Rheumatic fever.

Rheumatic fever is a multisystem inflammatory disease that occurs as a delayed sequel to group A streptococcal pharyngitis. It is less common than it was 50 years ago but is still a major cause of heart disease in developing areas of the world. The relationship between the site of infection, the type of causative organism, and susceptibility of the host is essential in the development of the disease. Its major clinical manifestations include carditis, migratory polyarthritis, chorea, erythema marginatum, and subcutaneous nodules. It can manifest as an acute febrile illness consisting of migratory polyarthritis involving the large joints, as carditis and valvulitis, or as Sydenham's chorea with involvement of the central nervous system. The disorder in its milder form resolves itself without sequelae. Carditis is the condition most associated with increased mortality and morbidity and may be fatal in its severe forms. Penicillin is the most appropriate primary and secondary prophylaxis. Anti- inflammatory agents provide symptomatic relief but do not prevent rheumatic heart disease.

A molecular beacon strategy for the thermodynamic characterization of triplex DNA: triplex formation at the promoter region of cyclin D1.

We studied the formation of triplex DNA in the purine-pyrimidine-rich promoter site sequence of cyclin D1, located at -116 to -99 from the transcription initiation site, with a molecular beacon comprised of a G-rich 18-mer triplex forming oligodeoxyribonucleotide. Formation of triplex DNA was monitored by enhanced fluorescence of the beacon, due to the weakening of fluorescence energy transfer, upon its binding to the target duplex. Electrophoretic mobility shift assay confirmed triplex DNA formation by these oligonucleotides. In low salt buffer (10 mM Na(+)), triplex DNA formation was not observed in the absence of a ligand such as spermine. At room temperature (22 degrees C), the equilibrium association constant (K(a)) calculated in the presence of 1 microM spermine and 10 mM Na(+) was 3.2 x 10(8) M(-1). The K(a) value was 1.0 x 10(9) M(-1) in the presence of 150 mM Na(+), and it increased by 10-fold by the addition of 1 mM spermine. Delta H, Delta S, and Delta G of triplex DNA formation, calculated from the temperature dependence of K(a) in the range of 20--45 degrees C, were -35.9 kcal/mol, -77 cal/(mol.K), and -13 kcal/mol, respectively, in the presence of 150 mM NaCl. The corresponding values were -52.9 kcal/mol, -132.5 cal/(mol.K), and -13.4 kcal/mol in the presence of 150 mM NaCl and 1 mM spermine. Structurally related polyamines exerted different degrees of triplex DNA stabilization, as determined by binding constant measurements. Comparison of spermine versus hexamine showed a 17-fold increase in the equilibrium association constant, whereas bis(ethyl) derivatization lead to a 4-fold decrease of this value. In the absence of added duplex and polyamines, the molecular beacon dissociated with a melting temperature of 67 degrees C. Thermodynamic parameters of beacon melting were calculated from the melting curve, and the Delta H, Delta S, and Delta G values were 37.8 kcal/mol, 112 cal/(mol.K), and 4.4 kcal/mol, respectively. These results demonstrate that molecular beacons can be used for the direct determination of the equilibrium association constants and thermodynamic parameters of triplex DNA formation in the presence of ligands such as polyamines.

Use of serum immune complexes in a new test that accurately confirms early Lyme disease and active infection with Borrelia burgdorferi.

The present recommendation for serologic confirmation of Lyme disease (LD) calls for immunoblotting in support of positive or equivocal ELISA. Borrelia burgdorferi releases large quantities of proteins, suggesting that specific antibodies in serum might be trapped in immune complexes (ICs), rendering the antibodies undetectable by standard assays using unmodified serum. Production of ICs requires ongoing antigen production, so persistence of IC might be a marker of ongoing or persisting infection. We developed an immunoglobulin M (IgM) capture assay (EMIBA) measuring IC-derived IgM antibodies and tested it using three well-defined LD populations (from an academic LD referral center, a well-described Centers for Disease Control and Prevention (CDC) serum bank, and a group of erythema migrans patients from whose skin lesions B. burgdorferi was grown) and controls (non-Lyme arthritis inflammatory joint disease, syphilis, multiple sclerosis, and nondisease subjects from a region where LD is endemic, perhaps the most relevant comparison group of all). Previous studies demonstrated that specific antigen-antibody complexes in the sera of patients with LD could be precipitated by polyethylene glycol and could then be disrupted with maintenance of the immunoreactivity of the released antibodies, that specific anti-B. burgdorferi IgM was concentrated in ICs, and that occasionally IgM to specific B. burgdorferi antigens was found in the IC but not in unprocessed serum. EMIBA compared favorably with commercial and CDC flagellin-enhanced enzyme-linked immunosorbent assays and other assays in confirming the diagnosis of LD. EMIBA confirmed early B. burgdorferi infection more accurately than the comparator assays. In addition, EMIBA more accurately differentiated seropositivity in patients with active ongoing infection from seroreactivity persisting long after clinically successful antibiotic therapy; i.e., EMIBA identified seroreactivity indicating a clinical circumstance requiring antibiotic therapy. Thus, EMIBA is a promising new assay for accurate serologic confirmation of early and/or active LD.

Lyme disease: a clinical update.

With adequate attention to specifics and details, the diagnosis and management of Lyme disease are usually relatively straight-forward. Still, there can be subtleties--for instance, in determining precisely what pathogen a tick bite transmitted, whether a patient's arthralgia is truly Lyme arthritis, or whether "positive" serologies represent refractory Lyme disease.

H9724, a monoclonal antibody to Borrelia burgdorferi's flagellin, binds to heat shock protein 60 (HSP60) within live neuroblastoma cells: a potential role for HSP60 in peptide hormone signaling and in an autoimmune pathogenesis of the neuropathy of Lyme disease.

Although Borrelia burgdorferi, the causative agent of Lyme disease, is found at the site of many disease manifestations, local infection may not explain all its features. B. burgdorferi's flagellin cross-reacts with a component of human peripheral nerve axon, previously identified as heat shock protein 60 (HSP60). The cross-reacting epitopes are bound by a monoclonal antibody to B. burgdorferi's flagellin, H9724. Addition of H9724 to neuroblastoma cell cultures blocks in vitro spontaneous and peptide growth-factor-stimulated neuritogenesis. Withdrawal of H9724 allows return to normal growth and differentiation. Using electron microscopy, immunoprecipitation and immunoblotting, and FACS analysis we sought to identify the site of binding of H9724, with the starting hypotheses that the binding was intracellular and not identical to the binding site of II-13, a monoclonal anti-HSP60 antibody. The current studies show that H9724 binds to an intracellular target in cultured cells with negligible, if any, surface binding. We previously showed that sera from patients with neurological manifestations of Lyme disease bound to human axons in a pattern identical to H9724's binding; these same sera also bind to an intracellular neuroblastoma cell target. II-13 binds to a different HSP60 epitope than H9724: II-13 does not modify cellular function in vitro. As predicted, II-13 bound to mitochondria, in a pattern of cellular binding very different from H9724, which bound in a scattered cytoplasmic, nonorganelle-related pattern. H9724's effect is the first evidence that HSP60 may play a role in peptide-hormone-receptor function and demonstrates the modulatory potential of a monoclonal antibody on living cells.

Molecular biology and immunology for clinicians, 14: Antigen presenting cells--Class II.

Pivotal to immunity and auto-immunity is the ability of the human immune response to make antigen-specific responses, both cellular and humoral. T- and B-cells contain within themselves the ability to recognize and react to specific antigens, but they must be made aware of the presence of their target in the surrounding environment to respond. Turns out this part of the education of T-cells (not B-cells, which are activated by specific antigens in a different manner) is provided by a large number of cells, all coming under the umbrella term: antigen-presenting cells. Understanding how these cells take up molecules from the environment or acquire protein molecules from the intracellular milieu, manipulate them, and then offer the modified material to engage potentially responding cells in an immunological educational conversation is crucial to understanding normal immune function and, of course, auto-immunity and other forms of immune dysregulation. In the broadest of terms, there are two sources of proteins: endogenous (produced within the cell) and exogenous (produced outside of the cell), and there are two not entirely mutually exclusive pathways involved in antigen processing and presentation. To decrease confusion between these two separate pathways antigens, I will proceed with a description of the latter in this paper and cover the former in the next paper in this series. So, now on to antigen processing and presentation of proteins.

Molecular biology and immunology for clinicians 15: Antigen presenting cells--class I.

Class I-bearing antigen presenting cells (APCs) monitor intracellular proteins which are cellular proteins made on a routine basis, endogenous proteins made by stressed cells, proteins made by infected or transformed cells, or proteins made by intracellular pathogens, e.g., viruses, chlamydiae, mycoplasma, Listeria, and some Enterobacteriaceae. The mechanisms by which peptides interact with and are expressed by class I complexes on the surface of APCs is described and contrasted with the circumstances of class II antigen presentation.

The role of catastrophizing in the pain and depression of women with fibromyalgia syndrome.

OBJECTIVE: Although 2 recent studies have found associations between catastrophizing and poor medical outcomes in patients with fibromyalgia syndrome (FMS), neither assessed these findings in comparison with a similar group of patients with chronic pain. Our study examined the complex relationships between depression, catastrophizing, and the multidimensional aspects of pain in women with FMS and compared these relationships with those in women with rheumatoid arthritis (RA). METHODS: Sixty-four FMS patients and 30 RA patients completed the Coping Strategies Questionnaire (CSQ), the Beck Depression Inventory II (BDI-II), and the McGill Pain Questionnaire. RESULTS: Compared with subjects with RA, FMS subjects scored significantly higher on the catastrophizing subscale of the CSQ. FMS patients also earned higher scores on overall depression and on the cognitive subscale of the BDI-II. Furthermore, the relationship between catastrophizing and depression was significant in the FMS group only. Regression analyses revealed that in FMS, catastrophizing as a measure of coping predicted patients' perception of pain better than demographic variables such as age, duration of illness, and education. CONCLUSION: Cognitive factors, such as catastrophizing and depressive self-statements, have a more pronounced role in the self-reported pain of patients with FMS than in patients with RA. Clinically, this indicates that treating pain and depression in FMS by adding cognitive therapy and coping skills components to a comprehensive treatment program may improve the outcomes obtained with pharmacologic interventions.

Immune complexes from serum of patients with lyme disease contain Borrelia burgdorferi antigen and antigen-specific antibodies: potential use for improved testing.

We report sequestration of specific IgM anti-Borrelia burgdorferi (Bb) and Bb antigens within immune complexes (ICs) isolated from serum of patients with Lyme disease (LD). The relative enrichment in specific IgM measured by ELISA was apparent, even after correcting for differences in total IgM concentration in serum versus ICs. Immunoblot demonstrated that ICs contained antibodies against specific Bb proteins, whereas reactivity was absent or significantly lessened in unprocessed serum. This is the first study to show ICs containing Bb antigen identified by immunoblot with anti-Bb monoclonal antibody. ICs may be a useful source of antigen and antibody for development of more-accurate testing for LD.

Detection of multiple reactive protein species by immunoblotting after recombinant outer surface protein A lyme disease vaccination.

Laboratory confirmation of the diagnosis of Lyme disease is based on the detection of an immune response to Borrelia burgdorferi. The serodiagnosis of B. burgdorferi infection is complex and may be further confounded by the immune response to the recombinant outer surface protein A (OspA) Lyme disease vaccine. To describe how the serological response to the recombinant OspA Lyme disease vaccine affects testing for antibody to B. burgdorferi, 240 specimens from 80 study subjects were obtained at defined intervals after recombinant OspA Lyme disease vaccination. Samples were tested by indirect enzyme-linked immunosorbent assay (ELISA), antibody capture enzyme immunoassay (EIA), and Western blotting (WB). After recombinant OspA Lyme disease vaccination, ELISA for 98% of the study subjects revealed reactivity. WB with use of OspA-containing B. burgdorferi strains as sources of antigens demonstrated multiple bands. Results of testing with a US Food and Drug Administration-approved WB kit showed homogeneous reactivity in the molecular weight region >30 kDa. Testing with OspA-free strains completely eliminated all vaccine-associated reactivity by both antibody capture EIA and WB.

Molecular biology and immunology for clinicians, 12: T-cell co-stimulatory molecules.

T-cells are activated by their interaction with antigen-presenting cells. Antigen-presenting cells process and then express peptide fragments of the target protein in a complex with self-proteins known as major histocompatibility complex (MHC) proteins on the antigen-presenting cells' surface. However, the interaction of T-cell with antigen on the antigen-presenting cell is not sufficient to elicit T-cell activation. The T-cell must receive a second signal from the antigen-presenting cell. These "co-stimulatory signals" are mediated by other proteins on the antigen-presenting cell surface that interact with T-cell surface proteins other than the antigen receptor, the protein complex receiving the peptide fragment's specific antigen signal. Some of these co-stimulatory proteins are constitutively expressed, some are up-regulated during an immune response; some interactions stimulate activation, some suppress it. Thus, these receptor-ligand protein pairs represent new sites for blockade of immune responses in immunologically-mediated diseases, like rheumatoid arthritis, lupus, and transplant graft rejection.

Antibiotics for the treatment of rheumatologic syndromes.

Design of rational therapy depends on knowledge of the causes of the disease, which is knowledge often lacking in rheumatology. There have been theories of infectious causes of many rheumatologic diseases but no proof. The seductive possibility of an infectious etiology has led to the use of antibiotics for treating these diseases. This article reviews the effectiveness of antibiotics against rheumatologic syndromes, including rheumatoid arthritis and Lyme disease.

Activation of nuclear factor kappaB by polyamines in breast cancer cells.

Polyamines-putrescine, spermidine, and spermine-are involved in the growth of breast cancer cells. A possible target of polyamine action is at the site of interaction of transcription factors with their response elements. NF-kappaB is a member of the rel family of transcription factors that regulate transcription of genes in the proliferative/anti-apoptotic pathways. We performed electrophoretic mobility shift assays to study the role of polyamines in NF-kappaB binding to NF-kappaB response elements (NREs), the consensus sequence of which is GGGGAATTCCCC. Using cellular extract from MCF-7 breast cancer cells, we found very little binding of NF-kappaB to NRE in the absence of polyamines. Addition of 1 mM spermidine or spermine caused a 4- and 6-fold increase in NF-kappaB-NRE binding, respectively. Putrescine induced a 2-fold increase in the binding at 2 mM concentration. Using antibody supershift assays, we identified the p50 subunit of NF-kappaB to be a major component in NF-kappaB-NRE complex formation in the presence of polyamines. However, the decreased intensity of the band corresponding to NF-kappaB-NRE complex in the presence of anti-p65, c-rel, relB and p52 antibodies suggested the participation of these subunits also. Spermine also stimulated NF-kappaB-NRE binding using cellular extracts from other breast cancer cell lines and a normal breast epithelial cell line. A differential effect of spermine analogues on NF-kappaB-NRE binding was observed, with spermine exerting the maximal effect. CD spectra of NRE containing oligonucleotides was asymmetric and distinct from that of a typical B-DNA CD spectrum. A concentration-dependent increase in T(m) of the duplex NRE was seen in the presence of polyamines. In transient transfection experiments using an NF-kappaB driven secreted alkaline phosphatase (SEAP) reporter, spermine induced NF-kappaB activity by approximately 2-fold as compared to controls. Spermine induced activation of NF-kappaB was also confirmed using an NF-kappaB-EGFP (enhanced green fluorescent protein) vector in transient transfections in which expression of the green fluorescent protein was visualized by fluorescence microscopy. These data show a gene regulatory function of polyamines involving enhanced binding of NF-kappaB to NRE and a possible mechanism for the action of polyamines in breast cancer cell proliferation.

Facilitation of the cellular uptake of a triplex-forming oligonucleotide by novel polyamine analogues: structure-activity relationships.

The inefficient uptake of oligodeoxynucleotides, including that of TFO, through the cell membrane is a limiting factor in developing gene therapy approaches for cancer and other diseases. To develop a new strategy for oligonucleotide delivery into the nucleus, we synthesized a series of novel polyamine analogues and examined their effects on the uptake of a 37-mer [32P]-labeled TFO, targeted to the promoter region of c-myc oncogene. We used MCF-7 breast cancer cells to investigate the efficacy of polyamines on the internalization of the TFO. The uptake of TFO was enhanced by complexing it with several unsubstituted polyamine analogues at 0. 1-5 microM concentrations, with up to 6-fold increase in TFO uptake in the presence of a hexamine, 1,21-diamino-4,9,13, 18-tetraazahenicosane (H2N(CH2)(3)NH(CH2)(4)NH(CH2)(3)NH(CH2)(4)NH(CH2)(3)NH(2) or 3-4-3-4-3). TFO uptake increased with the cationicity of the polyamines; however, bis(ethyl) substitution and structural features of the methylene bridging region had significant effects on TFO uptake. The majority of labeled TFO was recovered from the nuclear fraction containing genomic DNA. Electrophoretic mobility shift assay revealed enhanced binding of TFO to a target duplex containing promoter region sequence of c-myc oncogene. Treatment of MCF-7 cells with the TFO complexed with 0.5 microM 3-4-3-4-3 suppressed c-myc mRNA level by 65%, as determined by Northern blot analysis. These data indicate a novel approach to deliver oligodeoxynucleotides to the cell nucleus, and suppress the expression of target genes, and provide new insights into the mechanism of oligonucleotide transport in living cells.