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排序方式: 共有436条查询结果,搜索用时 15 毫秒
1.
C3d binding to the circumsporozoite protein carboxy-terminus deviates immunity against malaria 总被引:5,自引:0,他引:5
Bergmann-Leitner ES Scheiblhofer S Weiss R Duncan EH Leitner WW Chen D Angov E Khan F Williams JL Winter DB Thalhamer J Lyon JA Tsokos GC 《International immunology》2005,17(3):245-255
The immunogenicity of recombinant protein or anti-viral DNA vaccines can be significantly improved by the addition of tandem copies of the complement fragment C3d. We sought to determine if the efficacy of a circumsporozoite protein (CSP)-based DNA vaccine delivered to mouse skin by gene gun was improved by using this strategy. Instead, we found that C3d suppressed the protective immunity against Plasmodium berghei malaria infection and deviated immunity, most notably by suppressing the induction of antibodies specific for the CSP C-terminal flanking sequence and by suppressing the induction of CSP-specific IL-4-producing spleen cells. We further showed that C3d bound to the C-terminal flanking sequence of the CSP, which may explain the immune deviation observed in CS/C3d chimeric antigen. We have thus identified C3d-mediated epitope masking and shifting of both the humoral and cellular immune responses as a potential novel escape mechanism, which plasmodia may use to divert the induction of protective immunity. 相似文献
2.
Federica Cavallo Alfonso Martin-Fontecha Matteo Bellone Silvia Heltai Evelina Gatti Paola Tornaghi Massimo Freschi Guido Forni Paolo Dellabona Giulia Casorati 《European journal of immunology》1995,25(5):1154-1162
Although the transfection of B7-1 cDNA into a few mouse tumor cell lines can induce anti-tumor T cell immunity, its expression alone is ineffective in many other tumor cell lines tested. We were interested to study what factors limit B7-1 co-stimulatory activity, and decided to investigate whether B7-1 requires the cooperation of ICAM-1 to provide the minimal co-stimulatory signal for establishing an efficient anti-tumor immunity. We show that the transfection of B7-1 cDNA into three ICAM-1+ (plasmocytoma J558L, T lymphomas EL-4 and RMA), but not into two ICAM-1? tumor cell lines (adenocarcinoma TS/A and melanoma B16.F1), is sufficient to induce their complete rejection in syngeneic mice. The expression of ICAM-1 is necessary for the rejection of the B7 expressing tumors, since the primary response elicited by B7-1+ EL-4 and RMA clones expressing reduced levels of ICAM-1 is severely reduced. Furthermore, super-transfection of ICAM-1 cDNA into B7-1+ adenocarcinoma and melanoma clones optimizes their primary rejection. Histologic examination of transfected tumors reveals that B7-1 and ICAM-1 exert a potent pro-inflammatory activity. The intra-tumor infiltration is composed of both eosinophils and lymphomono-cytes, and is already massive 5 days after the tumor challenge. The primary rejection of the B7-1+ ICAM-1+ tumors depends critically on CD8+ T cells, natural killer cells and granulocytes, but is independent of CD4+ T cells. Remarkably, in addition to its effects on the early phases of the immune response, the co-expression of ICAM-1 and B7-1 on tumors is also necessary for the efficient induction of a memory response. In fact, only the primary challenge with B7-1+, ICAM-1+ tumor cells protects the majority of the mice from a second injection of parental tumor cells. Collectively, our findings indicate that B7-1 and ICAM-1 are fundamental components for triggering the primary rejection of tumors and establishing a protective memory response. These findings may help to define new strategies for the rational application of co-stimulation in tumor immunotherapy. 相似文献
3.
The clinical-grade 42-kilodalton fragment of merozoite surface protein 1 of Plasmodium falciparum strain FVO expressed in Escherichia coli protects Aotus nancymai against challenge with homologous erythrocytic-stage parasites 总被引:4,自引:0,他引:4
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Darko CA Angov E Collins WE Bergmann-Leitner ES Girouard AS Hitt SL McBride JS Diggs CL Holder AA Long CA Barnwell JW Lyon JA 《Infection and immunity》2005,73(1):287-297
A 42-kDa fragment from the C terminus of major merozoite surface protein 1 (MSP1) is among the leading malaria vaccine candidates that target infection by asexual erythrocytic-stage malaria parasites. The MSP1(42) gene fragment from the Vietnam-Oak Knoll (FVO) strain of Plasmodium falciparum was expressed as a soluble protein in Escherichia coli and purified according to good manufacturing practices. This clinical-grade recombinant protein retained some important elements of correct structure, as it was reactive with several functional, conformation-dependent monoclonal antibodies raised against P. falciparum malaria parasites, it induced antibodies (Abs) that were reactive to parasites in immunofluorescent Ab tests, and it induced strong growth and invasion inhibitory antisera in New Zealand White rabbits. The antigen quality was further evaluated by vaccinating Aotus nancymai monkeys and challenging them with homologous P. falciparum FVO erythrocytic-stage malaria parasites. The trial included two control groups, one vaccinated with the sexual-stage-specific antigen of Plasmodium vivax, Pvs25, as a negative control, and the other vaccinated with baculovirus-expressed MSP1(42) (FVO) as a positive control. Enzyme-linked immunosorbent assay (ELISA) Ab titers induced by E. coli MSP1(42) were significantly higher than those induced by the baculovirus-expressed antigen. None of the six monkeys that were vaccinated with the E. coli MSP1(42) antigen required treatment for uncontrolled parasitemia, but two required treatment for anemia. Protective immunity in these monkeys correlated with the ELISA Ab titer against the p19 fragment and the epidermal growth factor (EGF)-like domain 2 fragment of MSP1(42), but not the MSP1(42) protein itself or the EGF-like domain 1 fragment. Soluble MSP1(42) (FVO) expressed in E. coli offers excellent promise as a component of a vaccine against erythrocytic-stage falciparum malaria. 相似文献
4.
P Leszczynski A van Belkum H Pituch H Verbrugh F Meisel-Mikolajczyk 《Journal of clinical microbiology》1997,35(11):2899-2903
Bacteroides fragilis is an anaerobic bacterial species that is involved in gynecological infections and pathology. The incidence of vaginal carriage is largely unknown, and in order to study this, 120 pregnant women attending a general hospital for delivery were examined. Cultures were positive for eight of these women (6.6%). Interestingly, potential clonal relatedness could be demonstrated among several of the nonenterotoxigenic B. fragilis strains. Among the strains, only one produced metalloprotease enterotoxin. The presence of the gene for the metalloprotease, giving rise to the pathogenic effect on cultured eukaryotic HT29/C1 cells, was confirmed by a newly designed specific PCR assay. The enterotoxigenic B. fragilis (ETBF) strain was analyzed with the help of arbitrarily primed PCR (AP-PCR) and PCR-mediated ribotyping. The ETBF strain was shown to be genetically different compared to several other strains obtained from diverse sources. Our data indicate a relatively high vaginal B. fragilis carriage rate among pregnant women in Warsaw, Poland. Although neither ETBF nor B. fragilis colonization presented a clinical problem, the possible genetic relatedness among the colonizing B. fragilis strains indicates the need for additional research in the field of ETBF transmission and molecular epidemiology. 相似文献
5.
Mosaicism of a novel variant in the ANKRD11 gene in a child with a mild KBG phenotype: A case report
6.
Roger Suau Marta Vidal Ruth Aguilar Gemma Ruiz-Olalla Miquel Vázquez-Santiago Chenjerai Jairoce Augusto J. Nhabomba Ben Gyan David Dosoo Kwaku Poku Asante Seth Owusu-Agyei Joseph J. Campo Luis Izquierdo David Cavanagh Ross L. Coppel Virander Chauhan Evelina Angov Sheetij Dutta Carlota Dobaño 《Vaccine》2021,39(4):687-698
BackgroundThe evaluation of immune responses to RTS,S/AS01 has traditionally focused on immunoglobulin (Ig) G antibodies that are only moderately associated with protection. The role of other antibody isotypes that could also contribute to vaccine efficacy remains unclear. Here we investigated whether RTS,S/AS01E elicits antigen-specific serum IgA antibodies to the vaccine and other malaria antigens, and we explored their association with protection.MethodsNinety-five children (age 5–17 months old at first vaccination) from the RTS,S/AS01E phase 3 clinical trial who received 3 doses of RTS,S/AS01E or a comparator vaccine were selected for IgA quantification 1 month post primary immunization. Two sites with different malaria transmission intensities (MTI) and clinical malaria cases and controls, were included. Measurements of IgA against different constructs of the circumsporozoite protein (CSP) vaccine antigen and 16 vaccine-unrelated Plasmodium falciparum antigens were performed using a quantitative suspension array assay.ResultsRTS,S vaccination induced a 1.2 to 2-fold increase in levels of serum/plasma IgA antibodies to all CSP constructs, which was not observed upon immunization with a comparator vaccine. The IgA response against 13 out of 16 vaccine-unrelated P. falciparum antigens also increased after vaccination, and levels were higher in recipients of RTS,S than in comparators. IgA levels to malaria antigens before vaccination were more elevated in the high MTI than the low MTI site. No statistically significant association of IgA with protection was found in exploratory analyses.ConclusionsRTS,S/AS01E induces IgA responses in peripheral blood against CSP vaccine antigens and other P. falciparum vaccine-unrelated antigens, similar to what we previously showed for IgG responses. Collectively, data warrant further investigation of the potential contribution of vaccine-induced IgA responses to efficacy and any possible interplay, either synergistic or antagonistic, with protective IgG, as identifying mediators of protection by RTS,S/AS01E immunization is necessary for the design of improved second-generation vaccines.Clinical trial registration: ClinicalTrials.gov: NCT008666191. 相似文献
7.
Giovina De Rosa Arnerico Testa Maurizio Maurizi Maria Antonietta Satta Claudia Aimoni Alberto Artuso Evelina Silvestri Vittoria Rufini Luigi Troncone 《European journal of nuclear medicine and molecular imaging》1990,17(3-4):179-184
A young woman with a thyroid papillary carcinoma behaving as an autonomously hyperfunctioning nodule is described. Only 17 similar patients have been seen in the past 25 years. It is emphasized that hyperthyroidism does not exclude malignant disease in hot nodules. This possibility suggests that all thyroid nodules, either cold or hot, require careful management. Therefore, in at risk cases, surgery could be the most useful treatment. 相似文献
8.
Both caffeine and the perception of refreshment delivered by cooling, tingling, and mouth-watering flavors have individually been shown to positively impact cognitive performance and mood, though presently there is limited evidence on their possible combined effects. This study explored the contribution of refreshing compounds in beverages, namely, carbon dioxide and citric acid, on the acute effects of caffeine on sustained attention and self-rated physical and mental energy. A randomized, controlled crossover trial was conducted by testing three products: a carbonated caffeinated beverage; a comparator caffeinated beverage; and a flavor-matched control beverage. Findings from 24 healthy adults revealed product-dependent variations in cognitive performance during a 60-min visual sustained-attention task, suggesting that the carbonated-caffeinated beverage led to faster, greater and more consistent levels of accuracy, compared to the control beverage. Specifically, significant differences were found between: (1) the carbonated-caffeinated beverage and the caffeinated beverage, and (2) between the caffeinated beverage and the control beverage for number of hits, reaction time and false alarm scores. Both caffeinated beverages led to higher physical and mental energy, and lower physical and mental fatigue 60-min post-consumption. These findings suggest beneficial effects on sustained attention through the combination of caffeine with refreshing compounds. 相似文献
9.
Evelina Chapman Ludovic Reveiz Amy Chambliss Stephanie Sangalang Xavier Bonfill 《Journal of clinical epidemiology》2013,66(1):105-112
ObjectivesTo use an “evidence-mapping” approach to assess the usefulness of Cochrane reviews in identifying research gaps in the maternal health.Study Design and SettingThe article describes the general mapping, prioritizing, reconciling, and updating approach: (1) identifying gaps in the maternal health research using published systematic reviews and formulating research questions, (2) prioritizing questions using Delphi method, (3) reconciling identified research priorities with the existing literature (i.e., searching of ongoing trials in trials registries), (4) updating the process. A comprehensive search of Cochrane systematic reviews published or updated from January 2006 to March 2011 was performed. We evaluated the “Implications for Research” section to identify gaps in the research.ResultsOur search strategy identified 695 references; 178 systematic reviews identifying at least one research gap were used. We formulated 319 research questions, which were classified into 11 different categories based on the direct and indirect causes of maternal mortality: postpartum hemorrhage, abortion, hypertensive disorders, infection/sepsis, caesarean section, diabetes, pregnancy prevention, preterm labor, other direct causes, indirect causes, and health policies and systems. Most research questions concerned the effectiveness of clinical interventions, including drugs (42.6%), nonpharmacologic interventions (16.3%), and health system (14.7%).ConclusionIt is possible to identify gaps in the maternal health research by using this approach. 相似文献
10.