bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modulation of the allergic reactivity of slum children by helminthic infection
Authors: HAGEL ISABEL , LYNCH NEIL R. , PÉREZ MIREYA , PRISCO MARIA C.DI , LÓPEZ REINA , ROJAS EDWARD 
Published: October 2007

SummaryInfection by helminthic parasites can cause the polyclonal stimulation of IgE synthesis, possibly via an enhanced production of interleukin‐4 (IL‐4), and this has been suggested to influence the allergic reactivity of tropical populations where these parasites are endemic. We evaluated a group of urban slum children in Caracas, Venezuela, with a high prevalence of helminthic infection (70.8%), to establish the relationship between the elevated IgE levels (3696 IU/ml) induced by these parasites and various aspects of the allergic response. Although the absolute levels of IL‐4 detected in the sera of these children were low (0.65 ± 0.20 ng/ml), a strong positive correlation (r = 0.78) was found between these and serum IgE. The cutaneous immediate hypersensitivity reactivity to extracts of common environmental allergens was relatively low (17.5% to house dust), although that to Ascaris extract was moderately high (49.4%). Significant inverse correlations were found between total IgE levels and the different skin test reaction diameters, including Ascaris. The positivity of Prausnitz‐Kustner passive transfer tests was low in this group (34%), with a strong inverse correlation (r= ‐0.75) being found between this and total IgE levels. Significant inverse correlations were also found between total IgE levels and specific IgE antibody to environmental allergens, and to Ascaris antigen. We suggest that the polyclonal production of IgE stimulated by helminthic infection can suppress the allergic response to environmental and parasite allergens via both mast cell saturation and inhibition of specific IgE production.
The schistosomulicidal activity and the production of IL‐1 and TNF‐α by peritoneal macrophages from infected mice and their potentiation by muramyl tripeptide‐phosphatidyl ethanolamine (MTP‐PE) treatment
Authors: SEGER M. , GOLD D. , LENGY J. , PAULI H. , KEISARI Y. 
Published: October 2007

SummaryProduction of TNF‐α and IL‐1 by adherent peritoneal exudate macrophages (APEM) was monitored for 20 weeks in Schistosoma mansoni infected mice in comparison to their schistosomulicidal activity. LPS‐triggered IL‐1 and TNF‐α production by APEM peaked 10 weeks post infection (p.i.) and declined thereafter. The schistosomulicidal activity of APEM also peaked after 10 weeks but remained elevated thereafter. Infected mice were also treated with the immunostimulator liposomal muramyl tripeptide‐phosphatidyl ethanolamine (MTP‐PE) 6 or 10 weeks p.i., and their APEM were tested 4 weeks later. APEM from such treated animals showed elevated IL‐1 and TNF‐α production when treatment commenced 6 weeks p.i., while their schistosomulicidal activity increased when treatment commenced either 6 or 10 weeks p.i. The L‐arginine inhibitor, NG monomethyl arginine, markedly inhibited the schistosomulicidal activity but not the IL‐1 and TNF‐α production of APEM. Our results show that monokine production increases during the acute phase of infection and declines during its chronic phase, while macrophage schistosomulicidal activity remains constant throughout. Furthermore, TNF‐α or IL‐1 may play a minor role in APEM mediated killing of schistosomula.
Immunological relationships during primary infection with Heligmosomoides polygyrus (Nematospiroides dubius): parasite specific IgG1 antibody responses and primary response phenotype
Authors: WAHID F. N. , BEHNKE J. M. 
Published: October 2007

SummaryIgG1 antibody responses to Heligmosomoides polygyrus were measured in eight mouse strains supporting acute (< 8 weeks, SJL, SWR), intermediate (10–20 weeks, NIH, BALB/c) or chronic (> 25 weeks, C57BL/0, CBA, C3H, AKR) primary infections. Mice supporting acute or intermediate infections produced more intense antibody responses and total serum IgG1 concentrations were higher than in mice tolerating chronic infections. Positive correlations across mouse strains between the intensity of the antibody response and the percentage loss of worms in weeks 6 and 10 were established. No correlation was found between the response within mouse strains and loss of worms by individual mice. Heavy infections gave marginally higher antibody titres than low intensity infections, but few significant differences were detected and it was concluded that infection intensity did not markedly influence the magnitude of the antibody response. Male and female mice responded similarly despite the earlier loss of worms from females. No association was found between the primary response phenotype and recognition of particular antigens in Western blot analysis, nor did intensity of infection or host gender affect recognition. The possibility that immunomodulatory properties of adult worms may have had a differential influence on ability of strains of contrasting response phenotype to mount IgG1 responses was discussed.
Stage and isotype specific immune responses in a rat model of filariasis
Authors: LAWRENCE R. A. , DENHAM D. A. 
Published: October 2007

SummaryInbred PVG rats infected with 100 Brugia pahangi infective larvae (L3) divide into rats that develop microfilaraemic infection (Mf+), and those that remain microfilaria negative (Mf‐). All rats had high levels of specific IgG to adult worm and L3 extracts, however, after the onset of microfilaraemia, Mf+ rats had significantly higher levels of IgG to Mf extract. Mf+ rats recognized several antigenic components of each developmental extract that were not responded to by Mf‐ rats. In particular Mf+ rats recognized a triplet of proteins of 61‐67 kD in microfilarial extract from day 74 post infection onwards. This indicated that these proteins were stage specific to Mf and Mf‐ rats had not been exposed to Mf rather than Mf absence being due to a protective antibody response. Analysis of the immunoglobulin isotype usage during infection revealed that each isotype was independent both in its period of induction and the developmental stage to which it responded. The predominant isotypes responding throughout infection were IgG1, IgG2a and IgM. Specific IgG2b and IgG2c were elevated early in infection but after the onset of microfilaraemia antibody of these subclasses was suppressed. The antigenic profiles recognized on immunoblots by IgG1, IgG2a and IgM were very similar.
Type I hypersensitivity reactions in intestinal mucosae from rats infected with Fasciola hepatica
Authors: O'MALLEY K. E. , SLOAN T. , JOYCE P. , BAIRD A. W. 
Published: October 2007

SummaryType I hypersensitivity reactions in the intestinal tract of sensitized animals may contribute to resistance to reinfection with Fasciola hepatica. Colonic mucosae isolated from previously infected rats were voltage clamped in Ussing chambers. Antigen was prepared as a crude homogenate from adult liver fluke. Assay of serum antibodies against fluke antigen confirmed sensitization. Antigen challenge evoked a rapid onset, transient inward current in sensitized but not in control preparations. Chloride secretion accounted for at least part of the response since the loop diuretic bumetanide reduced the effect of antigen by 61%. Anti‐rat IgE mimicked the response to antigen and desensitized tissues to subsequent antigen challenge. Local synthesis of eicosanoids may mediate the response to antigen since the cyclo‐oxygenase inhibitor piroxicam reduced the response by 76%. In contrast, mepyramine which is a histamine receptor antagonist did not alter the ion transport response evoked by antigen. Tetrodotoxin reduced the response to antigen by 53% implicating intrinsic neurons within the lamina propria as effector cells in the responses of this tissue to antigen. We propose that antigen stimulation of electrogenic chloride movement and consequent fluid secretion in vivo may contribute to a local effector mechanism in prevention of reinfection of previously sensitized hosts.
Effect of macrophage infection by Leishmania on the proliferation of an antigen‐specific T‐cell line, TPB1, to a non‐parasite antigen
Authors: LYTTON SIMON D. , MOZES EDNA , JAFFE CHARLES L. 
Published: October 2007

SummaryThe ability of Leishmania mexicana amazonensis to inhibit antigen specific T‐cell proliferation against a non‐parasite polypeptide antigen, poly(LTyr, LGlu)‐poly(DLAla)–poly(LLys), was examined. Infection of mouse peritoneal macrophages by promastigotes blocked the proliferation of the T‐cell line, TPB1. This effect was correlated with the level of parasite infection, and the timing of macrophage infection and antigen addition. Peritoneal macrophages from both BALB/b and C57BL/6 mice showed reduced ability to serve as antigen presenting cells.
Immunosuppression in trypanotolerant N'Dama cattle following Trypanosoma congolense infection
Authors: FLYNN J. N. , SILEGHEM M. 
Published: October 2007

SummaryTsetse‐transmitted Trypanosoma congolense infection causes an impairment of in vitro T cell proliferative responses in Boran (Bos indicus) cattle. To assess the importance of this phenomenon as it may relate to the ability of trypanotolerant cattle to control infection with trypanosomes, T cell proliferative responses to mitogenic stimulus with Concanavalin A were measured in N'Dama (Bos taurus,) cattle throughout infection. The responses of peripheral blood mononuclear cells from Boran and N'Dama cattle were similar. Depressed proliferative responses were observed with cells of both breeds at 12 days post infection, after which the responses returned to levels similar to those recorded pre‐infection. Immunosuppression was also studied in the lymph nodes of a major histocompa‐tibility complex (MHC)‐matched pair of N'Dama cattle. Lymph node cells from the infected animal failed to respond to mitogenic stimulus. Co‐culture experiments in which the cells from this node were mixed with either lymph node cells or peripheral blood mononuclear cells from the non‐infected MHC‐compatible animal revealed the presence of suppressor cells, acting in a prostaglandin‐independent manner, capable of arresting mitogen‐induced T cell proliferation.
Granulomatous hypersensitivity to Schistosoma mansoni EGG antigens in human schistosomiasis. IV. A role for prostaglandin‐induced inhibition of in vitro granuloma formation
Authors: GOES ALFREDO M. , REZENDE SIMONE A. , GAZZINELLI GIOVANNI , DOUGHTY BARBARA L. 
Published: October 2007

SUMMARYThe prostaglandins (PG) are known to regulate immune cell function(s) and participate in the progression of both acute and chronic inflammatory reactions. Using an in vitro model of Schistosoma mansoni egg‐induced hypersensitivity granulomas, we have delineated the role of immune complexes (IC) in the induction and release of PG and their inhibitory effects on granuloma development. The hypersensitivity‐type granuloma reaction to soluble egg antigen (SEA) was examined using a model of in vitro granuloma formation. Our results show that granuloma formation was dramatically suppressed by the addition to the granuloma cultures of IC, PGE1, PGE2, while PGF2 alpha had no significant effect. The inhibition of the PG function was achieved by the introduction of anti‐PG antibodies that blocked suppression of granuloma formation. It appears in this model system that IC may inhibit the activity of granuloma formation by stimulating the monocyte‐macrophage lineage to release inhibitory mediators. Our results suggest that the prostaglandins E series may be important in the generation and maintenance of suppression of the granulomatous inflammatory response to S. mansoni egg antigens.
Inhibition of Plasmodium falciparum growth in vitro by CD4+ and CD8+ T cells from non‐exposed donors
Authors: H. FELL ANDREW , CURRIER JEFF , F. GOOD MICHAEL 
Published: October 2007

SUMMARYT cells from most adult non‐exposed donors, which express a memory phenotype (CD45RO+), can respond by proliferation to P. falciparum asexual stages in vitro. Such cells may have arisen from exposure to environmental organisms. To address the efficacy of such cells in eliminating parasites and investigate the mechanisms involved, we have used an in vitro assay where parasite growth can be precisely monitored in the presence of different cell preparations. Unfractionated peripheral blood mononuclear cells (PBMC) from both malaria‐exposed and non‐exposed donors inhibited parasite growth by up to 62% in a two day assay. Purified T cells in the presence of adherent cells had a similar effect, but purified T cells alone or adherent cells alone had minimal effect. Antigens released at the time of schizont rupture were maximally effective in stimulating interferon‐γ (IFNγ) production. Neutralizing antibodies to IFNγ showed a partial reduction of growth inhibition in some individuals tested suggesting that different mechanisms may be operative. Neutralizing antibody to TNFα had a partial effect in combination with anti‐IFNγ. Antibodies to IL‐1 and IL‐4 had no effect. T cell fractionation experiments showed that while purified CD4+ T cells from some donors produced IFNγ and inhibited parasite growth, purified CD8+ T cells could inhibit parasite growth to a greater extent without production of detectable IFNγ. Four parasitised red blood cell clones (CD4+, TCRαβ+, IFNγ producing) derived from non‐exposed donors inhibited parasite growth to comparable levels, but one clone showed low production of IFNγ whilst the other three produced high levels. Our data show that T cells from non‐exposed donors have the potential to eliminate malaria parasites via non‐IFNγ dependent mechanisms. Such mechanisms may contribute to a degree of innate resistance to malaria in vivo, and may be able to be targeted by malaria vaccine programs.
Antigen presentation by epidermal langerhans cells in experimental cutaneous leishmaniasis
Authors: AXELROD OFRA , KLAUS SIDNEY , FRANKENBURG SHOSHANA 
Published: October 2007

SUMMARYCutaneous leishmaniasis is a disease induced by intradermal injection of leishmania promastigotes. Since the first cells the parasite encounters are those of the skin, the involvement of this organ in the early immune response might be relevant to the outcome of the disease. In this study we examined the ability of epidermal langerhans cells (LC) to become infected in vivo and to function as antigen presenting cells during the early hours of infection with Leishmania major. Our experiments showed that LC from mice injected with parasites can present antigen to a leishmania‐specific T cell line when LC are obtained as early as four h after infection. The stimulation was specific, since LC from leishmania injected mice did not present antigen to an ovalbumin‐specific T cell line nor did LC from ovalbumin‐injected mice present antigen to the leishmania specific T cell line. Despite the ability of epidermal LC cells to present antigen, no parasites were detected in the epidermis, suggesting that these cells are not directly involved in establishing an infection.
Identification of a 94‐kilodalton antigen on Leishmania promastigote forms and its specific recognition in human and canine visceral leishmaniasis
Authors: ROLLAND LAURENCE , ZILBERFARB VLADIMIR , FURTADO ANDRE , GENTILINI MARC 
Published: October 2007

SUMMARYWe have analysed by immunoblotting sera from humans and dogs with visceral leishmaniasis, from the Old World as well as the New. When lysates of promastigotes are used as antigens, antibodies against a 94 kDa Leishmania component are detected, regardless of the age and geographical origin of the patient, the serum antibody titre as measured by indirect immunofluorescence, and the number of arcs in counterimmunoelectrophoresis. Low dilutions of sera from patients with Old and New World cutaneous leishmaniasis did not react with the 94‐kDa antigen, whatever the species of Leishmania used as antigens. Sera from patients with other infections than leishmaniases, or without infection, are negative, even at low dilution. Anti‐94 kDa antibodies were detected in the sera of Leishmania‐infected dogs from both the Old and the New World. When lysates of Leishmania mexicana axenic amastigotes are used as antigens, the 94‐kDa antigen was little or none identified by sera from humans and dogs with visceral leishmaniasis, and never recognized by control sera. Thus, the specific recognition of the 94‐kDa promastigote antigen in human and canine visceral leishmaniasis suggests that this antigen could be a potential candidate in the differential immunodiagnosis of the disease.
Neospora caninumin dogs: detection of antibodies by ELISA using an iscom antigen
Authors: BJÖRKMAN C. , LUNDÉN A. , HOLMDAHL J. , BARBER J. , TREES A. J. , UGGLA A. 
Published: October 2007

SUMMARYAn indirect enzyme linked immunosorbent assay (ELISA) for detection of antibodies toNeospora caninumin serum from dogs is described. Extracted tachyzoite proteins incorporated into immunostimulating complexes (iscoms) were used as coating antigen. A mixture of a monoclonal antibody to dog immunoglobulin G and a horse radish peroxidase conjugated antibody to mouse Ig was used to detect bound antibody. When the iscom preparation was analysed by means of sodium dodecyl sulphate polyacrylamide gel electrophoresis it appeared to consist of a restricted number of proteins compared with whole parasite homogenates. In immunoblot analysis, usingN. caninumpositive sera from rabbits and dogs as probes, the major antigens recognized had approximate molecular weights between 30 and 45 and 17 to 19kDa. Compared with an ELISA using a crude solubilized tachyzoite antigen, the iscom ELISA substantially improved the sensitivity and specificity (to 97·6% and 95·6%, respectively, against an immunofluorescence test, IFAT, as indicator of true status). There was a statistically significant positive correlation between IFAT titres and iscom ELISA OD450values. The iscom ELISA absorbances (and the IFAT titres) of dogs with proven clinical infections were not higher than those from nonclinically affected, putatively infected dogs.
Vaccination against the cat flea Ctenocephalides felis felis
Authors: HEATH ANDREW W. , ARFSTEN ANN , YAMANAKA MILES , DRYDEN MICHAEL W. , DALE BEVERLY 
Published: October 2007

SUMMARYNon‐chemical control of haematophagous parasites is a desirable goal. We report here on the use of concealed antigens from the major digestive organ of the cat‐flea as vaccine components. Rabbits were immunized with various antigens from cat flea midguts, and immunoglobulin from these rabbits was fed to cat fleas in an artifical feeding system. Antibody produced against soluble antigens from the midguts of fed fleas was able to kill fleas in this system. Dogs were then immunized with various antigen preparations, and challenged for a week with live fleas. Significantly fewer live fleas were recovered from dogs immunized with fed midgut supernatant, and recovered live female fleas produced significantly fewer eggs. This study indicates the possibility of vaccination as a means of control of flea, and possibly other blood sucking insect populations.
Immunosuppression by a neutral thiol protease from parasitic helminth larvae in mice
Authors: HAMAJIMA F. , YAMAMOTO M. , TSURU S. , YAMAKAMI K. , FUJINO T. , HAMAJIMA H. , KATSURA Y. 
Published: October 2007

SUMMARYThe composition and immunological suppression of a novel proteinaceous material, a neutral thiol protease (NTP), isolated from the metacercaria of the helminth Paragonimus westermani are reported. From cDNA cloning and sequencing, the protease was found to be composed of 215 amino acid residues and closely resembled the known cysteine proteases. Treatment of adult mice with the enzyme suppressed the delayed footpad reaction and haemagglutinin antibody production, and reduced expression of the major histocompatibility complex and interleukin 2 receptor on lymphocytes, and induced suppressor cells in the spleen. In addition, stable and long‐term skin graft survival was achieved by concomitant administration of the enzyme at a low dose.
Selective effector mechanisms for the expulsion of intestinal helminths
Authors: NAWA YUKIFUMI , ISHIKAWA NAOTO , TSUCHIYA KIMIYUKI , HORII YOICHIRO , ABE TATSUYA , KHAN AZHARUL I. , SHI BING , ITOH HIROSHI , IDE HISAMITSU , UCHIYAMA FUKUMI 
Published: October 2007

SUMMARYIn the middle of the era of molecular biology, much less attention is paid to in vivo phenomena. However, carefully designed experimental systems in vivo still can provide valuable information as to the mechanisms underlying the establishment and maintenance of host‐parasite relationships. In this review we describe the advantage of using concurrent infections with appropriately chosen combinations of different genera or different maturation stages of parasites to segregate the cellular responses of the host. By means of simple experimental approaches we have found that mucosal mast cells and goblet cells, both of which have long been considered as non‐specific effectors, are in fact highly selective and specific effector cells of the host defence mechanisms capable of acting on the establishment and the expulsion of intestinal helminths.
Effect of heavy metal emission on the immune response of sheep with experimental fasciolosis
Authors: BOROŠKOVÁ Z. , BENKOVÁ M. , ŠOLTÝS J. , KRUPICER I. 
Published: October 2007

SUMMARYThe effect of industrial heavy metal emission on immune reactions was studied in lambs subsequently infected with Fasciola hepatica. The heavy metal emission (Cu,Hg,Pb,Cd,Cr,Zn) was collected from grass at 5km distance from a mercury plant. Administration of the emission for 28 days prior to infection of the animals reduced the percent circulating T‐ and B‐cell populations when compared with untreated animals and animals infected with F. hepatica only. The administration of emission had no suppressive effects on the levels of circulating antibodies to F. hepatica following infection. The intensity of liver infection with mature F. hepatica in the emission‐fed and infected lamb group increased by 21·5%. This difference in comparison with control infected animals was not significant.
Cellular and humoral responses to antigenic subunits of Echinococcus granulosus cyst fluid in hydatid patients
Authors: PROFUMO E. , ORTONA E. , RIGANO R. , GIOIA I. , NOTARGIACOMO S. , IOPPOLO S. , SIRACUSANO A. 
Published: October 2007

SUMMARYThe hydatid fluid antigenic subunits which stimulate the proliferative response of T cells in PBMC isolated by hydatid patients were identified. In the same subjects, the serum IgG antibody profiles were determined by immuno‐blotting to compare T cell activation and IgG production. The study was carried out on 18 patients with clinically and serologically diagnosed hydatidosis and on ten healthy blood donors. To assess the proliferative response to the different antigenic subunits, sheep hydatid fluid was separated by the SDS‐PAGE and the fractions were blotted onto nitrocellulose and solubilized. The comparison between immunoblotting and PBMC proliferation assay shows that the 55 and 65kDa subunits of antigen 5 and the 12kDa subunit of antigen B are the most reactive subunits in the two techniques. The 16 and 20 kDa subunits of antigen B are more reactive in PBMC proliferation assay than in immunoblotting, thus assigning a specific role to antigen B in cellular response.