bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gene Expression Profiling of Peripheral Blood Mononuclear Cells from Cattle Infected withMycobacterium paratuberculosis
Authors: Coussens Paul M. , Colvin Christopher J. , Wiersma Kacie , Abouzied Amy , Sipkovsky Sue 
Published: September 2002

ABSTRACTA bovine-specific cDNA microarray system containing 721 unique leukocyte expressed sequence tags (ESTs) and amplicons representing known genes was used to compare gene expression profiles of peripheral blood mononuclear cells (PBMCs) from clinical and subclinical Johne's disease-positive Holstein cows (n= 2 per group). Stimulation of PBMCs from clinically infected cows withMycobacterium paratuberculosistended to decrease expression of 83 genes (fold change, >1.5). Of these 83 genes, 16 displayed significant down regulation across both clinical cows (P< 0.1), including genes encoding microspherule protein 1, fibroblast growth factor, and the Lyn B protein kinase. Only eight genes from PBMCs of clinically infected cows exhibited a modest up regulation following stimulation withM. paratuberculosis, including those encoding bovine CD40L, gamma interferon, interleukin-10 (IL-10), and tissue inhibitor of matrix metalloproteinases (TIMP) 4. In contrast, stimulation of PBMCs from subclinically infected cows withM. paratuberculosistended to up regulate expression of 71 genes representing 68 unique transcripts. Of these, 11 genes showed significant up regulation (fold change, >1.5;P< 0.1) across both animals, including those encoding bovine CD40L, several matrix metalloproteinases, and SPARC (secreted protein, acidic and rich in cystine). Repression of gene expression was also observed in PBMCs from the subclinical cows, with 16 genes being significantly down regulated (fold change, >1.5;P< 0.1) across both animals, including those encoding the bovine orthologs of cytochrome oxidase subunit III, IL-1 receptor type I, and fibrinogen-like 2 protein. Only one clone, representing an unknown bovine EST, was similarly down regulated in PBMCs from both the clinical and subclinical cows. Thus, the most prominent change induced by exposure of PBMCs from clinical cows toM. paratuberculosisin vitro tended to be repression of gene expression, while changes in similarly treated PBMCs from subclinical cows was balanced between gene activation and repression. Comparison of gene expression profiles between PBMCs from clinical and uninfected (control) cows stimulated with the general mitogen concanavalin A were highly similar (overallr= 0.84), suggesting thatM. paratuberculosis-induced gene repression in clinically infected cow PBMCs was not due to a general failure of the immune response in these animals.
Representational Difference Analysis between Afa/Dr Diffusely Adhering
Escherichia coli
and Nonpathogenic
E. coli
K-12
Authors: Blanc-Potard Anne-Beatrice , Tinsley Colin , Scaletsky Isabel , Le Bouguenec Chantal , Guignot Julie , Servin Alain L. , Nassif Xavier , Bernet-Camard Marie-Francoise 
Published: September 2002

ABSTRACT

Diffusely adhering
Escherichia coli
strains harboring Afa/Dr adhesins (Afa/Dr DAEC) have been associated with diarrhea and urinary tract infections (UTIs). The present work is the first extensive molecular study of a Afa/Dr DAEC strain using the representational difference analysis technique. We have searched for DNA sequences present in strain C1845, recovered from a diarrheagenic child, but absent from a nonpathogenic K-12 strain. Strain C1845 harbors part of a pathogenicity island (PAI
CFT073
) and several iron transport systems found in other
E. coli
pathovars. We did not find genes encoding factors known to subvert host cell proteins, such as type III secretion system or effector proteins. Several C1845-specific sequences are homologous to putative virulence genes or show no homology with known sequences, and we have analyzed their distribution among Afa/Dr and non-Afa/Dr clinical isolates and among strains from the
E. coli
Reference Collection. Three C1845-specific sequences (MO30, S109, and S111) have a high prevalence (77 to 80%) among Afa/Dr strains and a low prevalence (12 to 23%) among non-Afa/Dr strains. In addition, our results indicate that strain IH11128, an Afa/Dr DAEC strain recovered from a patient with a UTI, is genetically closely related to strain C1845.
Identification of Two Distinct Subpopulations ofLeishmania major-Specific T Helper 2 Cells
Authors: Kropf Pascale , Herath Shanti , Tewari Rita , Syed Nelofer , Klemenz Roman , Müller Ingrid 
Published: September 2002

ABSTRACTIt is widely accepted that a strong Th2 response is responsible for nonhealingLeishmania majorinfections in BALB/c mice. This Th2 response has been thoroughly documented by measuring the levels of Th2 cytokines produced by CD4+T cells present in the lymphoid organs by enzyme-linked immunosorbent assay and PCR. However, the cytokine profile ofL. major-specific Th2 cells has never been determined. In this study, we used the recently described Th2 marker T1/ST2 to characterize Th2 cells during the course of nonhealingL. majorinfection. We analyzed the intracellular cytokine profile of CD4+T1/ST2+T cells and showed that they clearly displayed a Th2 phenotype, as they expressed interleukin 4 (IL-4), IL-10, and IL-5. In addition, we detected another population of Th2 cells among the CD4+T1/ST2−T cells that expressed IL-4 and IL-10 but excluded IL-5. In summary, we show here that two type 2 subpopulations are present in the lymphoid organs ofL. major-infected BALB/c mice; Th2 cells from both subsets expressed IL-4 and IL-10, but they could be distinguished by their expression of IL-5 and T1/ST2.
Major Histocompatibility Complex Class II DR-Restricted Memory CD4+T Lymphocytes Recognize Conserved Immunodominant Epitopes ofAnaplasma marginaleMajor Surface Protein 1a
Authors: Brown Wendy C. , McGuire Travis C. , Mwangi Waithaka , Kegerreis Kimberly A. , Macmillan Henriette , Lewin Harris A. , Palmer Guy H. 
Published: September 2002

ABSTRACTNative major surface protein 1 (MSP1) ofAnaplasma marginale, composed of covalently associated MSP1a and MSP1b proteins, stimulates protective immunity in cattle against homologous and heterologous strain challenge. Protective immunity against pathogens in the familyAnaplasmataceaeinvolves both CD4+T cells and neutralizing immunoglobulin G. Thus, an effective vaccine should contain both CD4+T- and B-lymphocyte epitopes that will elicit strong memory responses upon infection with homologous and heterologous strains. Previous studies demonstrated that the predominant CD4+T-cell response in MSP1 vaccinates is directed against the MSP1a subunit. The present study was designed to identify conserved CD4+T-cell epitopes in MSP1a presented by a broadly represented subset of major histocompatibility complex (MHC) class II molecules that would be suitable for inclusion in a recombinant vaccine. Transmembrane protein prediction analysis of MSP1a from the Virginia strain revealed a large hydrophilic domain (HD), extending from amino acids (aa) 1 to 366, and a hydrophobic region extending from aa 367 to 593. The N terminus (aa 1 to 67) includes one 28-aa form A repeat and one 29-aa form B repeat, which each contain an antibody neutralization-sensitive epitope [Q(E)ASTSS]. In MSP1 vaccinates, recombinant MSP1a HD (aa 1 to 366) stimulated recall proliferative responses that were comparable to those against whole MSP1a excluding the repeat region (aa 68 to 593). Peptide mapping determined a minimum of five conserved epitopes in aa 151 to 359 that stimulated CD4+T cells from cattle expressingDR-DQhaplotypes common in Holstein-Friesian breeds. Peptides representing three epitopes (aa 231 to 266, aa 270 to 279, and aa 290 to 319) were stimulatory for CD4+T-cell clones and restricted by DR. A DQ-restricted CD4+T-cell epitope, present in the N-terminal form B repeat (VSSQSDQASTSSQLG), was also mapped using T-cell clones from one vaccinate. Although form B repeat-specific T cells did not recognize the form A repeat peptide (VSSQS_EASTSSQLG), induction of T-cell anergy by this peptide was ruled out. The presence of multiple CD4+T-cell epitopes in the MSP1a HD, in addition to the neutralization-sensitive epitope, supports the testing of this immunogen for induction of protective immunity againstA. marginalechallenge.
Cholera Toxin and Heat-Labile Enterotoxin Activate Human Monocyte-Derived Dendritic Cells and Dominantly Inhibit Cytokine Production through a Cyclic AMP-Dependent Pathway
Authors: Bagley Kenneth C. , Abdelwahab Sayed F. , Tuskan Robert G. , Fouts Timothy R. , Lewis George K. 
Published: September 2002

ABSTRACTCholera toxin (CT) and heat-labile enterotoxin (LT) are powerful mucosal adjuvants whose cellular targets and mechanism of action are unknown. There is emerging evidence that dendritic cells (DC) are one of the principal cell types that mediate the adjuvant effects of these toxins in vivo. Here we investigate the effects of CT and LT on the maturation of human monocyte-derived DC (MDDC) in vitro. We found that an enzymatically active A domain is necessary for both CT and LT to induce the maturation of MDDC and that this activation is strictly cyclic AMP (cAMP) dependent. ADP-ribosylation-defective derivatives of these toxins failed to induce maturation of MDDC, whereas dibutyryl-cyclic-3′,5′-AMP and Forskolin mimic the maturation of MDDC induced by CT and LT. In addition, an inhibitor of cAMP-dependent kinases, Rp-8-Br-cAMPs, blocked the ability of CT, LT, and Forskolin to activate MDDC. CT, LT, dibutyryl-cyclic-3′,5′-AMP, and Forskolin also dominantly inhibit interleukin 12 and tumor necrosis factor alpha production by MDDC in the presence of saturating concentrations of lipopolysaccharide. Taken together, these results show that the effects of CT and LT on MDDC are mediated by cAMP.
Effect of
omp10
or
omp19
Deletion on
Brucella abortus
Outer Membrane Properties and Virulence in Mice
Authors: Tibor Anne , Wansard Valérie , Bielartz Valery , Delrue Rose-May , Danese Isabelle , Michel Patrick , Walravens Karl , Godfroid Jacques , Letesson Jean-Jacques 
Published: September 2002

ABSTRACT

The distinctive properties of
Brucella
outer membrane have been considered to be critical for
Brucella
sp. virulence. Among the outer membrane molecules possibly related to these properties, Omp10 and Omp19 are immunoreactive outer membrane lipoproteins. Moreover, these proteins of
Brucella
could constitute a new family of outer membrane proteins specifically encountered in the family
Rhizobiaceae
. We evaluated the impact of
omp10
or
omp19
deletion on
Brucella abortus
outer membrane properties and virulence in mice. The
omp10
mutant was dramatically attenuated for survival in mice and was defective for growth in minimal medium but was not impaired in intracellular growth in vitro, nor does it display clear modification of the outer membrane properties. Significantly fewer brucellae were recovered from the spleens of mice infected with the
omp19
mutant than from those of mice infected with the parent strain at 4 and 8 weeks postinfection. The
omp19
mutant exhibited an increase in sensitivity to the polycation polymyxin B and to sodium deoxycholate. These results indicate that inactivation of the
omp19
gene alters the outer membrane properties of
B. abortus
.
Genetic Immunization Elicits Antigen-Specific Protective Immune Responses and Decreases Disease Severity inTrypanosoma cruziInfection
Authors: Garg Nisha , Tarleton Rick L. 
Published: September 2002

ABSTRACTImmunity toTrypanosoma cruzirequires elicitation of humoral and cell-mediated immune responses to extracellular trypomastigotes and intracellular amastigotes. In this study, the effectiveness of theT. cruzitrans-sialidase family (ts) genesASP-1,ASP-2, andTSA-1as genetic vaccines was assessed. Immunization of mice with plasmids encodingASP-1,ASP-2, orTSA-1elicited poor antigen-specific cytotoxic-T-lymphocyte (CTL) activity andT. cruzi-specific antibody responses. Codelivery of interleukin-12 and granulocyte-macrophage colony-stimulating factor plasmids with antigen-encoding plasmids resulted in a substantial increase in CTL activity and antibody production and in increased resistance toT. cruziinfection. In pooled results from two to four experiments, 30 to 60% of mice immunized with antigen-encoding plasmids and 60 to 80% of mice immunized with antigen-encoding plasmids plus cytokine adjuvants survived a lethal challenge withT. cruzi. In comparison, 90% of control mice injected with empty plasmid DNA died during the acute phase of infection. However, the pool of three ts genes provided no greater protection than the most effective single gene (ASP-2) either with or without coadministration of cytokine plasmids. Importantly, the extent of tissue parasitism, inflammation, and associated tissue damage in skeletal muscles during the chronic phase ofT. cruziinfection in mice immunized with antigen-encoding plasmids plus cytokine adjuvants was remarkably reduced compared to mice immunized with only cytokine adjuvants or empty plasmid DNA. These results identify new vaccine candidates and establish some of the methodologies that might be needed to develop effective vaccine-mediated control ofT. cruziinfection. In addition, this work provides the first evidence that prophylactic genetic immunization can prevent the development of Chagas’ disease.
Differential Responses of Bovine Macrophages toMycobacterium aviumsubsp.paratuberculosisandMycobacterium aviumsubsp.avium
Authors: Weiss Douglas J. , Evanson Oral A. , Moritz Andreas , Deng Ming Qi , Abrahamsen Mitchell S. 
Published: September 2002

ABSTRACTMycobacterium aviumsubsp.paratuberculosisandMycobacterium aviumsubsp.aviumare antigenically and genetically similar organisms; however, they differ in their virulence for cattle.M. aviumsubsp.paratuberculosiscauses a chronic intestinal infection leading to a chronic wasting disease termed paratuberculosis or Johne's disease, whereasM. aviumsubsp.aviumcauses only a transient infection. We compared the response of bovine monocyte-derived macrophages to ingestion ofM. aviumsubsp.paratuberculosisandM. aviumsubsp.aviumorganisms by determining organism survival, superoxide and nitric oxide production, and expression of the cytokines tumor necrosis factor alpha (TNF-α), gamma interferon (IFN-γ), interleukin-8 (IL-8), IL-10, IL-12, and granulocyte-monocyte colony-stimulating factor (GM-CSF). UnlikeM. aviumsubsp.paratuberculosis, macrophages were able to kill approximately half of theM. aviumsubsp.aviumorganisms after 96 h of incubation. This difference in killing efficiency was not related to differences in nitric oxide or superoxide production. Compared to macrophages activated with IFN-γ and lipopolysaccharide, macrophages incubated withM. aviumsubsp.paratuberculosisshowed greater expression of IL-10 and GM-CSF (all time points) and IL-8 (72 h) and less expression of IL-12 (72 h), IFN-γ (6 h), and TNF-α (6 h). When cytokine expression by macrophages incubated withM. aviumsubsp.paratuberculosiswas compared to those of macrophages incubated withM. aviumsubsp.avium,M. aviumsubsp.paratuberculosis-infected cells showed greater expression of IL-10 (6 and 24 h) and less expression of TNF-α (6 h). Therefore, the combination of inherent resistance to intracellular degradation and suppression of macrophage activation through oversecretion of IL-10 may contribute to the virulence ofM. aviumsubsp.paratuberculosisin cattle.
Cytokine Profiles of Patients Infected withMycobacterium ulceransand Unaffected Household Contacts
Authors: Gooding Travis M. , Johnson Paul D. R. , Smith May , Kemp Andrew S. , Robins-Browne Roy M. 
Published: September 2002

ABSTRACTMycobacterium ulcerans, the cause of Buruli ulcer, is an environmental mycobacterium with a distinct geographic distribution. The reasons why only some individuals who are exposed toM. ulceransdevelop ulcers are not known but are likely to reflect individual differences in the immune response to infections with this bacterium. In this study, we investigated cytokine profiles of peripheral blood mononuclear cells (PBMC) from 23 Buruli ulcer patients and 25 household contacts in a region of Australia where Buruli ulcer is endemic. The results showed that following stimulation withM. ulceransorMycobacterium bovisBCG, PBMC from Buruli ulcer patients mounted a Th2-type response, which was manifested by the production of mRNA for interleukin 4 (IL-4), IL-5, IL-6, and IL-10, whereas unaffected contacts responded mainly with the Th1 cytokines gamma interferon (IFN-γ) and IL-12. For example, mRNA for IL-4 was detected in 18 of 23 patients but in only 3 of 25 control subjects (P< 0.0001). By contrast, PBMC from 21 of 25 unaffected individuals produced IFN-γ compared with 3 of 23 patients (P< 0.0001). IFN-γ release following stimulation with mycobacteria was markedly reduced in affected subjects. Frequencies of antibodies toM. ulceransin serum samples from affected and unaffected subjects were similar, indicating that many of the control subjects had been exposed to this bacterium. Together, these findings suggest that a Th1-type immune response toM. ulceransmay prevent the development of Buruli ulcer in people exposed toM. ulcerans, but a Th-2 response does not.
Bacterial Artificial Chromosome-Based Comparative Genomic Analysis Identifies
Mycobacterium microti
as a Natural ESAT-6 Deletion Mutant
Authors: Brodin Priscille , Eiglmeier Karin , Marmiesse Magali , Billault Alain , Garnier Thierry , Niemann Stefan , Cole Stewart T. , Brosch Roland 
Published: September 2002

ABSTRACT

Mycobacterium microti
is a member of the
Mycobacterium tuberculosis
complex that causes tuberculosis in voles. Most strains of
M. microti
are harmless for humans, and some have been successfully used as live tuberculosis vaccines. In an attempt to identify putative virulence factors of the tubercle bacilli, genes that are absent from the avirulent
M. microti
but present in human pathogen
M. tuberculosis
or
Mycobacterium bovis
were searched for. A minimal set of 50 bacterial artificial chromosome (BAC) clones that covers almost all of the genome of
M. microti
OV254 was constructed, and individual BACs were compared to the corresponding BACs from
M. bovis
AF2122/97 and
M. tuberculosis
H37Rv. Comparison of pulsed-field gel-separated DNA digests of BAC clones led to the identification of 10 regions of difference (RD) between
M. microti
OV254 and
M. tuberculosis
. A 14-kb chromosomal region (RD1
mic
) that partly overlaps the RD1 deletion in the BCG vaccine strain was missing from the genomes of all nine tested
M. microti
strains. This region covers 13 genes, Rv3864 to Rv3876, in
M. tuberculosis
, including those encoding the potent ESAT-6 and CFP-10 antigens. In contrast, RD5
mic
, a region that contains three phospholipase C genes (
plcA
to -
C
), was missing from only the vole isolates and was present in
M. microti
strains isolated from humans. Apart from RD1
mic
and RD5
mic
other
M. microti
-specific deleted regions have been identified (MiD1 to MiD3). Deletion of MiD1 has removed parts of the direct repeat region in
M. microti
and thus contributes to the characteristic spoligotype of
M. microti
strains.
Tissue Selectivity of Interferon-Stimulated Gene Expression in Mice Infected with Dam+versus Dam−Salmonella entericaSerovar Typhimurium Strains
Authors: Shtrichman Ronit , Heithoff Douglas M. , Mahan Michael J. , Samuel Charles E. 
Published: September 2002

ABSTRACTThe host interferon (IFN) system plays an important role in protection against microbial infections.Salmonella entericaserovar Typhimurium is highly virulent in the mouse model, whereas mutants that lack DNA adenine methylase (Dam−) are highly attenuated and elicit fully protective immune responses against murine typhoid fever. We examined the expression of IFN-responsive genes in several mouse tissues following infection with Dam+or Dam−Salmonella.Infection of mice with Dam+Salmonellaresulted in the induction of host genes known to be indicators of IFN bioactivity and regulated by either IFN-α/β (Mx1) or IFN-γ (class II transactivator protein [CIITA] and inducible nitric oxide synthase [iNOS]) or by both IFN-α/β and IFN-γ (RNA-specific adenosine deaminase [ADAR1] and RNA-dependent protein kinase [PKR]) in a tissue-specific manner compared to uninfected animals. Since the Mx1 promoter is IFN-α/β specific and theMx1gene is not inducible directly by IFN-γ, these data suggest a role of IFN-α/β in the host response toSalmonellainfection. Mice infected with Dam−Salmonellashowed reduced expression of the same set of IFN-stimulated genes (ISGs) as that observed after infection with wild-typeSalmonella.The reduced capacity to induce ISGs persisted in Dam−-vaccinated mice after challenge with the virulent (Dam+) strain. Finally, although no Dam−organisms were recovered from the liver or spleen after oral infection of mice, ADAR, PKR, Mx, and CIITA expression levels were elevated in these tissues relative to those in uninfected mice, suggestive of the distant action of a signaling molecule(s) in the activation of ISG expression.
Enhanced Immunogenicity of Pneumococcal Surface Adhesin A by Genetic Fusion to Cytokines and Evaluation of Protective Immunity in Mice
Authors: Gor Dennis O. , Ding Xuedong , Li Qing , Schreiber John R. , Dubinsky Michael , Greenspan Neil S. 
Published: September 2002

ABSTRACTImmunization of mice with pneumococcal surface adhesin A (PsaA) emulsified in complete Freund's adjuvant (CFA) provides protection against systemic infection withStreptococcus pneumoniae. Because the use of CFA is not acceptable in humans, we sought to develop alternative means of enhancing the immunogenicity of protein antigens of potential use in pneumococcal vaccines. We designed a series of genetic constructs in which coding sequences for PsaA were linked to sequences encoding either murine interleukin-2 (mIL-2), mIL-4, or two copies of an immunostimulatory nonapeptide derived from mIL-1β. The PsaA-cytokine constructs were cloned and expressed inEscherichia coli. Mice immunized twice with PsaA-IL-2, or PsaA-IL-4 responded with PsaA-specific antibody production comparable in magnitude to that of mice primed with PsaA in CFA and boosted with PsaA in incomplete Freund's adjuvant (PsaA-Adj). Antibodies elicited by PsaA-Adj were predominantly of the immunoglobulin G1 (IgG1) subclass, while PsaA-IL-2 and PsaA-IL-4 elicited substantial amounts of IgG2a in addition to IgG1. Mice immunized with PsaA-Adj or PsaA-IL-4 were partially protected against intraperitoneal challenge with virulentS. pneumoniae(30% overall survival beyond 15 days postchallenge). Mice immunized with PsaA and no adjuvant or PsaA-IL-2 exhibited 0 or 5% survival rates, respectively, following challenge. In contrast, mice immunized twice with capsular polysaccharide were 100% protected. The modest levels of protection seen in mice immunized with PsaA and its more immunogenic derivatives may be explained in part by the relative inaccessibility of antibody to PsaA on the surface of encapsulatedS. pneumoniae.