unable to protect against malaria, and may be preferentially expanded following exposure to malaria sporozoites. Thus, cross‐reactive organisms have the potential to skew the repertoire of sporozoite‐induced T cells and affect the induction of protective immunity. This is analogous to the concept of ‘original antigenic sin’ whereby prior exposure to one strain of influenza virus was shown to be able to divert the antibody response to a second challenging strain to focus on the shared (cross‐reactive) epitopes.
Synthesis of tumour necrosis factor‐alpha and interferons by mononuclear cells from Theileria annulata‐infected cattle
Authors: PRESTON PATRICIA M. , BROWN C. G. D. , ENTRICAN G. , RICHARDSON WENDY , BOID R.
Published: October 2007

Bovine macrophage‐derived tumour necrosis factor‐alpha/ cachectin (TNF‐α) was synthesized when peripheral blood mononuclear cells (PBMC) and purified adherent PBMC from naïve and Theileria annulata‐infected cattle were incubated in vitro with concanavalin A (Con‐A) or bovine recombinant interferon gamma (Bo rIFN‐γ). TNF‐α production was also induced when adherent PBMC were cultured with T. annulata macroschizont‐infected cells. In contrast, non‐adherent PBMC from sublethally infected cattle produced interferon (IFN) when incubated with Hu rIL‐2, Con‐A, phytohaemagglutinin (PHA) or T. annulata macroschizont‐infected cells growing as cell lines in vitro. Whilst PBMC from lethally infected cattle spontaneously produced IFN‐γ during advanced stages of infection, the sera of such animals contained type 1 IFN (alpha/beta). IFN was also produced by T. annulata macroschizont‐infected cell lines maintained in vitro. This work suggests that cytokines serve as crucial links between proliferating Theileira‐infected cells and the characteristic clinical symptoms of tropical theileriosis.
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

The 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

Significant 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

A 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

The 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

The 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

A 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

A 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

Techniques 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

Chronic 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

Adherent 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

Cellular 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

Protective 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

Bovine 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

Mitogen‐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

In 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

We 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.
Cytokine profiles for human Vγ9+ T cells stimulated by Plasmodium falciparum
Authors: GOODIER MARTIN R. , LUNDQVIST CARINA , HAMMARSTRÖM MARIE‐LOUISE , TROYE‐BLOMBERG MARITA , LANGHORNE JEAN
Published: October 2007

Vγ9+ T cells from malaria non‐exposed donors make proliferative responses to Plasmodium falciparum on in vitro stimulation. Vγ9+ cells are strongly activated by components of the schizont stage of the parasite and by antigens released into the culture upon schizogony, while CD4+ Vγ9‐ cells are stimulated by the earlier stages of the parasite. Using reverse transcriptase‐polymerase chain reaction (RT‐PCR) we determined mRNA expression for 14 cytokines in highly purified Vγ9+ cells enriched by positive selection after in vitro stimulation with P. falciparum schizont antigens. Interferon‐γ (IFN‐γ) and Tumor Necrosis Factor‐α (TNF‐α) were detected in all samples tested. The majority of samples also expressed TNF‐β, transforming growth factor‐β (TGF‐β) and Interleukin‐8 (IL‐8). Only occasional samples expressed IL‐2, IL‐5 and IL‐10. Using the ELISPOT assay we found that a large fraction of the reactive Vγ9+ cells produced IFN‐γ and that γδ T cells are the major producers of IFN‐γ in cultures stimulated with schizont antigens. The majority of Vγ9+ cells in these cultures also express the membrane‐bound form of TNF‐α. Expression of these cytokines speaks for a cytolytic and/or inflammatory role of γδ cells in the response to malaria in non‐exposed individuals.
Development of immunity to malaria may not be an entirely active process
Authors: GOOD MICHAEL F.
Published: October 2007

It has never been explained why it takes so long for humans to develop immunity to malaria, although factors such as antigenic variation, antigenic polymorphism, and poor immunological responses to critical antigens are thought to be important. Models of malaria, particularly in rodents, have not been helpful. The course of malaria infection differs considerably between humans and rodents. Mice rapidly develop immunity whereas for most humans it takes several years of exposure for this to occur. Mice typically exhibit high parasitaemias whereas humans typically do not. A significant difference in the immune response of humans and mice to malaria parasites might, in part, explain these differences. Most humans have a preexisting population of activated malaria parasite‐specific T cells (cross‐reactive T cells) which we have referred to as ‘natural’ T cells, but such cells have not been observed in mice. These cells, many of which secrete interferon‐γ), might control parasitaemia early in the infection, but a by‐product of their further activation by malaria parasites might be disease symptoms. Development of immunity has been thought of as an active process–acquisition of specific antibody and effector T cell responses. However, it might in part reflect induction of tolerance of this preexisting population of disease‐inducing Tcells as a result of chronic parasitaemia. The initial presence of these Th1‐like cells may also impede the development of a Th2‐like response necessary for the production of protective antibodies. Persistent cross‐reactive stimulation may significantly impede this process.
Toxocara canis adult worm antigen induces proliferative response of healthy human peripheral blood mononuclear cells
Authors: INUO GEN , AKAO NOBUAKI , OHSAKA HITOSHI K. , SAITO ICHIRO , MIYASAKA NOBUYUKI , FUJITA KOICHIRO
Published: October 2007

The proliferative response of human peripheral blood mononuclear cells (PBMC) from healthy donors to Toxocara canis adult worm antigens (TcA) was examined. PBMC from all donors examined (n= 1) strongly responded to TcA in a dose‐dependent fashion after six days of culture, irrespective of their serological reactivity. In contrast, cord blood mononuclear cells did not react to TcA. The proliferation of PBMC in response to TcA was completely inhibited by anti‐HLA‐DR antibody. Purified CD4+ T cells reconstituted with autologous irradiated antigen presenting cells (APC) vigorously proliferated in response to TcA, but this was abrogated by pretreatment of APC with paraformaldehyde. Significant IL‐2, IL‐3, IL‐4, IL‐5 andlFN‐j mRNA expression was detected in PBMC stimulated with TcA, with expression peaking at 72 h after stimulation. IL‐1β, IL‐6, IL‐10 and GM‐CSF mRNA expression was also upregulated, peaking at 24 h after stimulation. Taken together, these results suggest that adult T. canis‐derived antigens have the ability to activate human PBMC as conventional antigens, possibly due to their cross‐reactivity, which may be involved in the host defence against helminth infection.
Anti‐interleukin‐4 treatment diminishes secretion of Th2 cytokines and inhibits hepatic fibrosis in murine schistosomiasis japonica
Authors: CHEEVER ALLEN W. , FINKELMAN FRED D. , COX TERESA M.
Published: October 2007

Anti‐interleukin‐4 (IL‐4) treatment o/“Schistosoma japo‐nicum‐infected mice markedly inhibited in vitro secretion of the Th2 cytokines IL‐4 and IL‐5 from antigen‐stimulated spleen cells, but enhanced the secretion of the Th1 cytokine IFN‐γ. IL‐2 secretion was unaffected. Hepatic fibrosis was markedly diminished in anti‐IL‐4‐treated‐mice at ten weeks of infection while granulomas around S. japonicum eggs in the livers were slightly‐to‐moderately increased in size. The number of eggs per worm pair in the tissues and feces did not differ significantly in treated and untreated mice. These findings suggest that Th2 cytokine responses are important in the genesis of schistosomal hepatic fibrosis.
Reserpine‐induced sulphomucin production by goblet cells in the jejunum of rats and its significance in the establishment of intestinal helminths
Authors: ISHIKAWA N. , SHI B.‐B. , KHAN A. I. , NAWA Y.
Published: October 2007

The present investigation was undertaken to determine whether reserpine‐induced increase in the sulphation of the small intestinal goblet cell mucins of rats affects the establishment of intestinal helminths. When Wistar rats were given daily intraperitoneal injections of reserpine for seven days and were then implanted intraduodenally with 500 Strongyloides venezuelensis adult worms, the number of adult worms established in the intestine of reserpine‐treated rats was about half of that established in controls. Furthermore, when mast cell‐deficient Ws/Ws rats were treated with reserpine and implanted concurrently with S. venezuelensis and Nippostrongylus brasiliensis adult worms, the establishment of the former, but not the latter, was significantly suppressed. These results imply that the physicochemical properties of the mucins produced and secreted by the small intestinal goblet cells may be critical for the establishment of particular species of intestinal helminths.
Characterization of epitopes on excretory‐secretory antigens of Taenia saginata metacestodes recognized by monoclonal antibodies with immunodiagnostic potential
Authors: DRAELANTS E. , BRANDT J.R.A. , KUMAR V. , GEERTS S.
Published: October 2007

Four monoclonal antibodies (MoAbs) produced against the excretory‐secretory (ES) antigens o/Taenia saginata metacestodes are currently used for the detection of circulating antigen in the sera of cattle with bovine cysticercosis. The epitopes recognised by these MoAb were characterized by periodate oxidation, alkaline borohydride and heat treatment, trichloroacetic acid precipitation, enzymatic proteolysis and deglycosylation of the ES‐products. These results together with those of the homologous sandwich, inhibition and competition ELISAs showed that three repetitive epitopes are recognized, which are present on the tegument and on the ES‐products of T. saginata metacestodes. They are different from phos‐phorylcholine and seem to be either of carbohydrate or partly carbohydrate/partly protein nature.
Relationship between granulocyte macrophage‐colony stimulating factor, tumour necrosis factor‐α and Trypanosoma cruzi infection of murine macrophages
Authors: FONTT ELIZABETH OLIVARES , VRAY BERNARD
Published: October 2007

Gamma interferon (IFN‐γ)‐activated macrophages control Trypanosoma cruzi infection via nitric oxide (NO), recently recognized as a major effector molecule. Granulocyte macrophage‐colony stimulating factor (GM‐CSF) is a multipotent cytokine secreted by macrophages and many other cells. It induces the production of tumour necrosis factor alpha (TNF‐α), another cytokine also secreted by macrophages and involved in the control of T. cruzi infection. However, no data are available on the relationship between GM‐CSF, TNF‐a and NO produced by macrophages activated by IFN‐γ and infected with T. cruzi. To highlight this relationship, mouse peritoneal macrophages (MPM) and two c‐myc retrovirus‐induced macrophage cell lines (9.1.1 and BMM8), respectively characterized by a constitutive and an inducible production of GM‐CSF, were activated with I FN–γ and/or GM‐CSF and infected with T. cruzi. Our results indicate that T. cruzi upregulates GM‐CSF release from MPM and from the two macrophage cell lines, activated (or not) by IFN‐γ. A high autocrine production of GM‐CSF or an exogenous supply of GM‐CSF is correlated with an enhanced release of TNF‐α and NO, inducing an improved control of T. cruzi infection by IFN‐γ‐activated MPM.
Genetic control of immunity to Heligmosomoides polygyrus: fixed H‐2 E positive but not H‐2 negative cells can present antigen to a parasite‐specific T cell hybridoma
Authors: ROBINSON MICHAEL , GUSTAD THOMAS R. , GARNER STEPHANIE D. , DAVID CHELLA S.
Published: October 2007

A number of T cell hybridomas were produced to adult worm homogenate (AWH) antigen of the nematode parasite Heligmosomoides polygyrus. All of the hybridomas were of the H‐2d haplotype and could potentially accept antigen in the context of either the Ad or Ed, H‐2 molecules. Three types of antigen presentation were observed, with some of the T cell hybridomas accepting antigen in the context of the E and some in the context of the A molecule. A third type of hybridoma responded to antigen presented by paraformaldehyde fixed APC, but only when APCs were Epositive. These same hybridomas, were however, stimulated by A WH, when the antigen was presented by syngeneic but unfixed, E positive or E negative A PC. Therefore these data indicate that certain H. polygyrus‐specfic T cell hybridomas can accept parasite antigen when presented in the context of either the H‐2 A or E molecule, but the presentation of antigen by the two different MHC Class II molecules, can apparently utilize differing processing mechanisms.,
Versuche zur Verlegung des Auftauvorganges von Tiefgefriersperma ins weibliche Genitale beim Rind
Authors: Stoye Von H. , Mahler R. , Dieckmann W.
Published: October 2007

Inhalt:

Nach Einbringen von tiefgefrorenem (—196° C) Samen‐Pellets in den Zervikalkanal von 24 Kühen warden nur die gleichen geringgradigen submukösen, petechialen Blutungen an der Schleimhaut festgestellt wie bei 14 Kontrolltieren, die man mit Flüssigsamen besamt hatte oder bei denen lediglich eine Pipette intrazervikal eingeführt worden war.

Contents:

After the introduction of deep‐freeze (—196° C) semen pellets into the cervical canal of 24 cows, the same slight degree of submucous petechial bleeding of the mucous membrane was observed as in 14 control animals inseminated with liquid semen or in which only a pipette had been introduced intracervically.
Ergebnisse von Fruchtbarkeitsuntersuchungen bei Ebern
Authors: Grauvogl Von A.
Published: October 2007

Inhalt:

Es wurden ambulant 240 ah unfruchtbar bezeichnete Eber untersucht. Die Auswertung der Untersuchungsprotokolle ergab: Nur etwa 1,5 % der adulten Eber einer Population waren unfruchtbar. Die Unfruchtbarkeit trat im ersten Halbjahr um das Doppelte gehäuft auf. Von allen als unfruchtbar bezeichneten Ebern erwies sich ein Drittel als fruchtbar. Von den restlichen Tieren konnte bei der Hälfte keine klinische Ursache ermittelt werden. Die Spermagewinnung war ohne Phantom und Sau im Östrus mögliçh. Ah häufigster Spermabefund bei den unfruchtbaren Ebern wurde ein zu hoher Anteil an Spermien mit Protoplasmatropfen festgestellt.

Die temporären Störungen der Sexualfunktionen anläSsZlich eines Herdenwechsels des Ebers ergaben die gröβten Schwierigkeiten für eine Fruchtbarkeitsdiagnose.

Contents:

240 boars, thought to be sterile, were examined in the herd. Evaluation of the results of the examination showed: only about 1.5 % of the adult boars in a herd were sterile. Sterility occurred twice as often in the first half‐year. A third of all the boars thought to be sterile proved not to be so. No clinical cause could be discovered in half of the remainder of the animals. It was possible to collect sperm without phantom or sow in oestrus. The most frequent finding in infertile boars was a too high percentage of sperms with protoplasma drops. Temporary disturbance of sexual functions due to movement to a new herd caused the greatest difficulties in diagnosing sterility.
Über die Häufigkeit der intrauterinen Eiüberwanderung beim Rind
Authors: Rüsse Von I.
Published: October 2007

Inhalt:

1892 Uteri von trächtigen Kühen wurden post mortem auf Überwanderung des Eies bin untersucht. Bei Einzelgravidität lag der Foetus in drei von 1795 Fällen nicht im korrespondierenden Uterushorn (0,17 %), d. h. das Corpus luteum graviditatis befand sich am gegenüberliegenden Ovar. Bei 98 Zwillings‐, bzw. Mehrlingsgraviditäten wurde eine Überwanderung in 6 Fällen beobachtet (6,1 %), in denen die beiden Eizellen jeweils vom gleichen Ovar stammten. Auf die 50 Fälle bezogen, in denen nur ein Ovar ovuliert hatte, betrug die Häufigkeit der Überwanderung 10,7 %.

Contents:

In post‐mortem examinations of uteri and ovaries in 1,892 pregnant cattle intrauterine migration of the ovum was found in three of the 1,795 single pregnancies (0.17 per cent) and in six of the 98 twin or multiple pregnancies (6.1 per cent). In the fifty twin pregnancies in which only one ovary had ovulated, migration occurred in 10.7 per cent.
Aktinomykotisches Granulom am Penis eines Stieres
Authors: Leidl Von W. , Weiss E.
Published: October 2007

Inhalt:

Es wird ein durch Aktinomyces Wolff‐Israeli hervorgerufenes Granulom am Penis eines Stieres beschrieben und uber die Behandlung und den Behandlungserfolg berichtet.

Contents:

A granuloma on a bull's penis, caused by actinomyces Wolff‐Israeli, is described and a report given of treatment and its success.
Die Steuerung der Ovulation
Authors: Berchtold Von M.
Published: October 2007

Inhalt:

Die heutigen Kenntnisse über die endogene und exogene Beeinflussung der Ovulation werden zusammenfassend dargestellt. Es wird auf Schwierigkeiten und Widersprüche bei der Interpretation experimenteller Befunde hingewiesen. Die mögliche Beteiligung der Gonadotropine als Effektoren bei der genabhängigen Proteinsynthese wird diskutiert.

Contents:

The present knowledge concerning the influence of endogenous and exogenous factors on the ovulation is summarized. Difficulties and contradictions in the interpretation of experimental results are stressed. The hypothesis is formed that gonadotropins may act as effectors in the course of the gene dependent protein synthesis.