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Judith A Whittum-Hudson

Publications and source records attributed to Judith A Whittum-Hudson.

14 recordsLinked to original sources
PubMed2006

Molecular mimicry and horror autotoxicus: do chlamydial infections elicit autoimmunity?

All species of the order Chlamydiales are obligate intracellular eubacterial pathogens of their various hosts. Two chlamydial species, Chlamydia trachomatis and Chlamydia pneumoniae, are primarily human pathogens, and each is known to cause important diseases. Some strains of C. trachomatis are sexually transmitted and frequently cause severe reproductive problems, primarily in women. Other strains of the organism serve as the aetiological agents for blinding trachoma, still the leading cause of preventable blindness in underdeveloped nations. C. pneumoniae is a respiratory pathogen known to cause community-acquired pneumonia. Importantly, both organisms engender an immunopathogenic response in the human host, and both have been associated with widely diverse, relatively common and currently idiopathic chronic diseases, most of which include an important autoimmune component. In this article, we explore the available experimental data regarding the possible elicitation of autoimmunity in various contexts by chlamydial infection, and we suggest several avenues for research to explore this potentially important issue further.

Animals↗
PubMed2006

Chlamydophila (Chlamydia) pneumoniae in the Alzheimer's brain.

We assessed the presence and characteristics of the intracellular pathogen Chlamydophila (Chlamydia) pneumoniae in brain-tissue samples from 25 patients with late-onset Alzheimer's disease (AD) and 27 non-AD control individuals. 20/27 AD patients, but only 3/27 controls, were PCR-positive in multiple assays targetting the Cpn1046 and Cpn0695 genes. Culture of the organism from brain-tissue homogenate from one AD patient, and assessment of various chlamydial transcripts in RNA preparations from several patients, demonstrated that the organisms were viable and metabolically active in those samples. Immunohistochemical analyses showed that astrocytes, microglia, and neurons all served as host cells for C. pneumoniae in the AD brain, and that infected cells were found in close proximity to both neuritic senile plaques and neurofibrillary tangles in the AD brain. These observations confirm and significantly extend our earlier study suggesting that this unusual pathogen may play a role in the neuropathogenesis characteristic of AD.

Aged↗
PubMed2006

Chlamydophila (Chlamydia) pneumoniae infection of human astrocytes and microglia in culture displays an active, rather than a persistent, phenotype.

BACKGROUND: The intracellular pathogen Chlamydia pneumoniae can cause persistent infections during which its morphologic, molecular, and pathogenic characteristics differ importantly from those of active infection. This bacterium was identified within astrocytes and microglia in the brain of late-onset Alzheimer disease patients. We investigated whether infection of these two host cell types displays an active or persistent growth phenotype. METHODS: The human astrocytoma and microglioma cell lines U-87 MG and CHME-5 (respectively) and the human epithelial cell line HEp-2 were infected by the standard method with C pneumoniae strain AR-39. Cultures were harvested at 24, 48, and 72 hours postinfection and subjected to analysis of inclusion morphology. DNA and RNA were prepared from portions of each infected culture sample and analyzed for relative chromosome accumulation and presence or absence of several specific bacterial mRNAs. RESULTS: Astrocytes and microglial cells infected in vitro with C pneumoniae displayed inclusions that were indistinguishable from those characteristic of active infection of the standard HEp-2 host cell line. Real time polymerase chain reaction (PCR) showed that the relative accumulation of chlamydial chromosome over time during infection of these two cell lines also was virtually identical to that in actively infected HEp-2 cells. Reverse transcriptase PCR (RT-PCR) analyses showed that mRNA from ftsK, pyk, and other chlamydial genes whose expression is abrogated during persistent infection were easily identifiable in infected CHME-5 and U-87 MG cells. CONCLUSIONS: In cultured human astrocytes and microglia, C pneumoniae displays an active, not a persistent, growth phenotype. This indicates normal passage through the developmental cycle with its probable concomitant destruction by lysis of some portion of host cells at the termination of that cycle.

Astrocytes↗
PubMed2004

Differential expression of three Chlamydia trachomatis hsp60-encoding genes in active vs. persistent infections.

Real time RT-PCR was used to assess expression of the three Chlamydia trachomatis hsp60-encoding genes (Ct110, Ct604, Ct755) over time in in vitro systems of active vs. persistent infection, and in synovial samples from patients with Chlamydia-induced arthritis. In HEp-2 cells actively infected with C. trachomatis (serovar K), mRNA from Ct110 (groEL) was apparent by 8 h post-infection (p.i.) and increased more than 10-fold through 48 h p.i.; mRNA from Ct604 followed a similar pattern. Transcripts from Ct755 were abundant at 8 h p.i. and remained 2-3-fold higher than those from Ct110 at all times. In persistently infected human monocytes in culture, expression of Ct110 and Ct755 was low from 1 to 7d p.i., while mRNA from Ct604 was abundant at 1d p.i. and increased more than 3-fold from 1 to 3d p.i., as the organism transited to the persistent state. Those mRNA levels remained high through 7d p.i. Real time analyses of RNA/cDNA from synovial tissue of patients with Chlamydia-associated arthritis showed high Ct604 mRNA levels, consistent with results from the in vitro monocyte system of persistence. These data demonstrate that each chlamydial hsp60-encoding gene is expressed independently, and that the three genes are expressed differentially in active vs. persistent infection. The results further suggest that the Ct604 gene product may function importantly during chlamydial persistence.

Adult↗
PubMed2004

Chemokines in autoimmune lacrimal gland disease in MRL/MpJ mice.

PURPOSE: MRL/MpJ-fas+/fas+ (MRL/+) and MRL/MpJ-fas(lpr)/fas(lpr) (MRL/lpr) mice undergo spontaneous development of inflammation of the lacrimal and salivary glands, similar to that in the human disorder Sjögren's syndrome. Previous work has shown that these lesions appear to be largely T helper (Th)-2-driven, as evidenced by the substantially greater expression of IL-4 than interferon-gamma. The relative contributions of selected chemokines associated with Th1 and Th2 immune responses were assessed. METHODS: Lacrimal glands from MRL/+ and MRL/lpr mice, at ages 1.5 through 9 months were evaluated by immunohistochemistry for the chemokines monocyte chemoattractant protein (MCP)-1 (also known as chemokine ligand [CCL]-2), MCP-5 (CCL12), thymus activation regulated chemokine (TARC; or CCL17), and macrophage-derived chemokine (MDC; or CCL22). Additional lacrimal glands were tested by real-time RT-PCR for chemokines MCP-1 and -5, which are associated with Th2 and Th1 responses, respectively. RESULTS: By immunohistochemistry a significantly greater proportion of mononuclear inflammatory cells in the lacrimal gland lesions stained for MCP-1 (29%-48% depending on age) compared with MCP-5 (1%-3% depending on age) both in MRL/+ (mean difference 34.2%, P < 0.001) and MRL/lpr (mean difference 33.6%, P < 0.001) substrains. Real-time RT-PCR studies showed higher transcript levels of MCP-1 compared with MCP-5, in both MRL/+ (median difference, 37.3; P < 0.0001) and MRL/lpr (median difference, 77.1; P < 0.0001) mice. Relative transcripts of MCP-1 increased with age in both MRL/+ mice (P = 0.02) and MRL/lpr mice (P = 0.03). Staining for TARC was present on lacrimal gland ductular cells but not on the infiltrating lymphocytes, and staining for MDC was present on scattered individual cells throughout the lacrimal gland, but not on infiltrating lymphocytes. CONCLUSIONS: The predominant expression of a Th2-associated chemokine in the lacrimal gland lesions in this murine model of Sjögren's syndrome may contribute to the predominantly Th2-type lymphoid infiltrate in these tissues.

Animals↗
PubMed2004

Inflammatory mediators in autoimmune lacrimal gland disease in MRL/Mpj mice.

PURPOSE: MRL/MpJ-fas(+)/fas(+) (MRL/+) and MRL/MpJ-fas(lpr)/fas(lpr) (MRL/lpr) mice are congenic substrains of mice that have spontaneously developing lacrimal and salivary gland inflammation and are models for the human disorder Sjögren's syndrome. Nitric oxide (NO) and tumor necrosis factor (TNF)-alpha are proinflammatory and potential mediators of tissue damage. The presence of the inducible form of nitric oxide synthase (iNOS), which catalyzes the production of NO, and the presence TNF-alpha in the lacrimal glands of MRL/MpJ mice were assessed. METHODS: Lacrimal glands from MRL/+ and MRL/lpr mice, at ages 1 through 9 months, were evaluated by real-time RT-PCR for iNOS and TNF-alpha mRNA and by immunohistochemistry for the presence of iNOS and of TNF-alpha. Age-matched BALB/c lacrimal glands were used as the control. RESULTS: By quantitative real-time PCR (qPCR), mRNA for iNOS was detected in the lacrimal glands in significantly greater amounts in both MRL/+ (median, normalized to 18S rRNA, 2.90; P < 0.0003) and MRL/lpr mice (median 6.84, P < 0.001) than in BALB/c mice (median 0.34). By qPCR, mRNA for TNF-alpha in the lacrimal glands was detected in significantly greater amounts in aged MRL/+ mice than in BALB/c mice (median, normalized to actin, 221.8 vs. 77.8, P = 0.011) and in MRL/lpr mice than in BALB/c mice (median 136.7 vs. 72.5, P = 0.001). Immunohistochemistry demonstrated both iNOS and TNF-alpha in scattered mononuclear cells throughout the lacrimal glands and in mononuclear cells at the junction of the focal inflammatory infiltrates and normal acinar tissue in both MRL/+ and MRL/lpr mice. CONCLUSIONS: As demonstrated by the greater presence of iNOS and TNF-alpha in the lacrimal glands of MRL/MpJ mice than in control glands, both NO and TNF-alpha are potential mediators of lacrimal gland damage in these murine models of Sjögren's syndrome.

Animals↗
PubMed2003

Biomimetic design in microparticulate vaccines.

Current efforts to improve the effectiveness of microparticle vaccines include incorporating biomimetic features into the particles. Many pathogens use surface molecules to target specific cell types in the gut for host invasion. This observation has inspired efforts to chemically conjugate cell-type targeting ligands to the surfaces of microparticles in order to increase the efficiency of uptake, and therefore the effectiveness, of orally administered microparticles. Bio-mimicry is not limited to the exterior surface of the microparticles. Anti-idiotypic antibodies, cytokines or other biological modifiers can be encapsulated for delivery to sites of interest as vaccines or other therapeutics. Direct mucosal delivery of microparticle vaccines or immunomodulatory agents may profoundly enhance mucosal and systemic immune responses compared to other delivery routes.

Animals↗
PubMed2003

Infectious agents and multiple sclerosis--are Chlamydia pneumoniae and human herpes virus 6 involved?

A good deal of evidence suggests an infectious component in the development of multiple sclerosis (MS) and, to date, some 20 bacteria and viruses have been associated with the disease. Recent independent sets of studies have implicated the respiratory bacterium Chlamydia pneumoniae and human herpes virus 6 (HHV-6) in the pathogenesis of MS. However, as is the case for essentially all earlier microbial associations, experimental evidence linking either this bacterium or this virus to MS is equivocal. We review the published reports concerning involvement of C. pneumoniae and HHV-6 in MS, and data relating to possession of the APOE epsilon 4 allele, which some studies indicate might influence how these or other pathogens affect disease genesis. Based on the large set of inconsistent observations available and given important new information regarding the neuropathology of MS, we contend that no conclusion is possible at this point regarding the potential role of either C. pneumoniae or HHV-6 in MS. We therefore propose future studies that should clarify whether, and if so how, these and other organisms function in the pathogenesis of this disease.

Apolipoprotein E4↗
PubMed2002

Chlamydia trachomatis genes whose products are related to energy metabolism are expressed differentially in active vs. persistent infection.

The Chlamydia trachomatis genome encodes glycolysis and pentose phosphate pathway enzymes, two ATP/ADP exchange proteins, and other energy transduction-related components. We asked if and when chlamydial genes specifying products related to energy transduction are expressed during active vs. persistent infection in in vitro models and in synovia from Chlamydia-associated arthritis patients. Hep-2 cells infected with K serovar were harvested from 0-48 h post-infection (active infection). Human monocytes identically infected were harvested at 1, 2, 3, 5 days post-infection (persistent). RNA from each preparation and from synovial samples PCR-positive/-negative for Chlamydia DNA was subjected to RT-PCR targeting (a) chlamydial primary rRNA transcripts and adt1 mRNA, (b) chlamydial mRNA encoding enzymes of the glycolysis (pyk, gap, pgk) and pentose phosphate (gnd, tal) pathways, the TCA cycle (mdhC, fumC), electron transport system (cydA, cydB), and sigma factors (rpoD, rpsD, rpoN). Primary rRNA transcripts and adt1 mRNA were present in each infected preparation and patient sample; controls were negative for chlamydial RNA. In infected Hep-2 cells, all energy transduction-related genes were expressed by approximately 11 h post-infection. In monocytes, pyk, gap, pgk, gnd, tal, cydA mRNA were present in 1-2-day-infected cells but absent at 3 days and after; cydB, mdhC, fumC were expressed through 5 days post-infection. RT-PCR targeting mRNA from sigma factor genes indicated that lack of these gene products cannot explain selective transcriptional down-regulation during persistence. Analyses of RNA from synovial tissues mirrored those from the monocyte system. These data suggest that in the first phase of active chlamydial infection, ADP/ATP exchange provides energy required for metabolism; in active growth, glycolysis supplements host ATP. In persistence host, rather than bacterially produced, ATP is the primary energy source. Metabolic rate in persistent C. trachomatis is lower than in actively growing cells, as judged from assays for relative chlamydial primary rRNA transcript levels in persistent vs. actively growing cells.

Adenosine Triphosphate↗
PubMed2002

Human herpesvirus 6 and Chlamydia pneumoniae as etiologic agents in multiple sclerosis - a critical review.

Multiple sclerosis (MS) is thought by many investigators to have an infectious component, and several microorganisms have been associated with the disease during the last three decades. Recent studies have implicated both human herpesvirus 6 (HHV-6) and the obligate intracellular bacterium Chlamydia pneumoniae in the etiology of MS. As with earlier studies of other potential agents, however, evidence linking either of these organisms to the disease is equivocal. In this article, we review data for and against involvement of HHV-6 and C. pneumoniae in MS, as well as evidence concerning auxiliary factors, such as possession of the APOE epsilon4 allele, which may influence the role of these organisms in pathogenesis. Further, we suggest several lines of investigation that should clarify whether either or both pathogens are associated meaningfully with this disease.

Antigens, Viral↗
PubMed2002

Cytokine and chemokine mRNA produced in synovial tissue chronically infected with Chlamydia trachomatis and C. pneumoniae.

OBJECTIVE: We used a highly quantitative real-time reverse transcription-polymerase chain reaction (RT-PCR) assay system to define the steady-state levels of mRNA encoding a large panel of soluble mediators of inflammation in synovial tissues from patients with chronic arthritis infected with Chlamydia trachomatis versus C. pneumoniae. METHODS: RNA/cDNA was prepared from synovial biopsies of 4 patients with chronic arthritis and joint infection with C. trachomatis, 6 with C. pneumoniae at that site, 3 uninfected healthy controls, and 3 patients with undifferentiated oligoarthritis (UO) who were PCR negative for all organisms assayed. Real-time RT-PCR was used to assess relative mRNA levels from 12 cytokine and 2 chemokine genes (IL-1alpha, IL-1beta, IL-2, IL-4, IL-5, IL-8, IL-10, IL-12p35, IL-12p40, IL-15, IFN-gamma, TNF-alpha, MCP-1, RANTES). Input loading was normalized to 18S rRNA. Data were obtained for each mRNA from each sample in triplicate in comparison to the same mRNA level in the controls. RESULTS: In most C. trachomatis infected synovial tissue samples, high levels of IL-10 mRNA were present, with less mRNA for IL-8, IL-15, IFN-gamma, and TNF-alpha. Synovial tissues from chronic arthritis patients with synovial C. pneumoniae showed significant levels of mRNA solely for IL-8 and IL-1beta. All other cytokine messengers assessed in each sample from each patient group were at or near control level. One patient with C. pneumoniae showed a high transcript level for RANTES, and one patient with C. trachomatis showed a high transcript level for MCP-1. No patient with UO showed elevated messenger level for any cytokines assayed, but RANTES mRNA was elevated in each. CONCLUSION: Our data suggest that while both C. trachomatis and C. pneumoniae have been associated with inflammatory joint disease, each elicits a somewhat different steady-state profile of mRNA encoding relevant cytokines and chemokines during chronic infection of synovial tissue. Precisely how these differing profiles relate to clinical aspects of synovial inflammation will require further study, but the observations confirm and extend data indicating potentially important differences in the pathobiology of these 2 bacterial species.

Adult↗
PubMed2001

Persistent Chlamydiae and chronic arthritis.

Urogenital infection with Chlamydia trachomatis can lead to development of an acute inflammatory arthritis, and this acute disease becomes chronic in some individuals. Research indicates that the organism is present in synovial tissue of patients with chronic disease in a persistent, rather than an actively growing, form. Importantly, metabolic and other characteristics of persistent Chlamydia differ from those of actively growing bacteria. Other studies suggest that Chlamydia pneumoniae can be found in a persistent state in the synovium and that it too may be involved in joint pathogenesis. These and other observations suggest a more complex role for the Chlamydiae in joint disease than previously recognized. This realization should engender a realignment of thinking among clinicians and researchers concerning both mechanisms of chlamydial pathogenesis in the synovium and design of new treatments for the disease.

Arthritis, Infectious↗
PubMedDate not supplied

The load of Chlamydia pneumoniae in the Alzheimer's brain varies with APOE genotype.

Studies from this laboratory have indicated that the intracellular eubacterial respiratory pathogen Chlamydophila (Chlamydia) pneumoniae is commonly found in brain regions displaying characteristic neuropathology in patients with late-onset Alzheimer's disease (AD) but not in congruent samples from non-AD control individuals. In later work, we provided evidence suggesting that some relationship exists between the APOE epsilon4 gene product and the pathobiology of this organism. In the present report, in situ hybridization analyses indicated that the number of C. pneumoniae-infected cells in affected brain regions of epsilon4-bearing AD patients was higher overall than that in congruent brain regions from AD patients lacking that allele. Quantitative real-time PCR analyses of AD brain tissue samples demonstrated that actual bacterial burden in those samples varied over several orders of magnitude, but that samples from epsilon4-bearing patients did have significantly higher bacterial loads than did congruent samples from patients without the allele (ANOVA, p<0.05). These results may explain in part the observations that epsilon4-bearing individuals have a higher risk of developing AD, and that such patients progress more rapidly to cognitive dysfunction than do individuals lacking this allele.

Aged↗