bluuebunny/crossref_metadata_2025_split huggingface dataset:
Taenia solium: mitogenic effect of larval extracts on murine B lymphocytes
Authors: SEALEY M. , RAMOS C. , WILLMS KAETHE , ORTIZ‐ORTIZ L. 
Published: October 2007

SUMMARYThe effect of an extract (CE) obtained from Cysticercus cellulosae on the proliferation of lymphocytes was studied in cultures of murine spleen cells. The addition of CE to the cultures resulted in the highly significant uptake and incorporation of tritiated thymidine (3H‐TdR) into DNA. This phenomena was dose‐dependent, with doses lower and higher than the optimal concentration causing less marked effects. The kinetic peak of this response was found to occur on day 2 of culture. CE evoked a proliferative response in cultures of spleen cells from congenitally athymic (nu/nu) BALB/c mice. Cultures of bone marrow‐derived (B) lymphocytes, generated by treatment of spleen cells with rabbit antithymocyte serum and complement, incorporated 3H‐TdR to a degree similar to that of normal spleen cell cultures. CE did not induce the proliferation of thymocytes. To eliminate the possibility that the mitogenic effect of CE was due to LPS, we carried out experiments using Polymyxin B (PB). CE was mitogenic after treatment with PB which inactivated the LPS effect. In addition, CE elicited 3H‐TdR uptake in spleen cells from the LPS nonresponsive C3H/HeJ mouse strain.
Effect of immunosuppression on the size and metastasis of amoebic liver abscesses in hamsters
Authors: GHADIRIAN E. , MEEROVITCH E. 
Published: October 2007

SUMMARYThe effect of T‐cell depletion on experimental hepatic amoebiasis in hamsters was investigated. Thymectomized and anti‐T‐cell (ATS) treated animals as well as sham‐operated and unoperated controls were inoculated intrahepatically, following laparotomy, at 7 weeks of age with 1 × 105 axenic trophozoites of Entamoeba histolytica. In neonatally thymectomized hamsters the mean weight of the liver abscess 10 days post‐inoculation was significantly greater than in neonatally sham‐operated or unoperated controls, but there was no significant difference between these groups of animals in the size of metastatic foci to other organs. On the other hand, a combination of neonatal thymectomy and ATS treatment enhanced both the size of the primary abscess in the liver and the size of metastases to other sites. Adult thymectomy did not have a significant effect either on the size of the primary abscess or on metastatic dissemination of amoebae from the liver. Treatment of hamsters with ATS shortly before or after intrahepatic challenge increased significantly the size of the abscess, but similar treatment 2–3 weeks prior to challenge had no effect. These observations suggest that thymus‐dependent cell‐mediated immunity plays an important role in the host response to E. histolytica infection.
Thymus graft reconstitution of T‐cell‐deprived mice infected with Trypanosoma musculi
Authors: TARGETT G.A.T. , LEUCHARS ELIZABETH , DAVIES A.J.S. , VIENS P. 
Published: October 2007

SUMMARYT‐cell‐deprived CBA mice were given thymus graft implants during the course of an infection with Trypanosoma musculi and at a time when the parasitaemia was high. As a consequence of the grafts, most of the mice survived the infection whereas control ungrafted mice died. In grafted animals there was generally a period of 6&80 days after grafting during which time parasitic numbers remained high, and a further period of 200 or more days when trypanosomes were still detectable in the circulation. The mice were highly variable in their responses and possible reasons for this are considered.
IgE antibody against surface antigens of Leishmania promastigotes in American cutaneous leishmaniasis
Authors: LYNCH NEIL R. , MALAVE CARIDAD , TURNER KEVEN J. , INFANTE BENITO 
Published: October 2007

Summary As IgE‐mediated immune mechanisms participate in the host defence against some types of parasites, we evaluated sera from American cutaneous leishmaniasis (ACL) patients for the presence of this antibody against Leishmania. Using monoclonal antibodies against human IgE and an immunoperoxidase staining technique, 48% of the patients sera tested were found to contain IgE antibody that bound strongly to Leishmania promastigotes. A much lower proportion of sera from non‐symptomatic subjects from either endemic or non‐endemic areas of the disease contained significant levels of and‐Leishmania IgE antibody (6–5% and 0% respectively). The results indicated that the IgE antibody bound predominantly to surface components of the promastigotes, and reactivity against the intracellular amastigote form of the parasite was rarely detected. Somewhat unexpectedly, in a small proportion of the sera, the IgE antibody showed apparent specificity for L. mexicana or L. braziliensis.This study demonstrates that ACL patients can develop anti‐Leishmania IgE antibody responses, that seem to be directed peferentially against surface antigens of promastigotes, and that can be strain specific. This raises the question as to the possible contribution of this antibody to the immune defence mechanisms against the parasite.
Variants with reduced virulence derived from Leishmania major after mutagen treatment
Authors: MARCHAND M. , DAOUD S. , TITUS R. G. , LOUIS J. , BOON T. 
Published: October 2007

Summary After several in vitro treatments of a virulent population of Leishmania major with the mutagen, N‐methyl‐N'‐nitro‐N‐nitrosoguanidine (MNNG), five clones (vir‐) were obtained that did not produce cutaneous lesions after subcutaneous injection of 106 promastigotes. All the control clones (vir+) obtained from the non‐mutagenized parasite population produced progressive cutaneous lesions with as few as 103 parasites. Late lesions were observed occasionally after injection of 107 vir‐ parasites. These late lesions appeared to result from the selection of virulent revertants, since parasites isolated from these lesions produced progressive lesions in BALB/c mice almost as readily as the control parasites.Two vir‐ clones, one vir+ clone and one revertant clone were examined for survival in BALB/c macrophages in vitro. All clones were taken up by the macrophages and transformed into amastigotes. However, vir‐ clones failed to multiply inside the macrophages.A vir‐ clone was found to protect mice against a subsequent challenge with vir+ parasites.
Cysticercosis: cellular immune responses during primary and secondary infection
Authors: MEEUSEN E. , BARCHAM G. J. , GORRELL M. D. , RICKARD M. D. , BRANDON M. R. 
Published: October 2007

Summary Immune reactions to cysticercosis have been extensively studied in mice. The lack of significant lymphocyte infiltration into the livers of infected mice and the obvious role of antibodies in rejection has led to the general conclusion that cellular reactions do not play a role in protection against this disease. In contrast, the present study examining the immune response to cestode infections in a large animal model (sheep) revealed the presence of a massive and highly organized cellular infiltration in the livers after a secondary Taenia hydatigena infection. The majority of the infiltrating lymphocytes were of the CD4+ phenotype with much fewer CD8+ cells present. While most γδ‐TCR+ cells in peripheral blood are SBU‐T19+, the majority of γδ ‐TCR+ lymphocytes in the liver lesions are SBU‐T19‐ suggesting selective migration of these cells into the lesions. In contrast to the diffuse distribution of T cells in the lesions, B cells were present as distinct aggregates.In primary T. hydatigena infections, host class I and class II MHC antigens were shown, for the first time in cestode infections, to be absorbed onto the surface of the metacestode bladderwall indicating their possible involvement in parasite survival. No immune reactions were observed close to the parasite although lymphocytes and eosinophils were infiltrating the adjacent portal tract areas. Most lymphocytes in both primary and secondary infections were positive for MHC class II antigens suggesting selective recruitment of activated cells to the site of infection.Significant changes in relative and absolute numbers of lymphocyte subpopulations were also observed in the draining hepatic lymph nodes dominated by a massive increase of B cells. In contrast, at the peak of local cellular infiltration, no changes in lymphocyte subpopulations were observed in peripheral blood showing the limited usefulness of this compartment in studying cellular changes in localized infections.The vigorous cellular response observed in the livers of sheep contrasts sharply with the lack of lymphocyte infiltration reported in mice indicating that small animal models may not be appropriate to study cellular responses to cysticercosis in large animals and man.
Extracts of mosquito salivary gland inhibit tumour necrosis factor alpha release from mast cells
Authors: BISSONNETTE ELYSE Y. , ROSSIGNOL PHILIPPE A. , BEFUS A. DEAN 
Published: October 2007

SUMMARYExtracts of salivary glands of the yellow fever mosquito Aedes aegypti inhibit tumour cell‐stimulated release of tumour necrosis factor alpha (TNFα) from rat mast cells, but do not inhibit antigen‐induced histamine secretion. This inhibitory activity for TNFα is found in salivary glands of female but not in male mosquitoes. This inhibition is not mediated by bacterial contamination (LPS), by calcitonin gene related peptide (CGRP), nerve growth factor (NGF), epidermal growth factor (EGF) or transforming growth factor β (TGFβ). The factor(s) has a molecular weight > 10 kDa and is neutralized by boiling for 10 min or heating at 56°C for 30 min. The modulation of this proinflammatory mediator, TNFα, produced by mast cells in sites of blood feeding may facilitate completion of the blood meal, and as reported for certain vector‐transmitted parasites, may enhance infectivity.
Mice immunized with a synthetic peptide construct corresponding to an epitope present on a Plasmodium falciparum antigen are protected against Plasmodium chabaudi challenge
Authors: LORD ROGER , JONES GRAHAM L. , SPENCER LISA , SAUL ALLAN 
Published: October 2007

SummaryInhibitory monoclonal antibody (MoAb) 8E7/55 recognizes a parasitophorous vacuole membrane (PVM) antigen in Plasmodium falciparum. Previous studies have identified the epitope, DNNLVSGP, recognized by the MoAb. A synthetic peptide containing this sequence was synthesized and coupled to diphtheria toxoid (DT) and was found capable of generating antibodies when used as an immunogen in mice which recognize the native antigen exp‐1. In this study we demonstrate the ability of the MoAb and antisera generated against the peptide construct to recognize a 54 kD PVM antigen in Plasmodium chabaudi. The P. chabaudi antigen is synthesized in trophozoites and released to the surrounding culture media outside the parasitized erythrocyte. Mice immunized with the peptide conjugate are protected when challenged with a lethal strain of P. chabaudi. Protection in the mice correlated with the antibody titre prior to challenge. If the PVM antigen from P. chabaudi is a homologue of exp‐1 from P. falciparum, then these experiments may provide a guide to the antibody titres required in human trials before antibody mediated protection could be expected. The discovery that a PVM localized antigen is secreted into the surrounding in vitro culture media provides us with a valuable model system for further investigation of protein trafficking pathways in malaria‐infected erythrocytes.
Murine tumour necrosis factor plays a protective role during the initial phase of the experimental infection with Trypanosoma brucei brucei
Authors: MAGEZ STEFAN , LUCAS RUDOLF , DARJI AYUB , SONGA EMMANUEL BAJYANA , HAMERS RAYMOND , BAETSELIER PATRICK DE 
Published: October 2007

SummarySoluble extracts from salivarian trypanosomes (Trypanosoma brucei brucei, T. evansi and T. congolense) were shown to be capable of inducing murine tumour necrosis factor (mTNF) secretion, both in vivo and in vitro, whereas the soluble extract of an intracellular trypanosome (T. cruzi) failed to do so. Furthermore, the role of mTNF during the initial phase of experimental infections with T. brucei was studied by treating infected mice with mTNF‐inducing trypanosoma soluble extract and with neutralizing monoclonal anti‐mTNF antibodies. Treatment of the infected animals with different doses of T. brucei soluble extract resulted in a lower first parasitaemia peak (low lysate dose) and in a longer survival time or in a nearly total inhibition of parasite development (high lysate dose). Cotreatment of the infected mice with both anti‐mTNF antibodies and a high dose of soluble extract completely restored the parasite development in both trypanosusceptible C3H/He mice and trypanosubtolerant CBA/Ca mice, indicating a protective role of mTNF during the parasitaemia. Collectively these results suggest a negative influence of mTNF on T. brucei development in vivo.
Different susceptibility to the IL‐3 induced‐protective effects between Strongyloides ratti and Nippostrongylus brasiliensis in C57BL/6 mice
Authors: ABE TATSUYA , SUGAYA HIROKO , YOSHIMURA KENTARO 
Published: October 2007

SummaryRepetitive administration of recombinant IL‐3 induced protection against Strongyloides ratti but not against Nippostrongylus brasiliensis in C57BL/6 mice. Numbers of S. ratti were negligible from day 4 to day 6 post‐infection in mice injected with IL‐3, whereas N. brasiliensis burdens were almost equal from day 4 to day 6 between mice injected with IL‐3 or with medium. Mice treated with IL‐3 and then concurrently infected with S. ratti and N. brasiliensis were protected from intestinal S. ratti but not from N. brasiliensis. The numbers of intestinal mucosal mast cells were increased by the repetitive IL‐3 treatment on one day after the final injection and was augmented by subsequent infection with both nematodes.
The role of OX22− helper T cells in protective immunity to reinfection with Taenia taeniaeformis in rats
Authors: ASANO KAZUHITO , ITO AKIRA , OKAMOTO KEN‐ICHI 
Published: October 2007

SummarySpleen cells (SpC) and mesenteric lymph node cells (MLNC) from F344 donor rats actively immunized by oral inoculation with Taenia taeniaeformis eggs were syngeneically transferred into previously uninfected recipient rats by intravenous injection. Recipient rats were challenged with eggs after cell transfer. The degree of immunity was assessed by counting the number of growing metacestodes (MC) in the liver and compared with that in controls. Transfer of 2 × 108 SpC, obtained from donors immunized for ten or more (but not for three or five) days before cell transfer inhibited the establishment of most of MC. There were approximately 86–88% reductions in MC recoveries. SpC (2 × 108) obtained from donors immunized for ten days inhibited the establishment of most of MC in recipient rats when transferred nought, two, or 24 h (but not 48 h) before egg challenge. Functional cells in the immune SpC were helper T cells W3/25+, OX8− and OX22−. However, immune MLNC obtained from donors immunized for three to ten days before cell transfer had no effect on transferring immunity.
Characterization of allergens of the cat flea, Ctenocephalides felis: detection and frequency of IgE antibodies in canine sera
Authors: GREENE W. K. , CARNEGIE R. L. , SHAW S. E. , THOMPSON R. C. A. , PENHALE W. J. 
Published: October 2007

SummaryFlea allergens, fractionated by polyacrylamide gel electro‐phoresis and transferred to nitrocellulose, were identified using 20 flea‐allergic dog sera in an enhanced chemilumi‐nescent assay for canine IgE antibodies. At least 15 different flea components in the molecular weight range of 14–150 K bound IgE and every serum demonstrated a different pattern of binding. Three of the components with apparent molecular weights of 25, 40 and 58 K were each bound by at least 40% of the sera. No reactivity was seen when normal dog sera were used. These results demonstrate a greater number of flea allergens and a far greater diversity of the IgE antibody response to flea allergens than has previously been described, and suggest that immediate hypersensitivity may be an important mechanism in the pathogenesis of canine flea allergy.
Characterization of epitopes on a 32 kDa merozoite surface protein of Theileria sergenti
Authors: ZHUANG WEN ZHONG , KUBOTA SHUICHI , SUGIMOTO CHIHIRO , ONUMA MISAO 
Published: October 2007

SummaryEpitopes on a 32 kDa protein, which is an immunodominant major surface protein ofTheileria sergenti, recognized by anti‐merozoite monoclonal antibodies were characterized. The results of a competetive binding assay between monoclonal antibodies indicated that there were at least three epitopes in this protein. The presence of repeated epitopes was suggested by using two‐site enzyme‐linked immunosorbent assay. The protein was partitioned into the detergent phase of Triton X‐114 extracts, indicating that the 32 kDa protein is an integral membrane protein. Periodate treatment of 32 kDa protein implies that one epitope of the epitopes recognized by monoclonal antibody has a carbohydrate moiety.
Antigenic variants of Plasmodium chabaudi chabaudi AS and the effects of mosquito transmission
Authors: BRANNAN L. R. , McLEAN S. A. , PHILLIPS R. S. 
Published: October 2007

SummaryPrevious results, using a passive transfer assay, have shown that recrudescences of Plasmodium chabaudi chabaudi AS strain are antigenically different from the infecting parental population and also that the recrudescence appears to be a mix of antigenic types. This present study examines further these recrudescent populations using an indirect fluorescent antibody test on live, schizont‐infected red blood cells. This analysis shows that ten clones derived from a recrudescence are all antigenically different from the parent population and that some are different from each other. The use of this method to examine the antigenic types of recrudescent clones after transmission through mosquitoes also demonstrates a resulting change in antigenicity. Such results showing a link between mosquito transmission and varying antigenicity may have important implications in terms of immunity and vaccine development.
The immunogenicity of hookworm (Necator americanus) acetylcholinesterase (AChE) in man
Authors: BROWN ALAN , PRITCHARD DAVID IDRIS 
Published: October 2007

SummaryA number of different but complementary approaches have been used to demonstrate the immunogenicity of Necator americanus acetylcholinesterase to infected individuals. Western blotting of parasite somatic extracts with human post‐infection sera and a specific rabbit antiserum to AChE resulted in the development of almost identical antigen‐recognition profiles. AChE‐containing fractions produced by preparative iso‐electric focusing were subsequently shown to be antigenic in ELISA using post‐infection sera. This preliminary data was reinforced by the affinity‐purification of AChE by immobilized post‐infection IgG, and the immunoprecipitation of AChE activity from ES by post‐infection IgG. Finally, AChE purified by affinity chromatography on edrophonium chloride was shown to be antigenic by Western blotting, and in ELISA, against post‐infection sera, although a degree of re‐activity was also seen with normal human sera. This data is discussed in the context of the host‐parasite relationship.
Protective immunity and mast cell and eosinophil responses in mice infested with larval Haemaphysalis longicornis ticks
Authors: USHIO HIROKO , WATANABE NAOHIRO , KISO YASUO , HIGUCHI SEIICHI , MATSUDA HIROSHI 
Published: October 2007

SummaryWBB6F1 ‐+‐ /+ mice were infested with larval Haemaphysalis longicornis ticks twice at an interval of 14 days: apparent resistance against ticks was expressed in the second infestation. The first infestation induced degranula‐tion of a small number of mast cells at the feeding sites within 6 days, and resulted in two‐fold increases of mast cell numbers on day 14 with a significant elevation of total immunoglobulin E (IgE) levels in sera and high proportion of IgE‐bound mast cells. The second infestation resulted in the intensive degranulation of the increased mast cells at the feeding sites. Eosinophils infiltrated into the feeding sites of ticks: the second infestation led to a greater maximal level of the infiltrating eosinophils. These data suggest that the resistance against larval H. longicornis ticks in mice may be expressed as a result of immediate hypersensitivity and many eosinophils infiltrating from the blood to the feeding sites might contribute to the tick rejection.
Tumour necrosis factor and interleukin‐6 production induced by components associated with merozoite proteins of Plasmodium falciparum
Authors: JAKOBSEN P. H. , MOON R. , RIDLEY R. G. , BATE C. A. W. , TAVERNE J. , HANSEN M. B. , TAKACS B. , PLAYFAIR J. H. L. , MCBRIDE J. S. 
Published: October 2007

SummaryP. falciparum merozoite antigens, merozoite surface protein‐l (MSP‐1) and rhoptry associated protein‐1 (RAP‐1), were shown to be liberated into the supernatant of in vitro parasite cultures and to be included in the endotoxin‐like exoantigen complex, previously designated Ag7. Material affinity purified from culture supernatants, using immobilized monoclonal antibodies specific for RAP‐1 or MSP‐1, stimulated normal human mononuclear cells to produce TNF and IL‐6 in vitro. However, stimulation of TNF was absent, and that of IL‐6 was reduced, when the antigens were purified from detergent extracts of infected erythro‐cytes. These results indicate that the RAP‐1 and MSP‐1 proteins themselves do not stimulate the production of TNF. Instead, other components associating with these exoantigens may be responsible for the TNF production. Mouse antisera blocking TNF production stimulated by P. yoelii exoantigens also blocked TNF production stimulated by material affinity purified from P. falciparum culture supernatants using RAP‐1 specific monoclonal antibody, indicating the conserved structure of the TNF inducing component.
Protective CD4+ T‐cell lines raised against Plasmodium chabaudi show characteristics of either Th1 or Th2 cells
Authors: TAYLOR‐ROBINSON ANDREW W. , PHILLIPS R. STEPHEN 
Published: October 2007

SummarySplenic T‐lymphocyte lines were established in vitro from Plasmodium chabaudi‐infected NIH mice on days 16 and 20 of a primary infection, and from mice after two or three infections. Each line responded specifically to stimulation with a lysed soluble extract of P. chabaudi‐infected erythrocytes (pRBC), and displayed a CD4+ (L3T4+) surface phenotype. Both the day 16 and 20 cell lines, when stimulated in vitro, secreted interleukin‐2 (IL‐2) and γ‐interferon (IFN‐γ), indicative of their belonging to the T helper 1 (Th1) CD4+ subset. In contrast, both lines derived from reinfected mice secreted interleukin‐4 (IL‐4) and provided helper activity in antibody production to P. chabaudi in vitro, and thereby had the characteristics of Th2 cells. All four T‐cell lines provided significant protection to naïve mice infected with P. chabaudi. In immuno‐compromised mice, the day 16 T‐cell line was as protective as in naïve mice whereas the cell line from mice infected twice required the additional transfer of mature naïve splenic B cells to provide protection comparable to that seen in the immunocompetent naïve recipients. The results establish that protective immunity to P. chabaudi may be associated with the induction of CD4+ Tcells of either the Th1 or Th2 subset which confer protection against this malaria parasite by mechanisms independent of, and dependent upon, B‐cell involvement, respectively.