bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acquisition of Coinfection and Simultaneous Transmission of
Borrelia burgdorferi
and
Ehrlichia phagocytophila
by
Ixodes scapularis
Ticks
Authors: Levin Michael L. , Fish Durland 
Published: July 2002

ABSTRACT

The agents of Lyme disease (
Borrelia burgdorferi
) and human granulocytic ehrlichiosis (
Ehrlichia phagocytophila
) are both transmitted by the tick
Ixodes scapularis
. In nature, ticks are often infected with both agents simultaneously. We studied whether previous infection with either
Borrelia
or
Ehrlichia
in ticks would affect acquisition and transmission of a second pathogen.
Ehrlichia
-infected
I. scapularis
nymphs were fed upon
Borrelia
-infected mice, and
Borrelia
-infected
I. scapularis
nymphs were fed upon
Ehrlichia
-infected mice. The efficiency with which previously infected nymphal ticks acquired a second pathogen from infected hosts was compared to that of uninfected ticks. An average of 51% ± 15% of ticks acquired
Ehrlichia
from infected mice regardless of their prior infection status with
Borrelia
. An average of 85% ± 10% of ticks acquired
Borrelia
from infected mice regardless of their prior infection status with
Ehrlichia
. Also, we assessed the efficiency with which individual nymphs could transmit either agent alone, or both agents simultaneously, to individual susceptible hosts. An average of 76% ± 9% of
Borrelia
-infected ticks and 84% ± 10% of
Ehrlichia
-infected ticks transmitted these agents to mice regardless of the presence of the other pathogen. There was no evidence of interaction between the agents of Lyme disease and human granulocytic ehrlichiosis in
I. scapularis
ticks. The presence of either agent in the ticks did not affect acquisition of the other agent from an infected host. Transmission of the agents of Lyme disease and human granulocytic ehrlichiosis by individual ticks was equally efficient and independent. Dually infected ticks transmitted each pathogen to susceptible hosts as efficiently as ticks infected with only one pathogen.
Identification and Expression of a
Mycoplasma gallisepticum
Surface Antigen Recognized by a Monoclonal Antibody Capable of Inhibiting Both Growth and Metabolism
Authors: Yoshida Shigeto , Fujisawa Ayumi , Tsuzaki Yoshinari , Saitoh Shuji 
Published: July 2002

ABSTRACT

In order to identify antigenic proteins of
Mycoplasma gallisepticum
, monoclonal antibodies (MAbs) against virulent
M. gallisepticum
R strain were produced in mice. MAb 35A6 was selected for its abilities to inhibit both growth and metabolism of
M. gallisepticum
in vitro. The MAb recognized a membrane protein with an apparent molecular mass of 120 kDa. The corresponding gene, designated the mgc3 gene, was cloned from an
M. gallisepticum
genomic DNA expression library and sequenced. The mgc3 gene is a homologue of the ORF6 gene encoding 130-kDa protein in the P1 operon of
M. pneumoniae
and is localized downstream of the mgc1 gene, a homologue of the P1 gene. To assess the characteristics of MGC3 protein, all 10 TGA codons in the mgc3 gene, which encode a tryptophan in the
Mycoplasma
species, were replaced with TGG codons, and recombinant fowlpox viruses (FPV) harboring the altered mgc3 gene were constructed. One of the recombinant FPVs was improved to express MGC3 protein on the cell surface in which the signal peptide of MGC3 protein was replaced with one from Marek's disease virus gB. These results should provide the impetus to develop a vaccine based on MGC3 protein which can induce antibodies with both growth inhibition and metabolic-inhibition activities using a recombinant FPV.
Local Anticandidal Immune Responses in a Rat Model of Vaginal Infection by and Protection againstCandida albicans
Authors: de Bernardis Flavia , Santoni Giorgio , Boccanera Maria , Spreghini Elisabetta , Adriani Daniela , Morelli Luisella , Cassone Antonio 
Published: July 2002

ABSTRACTHumoral (antibody [Ab]) and cellularCandida-specific immune responses in the vaginas of pseudoestrus rats were investigated during three successive infections byCandida albicans. After the first, protective infection, Abs against mannan and aspartyl proteinase antigens were present in the vaginal fluid, and their titers clearly increased during the two subsequent, rapidly healing infections. In all animals, about 65 and 10% of vaginal lymphocytes (VL) were CD3+(T cells) and CD3−CD5+(B cells), respectively. Two-thirds of the CD3+T cells expressed the α/β and one-third expressed the γ/δ T-cell receptor (TCR). This proportion slightly fluctuated during the three rounds ofC. albicansinfection, but no significant differences between infected and noninfected rats were found. More relevant were the changes in the CD4+/CD8+T-cell ratio, particularly for cells bearing the CD25 (interleukin-2 receptor α) marker. In fact, a progressively increased number of both CD4+α/β TCR and CD4+CD25+VL was observed after the second and thirdCandidachallenges, reversing the high initial CD8+cell number of controls (estrogenized but uninfected rats). The CD3−CD5+cells also almost doubled from the first to the third infection. Analysis of the cytokines secreted in the vaginal fluid ofCandida-infected rats showed high levels of interleukin 12 (IL-12) during the first infection, followed by progressively increasing amounts of IL-2 and gamma interferon during the subsequent infections. No IL-4 or IL-5 was ever detected. During the third infection, VL with in vitro proliferative activity in response to an immunodominant mannoprotein antigen ofC. albicanswere present in the vaginal tissue. No response to this antigen by mitogen-responsive blood, lymph node, and spleen cells was found. In summary, the presence of protective Ab and T helper type 1 cytokines in the vaginal fluids, the in vitro proliferation of vaginal lymphocytes in response toCandidaantigenic stimulation, and the increased number of activated CD4+cells and some special B lymphocytes afterC. albicanschallenge constitute good evidence for induction of locally expressedCandida-specific Ab and cellular responses which are potentially involved in anticandidal protection at the vaginal level.
The SA85-1.1 Protein of theTrypanosoma cruzi trans-Sialidase Superfamily Is a Dominant T-Cell Antigen
Authors: Millar Amanda E. , Kahn Stuart J. 
Published: July 2002

ABSTRACTTrypanosoma cruzicurrently infects 18 million people, and 30% of those infected develop a chronic inflammatory process that causes significant morbidity or mortality. The major histocompatibility complex class II (MHC-II)-restricted T-cell response is critical to the control of the infection and to the ensuing inflammatory pathology. The specific epitopes or major antigens of this response have not been identified. The parasite simultaneously expresses variant members of thetrans-sialidase superfamily. To begin to analyze the MHC-II response to these variant proteins, the response to a single surface protein, SA85-1.1, was initiated. These studies have demonstrated that a biased gamma interferon (IFN-γ) response to the SA85-1.1 protein develops duringT. cruziinfection. In addition, adoptive transfer of a CD4 clone that recognizes an SA85-1.1 epitope, named epitope 1, and immunization with a peptide encoding epitope 1 were protective and suggested that epitope 1 may be immunodominant. In this report IFN-γ intracellular staining demonstrated that splenocytes from acutely and chronically infected mice, incubated with SA85-1.1 protein or peptides that encode epitope 1, result in IFN-γ synthesis by 4 to 6% of the splenic CD4 cells. These data indicate that duringT. cruziinfection epitope 1 is a major epitope and that 4 to 6% of the CD4 cells are stimulated by a singletrans-sialidase superfamily epitope and suggest that a combination oftrans-sialidase superfamily proteins combines to stimulate a majority of CD4 cells. These data suggest that duringT. cruziinfection the CD4 response to thetrans-sialidase superfamily is critical to the protective response and to the ensuing chronic inflammatory pathology.
Lack of Protection in Mice and Necrotizing Bronchointerstitial Pneumonia with Bronchiolitis in Guinea Pigs Immunized with Vaccines Directed against the hsp60 Molecule ofMycobacterium tuberculosis
Authors: Turner Oliver C. , Roberts Alan D. , Frank Anthony A. , Phalen Susan W. , McMurray David M. , Content Jean , Denis Olivier , D'Souza Sushila , Tanghe Audrey , Huygen Kris , Orme Ian M. 
Published: July 2002

ABSTRACTIn this study, the hsp60 and hsp70 heat shock protein antigens ofMycobacterium tuberculosiswere tested as potential vaccine candidates, using purified recombinant protein antigens or antigens encoded in the form of a DNA plasmid vaccine. Guinea pigs vaccinated with a mixture of the two proteins showed no evidence of resistance to low-dose aerosol challenge infection and quickly developed severe lung damage characterized by necrotizing bronchointerstitial pneumonia and bronchiolitis. As a result, we turned instead to a DNA vaccination approach using a plasmid encoding the hsp60 antigen ofM. tuberculosis. Although immunogenic in mice, vaccination with plasmid DNA encoding hsp60 was not protective in that model or in the guinea pig model and again gave rise to similar severe lung damage. This study seriously questions the safety of vaccines against tuberculosis that target highly conserved heat shock proteins.
Tuberculosis DNA Vaccine Encoding Ag85A Is Immunogenic and Protective When Administered by Intramuscular Needle Injection but Not by Epidermal Gene Gun Bombardment
Authors: Tanghe Audrey , Denis Olivier , Lambrecht Bénédicte , Motte Vinciane , van den Berg Thierry , Huygen Kris 
Published: July 2002

ABSTRACTImmunogenicity and protective efficacy of a DNA vaccine encoding Ag85A fromMycobacterium tuberculosiswere compared in BALB/c and C57BL (B6 and B10) mice immunized by intramuscular (i.m.) needle injection or epidermal gene gun (gg) bombardment. In BALB/c mice, gg immunization could induce elevated antibody and cytotoxic T lymphocyte responses with plasmid doses 50-fold lower than those required for i.m. immunization. Interleukin-2 (IL-2) and gamma interferon (IFN-γ) secretion, however, was much lower in gg-immunized than in i.m.-immunized BALB/c mice. On the other hand, C57BL mice reacted only very weakly to gg immunization, whereas elevated Ag85A-specific antibody, IL-2, and IFN-γ responses (significantly higher than in BALB/c mice) were detected following vaccination by the i.m. route. Antibody isotypes were indicative of Th2 activation following gg injection of BALB/c and of Th1 activation following i.m. injection of C57BL mice. Finally, C57BL but not BALB/c mice were protected by i.m. Ag85A DNA immunization against intravenousM. tuberculosischallenge, as measured by reduced numbers of CFU in spleen and lungs, compared to animals vaccinated with control DNA. Gene gun immunization was not effective in either BALB/c or C57BL mice. These results indicate that i.m. DNA vaccination is the method of choice for the induction of protective Th1 type immune responses with the Ag85A tuberculosis DNA vaccine.
Identification and HLA Restriction of Naturally Derived Th1-Cell Epitopes from the SecretedMycobacterium tuberculosisAntigen 85B Recognized by Antigen-Specific Human CD4+T-Cell Lines
Authors: Mustafa Abu S. , Shaban Fatema A. , Abal Adnan T. , Al-Attiyah Raja , Wiker Harald G. , Lundin Knut E. A. , Oftung Fredrik , Huygen Kris 
Published: July 2002

ABSTRACTAntigen 85B (Ag85B/MPT59) is a major secreted protein fromMycobacterium tuberculosiswhich is a promising candidate antigen for inclusion in novel subunit vaccines against tuberculosis (TB). The present study was undertaken to map naturally derived T-cell epitopes fromM. tuberculosisAg85B in relation to major histocompatibility complex (MHC) class II restriction. Antigen-specific CD4+T-cell lines were established from HLA-typed TB patients andMycobacterium bovisBCG vaccinees by stimulation of peripheral blood mononuclear cells with purified Ag85B in vitro. The established T-cell lines were then tested for proliferation and gamma interferon (IFN-γ) secretion in response to 31 overlapping synthetic peptides (18-mers) covering the entire sequence of the mature protein. The results showed that the epitopes recognized by T-cell lines from TB patients were scattered throughout the Ag85B sequence whereas the epitopes recognized by T-cell lines from BCG vaccinees were located toward the N-terminal part of the antigen. The T-cell epitopes represented by peptides p2 (amino acids [aa] 10 to 27), p3 (aa 19 to 36), and p11 (aa 91 to 108) were frequently recognized by antigen-specific T-cell lines from BCG vaccinees in both proliferation and IFN-γ assays. MHC restriction analysis demonstrated that individual T-cell lines specifically recognized the complete Ag85B either in association with one of the selfHLA-DRB1,DRB3, orDRB4gene products or nonspecifically in a promiscuous manner. At the epitope level, panel studies showed that peptides p2, p3, and p11 were presented to T cells by HLA-DR-matched as well as mismatched allogeneic antigen-presenting cells, thus representing promiscuous epitopes. The identification of naturally derived peptide epitopes from theM. tuberculosisAg85B presented to Th1 cells in the context of multiple HLA-DR molecules strongly supports the relevance of this antigen to subunit vaccine design.
Mechanical Fractionation Reveals Structural Requirements for Enteropathogenic
Escherichia coli
Tir Insertion into Host Membranes
Authors: Gauthier Annick , de Grado Myriam , Finlay B. Brett 
Published: July 2002

ABSTRACT

Enteropathogenic
Escherichia coli
(EPEC) inserts its receptor for intimate adherence (Tir) into host cell membranes by using a type III secretion system. Detergents are frequently used to fractionate infected host cells to investigate bacterial protein delivery into mammalian cells. In this study, we found that the Triton X-100-soluble membrane fraction from EPEC-infected HeLa cells was contaminated with bacterial proteins. We therefore applied a mechanical method of cell lysis and ultracentrifugation to fractionate infected HeLa cells to investigate the biology and biochemistry of Tir delivery and translocation. This method demonstrates that the translocation of Tir into the host cell membrane requires its transmembrane domains, but not tyrosine phosphorylation or binding to Tir's ligand, intimin.
Differential Expression of Caveolin-1 in Lipopolysaccharide-Activated Murine Macrophages
Authors: Lei Mei G. , Morrison David C. 
Published: July 2002

ABSTRACTFive reciprocal cycles of subtractive hybridization using cDNA generated from fibroblasts with normal lipopolysaccharide (LPS) responsiveness (lpsn) and from hyporesponsive (lpsd) fibroblasts have led to the finding that caveolin-1 is expressed at markedly higher levels of mRNA inlpsdthan inlpsnfibroblasts. Caveolin-1 message can also be readily detected via reverse transcription-PCR in the RAW264.7 and J774.1 macrophage-like cell lines as well as in primary thioglycolate (TG)-elicited mouse peritoneal macrophages. In RAW264.7 cells, both caveolin-1 mRNA and protein levels are down-regulated by LPS. In TG-elicited C3HeB/FeJ peritoneal macrophages, in contrast, expression of both caveolin-1 protein and mRNA is up-regulated in vitro in response to LPS stimulation. The up-regulation of caveolin-1 protein expression in C3HeB/FeJ peritoneal macrophages can be demonstrated at concentrations as low as 1.0 pg of LPS/ml. However, LPS concentrations approximately 4 orders of magnitude higher (104pg/ml) were required to stimulate the LPS-hyporesponsive C3H/HeJ mice peritoneal macrophages such that significant caveolin-1 protein up-regulation was detected. Caveolin-1, a principal component of plasmalemmal caveolae, has been reported as a potentially important regulator for signal transduction during cellular stimulation. The results described in this report suggest that caveolin-1 expression may be associated with LPS signaling/internalization.
Characterization of Lymphocyte Response in the Female Genital Tract during Ascending Chlamydial Genital Infection in the Guinea Pig Model
Authors: Rank Roger G. , Bowlin Anne K. , Kelly Kathleen A. 
Published: July 2002

ABSTRACT
It is well known that pathology caused by chlamydial infection is associated closely with the host response to the organism and that both innate and adaptive host responses contribute to tissue damage. While it is likely that the organism itself initiates the acute inflammatory response by eliciting cytokine and chemokine production from the host cell, the adaptive response is the result of activation of the cell-mediated immune response. While there are several studies describing the nature of the pathologic response in primate, guinea pig, and murine models, there is less information on the kinetics of the CD4 and CD8 response following primary and challenge infections. In this study, we have quantified by flow cytometry the mononuclear cell response to genital infection with the agent of guinea pig inclusion conjunctivitis in the cervix, endometrium, and oviducts at various times following a primary intravaginal infection and after a challenge infection. Tissues from individual animals were assessed for cells expressing CD4, CD8, or Mac-1 and for B cells. Peak responses of each subset occurred 10 to 14 days after a primary infection. The number of Mac-1-expressing cells in each tissue site was found to be dependent on the size of the inoculating dose of chlamydiae. The responses of each cell type were generally stronger in the cervix than in the upper genital tract. In contrast to the murine model but consistent with the primate models, there were equal numbers of CD4 and CD8 cells present in the infiltrates. Twenty-one days after challenge infection, which was performed 50 days after the primary infection, there was a significant increase in the number of CD4, CD8, and B cells in the oviduct compared to the number of these cells at the same time after a primary infection, providing clear cellular evidence for a cell-mediated immune pathologic response.
Homologous and Heterologous
Borrelia burgdorferi
Challenge of Infection-Derived Immune Rabbits Using Host-Adapted Organisms
Authors: Shang Ellen S. , Wu Xiao-yang , Lovett Michael A. , Miller James N. , Blanco David R. 
Published: July 2002

ABSTRACT

We have recently found that strain B31 infection-immune rabbits are completely protected against homologous challenge with large numbers (>10
6
) of host-adapted
Borrelia burgdorferi
(HAB) (E. S. Shang, C. I. Champion, X. Wu, J. T. Skare, D. B. Blanco, J. N. Miller, and M. A. Lovett, Infect. Immun. 68:4189–4199, 2000). In this study, we have extended these findings to determine whether B31 strain infection-immune rabbits are also protected against heterologous HAB challenge. Infection-immune rabbits challenged with large numbers (>10
6
) of homologous HAB strain B31 were completely protected from erythema migrans (EM) and skin and disseminated infection. In contrast, infection-immune rabbits challenged with heterologous HAB strains N40 and Sh-2-82 were completely susceptible to EM and skin and disseminated infection; challenge with strain 297 also resulted in EM and infection of the skin and viscera, but clearance of infection occurred 3 weeks postchallenge. These findings confirm that immunity elicited in rabbits by B31 strain infection confers complete protection against large-dose homologous HAB challenge but not against a heterologous strain.
Th1 AdjuvantN-Acetyl-d-Glucosamine Polymer Up-Regulates Th1 Immunity but Down-Regulates Th2 Immunity against a Mycobacterial Protein (MPB-59) in Interleukin-10-Knockout and Wild-Type Mice
Authors: Shibata Yoshimi , Honda Ikuro , Justice J. Paul , Van Scott Michael R. , Nakamura Reiko M. , Myrvik Quentin N. 
Published: July 2002

ABSTRACTTreatment of mice with heat-killed (HK)Mycobacterium bovisBCG or 1- to 10-μm chitin particles (nonantigenicN-acetyl-d-glucosamine polymers) is known to induce innate immune responses, including gamma interferon (IFN-γ) production, which plays a Th1 adjuvant role. However, HK BCG further induces prostaglandin E2-releasing spleen macrophages (Mφ) (PGE2-Mφ), which potentially inhibit Th1 adjuvant activities. We found that chitin particles did not induce PGE2-Mφ formation. To further assess whether chitin has Th1 adjuvant effects, interleukin-10 (IL-10)-knockout (KO) mice and their wild-type (WT, C57BL/6) controls were immunized with a 30-kDa MPB-59 mycobacterial protein mixed with chitin. Immunization with MPB-59 alone induced Th2 responses, characterized by increases in total serum immunoglobulin E (IgE) and specific serum IgG1 levels and spleen Th2 cells producing IL-4, IL-5, and IL-10. No IFN-γ-producing spleen Th1 cells, specific serum IgG2a, or delayed-type hypersentivity (DTH) footpad reactions were detected. On the other hand, chitin–MPB-59 immunization significantly increased spleen Th1 responses, DTH reaction, and serum IgG2a levels along with decreases of Th2 responses. The magnitude of these Th1 adjuvant effects was greater in IL-10-KO mice than in WT mice. In contrast, immunization with HK BCG–MPB-59 showed little or no Th1 adjuvant effect. These data indicate that chitin has a unique Th1 adjuvant effect on the development of Th1 immunity against a mycobacterial antigen. IL-10 down-regulates the adjuvant effect of chitin.
Effect of AttenuatedSalmonella entericaSerovar Typhimurium Expressing aStreptococcus mutansAntigen on Secondary Responses to the Cloned Protein
Authors: Jespersgaard Christina , Zhang Ping , Hajishengallis George , Russell Michael W. , Michalek Suzanne M. 
Published: July 2002

ABSTRACTAttenuatedSalmonella entericaserovar Typhimurium has been used for targeted delivery of recombinant antigens to gut- and nose-associated lymphoid tissues. Contradictory reports have described the effect of preexisting immunity to the antigen delivery vehicle. We decided to examine this discrepancy by studying the effect of immunizing mice by the intranasal (i.n.) route withSalmonellaexpressing an insoluble protein and to study the ability to augment recall responses by boosting with eitherSalmonella-expressed protein or purified soluble protein alone. The glucan-binding domain (GLU) of the enzyme glucosyltransferase (GTF), which is an important virulence factor ofStreptococcus mutans, was recombinantly expressed in the insoluble phase inS. entericaserovar Typhimurium, and the immunogenicity of this construct was studied in mice. We examined the induction of primary immune responses by insoluble GLU polypeptide delivered inSalmonellaat week 1 (groups 1 and 2) and recall responses after a week 15 boost with eitherSalmonellaexpressing GLU (group 1) or purified GLU polypeptide (groups 2 and 3). Group 4 served as the control and received phosphate-buffered saline alone by the i.n. route. Significant anti-GLU serum immunoglobulin G (IgG) levels were seen in groups 1, 2, and 3 at week 18 (P< 0.001), i.e., 3 weeks after the booster immunization. Mice in group 2, who receivedSalmonellafollowed by GLU, had the highest GLU-specific IgG levels among all groups. The serum IgG levels persisted in all responding groups for at least 7 weeks after the boost (week 22). The IgG2a/IgG1 subclass ratio of serum anti-GLU antibodies in group 1 significantly increased after the boost. These results support the induction of a type 1-like immune response to GLU after primary and booster immunizations withSalmonellaexpressing GLU. On the other hand, group 2 mice, which receivedSalmonellaexpressing GLU as the primary dose and soluble protein as the booster dose, exhibited a shift from a type 1-like to a more type 2-like immune response to GLU following the boost. These results indicate thatS. entericaserovar Typhimurium is an excellent delivery vehicle for the insoluble and recombinantly expressed GLU of GTF and that this construct was especially effective in priming the host for a secondary response to soluble GLU polypeptide.