bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel Antigen Identification Method for Discovery of Protective Malaria Antigens by Rapid Testing of DNA Vaccines Encoding Exons from the Parasite Genome
Authors: Haddad Diana , Bilcikova Erika , Witney Adam A. , Carlton Jane M. , White Charles E. , Blair Peter L. , Chattopadhyay Rana , Russell Joshua , Abot Esteban , Charoenvit Yupin , Aguiar Joao C. , Carucci Daniel J. , Weiss Walter R. 
Published: February 2004

ABSTRACTWe describe a novel approach for identifying target antigens for preerythrocytic malaria vaccines. Our strategy is to rapidly test hundreds of DNA vaccines encoding exons from thePlasmodium yoelii yoeliigenomic sequence. In this antigen identification method, we measure reduction in parasite burden in the liver after sporozoite challenge in mice. Orthologs of protectiveP. y. yoeliigenes can then be identified in the genomic databases ofPlasmodium falciparumandPlasmodium vivaxand investigated as candidate antigens for a human vaccine. A pilot study to develop the antigen identification method approach used 192P. y. yoeliiexons from genes expressed during the sporozoite stage of the life cycle. A total of 182 (94%) exons were successfully cloned into a DNA immunization vector with the Gateway cloning technology. To assess immunization strategies, mice were vaccinated with 19 of the new DNA plasmids in addition to the well-characterized protective plasmid encodingP. y. yoeliicircumsporozoite protein. Single plasmid immunization by gene gun identified a novel vaccine target antigen which decreased liver parasite burden by 95% and which has orthologs inP. vivaxandP. knowlesibut notP. falciparum. Intramuscular injection of DNA plasmids produced a different pattern of protective responses from those seen with gene gun immunization. Intramuscular immunization with plasmid pools could reduce liver parasite burden in mice despite the fact that none of the plasmids was protective when given individually. We conclude that high-throughput cloning of exons into DNA vaccines and their screening is feasible and can rapidly identify new malaria vaccine candidate antigens.
Antibodies That Inhibit Binding of
Plasmodium falciparum
-Infected Erythrocytes to Chondroitin Sulfate A and to the C Terminus of Merozoite Surface Protein 1 Correlate with Reduced Placental Malaria in Cameroonian Women
Authors: Taylor Diane Wallace , Zhou Aniong , Marsillio Lauren E. , Thuita Lucy W. , Leke Efua B. , Branch OraLee , Gowda D. Channe , Long Carole , Leke Rose F. G. 
Published: February 2004

ABSTRACT

Plasmodium falciparum
-infected erythrocytes often sequester in the placenta of pregnant women, producing placental malaria, a condition that can compromise the health of the developing fetus. Scientists are hopeful that a vaccine can be developed to prevent this condition. Immunological mechanisms responsible for eliminating parasites from the placenta remain unclear, but antibodies to the carboxyl-terminal 19-kDa segment of the merozoite surface protein 1 (MSP1-19), the ring-infected erythrocyte surface antigen (RESA), and an erythrocyte-surface ligand that binds chondroitin sulfate A (CSA-L) have been implicated. In addition, antibodies to sporozoite and liver-stage antigens could reduce initial parasite burdens. This study sought to determine if antibodies to the circumsporozoite protein (CSP), liver-stage antigen 1 (LSA1), RESA, MSP1-19, or CSA-L correlated with either the absence of placental parasites or low placental parasitemias. Using a frequency-matched case-control study design, we compared antibody levels in women (gravidity 1 to 11) with and without placental malaria. Results showed that women who were antibody negative for MSP1-19 were at a higher risk of having placental malaria than women with antibodies (
P
< 0.007). Furthermore, an association between high levels of antibodies that blocked the binding of infected erythrocytes to CSA and low placental parasitemias was observed (
P
= 0.02). On the other hand, women with high antibody levels at term to CSP, LSA1, and RESA were more likely to have placental malaria than antibody-negative women. Since antibodies to MSP1-19 and CSA-L were associated with reduced placental malaria, both antigens show promise for inclusion in a vaccine for women of child-bearing age.
Combination of the Cationic Surfactant Dimethyl Dioctadecyl Ammonium Bromide and Synthetic Mycobacterial Cord Factor as an Efficient Adjuvant for Tuberculosis Subunit Vaccines
Authors: Holten-Andersen L. , Doherty T. M. , Korsholm K. S. , Andersen P. 
Published: February 2004

ABSTRACTRecombinant, immunodominant antigens derived fromMycobacterium tuberculosiscan be used to effectively vaccinate against subsequent infection. However, the efficacy of these recombinant proteins is dependent on the adjuvant used for their delivery. This problem affects many potential vaccines, not just those for tuberculosis, so the discovery of adjuvants that can promote the development of cell-mediated immunity is of great interest. We have previously shown that the combination of the cationic surfactant dimethyl dioctadecyl ammonium bromide and the immunomodulator modified lipid A synergistically potentiates Th1 T-cell responses. Here we report a screening program for other adjuvants with reported Th1-promoting activity and identify a second novel adjuvant formulation that drives the development of Th1 responses with an extremely high efficacy. The combination of dimethyl dioctadecyl ammonium bromide and the synthetic cord factor trehalose dibehenate promotes strong protective immune responses, without overt toxicity, againstM. tuberculosisinfection in a vaccination model and thus appears to be a very promising candidate for the development of human vaccines.
Mycobacterium-InducibleNrampin Striped Bass (Morone saxatilis)
Authors: Burge Erin J. , Gauthier David T. , Ottinger Christopher A. , Van Veld Peter A. 
Published: February 2004

ABSTRACTIn mammals, the natural resistance-associated macrophage protein 1 gene,Nramp1, plays a major role in resistance to mycobacterial infections. Chesapeake Bay striped bass (Morone saxatilis) is currently experiencing an epizootic of mycobacteriosis that threatens the health of this ecologically and economically important species. In the present study, we characterized anNrampgene in this species and obtained evidence that there is induction followingMycobacteriumexposure. The striped bassNrampgene (MsNramp) and a 554-amino-acid sequence contain all the signal features of theNrampfamily, including a topology of 12 transmembrane domains (TM), the transport protein-specific binding-protein-dependent transport system inner membrane component signature, three N-linked glycosylation sites between TM 7 and TM 8, sites of casein kinase and protein kinase C phosphorylation in the amino and carboxy termini, and a tyrosine kinase phosphorylation site between TM 6 and TM 7. Phylogenetic analysis most closely groupedMsNrampwith other teleostNrampgenes and revealed high sequence similarity with mammalianNramp2. MsNrampexpression was present in all tissues assayed by reverse transcription-PCR. Within 1 day of injection ofMycobacterium marinum,MsNrampexpression was highly induced (17-fold higher) in peritoneal exudate (PE) cells compared to the expression in controls. The levels ofMsNrampwere three- and sixfold higher on days 3 and 15, respectively. Injection ofMycobacterium shottsiiresulted in two-, five-, and threefold increases in gene expression in PE cells over the time course. This report is the first report of induction of anNrampgene by mycobacteria in a poikilothermic vertebrate.
Blockade of Endogenous Leukotrienes Exacerbates Pulmonary Histoplasmosis
Authors: Medeiros Alexandra I. , Sá-Nunes Anderson , Soares Edson G. , Peres Camila M. , Silva Célio L. , Faccioli Lúcia H. 
Published: February 2004

ABSTRACTLeukotrienes are classical mediators of inflammatory response. New aspects of leukotriene function have recently been described. We examine here the previously unreported role that leukotrienes play in the regulation of cytokines in a murine model of histoplasmosis. We demonstrate that administration of MK 886, a leukotriene synthesis inhibitor, causedHistoplasma capsulatum-infected mice to die by the day 15 of infection, whereas the correlating death rate in untreated infected mice was 0%. Treating infected animals with MK 886 inhibited leukotriene synthesis but increased leukocyte recruitment to the lungs. Subsequent to this phenomenon, levels of tumor necrosis factor alpha, interleukin-1 (IL-1), IL-6, and KC chemoattractant cytokines and fungi in the lung parenchyma increased, as did inflammatory response. In contrast, IL-2, IL-5, IL-12, and gamma interferon cytokine levels actually decreased. Thus, murine response to pulmonary histoplasmosis may be leukotriene modulated. This finding may enable us to alter the course of the immune response and inflammation caused by histoplasmosis. The data from the present study suggest an important new strategy for immunologic or drug intervention in human patients.
Characterization of OralYersinia enterocoliticaInfection in Three Different Strains of Inbred Mice
Authors: Handley Scott A. , Dube Peter H. , Revell Paula A. , Miller Virginia L. 
Published: February 2004

ABSTRACTSeveral studies have highlighted differences in the resistances of various mouse strains to intravenous (i.v.) infection withYersinia enterocolitica. In particular, differences in resistance and immunological response between BALB/c and C57BL/6 mouse strains have been determined. Following i.v infection, C57BL/6 mice are more resistant toY. enterocoliticathan are BALB/c mice. However, becauseY. enterocoliticais typically a food-borne pathogen, the oral route of infection more accurately reflects the natural route of infection. Therefore, it was of interest to ascertain if the differences in resistance between mouse strains observed for an i.v. infection can be recapitulated following an oral infection. C57BL/6j, BALB/cj, and 129X1/Svj mouse strains presented no differences in 50% lethal dose (LD50) following oral infection withY. enterocolitica. Subsequent analysis of cytokine levels, bacterial colonization and immune cell populations following oral infection confirmed characteristics previously described following i.v.Y. enterocoliticainfection. All tissues analyzed from each mouse strain demonstrated a polarized Th1 cytokine profile and inflammatory cell influx throughout a 7-day course of infection. This immune response was present in all tissues and increased as bacterial colonization progressed. The lack of a differing LD50phenotype and common trends in immunological response among the three mouse strains tested suggests that oral infection is a useful model for studying the host response toY. enterocoliticainfection.
Relationship between Structures and Biological Activities of Mycoplasmal Diacylated Lipopeptides and Their Recognition by Toll-Like Receptors 2 and 6
Authors: Okusawa Tsugumi , Fujita Mari , Nakamura Jun-ichiro , Into Takeshi , Yasuda Motoaki , Yoshimura Atsutoshi , Hara Yoshitaka , Hasebe Akira , Golenbock Douglas T. , Morita Manabu , Kuroki Yoshio , Ogawa Tomohiko , Shibata Ken-ichiro 
Published: February 2004

ABSTRACTThe lipopeptide FSL-1 [S-(2,3-bispalmitoyloxypropyl)-Cys-Gly-Asp-Pro-Lys-His-Pro-Lys-Ser-Phe, Pam2CGDPKHPKSF] synthesized on the basis of the N-terminal structure of aMycoplasma salivariumlipoprotein capable of activating normal human gingival fibroblasts to induce the cell surface expression of ICAM-1 revealed an activity to induce production of monocyte chemoattractant protein 1, interleukin-6 (IL-6), and IL-8. FSL-1 also activated macrophages to produce tumor necrosis factor alpha as theMycoplasma fermentans-derived lipopeptide MALP-2 (Pam2CGNNDESNISFKEK), a potent macrophage-activating lipopeptide, did. The level of the activity of FSL-1 was higher than that of MALP-2. This result suggests that the difference in the amino acid sequence of the peptide portion affects the activity because the framework structure other than the amino acid sequence of the former is the same as that of the latter. To determine minimal structural requirements for the activity of FSL-1, the diacylglyceryl Cys and the peptide portions were examined for this activity. Both portions did not reveal the activity. A single amino acid substitution from Phe to Arg and a fatty acid substitution from palmitic acid to stearic acid drastically reduced the activity. Similar results were obtained in measuring the NF-κB reporter activity of FSL-1 to human embryonic kidney 293 cells transfected with Toll-like receptor 2 and 6, together with a NF-κB-dependent luciferase reporter plasmid. These results suggest that both the diacylglyceryl and the peptide portions of FSL-1 are indispensable for the expression of biological activities and for the recognition by Toll-like receptors 2 and 6 and that the recognition of FSL-1 by Toll-like receptors 2 and 6 appears to be hydrophobic.
Glycolytic and Gluconeogenic Growth of
Escherichia coli
O157:H7 (EDL933) and
E. coli
K-12 (MG1655) in the Mouse Intestine
Authors: Miranda Regina L. , Conway Tyrrell , Leatham Mary P. , Chang Dong Eun , Norris Wendy E. , Allen James H. , Stevenson Sarah J. , Laux David C. , Cohen Paul S. 
Published: February 2004

ABSTRACT

Escherichia coli
EDL933, an O157:H7 strain, is known to colonize the streptomycin-treated CD-1 mouse intestine by growing in intestinal mucus (E. A. Wadolkowski, J. A. Burris, and A. D. O'Brien, Infect. Immun.
58:
2438-2445, 1990), but what nutrients and metabolic pathways are employed during colonization has not been determined. In this study, when the wild-type EDL933 strain was fed to mice along with an EDL933 Δ
ppsA
Δ
pckA
mutant, which is unable to utilize tricarboxylic acid cycle intermediates and gluconeogenic substrates for growth, both strains colonized the mouse intestine equally well. Therefore, EDL933 utilizes a glycolytic substrate(s) for both initial growth and maintenance when it is the only
E. coli
strain fed to the mice. However, in the presence of large numbers of MG1655, a K-12 strain, it is shown that EDL933 utilizes a glycolytic substrate(s) for initial growth in the mouse intestine but appears to utilize both glycolytic and gluconeogenic substrates in an attempt to maintain colonization. It is further shown that MG1655 predominantly utilizes glycolytic substrates for growth in the mouse intestine whether growing in the presence or absence of large numbers of EDL933. Data are presented showing that although small numbers of EDL933 grow to large numbers in the intestine in the presence of large numbers of MG1655 when both strains are fed to mice simultaneously, precolonization with MG1655 affords protection against subsequent colonization by EDL933. Moreover, in mice that are precolonized with EDL933, small numbers of MG1655 are able to grow rapidly in the intestine and EDL933 is eliminated. In situ hybridization experiments using
E. coli
-specific rRNA probes showed that while MG1655 is found only in mucus, EDL933 is found both in mucus and closely associated with intestinal epithelial cells. The data are discussed with respect to competition for nutrients and to the protection that some intestinal commensal
E. coli
strains might afford against infection by O157:H7 strains.
Immunization with a DNA Vaccine Cocktail Protects Mice Lacking CD4 Cells against an Aerogenic Infection withMycobacterium tuberculosis
Authors: Derrick Steven C. , Repique Charlene , Snoy Philip , Yang Amy Li , Morris Sheldon 
Published: February 2004

ABSTRACTTuberculosis (TB) is the most common opportunistic disease and a potentially fatal complication among immunocompromised individuals infected with human immunodeficiency virus (HIV). Effective vaccination against TB in persons with HIV has been considered unlikely because of the central role that CD4 cells play in controlling tuberculous infections. Here we show that the vaccination of CD8−/−mice with a TB DNA vaccine cocktail did not significantly enhance protective responses to aMycobacterium tuberculosisinfection. In contrast, immunization with a DNA vaccine cocktail or with the current TB vaccine,Mycobacterium bovisBCG, induced considerable antituberculosis protective immunity in immune-deficient mice lacking CD4 cells. In vaccinated CD4−/−animals, substantially reduced bacterial burdens in organs and much improved lung pathology were seen 1 month after an aerogenicM. tuberculosischallenge. Importantly, the postchallenge mean times to death of vaccinated CD4−/−mice were significantly extended (mean with DNA cocktail, 172 ± 7 days; mean with BCG, 156 ± 22 days) compared to that of naïve CD4−/−mice (33 ± 6 days). Furthermore, the treatment of DNA-vaccinated CD4−/−mice with an anti-CD8 or anti-gamma interferon (IFN-γ) antibody significantly reduced the effect of immunization, and neither IFN-γ−/−nor tumor necrosis factor receptor-deficient mice were protected by DNA immunization; therefore, the primary vaccine-induced protective mechanism in these immune-deficient mice likely involves the secretion of cytokines from activated CD8 cells. The substantial CD8-mediated protective immunity that was generated in the absence of CD4 cells suggests that it may be possible to develop effective TB vaccines for use in HIV-infected populations.
Susceptibility to Tuberculosis: Clues from Studies with Inbred and Outbred New Zealand White Rabbits
Authors: Dorman Susan E. , Hatem Christine L. , Tyagi Sandeep , Aird Katherine , Lopez-Molina Javier , Pitt M. Louise M. , Zook Bernard C. , Dannenberg Arthur M. , Bishai William R. , Manabe Yukari C. 
Published: February 2004

ABSTRACTThe rabbit model of tuberculosis (TB) is important because rabbits develop a disease that is similar to TB in humans, namely, granulomas with caseous necrosis, liquefaction, and cavities. We describe here a comparison of inbred and outbred New Zealand White rabbits infected by aerosol with eitherMycobacterium tuberculosisErdman or H37Rv strain. Five weeks after infection with either bacillary strain, the inbred rabbits had significantly larger pulmonary tubercles than did outbred rabbits (2.7 versus 1.4 mm in diameter;P< 0.01). After infection with H37Rv, the inbred rabbits had significantly more pulmonary tubercles than did the outbred rabbits (98 ± 12 versus 33 ± 13;P< 0.01), with more mycobacterial CFU per tubercle (809 ± 210 versus 215 ± 115;P= 0.027) (means ± standard errors of the means). Compared with histologic examination of lung granulomas from outbred rabbits, histologic examination of those from inbred rabbits showed more caseous necrosis, more visible bacilli, and fewer mature epithelioid cells. The delayed-type hypersensitivity (DTH) responses to intradermal tuberculin were significantly lower, and peritoneal macrophages from uninfected inbred rabbits produced significantly less tumor necrosis factor alpha after lipopolysaccharide (LPS) stimulation in vitro than those from the outbred rabbits (2,413 ± 1,154 versus 8,879 ± 966 pg/ml). We conclude that these inbred rabbits were more susceptible to TB than their outbred counterparts and had an impaired ability to contain disease, resulting in more grossly visible tubercles that were larger than those observed in outbred rabbits. Preliminary evidence is presented for a cell-mediated immune defect with lower DTH responses and macrophages that have a decreased ability to respond to in vitro stimulation with LPS orM. tuberculosisinfection.
Porphyromonas gingivalisInduces Receptor Activator of NF-κB Ligand Expression in Osteoblasts through the Activator Protein 1 Pathway
Authors: Okahashi Nobuo , Inaba Hiroaki , Nakagawa Ichiro , Yamamura Taihei , Kuboniwa Masae , Nakayama Koji , Hamada Shigeyuki , Amano Atsuo 
Published: February 2004

ABSTRACTPorphyromonas gingivalis, an important periodontal pathogen, is closely associated with inflammatory alveolar bone resorption, and several components of the organism such as lipopolysaccharides have been reported to stimulate production of cytokines that promote inflammatory bone destruction. We investigated the effect of infection with viableP. gingivalison cytokine production by osteoblasts. Reverse transcription-PCR and real-time PCR analyses revealed that infection withP. gingivalisinduced receptor activator of nuclear factor κB (NF-κB) ligand (RANKL) mRNA expression in mouse primary osteoblasts. Production of interleukin-6 was also stimulated; however, osteoprotegerin was not. SB20350 (an inhibitor of p38 mitogen-activated protein kinase), PD98059 (an inhibitor of classic mitogen-activated protein kinase kinase, MEK1/2), wortmannin (an inhibitor of phosphatidylinositol 3 kinase), and carbobenzoxyl-leucinyl-leucinyl-leucinal (an inhibitor of NF-κB) did not prevent the RANKL expression induced byP. gingivalis. Degradation of inhibitor of NF-κB-alpha was not detectable; however, curcumin, an inhibitor of activator protein 1 (AP-1), prevented the RANKL production induced byP. gingivalisinfection. Western blot analysis revealed that phosphorylation of c-Jun, a component of AP-1, occurred in the infected cells, and an analysis of c-Fos binding to an oligonucleotide containing an AP-1 consensus site also demonstrated AP-1 activation in infected osteoblasts. Infection withP. gingivalisKDP136, an isogenic deficient mutant of arginine- and lysine-specific cysteine proteinases, did not stimulate RANKL production. These results suggest thatP. gingivalisinfection induces RANKL expression in osteoblasts through AP-1 signaling pathways and cysteine proteases of the organism are involved in RANKL production.
FimbriatedPorphyromonas gingivalisIs More Efficient than Fimbria-DeficientP. gingivalisin Entering Human Dendritic Cells In Vitro and Induces an Inflammatory Th1 Effector Response
Authors: Jotwani Ravi , Cutler Christopher W. 
Published: February 2004

ABSTRACTPorphyromonas gingivalisis a fimbriated mucosal pathogen implicated in chronic periodontitis (CP). The fimbriae are required for invasion of the gingival mucosa and for induction of CP in animal models of periodontitis. CP is associated with infection of immature dendritic cells (DCs) byP. gingivalisin situ and with increased numbers of dermal DCs (DDCs) and mature DCs in the lamina propria. The role of fimbriae in gaining entry into human DCs and how this modulates the inflammatory and effector immune responses, however, have not been explored. To address this, we generated monocyte-derived DCs (MDDCs) in vitro which phenotypically and functionally resemble DDCs. We show here that virulent fimbriatedP. gingivalis381, in contrast to its fimbria-deficient mutant,P. gingivalisDPG3, efficiently gains entry to MDDCs in a manner dependent on active cell metabolism and cytoskeletal rearrangement. In addition, uptake of 381, unlike DPG3, induces DCs to undergo maturation, upregulate costimulatory molecules, and secrete inflammation cytokines interleukin-1β (IL-1β), IL-6, tumor necrosis factor alpha, IL-10, and IL-12. Moreover, MDDCs pulsed with 381 also stimulated a higher autologous mixed lymphocyte reaction and induced a Th1-type response, with gamma interferon (IFN-γ) being the main cytokine. Monocytes used as controls demonstrated fimbria-dependent uptake of 381 as well but produced low levels of inflammatory cytokines compared to MDDCs. When MDDCs were pulsed with recombinant fimbrillin ofP. gingivalis(10 μg/ml), maturation of MDDCs was also induced; moreover, matured MDDCs induced proliferation of autologous CD4+T cells and release of IFN-γ. Thus, these results establish the significance ofP. gingivalisfimbriae in the uptake ofP. gingivalisby MDDCs and in induction of immunostimulatory Th1 responses.