bluuebunny/crossref_metadata_2025 huggingface dataset:
Flying foxes on Choiseul (Solomon Islands) – the need for conservation action
Authors: Bowen-Jones E. , Abrutat D. , Markham B. , Bowe S.
Published: November 2003

The Choiseul 1995 project spent 6 months studying the Chiroptera of Choiseul, one of the least disturbed and most poorly known islands in the Solomons. Among the results were: the rediscovery of a member of the Megachiropteran genus Pteralopex, which had been thought possibly extinct; a new record of another endemic pteropodid with a limited distribution; and evidence of a decline in the ‘commonest’ member of the family in the archipelago. The threats, present and future, to these animals and the forests of the island are discussed. An overview of the status of Pteralopex spp. in the Solomons provides an insight into the need for conservation action in the country as a whole.
The effects of the Rwandan civil war on poaching of ungulates in the Parc National des Volcans
Authors: Plumptre Andrew J. , Bizumuremyi Jean-Bosco , Uwimana Fidele , Ndaruhebeye Jean-Damascene
Published: November 2003

One of the greatest threats that the mountain gorilla Gorilla gorilla beringei faces is the repeated setting of snares for ungulates by people living adjacent to the Parc National des Volcans in Rwanda. Two vets (one expatriate and one Rwandan) are permanently employed to monitor the health of habituated groups of mountain gorillas and to remove snares if an animal becomes caught in one. This study examined how snaring has changed as a result of the Rwandan civil war and how ungulates in the park have been affected. In the region around the Karisoke Research Station ungulate numbers have remained stable and in the case of the black-fronted duiker Cephalophus nigrifrons they have increased at higher altitudes. However, a questionnaire survey among local people showed that there has been a perceived decrease in crop raiding by all ungulates in the west of the park, suggesting a decline in numbers. In the east of the park there appears to have been a decrease in the numbers of black-fronted duikers but an increase in the number of buffaloes Syncerus caffer. The price of bushmeat in real terms has decreased since the war, despite the increase in the price of domestic meat, and poachers interviewed were selling bushmeat more frequently than they did before the war. The level of poaching, therefore, appears to have increased since the war.
The saola Pseudoryx nghetinhensis in Vietnam – new information on distribution and habitat preferences, and conservation needs
Authors: Kemp Neville , Dilger Michael , Burgess Neil , Van Dung Chu
Published: November 2003

In 1995 a new population of the recently described, endangered bovid, the saola Pseudoryx nghetinhensis, was found in the forests of Bu Huong, Nghe An Province in Vietnam. The new records were to the north of the main known populations, and represent an important range extension for the species. The new population may number only 30 individuals and appears to be confined to river valleys in primary forest. Investigations at this site and a compilation of published and unpublished data suggest that the range of the species in Vietnam and Laos includes over 5000 sq km of mountainous terrain, four protected areas (Vu Quang and Pu Mat, Nature Reserves [Vietnam], Nakai Nam Theun and Hin Namnu National Biodiversity Conservation Areas [Laos]), and three proposed protected areas (Bu Hong [Vietnam], Nam Chuan and Nakai Nam Theun Northern Extension National Boidiversity Conservation Areas [Laos]). All known locations for the species are mountainous with steep river valleys, covered by evergreen or semideciduous forests between 300 and 1800 m, with low human disturbance. The main threats to its survival are hunting by local villagers and clearance of forests to provide farmland. Both need to be tackled if the saola and other forest-endemic species of this area are to persist.
Managing bushmeat hunting in Okapi Wildlife Reserve, Democratic Republic of Congo
Authors: Wilkie David S. , Curran Bryan , Tshombe Richard , Morelli Gilda A.
Published: November 2003

Projected rates of agricultural clearing in the Ituri Forest of north-eastern Democratic Republic of Congo range from 0 to 0.1 per cent per year and suggest that deforestation for subsistence agriculture is not an immediate threat to the integrity of the Okapi Wildlife Reserve (OWR). If the human population continues to grow at over 3 per cent per annum, and bushmeat continues to be a major source of income for rural communities, subsistence-level exploitation of bushmeat may, however, not be sustainable. This paper proposes management approaches that address the demand for and supply of bushmeat, which are targeted at those political districts within the OWR where hunting is the greatest threat to populations of bushmeat species. These management approaches are designed to help conserve the Ituri's natural resources without compromising the health and income security of rural communities.
Mammals, birds and reptiles of Dibru-Saikhowa Sanctuary, Assam, India
Authors: Choudhury Anwaruddin
Published: November 2003

Dibru-Saikhowa Sanctuary protects 340 sq km of the floodplains of the Brahmaputra and Lohit rivers in eastern Assam state, north-eastern India. It provides habitat for several threatened species, including Asian elephant and tiger. The sanctuary suffers from several problems, however, including illegal tree felling, the scarcity of safe, high ground for animals during the annual floods and insufficient staff and resources. The author makes recommendations for improving the conservation value of the sanctuary.
Status of selected mammal species in North Myanmar
Authors: Rabinowitz Alan , Khaing Saw Tun
Published: November 2003

During 1996 and 1997, data on the status of selected mammal species were collected from a remote region of North Myanmar. Of the 21 species discussed in this paper, the black muntjac, stone marten and blue sheep are new records for the country. One species, the leaf muntjac, has never been described. At least three species that once inhabited the region – elephant, gaur and Sumatran rhinoceros – are no longer present, and the tiger has been nearly extirpated. Himalayan species that are declining elsewhere, such as takin, red goral and red panda, are still relatively abundant despite hunting pressures. Musk deer are in serious decline. The wolf, while not positively confirmed, may be an occasional inhabitant of North Myanmar.
Ten years of Arabian oryx conservation breeding in Saudi Arabia – achievements and regional perspectives
Authors: Ostrowski Stéphane , Bedin Eric , Lenain Daniel M. , Abuzinada Abdulaziz H.
Published: November 2003

The National Commission for Wildlife Conservation and Development was established in 1986 to oversee all wildlife conservation programmes in Saudi Arabia. The Arabian oryx Oryx leucoryx is one of the flagship species of the Saudi Arabian reintroduction policy. It has been captive-bred since 1986 at the National Wildlife Research Center near Taif. With the creation of a network of protected areas in the former distribution range of the species, attention has shifted to the release of captive-bred oryx into Mahazat as-Sayd and 'Uruq Bani Ma'arid reserves. Similar programmes carried out in other countries of the Arabian Peninsula underline the need for regional co-operation and pan-Arabic public awareness programmes, in addition to captive-breeding and reintroduction projects.
Heterologous expression of the cuticular glutathione peroxidase of lymphatic filariae in an attenuated vaccine strain of Salmonella typhimurium abrogates H‐2 restriction of specific antibody responses
Authors: CHACÓN MATILDE R. , LONDOÑO PATRICIA , DOUGAN GORDON , SELKIRK MURRAY E.
Published: November 2003

The major soluble cuticular glycoprotein of lymphatic filariae, gp29, has been expressed in the Salmonella typhimurium aroA aroD live vaccine strain BRD509. Two distinct constructs were generated: a) pgp29, in which gp29 was expressed directly via the inducible promoter nirB, or b) pTetC‐gp29, in which it was expressed as a C‐terminal fusion to the non‐toxic immunogenic fragment C of tetanus toxin, again under the control of nirB. In both cases, plasmid stability in vivo was demonstrated by recovery of recombinant bacteria from livers and spleens of mice immunized via the intravenous route. Negligible gp29‐specific antibodies were detected in animals immunized with bacteria expressing the fragment C fusion protein, but bacteria expressing the non‐fused protein resulted in gp29‐specific antibody production in a proportion of animals immunized. Notably, a number of BALB/c and B10.D2/n (i.e. mice of the H‐2d haplotype) responded, in contrast to previously documented non‐responsiveness during infection, or immunization with parasite extracts. Presentation of gp29 by live attenuated S. typhimurium resulted in a broad spectrum of antigen‐specific IgG isotypes.
Selected P. falciparum specific immune responses are maintained in AIDS adults in Burkina Faso
Authors: MIGOT F. , OUEDRAOGO J.B. , DIALLO J. , ZAMPAN H. , DUBOIS B. , SCOTT‐FINNIGAN T. , .SANOU P.T , DELORON P.
Published: November 2003

In tropical areas where Plasmodium falciparum malaria is endemic, co‐infection with HIV‐1 does not lead to a worsening of malaria, raising questions about the immunological interactions between both infections. Alterations of immune response to malaria during HIV‐1 infection was investigated in the town of Bobo Dioulasso, Burkina Faso. Sixty‐six adults were enrolled, including 37 HIV‐1 positive subjects with <250 CD4+ cells/μl and clinical AIDS, and 29 HIV‐1 negative healthy subjects. In vitro lymphocyte proliferation and cytokine (IFN‐γ, IL‐2 and IL‐4) production were assessed in isolated mononuclear cells (PBMC) in presence of PHA, PPD or three malarial antigens: the baculovirus‐expressed protein from P. falciparum Merozoite Surface Protein‐1, a P. falciparum in vitro culture and a crude schizont extract. Compared with healthy subjects, AIDS patients presented with decreased levels of cell proliferation and of IFN‐γ and IL‐2 production, in response to all antigens except the schizont extract. Similar levels of IL‐4 production were obtained in both groups. Mitogenic stimulation of whole blood cultures was also performed, and revealed similar trends in cytokine production as in PBMC cultures. These results show that some components of the specific human immune responses to falciparum parasites may not be modified during AIDS, in spite of the strong cellular alterations induced by HIV, namely the decrease of the CD4+ lymphocyte subset.
Homologous and heterologous protective immunity to Egyptian strains of Schistosoma mansoni and S. haematobium induced by ultraviolet‐irradiated cercariae
Authors: DEAN D.A. , MANGOLD B.L. , HARRISON R.A. , RICCIARDONE M.D.
Published: November 2003

C57BL/6 and Balb/c mice were immunized with ultraviolet‐irradiated cercariae of Egyptian strains of Schistosoma mansoni and S. haematobium, challenged with non‐irradiated cercariae of the homologous or heterologous species, and assayed for protection against challenge infection by comparing the adult worm burdens of immunized and non‐immunized mice. Homologous protection (per cent reduction in worm recovery) ranged from 56% to 69% for S. mansoni and 88% to 99% for S. haematobium. Significant heterologous protection was consistently induced against S. haematobium by immunization with S. mansoni, but not against S. mansoni by immunization with S. haematobium. These results are discussed in relation to those of previous studies and in terms of implications for vaccine development.
Identification of Plasmodium falciparum MSP‐1 peptides able to bind to human red blood cells
Authors: URQUIZA MAURICIO , RODRIGUEZ LUIS E. , SUAREZ JORGE E. , GUZMÁN FANNY , OCAMPO MARISOL , CURTIDOR HERNANDO , SEGURA CESAR , TRUJILLO ESPERANZA , PATARROYO MANUEL E.
Published: November 2003

To determine amino acid sequences of the Plasmodium falciparum MSP‐1 protein that interact with red blood cell membranes in a specific receptor‐ligand interaction, 78 sequential peptides, 20 amino acids long and spanning the entire length of the molecule, were synthesized and analysed with a specific binding assay developed for this purpose. Results show that peptides based on conserved and dimorphic regions of MSP‐1, interact with human red blood cells (RBCs). This interaction occurs predominantly with peptides contained within the MSP‐1 proteolytic fragments of 83 kDa, 38 kDa, 33 kDa and 19 kDa. Affinity constants of these peptides were between 140 and 250 nM. Peptide‐RBC binding post enzyme treatment showed that the RBC receptors are not sialic acid dependent and appear to be proteic in nature. Some of these peptides inhibited merozoite invasion of RBCs yet did not inhibit intra‐erthrocytic development. These peptides, in conjunction with those from other merozoite surface proteins, may be used to rationally design a second generation of synthetic peptide‐based malaria vaccines.
Humoral immune responses in Gambians to Pfs16, an immunodominant, Plasmodium falciparum integral membrane protein
Authors: BAKER D.A. , DRAKELEY C.J. , ONG C.S.L. , LULAT A.G‐M.I. , GREENWOOD B.M. , TARGETT G.A.T.
Published: November 2003

Naturally acquired humoral immune responses to Pfs16, an integral membrane protein expressed in Plasmodium falciparum gametocytes and sporozoites, were investigated in The Gambia. A high prevalence of antibodies to this molecule was detected by peptide ELISA. Ninety‐three per cent of the people taking part in a survey at the end of the rainy season (November) had serum antibodies to one or more synthetic peptides spanning the sequence; 88% reacted with one particular peptide sequence (IMLIILSGIVGFKVK) whereas only one out of ten non‐Gambians (taking anti‐malarial prophylaxis with no history of infection) reacted with the peptide. Epitope mapping with mouse MoAbs has shown that this peptide is located on a part of the molecule differing from immunodominant regions of the molecule identified in a previous study in Papua New Guinea.
Correlation of antigen specific IgG and IgG(T) responses with Anoplocephala perfoliata infection intensity in the horse
Authors: PROUDMAN C.J. , TREES A.J.
Published: November 2003

There is increasing interest in the application of serological methods to macro‐parasite infections to indicate infection intensity, which in turn is related to pathogenicity. Colic is the single most important cause of mortality in horses and there is evidence that a proportion of colic cases are associated with infection with the intestinal cestode Anoplocephala perfoliata. In order to develop better tools to investigate this association, the correlation between antigen‐specific equine IgG and IgG(T) and infection intensity of A. perfoliata was investigated. Affinity purification of a 12/13 kDa protein doublet from crude excretory/secretory (E/S) products, and its use in enzume linked immunosorbent assays (ELISA) is described. Its use in the immunodiagnosis of equine cestodosis and the correlation of anti‐12/13 kDa IgG and IgG(T) with parasite burden is investigated using sera from 94 horses of known tapeworm infection intensity. The anti‐12/13 kDa IgG and IgG(T) ELISAs gave correlation coefficients with infection intensity of 0.56 and 0.63 respectively. Linear regression analysis also indicated that anti‐12/13 kDa IgG(T) was the best predictor of infection intensity. The decay of anti‐12/13 kDa IgG(T) in horses following the elimination of A. perfoliata is demonstrated for four horses. Specificity of the anti‐12/13 kDa IgG(T) ELISA is investigated with sera from 33 A. perfoliata negative horses with other helminth infections. Immunoblotting studies demonstrate no cross‐reactivity between A. perfoliata 12/13 kDa antigen and the protein antigens of other helminths. It is concluded that assay of anti‐12/13 kDa IgG(T) provides a useful tool for the assessment of A perfoliata infection intensity for clinical diagnosis and for epidemiological studies.
MALARIA CELLULAR IMMUNE RESPONSES IN NEONATES FROM CAMEROON
Authors: FIEVET Nadine , RINGWALD Pascal , BICKII Jean , DUBOIS BÉatrice , MAUBERT Bertrand , Yves LE HESRAN Jean , COT Michel , DELORON Philippe
Published: November 2003

T cell responses to leucoagglutinin, PPD, and seven Plasmodium falciparum blood stages antigens were investigated in 164 cord blood samples from Cameroonian neonates. In vitro T cell responses were measured by lymphocyte proliferation, and IL‐2, IFN‐γ, and IL‐4 release in the presence of crude schizont extract, purified Pf155/RESA protein, and synthetic peptides from Pf155/RESA. Following culture in presence of leucoagglutinin or PPD, proliferation and cytokine production were very low, as compared to adults from the same area. Interestingly, following stimulation of cord blood lymphocytes by malaria antigens, the percentage of responders and the mean level of positive responses were of the same order than those observed in adults for IL‐2 production, while proliferative and IL‐4 responses were only marginally decreased. Conversely, IFN‐γ production was highly reduced, as compared to adults. Our results demonstrate that prenatal immune priming to malarial antigens is common in this area and that the fetal immune system is able to respond to antigenic stimuli, as cells proliferate and generate cytokines. As cord blood lymphocytes may be induced to differentiate into effector cells producing predominantly Th1 or Th2 cytokines, malaria during pregnancy might direct the functional capacity of fetal T cells to respond to further infection.
Host‐protective fragments and antibody binding epitopes of the Taenia ovis 45W recombinant antigen
Authors: LIGHTOWLERS M.W. , WATERKEYN J.G. , ROTHEL J.S. , GAUCI C.G. , HARRISON G.B.L.
Published: November 2003

The protective efficacy of a recombinant Taenia ovis vaccine antigen, 45W, was compared in sheep vaccine trials with antigen expressed by the full length 45W cDNA and by incomplete copies of the cDNA. Vaccine trials were also carried out using antigen expressed by a cDNA (45S) having a sequence similar, but not identical, to 45W. Stability of the 45W antigen expressed in Escherichia coli was found to be increased after deletion of cDNA sequence encoding 19 COOH‐terminal amino acids. This truncated form of the antigen was designated 45WB/X. Vaccination of sheep with antigen expressed by 45W, 45WB/X, as well as full length 45W and 45S cDNAs, induced high levels of protection. Vaccination with antigen expressed by an incomplete copy of the 45S cDNA clone did not induce protection. Comparison of deduced amino acid sequences for these clones suggests that the host‐protective epitope(s) of the 45W antigen occur on either or both of the 23 and 9 amino acid peptides at the amino and carboxyl termini of 45W, respectively. Antibody binding epitopes of 45W were investigated in ELISA using overlapping 9 amino acid peptides. Protection was found to correlate with the induction of antibody to two 9 amino acid peptides.
Influence of adjuvants on murine immune responses against the C‐terminal 19 kDa fragment of Plasmodium vivax merozoite surface protein‐1 (MSP‐1)
Authors: Yang Chunfu , Collins William E. , Xiao Lihua , Patterson Pamela S. , Reed Robb C. , Hunter Robert L. , Kaslow David C. , Lal Altaf A.
Published: November 2003

The immunogenicity of a yeast‐expressed 19 kDa fragment of P vivax MSP‐1 in the presence of different adjuvant formulations was evaluated. ICR mice were immunized with the 19 kDa antigen, using Freund's, alum, and block copolymer P1005 in water‐in‐oil (W/O) or oil‐in‐water (O/W) emulsions with or without detoxified lipopolysaccharide (RaLPS) as adjuvants. Five weeks following immunization with the antigen, mice were boosted with asexual blood‐stage antigens. Three weeks after the last immunization with the 19 kDa antigen, mice from the Freund's group and most groups that received P1005 as adjuvant had higher total IgG titres than those that received alum as adjuvant or antigen alone. Antibody responses after the antigen immunization were predominantly of the IgG1 isotype, but mice in the Freund's and P1005 (W/O or O/W emulsion with or without RaLPS) groups also had high titres of IgG2a and IgG2b. Antibody titres against merozoites increased in all groups after the parasite antigen boost. IgG2a levels in the group that received antigen in P1005 plus RaLPS in the W/O emulsion were higher than those receiving Freund's, alum or the other copolymer adjuvants. The high IgG2a titres in this group were associated with reduced IL‐10 production.
Two different 8 kDa monomers are involved in the oligomeric organization of the native Echinococcus granulosus antigen B
Authors: GONZÁLEZ GUALBERTO , NIETO ALBERTO , FERNÁNDEZ CECILIA , O¨RN ANDERS , WERNSTEDT CHRISTER , HELLMAN ULF
Published: November 2003

The present work describes the purification and characterization of antigen B (AgB), the thermostable lipoprotein from E. granulosus. Native AgB was purified to homogeneity by a new strategy involving adsorption on DEAE‐Sepharose, followed by immunopurification. The purified antigen was analysed using mapped monoclonal antibodies (MoAbs) and peptide isolation by in situ digestion in gels after SDS‐PAGE. Epitope mapping of 7 MoAbs using PEPSCAN, synthetic peptides and competition studies, revealed that six of them defined epitopes which clustered the N‐terminal extension of a 8 kDa subunit of AgB, whilst the remaining one reacted against the stretch RGLIAEGE, corresponding to the C‐terminus. The epitopes defined by the seven MoAbs were found to be present in all the subunits. Furthermore, the similarities of the peptide finger prints obtained by HPLC analysis and amino acid sequencing of tryptic peptides isolated from the 8, 16 and 24 kDa subunits, indicated that they have most if not all the amino acid sequence in common. We also found evidence that the band representing a component of an apparent molecular weight of 8 kDa in SDS‐PAGE, believed to be the smallest subunit of AgB, contained at least two components, which may constitute the building blocks of the higher molecular weight subunits.
HPLC fractionated soluble egg antigen from Schistosoma mansoni elicits a heterogeneous human immune response
Authors: MOYES RITA B. , ALVES‐OLIVEIRA LUCIA F. , PARRA JUCARA C. , GAZZINELLI GIOVANNI , DOUGHTY BARBARA L.
Published: November 2003

Peripheral blood mononuclear cells (PBMC) from five chronic schistosomiasis patients, three former patients, a SEA sensitized individual, and normal controls were tested in lymphoblastogenesis assays for their ability to proliferate in response to soluble egg antigen (SEA) and soluble worm antigen preparation (SWAP) from Schistosoma mansoni. Cells from all patients and the SEA sensitized individual gave significantly higher responses than the normal controls when stimulated with SEA and SWAP. However, the chronic patients’ SEA responses were much lower than those of the former patients and the SEA sensitized individual. When cells from the same donors were tested in the in vitro granuloma assay, all produced significant granulomatous responses except the normal controls. Once it was established that all individuals in the study gave significant lymphoproliferative responses and granulomatous reactions, SEA was subjected to HPLC fractionation to identify immunogenic protein components of SEA. HPLC separation yielded 25 major fractions. SEA responses from the sensitized individual and former patients exhibited broad, unregulated responsiveness including fractions with neutral, less charged proteins while the chronic patients demonstrated a more restricted range of responsiveness. SEA‐HPLC fractions 14, 21, and 22 contain the most immunodominant proteins based on cellular proliferation data from reactive individuals tested.
Purification and N‐terminal amino acid sequencing of Echinococcus granulosus antigen 5
Authors: ZHANG LI‐HUA , McMANUS D.P.
Published: November 2003

Antigen 5, a major parasite‐derived lipoprotein of unilocular hydatid (Echinococcus granulosus) cyst fluid, comprises subunits of 56–70 kDa which dissociate on disulphide bound reduction to two subunits of approximately 25 and 38 kDa on SDS‐PAGE. The 38 kDa component is recognized as a potentially important diagnostic marker for cystic hydatid disease. Single dimensional SDS‐PAGE, two dimensional (2‐D) gel electrophoresis, modified ‘2‐D’ gel electrophoresis, immunoaffinity‐purification and HLPC were employed to purify antigen 5. Subsequent N‐terminal sequencing suggested that antigen 5 isoforms exist due to the identification of a single amino acid sequence with alternative residues at some positions. An 18 amino acid consensus N‐terminal sequence was derived for antigen 5 as a result of comparing the sequences obtained by the different fractionation methods. No homology was revealed to any previously identified protein including putative antigen 5 amino acid sequences. A synthetic peptide, mimicking the N‐terminal consensus sequence, did not bind with patient sera (confirmed positive to antigen 5) or an anti‐antigen 5 MoAb. Protein sequences (16 residues compared) for the 38 kDa subunit from sheep and horse (representing different strains of E.  granulosus) cyst fluids were very similar except for differences at three positions. 2‐D and modified ‘2‐D’ gel electrophoresis, in combination with immunoblot analysis, indicated the presence of more than one protein in the 38 kDa region of SCF capable of binding the anti‐antigen 5 MoAb.
Macrophage modifying factor secreted by the tetrathyridia of Mesocestoides corti (cestoda): monoclonal antibody to the modifying factor antagonizes its immunological activity
Authors: KADIAN S.K. , DIXON J.B. , CARTER S.D. , JENKINS P.
Published: November 2003

Immunomodulation of macrophage activity by in vitro secretions of Mesocestoides corti has been previously demonstrated. The modifying activity secreted by M. corti had the effect of reducing the normal accessory function of macrophages in a Con‐A‐activated lymphocyte proliferation assay. This paper describes the purification of the modifying activity by FPLC techniques and the generation of a monoclonal antibody (MoAb) to this molecule in mice. The MoAb bound immunomodulatory FPLC fractions of M. corti in an ELISA. When MoAb was applied in conjunction with immunomodulatory parasite secretions to macrophages in vivo or in vitro, the modifying effect of the secretions was abolished. This profound effect of the MoAb should help to elucidate the mechanisms by which metacestode parasites avoid host immune responses and may enable therapeutic intervention.
Involvement of accessory cells in the Trypanosoma cruzi‐induced inhibition of the polyclonal response of T lymphocytes
Authors: MOTRÁN CRISTINA , GRUPPI ADRIANA , VULLO CARLOS M. , PISTORESI‐PALENCIA MARIA C. , SERRA HORACIO M.
Published: November 2003

Infection with Trypanosoma cruzi is characterized by hyporesponsiveness of the immune system during the acute phase of infection. To better understand the immunological mechanisms affected by T. cruzi, we studied if a reduced T cell proliferative response could originate from an inability of T cells to proliferate or a functional deficiency at the level of accessory cells (AC). The inhibitory effect exerted by T. cruzi was during the induction phase of the lymphoproliferative response, suggesting the participation of AC in the hyporesponse. Then we further investigated the potential of the parasite to interfere with accessory cell‐dependent and ‐independent pathways of human T cell proliferation. Peripheral blood mononuclear cells and peripheral blood lymphocytes from healthy individuals, enriched for T cells, were analysed with regard to their proliferative capacity using: phytohaemagglutinin, immobilized anti‐CD3 monoclonal antibody (MoAb) and MoAb to the CD28 antigen, anti‐CD3 MoAb and recombinant IL‐2 and anti‐CD3 MoAb plus phorbol myristate acetate in the presence of parasites. Significant suppression of the proliferative response was caused by the parasite only when AC were present. The parasite markedly reduced the surface expression of HLA‐DR and CD11b antigens, key molecules in PHA‐induced proliferation. Addition of indomethacin to the culture failed to reverse the inhibitory effect of the parasites, suggesting that prostaglandin E2 was not involved. These data suggest that AC in contact with T. cruzi become incompetent as antigen presenting cell because they are unable to induce a normal proliferative response in T lymphocytes.
Structural and molecular specificity of antibody responses in mice immune to third stage larvae of Onchocerca volvulus
Authors: YUTANAWIBOONCHAI W. , BRIGANDI R.A. , ROTMAN H.L. , ABRAHAM D.
Published: November 2003

Immunization of mice with irradiated Onchocerca volvulus infective stage larvae (L3) has been demonstrated to confer protection against challenge infections with these larvae. Additionally, cytokine level measurements and cytokine depletion studies have shown that both IL‐4 and IL‐5 are important in generating a protective immune response against O. volvulus challenge infections, thus suggesting a dependency of protective immunity on IgG1, IgE and/or eosinophils. In the present study, we examined the humoral responses of immunized mice to O. volvulus L3 antigens. ELISA measurements of total serum antibody levels indicated that IgE was the only antibody isotype elevated in mice immunized with O. volvulus L3. IgM from immunized mice was the only isotype that recognized surface antigens on intact O. volvulus L3. IgG1, IgG3, IgE and IgA recognized internal parasite antigens on O. volvulus L3 frozen sections. Western blot analysis of L3 proteins showed that in serum from mice immunized with O. volvulus L3 IgG1, IgG2a/2b, IgA, and IgE, as well as IgM, recognized unique L3 proteins. Antibodies in serum from L3 immunized mice were able to detect O. volvulus adult antigens in a pattern similar to the recognition found in O. volvulus L3. Some L3 antigens were shared by adults, while other antigens were L3 specific. The ELISA, immunohistochemistry and Western blot findings thus demonstrate a complex pattern of antigen recognition of parasite antigens by antibodies found in mice immune to the L3 of O. volvulus
Association between anti‐Pfs48/45 reactivity and P. falciparum transmission‐blocking activity in sera from Cameroon
Authors: ROEFFEN W. , MULDER B. , TEELEN K. , BOLMER M. , ELING W. , TARGETT G.A.T. , BECKERS P.J.A. , SAUERWEIN R.
Published: November 2003

Pfs48/45, a sexual stage parasite protein doublet of P. falciparum, is a target of antibodies which inhibit the development of the parasite in the mosquito. Twenty‐eight (54%) out of 52 sera of gametocyte carriers from Cameroon reduced infectivity in the mosquito membrane feeding bioassay to less than 20% of the controls. These 52 sera were analysed by competition ELISAs for the presence of antibodies capable of competing the binding of six monoclonal antibodies (MoAbs) directed against five different epitopes on Pfs48/45. The percentage of these 52 Cameroon sera that competed with one of the MoAbs ranged from 13% (epitope I) to 33% (epitope IIc). Comparison of activity in the transmission‐blocking assay ( ≥80%) and in the Pfs48/45 competition ELISA show a relative specificity of 100% (24 of 24) and a relative sensitivity of 75% (21 of 28). Non‐blocking sera showed no competition with any of the MoAbs. These MoAbs were further used to study the diversity of epitopes among isolates of P. falciparum using a two‐site ELISA. MoAbs against epitope I, III and V reacted with four different isolates whereas epitope II could be subdivided into three epitopes. None of the isolates reacted with MoAb 3G12 (epitope IV). Using these four different isolates, the competition ELISA titre varies from 1/20 to 1/80 and no significant differences are found between the isolates except for epitope II where only three out of 11 positives for epitope IIa were also positive for epitope IIc.
Fasciola hepatica: rapid switching of stage‐specific antigen expression after infection
Authors: TKALCEVIC JOSEPHINE , BRANDON MALCOLM R. , MEEUSEN ELS N.T.
Published: November 2003

Early developmental stages of the trematode parasite Fasciola hepatica were collected from the peritoneal cavity and liver of mice during a ten day infection period. Using one dimensional SDS‐PAGE, differences in protein expression profiles were observed in stages collected on the same day post‐infection in different physiological locations and also in juvenile parasites collected from the same location on different days post‐infection. Four rat monoclonal antibodies were raised against the parasite using lymph nodes draining infected tissues. Three monoclonal antibodies, FY3‐1, FY3‐2 and FY4‐7, were generated using cells from the mesenteric lymph node of recently challenged immune rats, while FY1‐6 was derived from hepatic lymph node cells of a chronically infected rat. The epitope recognized by FY3‐2 appeared to be carbohydrate in nature and was present on the surface of newly excysted juveniles. Immunoblots revealed that the antigens recognized by FY3‐1, FY3‐2 and FY4‐7 were only expressed for two days after infection. In contrast, FY1‐6 recognized epitopes expressed across all developmental stages screened. The rapid changes in protein and antigen expression observed during the early stages of infection may assist the parasite to evade the host immune response.
Evidence for the existence of ganglioside molecules in the antigen of Entamoeba histolytica
Authors: SORICE M. , GRIGGI T. , NICODEMO G. , GAROFALO T. , MARANGI M. , SANGUIGNI S. , BECKER S.I. , MIRELMAN D.
Published: November 2003

Gangliosides were found to be present in Entamoeba histolytica. They were extracted from lyophilized trophozoites of the pathogenic strain HM‐1:IMSS and purified by high performance thin‐layer chromatography. Two resorcinol‐positive bands, comigrating with GM2 and GD1a were demonstrated, revealing the existence of ganglioside molecules in Entamoeba histolytica. The GM2 content, determined as lipid‐bound sialic acid, was 1.5 μg/108 amoebae, the content of the GD1a comigrating band was 0.32 μg/108 amoebae. The identity of the GM2 comigrating band was confirmed by TLC immunostaining, using the monoclonal anti‐GM2 antibody GMB28. Furthermore, six out of ten anti‐amoeba positive sera selectively reacted with the GM2 comigrating band, as revealed by immunostaining on TLC plates. Absorption tests revealed that preincubation of anti‐amoeba positive sera with standard GM2 was followed by a significant decrease in the reaction with amoeba trophozoites by indirect immunofluorescence. These results demonstrate that a GM2 comigrating component of Entamoeba histolytica may be one of the antigens responsible for the appearance of circulating antibodies in patients with amoebiasis.
Immune responses associated with protection in sheep vaccinated with a recombinant antigen from Taenia ovis
Authors: ROTHEL J.S. , LIGHTOWLERS M.W. , SEOW H.‐F. , WOOD P.R. , ROTHEL L.J. , HEATH D.D. , HARRISON G.B.L.
Published: November 2003

This paper describes the evaluation of the protective antibody response of sheep to vaccination against Taenia ovis infection with a defined recombinant antigen (45W). Sera from 181 vaccinated sheep, collected prior to experimental challenge with T.ovis, were assessed for 45W specific IgA, IgG, IgG1, IgG2 and IgM levels and these results correlated with protection data. There were significant relationships (P < 0.001) between IgG, IgG1 and IgG2 titres and protection. Serum IgA levels did not correlate with protection and there were no significant levels of 45W specific IgM detected. Killing of several other taeniid cestodes has been shown to be complement mediated and the findings in this study are consistent with the involvement of this immune mechanism in 45W vaccinated sheep. A comparison of the adjuvants used in this study (saponin and oil in water) demonstrated that whereas both adjuvants stimulated the production of similar levels of 45W specific IgG1, the IgG2 response was significantly higher in sheep vaccinated with oil adjuvant.
A single gene copy merozoite surface antigen and immune evasion?
Authors: O'DEA K.P. , McKEAN P.G. , JARRA W. , BROWN K.N.
Published: November 2003

During the course of chronic malaria infection antigenic variants of a parasite antigen are expressed and exposed on the surface of infected erythrocyte membranes. There also exists a number of apparently invariant single gene copy blood‐stage antigens, exposed or non‐exposed, which have been shown to afford immunity under experimental conditions. To determine why the host, presented with invariant ‘protective’ antigens, is unable to control infections effectively, immunity to a representative single gene copy antigen, the merozoite surface protein 1 (MSP1) was investigated in Plasmodium chabaudi chabaudi AS, a murine model of chronic malaria. Immunization with monoclonal antibody affinity purified native MSP1 resulted in enhanced control of parasitaemia on challenge, irrespective of the parasite inoculum size; challenge with a single parasite, however, suggested that expansion of resistant parasite subpopulations was not occurring. Challenge of mice immunized with recombinant fusion proteins encoding N‐ or C‐terminal regions of the P.c. chabaudi AS MSP1 produced inconsistent effects, often parasitaemias were indistingishable from controls despite significant anti‐MSP1 antibody responses. The not unlikely contamination of MSP1 native preparations with erythrocyte (E) components was considered. Immunization with a mixture of the MSP1 C‐terminus recombinant polypeptide and a Triton X‐100 solubilized lysate of normal E resulted in enhanced control of parasitaemia, however, no effect was seen after administration of either component on its own. Co‐immunization of E with the N‐terminus polypeptide reversed the inhibition seen, on this occasion with this construct alone.
Comparative vaccination of cattle against Boophilus microplus with recombinant antigen Bm86 alone or in combination with recombinant Bm91
Authors: WILLADSEN PETER , SMITH DON , COBON GARY , McKENNA ROBERT V.
Published: November 2003

Cattle were vaccinated either with a single recombinant tick antigen, Bm86 or with a combination of two recombinant antigens, Bm86 and Bm91 from the tick Boophilus microplus. In three experiments, the responses of cattle to subsequent challenge with the tick were assessed. The addition of the Bm91 antigen enhanced the efficacy of the vaccination over that with Bm86 alone to a statistically significant degree. Moreover, co‐vaccination with two antigens did not impair the response of cattle to the Bm86 antigen. Finally, responses of individual cattle to the two antigens were independent. All of these results may be relevant to the increase in efficacy expected from a dual antigen vaccine.
Identification and characterization of human B‐cell epitopes in recombinant antigens of Leishmania aethiopica
Authors: OSLAND ARVE , BEYENE DEMISSEW , VEFRING HEGE K. , DE WIT TOBIAS RINKE , WRIGHT MARIANNE S.
Published: November 2003

Recombinant DNA fragments from Leishmania aethiopica that code for epitopes which react with human antibodies have been characterized by cross‐hybridization studies and DNA sequence analysis. Twenty clones could be grouped into seven different groups (I–VII), probably representing seven different L. aethiopica antigens. The DNA sequences of representative clones from the seven groups have been obtained and the amino acid sequence of the respective recombinant antigens established. The recombinant antigens have been analysed by epitope scanning with patient sera, and octapeptides that contain potential B‐cell epitopes have been identified in all seven recombinant antigens. These octapeptides have further been tested with additional patient sera and control sera, and three octapeptides (HAFCHEEG, YHSSVVHD and SYAPCSLK) were found to contain major epitopes recognizing specific antibodies in nine, seven and four, respectively, of the twenty sera tested. Fifteen of the twenty sera reacted with one or more of these three octapeptides.
Increased expression and secretion of ICAM‐1 during experimental infection with Trypanosoma cruzi
Authors: LAUCELLA SUSANA , SALCEDO ROSALBA , CASTAÑOS‐VELEZ ESMERALDA , RIARTE ADELINA , DE TITTO ERNESTO H. , PATARROYO MANUEL , ÖRN ANDERS , ROTTENBERG MARTÍN E.
Published: November 2003

In the present study we demonstrate that spleens and hearts from BALB/c mice infected with the virulent Tulahuén or the low virulent CA‐I strains of Trypanosoma cruzi, contain substantially higher ICAM‐1 transcripts than uninfected controls. ICAM‐1 expression in heart cells was also increased at the protein level, as measured by flow cytometry, ELISA and immunohistochemistry. The adhesive receptor was observed not only on inflammatory cells but also on sarcolemma of cardiac myocytes from T. cruzi infected mice. ICAM‐1 expression was higher during the acute phase than in the chronic phase of infection, and paralleled the density of inflammatory leukocytes. Elevated titres of soluble ICAM‐1 (s‐ICAM‐1) were detected in sera from mice during the acute phase of infection with CA‐I or Tulahuén parasites. Cytokines, including IFN‐γ, IL‐1α, IL‐6 and TNF‐α have been shown to modulate expression of ICAM‐1. Spleens and hearts from mice infected with CA‐I or Tulahuén strains showed increased accumulation of mRNAs specific for these cytokines, which peaked during the acute phase of infection. However, IFN‐γ activity was not necessary for ICAM‐1 induction, as its levels were also increased during infection in IFN‐γ receptor knock‐out (IFN‐γR−) mice. Upregulation of ICAM‐1 expression might be a direct consequence of parasite infection, since its density on cell lines of different lineages was enhanced after 24 or 48 h of infection with T. cruzi
Enzymatic effect of hypodermin A, a parasite protease, on bovine lymphocyte membrane antigens
Authors: Moiré Nathalie , Nicolas‐Gaulard Isabelle , Le Vern Yves , Boulard Chantal
Published: November 2003

The protease hypodermin A (HA) is produced by the parasitic warble‐fly larva and is implicated in the modulation of the bovine immune system. This study examines the effect of this enzyme on the cell surface markers of bovine lymphocytes. HA interfered with the binding of all anti‐lymphocyte receptor antibodies tested. Anti‐BoCD2 and CD5 staining was completely abolished. But the mean fluorescence intensity (MFI) only was diminished for antibodies against BoCD4, CD8 and CD18. On the contrary, the MFI for anti‐MHC Cl I molecules staining was increased. This effect of HA began as early as one h, and was reversed by removal of HA. Heating or PMSF treatment, which both inhibit protease activity, abolished the action of HA on the surface antigens. The HA concentrations (100 μg/ml) needed to alter antibody binding were similar to those that inhibited phytohaemagglutinin (PHA)‐induced proliferation. These results show that enzymatic activity of HA on lymphocyte surface markers may be implicated in the inhibition of lymphocyte proliferation.
Protective immunity induced by vaccination with two Haemonchus contortus excretory secretory proteins in sheep
Authors: SCHALLIG HENK D.F.H. , VAN LEEUWEN MARIANNE A.W. , CORNELISSEN ALBERT W.C.A.
Published: November 2003

Two excretory secretory (ES) antigens of adult Haemonchus contortus with molecular weights of 15 and 24 kDa, respectively, were evaluated as protective immunogen against haemonchosis. Sheep were vaccinated three times and subsequently challenged with 20 000 infective larvae. Vaccination induced significant reduction (>70%) in mean faecal egg counts and abomasal worm burden compared to the non‐vaccinated control group or adjuvant control group. Vaccination induced ES‐specific antibodies and stimulated infiltration of mast cells in the abomasal tissue.
CD4+ T lymphocytes contribute to protective immunity induced in sheep and goats by Haemonchus contortus gut antigens
Authors: KARANU FRANCIS N. , McGUIRE TRAVIS C. , DAVIS WILLIAM C. , BESSER THOMAS E. , JASMER DOUGLAS P.
Published: November 2003

Immunization with parasite antigens derived from the gut of adult Haemonchus contortus induces significant levels of protection against the parasite in sheep and goats. However, the mechanisms of immunity involved in this protection are not clear. Here, we investigate the requirement for CD4+ T lymphocytes in gut antigen‐induced immunity against H. contortus. Gut antigen immunized animals were depleted (>98%) of their CD4+ T lymphocytes in peripheral blood by intravenous injection of an anti‐CD4 MoAb. Depletion in peripheral blood persisted for at least eight days, after which there was gradual recovery of CD4+ T lymphocytes. Serum antibody levels in gut antigen‐immunized animals correlated significantly with worm parameters, suggesting a contribution by antibody to the immunity observed. By covariate analysis, using ELISA OD as the covariate, CD4+ T lymphocyte depletion was shown to partially abrogate immunity induced by gut antigen immunization, against challenge infection with H. contortus. The greatest effect of CD4+ T lymphocyte depletion was observed at 14 days post‐infection, with differences between CD4+ T lymphocyte depleted and intact animals less apparent between days 21 and 25. Collectively, our data indicate that CD4+ T lymphocytes contribute to immunity induced by gut antigens. Our results also suggest that antibody works synergistically with CD4+ T lymphocytes to confer this immunity.
Secondary Echinococcus multilocularis infection in A/J mice: delayed metacestode development is associated with Th1 cytokine production
Authors: EMERY ISABELLE , LIANCE MARTINE , LECLERC CLAUDE
Published: November 2003

The course of Echinococcus multilocularis infection was studied in four different strains of mice after intrahepatic inoculation of a metacestode homogenate. Among these strains of mice, A/J and BALB/c mice were characterized, respectively, as the most resistant and susceptible strains. Although there was no significant difference between the mean surface of hepatic metacestodes of these two strains of mice at any examination time, 13 weeks after infection, the mean metastatic burden of A/J mice was significantly lower than that of BALB/c mice. Moreover, at this time, some BALB/c mice spontaneously died from their infection whereas all A/J mice remained in good health.

The relative resistance of A/J mice to parasite development was associated with a strong and sustained in vitro spleen cell proliferative response to a crude E. multilocularis extract as well as with a high parasite‐induced production of IFN‐γ and IL‐2. The susceptibility of BALB/c mice was on the contrary associated with a high IL‐4 production. Interestingly, the parasite extract also stimulated a significant IL‐4 production by spleen cells of uninfected susceptible BALB/c mice, but not by control A/J mouse spleen cells. Altogether, these results suggest that the relative resistance of A/J mice to E. multilocularis growth is associated with the development of T cell responses characterized by the production of high levels of Th1 cytokines.