Generation and differentiation of induced pluripotent stem cells reveal ankylosing spondylitis risk gene expression in bone progenitors.

Axial spondyloarthritis (axSpA), which encompasses ankylosing spondylitis, is a complex genetic disease. Aberrant bone formation is a key feature of pathogenesis that can lead to ankylosis of the spine. Our objective is to determine, whether genes whose variants confer susceptibility to AS are expressed in bone progenitors like mesenchymal stem cells (MSCs).

HLA-B27 misfolding and ankylosing spondylitis.

Understanding how HLA-B27 contributes to the pathogenesis of spondyloarthritis continues to be an important goal. Current efforts are aimed largely on three areas of investigation; peptide presentation to CD8T cells, abnormal forms of the HLA-B27 heavy chain and their recognition by leukocyte immunoglobulin-like receptors on immune effector cells, and HLA-B27 heavy chain misfolding and intrinsic biological effects on affected cells. In this chapter we review our current understanding of the causes and consequences of HLA-B27 misfolding, which can be defined biochemically as a propensity to oligomerize and form complexes in the endoplasmic reticulum (ER) with the chaperone BiP (HSPA5/GRP78).

HLA-B27 alters the response to tumor necrosis factor α and promotes osteoclastogenesis in bone marrow monocytes from HLA-B27-transgenic rats.

Objective: To determine whether HLA-B27 expression alters the response of bone marrow monocytes from HLA-B27/human β2 -microglobulin-transgenic (B27-Tg) rats to tumor necrosis factor α (TNFα) and, if so, whether this affects the cells involved in bone homeostasis.

Methods: Bone marrow monocytes were treated with RANKL or with TNFα to promote osteoclast formation. Osteoclasts were quantified by counting.

Immature cell populations and an erythropoiesis gene-expression signature in systemic juvenile idiopathic arthritis: implications for pathogenesis.

Introduction: Previous observations suggest that active systemic juvenile idiopathic arthritis (sJIA) is associated with a prominent erythropoiesis gene-expression signature. The aim of this study was to determine the association of this signature with peripheral blood mononuclear cell (PBMC) subpopulations and its specificity for sJIA as compared with related conditions.

Methods: The 199 patients with JIA (23 sJIA and 176 non-sJIA) and 38 controls were studied.

From HLA-B27 to spondyloarthritis: a journey through the ER.

Almost four decades of research into the role of human leukocyte antigen-B27 (HLA-B27) in susceptibility to spondyloarthritis has yet to yield a convincing answer. New results from an HLA-B27 transgenic rat model now demonstrate quite convincingly that CD8(+) T cells are not required for the inflammatory phenotype. Discoveries that the HLA-B27 heavy chain has a tendency to misfold during the assembly of class I complexes in the endoplasmic reticulum (ER) and to form aberrant disulfide-linked dimers after transport to the cell surface have forced the generation of new ideas about its role in disease pathogenesis.

HLA-B27 misfolding and spondyloarthropathies.

HLA-B27 plays a central role in the pathogenesis of many spondyloarthropathies and in particular ankylosing spondylitis. The observation that the HLA-B27 heavy chain has a tendency to misfold has raised the possibility that associated diseases may belong in a rapidly expanding category of protein misfolding disorders. The synthesis of the HLA-B27 heavy chain, assembly with beta2m and the loading of peptide cargo, occurs in the endoplasmic reticulum (ER) before transport to the cell surface.

HLA-B27 misfolding and spondyloarthropathies.

HLA-B27 plays a central role in the pathogenesis of many spondyloarthropathies and in particular ankylosing spondylitis. The observation that the HLA-B27 heavy chain has a tendency to misfold has raised the possibility that associated diseases may belong in a rapidly expanding category of protein misfolding disorders. The synthesis of the HLA-B27 heavy chain, assembly with beta(2)m and the loading of peptide cargo, occurs in the endoplasmic reticulum (ER) before transport to the cell surface.

The interleukin-23/interleukin-17 axis in spondyloarthritis.

Purpose Of Review: To inform readers of recent advances in our understanding of the development and function of Th17 T cells and emerging data suggesting that the interleukin-23/interleukin-17 axis may be involved in the pathogenesis of spondyloarthritis.

Recent Findings: The discovery of CD4+ Th17 T cells and the interleukin-23/interleukin-17 axis has challenged existing paradigms and the role of Th1 T cells in many autoimmune diseases. The development and cytokine profile of Th17 T cells differs in mice and humans.

Importance of murine study design for testing toxicity of retroviral vectors in support of phase I trials.

Although retroviral vectors are one of the most widely used vehicles for gene transfer, there is no uniformly accepted pre-clinical model defined to assess their safety, in particular their risk related to insertional mutagenesis. In the murine pre-clinical study presented here, 40 test and 10 control mice were transplanted with ex vivo manipulated bone marrow cells to assess the long-term effects of the transduction of hematopoietic cells with the retroviral vector MSCV-MGMT(P140K)wc. Test mice had significant gene marking 8-12 months post-transplantation with an average of 0.

Development and validation of a whole-cell inhibition assay for bacterial methionine aminopeptidase by surface-enhanced laser desorption ionization-time of flight mass spectrometry.

Bacterial methionine aminopeptidase (MAP) is a protease that removes methionine from the N termini of newly synthesized bacterial proteins after the peptide deformylase enzyme cleaves the formyl group from the initiator formylmethionine. MAP is an essential bacterial gene product and thus represents a potential target for therapeutic intervention. A fundamental challenge in the antibacterial drug discovery field is demonstrating conclusively that compounds with in vitro enzyme inhibition activity produce the desired antibacterial effect by interfering with the same target in whole bacterial cells.

Stem cell clonality and genotoxicity in hematopoietic cells: gene activation side effects should be avoidable.

Two serious adverse events involving activation of the LMO2 oncogene through retrovirus vector insertion in the otherwise extremely successful first gene therapy trial for X-linked severe combined immunodeficieny type 1 (SCID-X1) had initially caused widespread concern in the patient and research communities. Careful consideration 1 year after diagnosis of the second case still finds 12 of the treated patients clearly benefiting from gene therapy (freedom from treatment failure, 80%; survival 100%), a situation that should not portend the end of gene therapy for this disease, and is, in fact encouraging. While current approaches are justified to treat patients with otherwise life-threatening disorders, a broad consensus has developed that systematic basic research is required to further understand the pathophysiology of these serious adverse events and to provide new insights, enabling safer and more effective gene therapy strategies.

Effect of Australian tea tree oil on the viability of the wall-less bacterium Mycoplasma pneumoniae.

In vitro assays using a variety of essential oils revealed a particularly high antibacterial effect of Australian tea tree oil (TTO) on a great number of gram-negative and gram-positive bacteria of unrelated phylogenetic origin. In the present study, the susceptibility of cell wall-less bacteria such as the human pathogenic bacterium Mycoplasma pneumoniae to Australian tea tree oil was examined. The minimum inhibitory concentration (MIC) was determined to be 0.

Visualization of the attachment organelle and cytadherence proteins of Mycoplasma pneumoniae by immunofluorescence microscopy.

A method was developed for protein localization in Mycoplasma pneumoniae by immunofluorescence microscopy. The P1 adhesin protein was revealed to be located at least at one cell pole in all adhesive cells, as has been observed by immunoelectron microscopy. Cell images were classified according to P1 localization and assigned by DNA content.

Two cases of fulminant Mycoplasma pneumoniae pneumonia within 4 months.

We report the clinical course and diagnostic findings in two patients with life-threatening Mycoplasma pneumoniae (MP) pneumonia who were treated in the same hospital in the course of only 4 months. The patients were previously healthy adults, aged 31 and 37 years, respectively. In both of them severe complications occurred which coincided with the acute MP respiratory infection.

Evidence for infection with Chlamydia pneumoniae in a subgroup of patients with multiple sclerosis.

In a pilot study, we identified Chlamydia pneumoniae in the cerebrospinal fluid by polymerase chain reaction in 5 of 10 patients with definite multiple sclerosis (MS). In a second series, 2 of 20 patients with definite MS and 3 of 17 patients with possible/probable MS or MS variants, but none of 56 patients with other neurological, diseases were polymerase chain reaction-positive. We confirm that C.

Proteins complexed to the P1 adhesin of Mycoplasma pneumoniae.

Adherence of Mycoplasma pneumoniae to host cells requires several mycoplasmal membrane proteins and cytoskeleton-like proteins in addition to the adhesin P1, a transmembrane protein of 170 kDa. To analyse interactions of the P1 adhesin with other membrane proteins or with cytoskeleton-like proteins, cross-linking studies were performed in vivo using the permeant reagent paraformaldehyde. The cross-linked protein complex was isolated by immunoaffinity chromatography, and proteins complexed to the P1 protein were identified by immunoblot analysis followed by high mass accuracy tryptic peptide mapping using matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS).

The 40- and 90-kDa membrane proteins (ORF6 gene product) of Mycoplasma pneumoniae are responsible for the tip structure formation and P1 (adhesin) association with the Triton shell.

After Triton X-100 treatment of Mycoplasma pneumoniae cells, a portion of the adhesin P1 (transmembrane protein) proved to remain tightly associated with the Triton insoluble material (Triton shell) as shown previously by several authors. However, the spontaneous loss of two cytadherence-associated membrane proteins of 90 and 40 kDa (gene product of the open reading frame 6 of the P1 operon) in a hemadsorption-negative mutant, designated M5, resulted in a 100% release of the P1 protein into the Triton phase and in the lack of the characteristic tip-like attachment organelle of M. pneumoniae indicating an essential role of the open reading frame 6 gene product in tip structure formation.

The adhesin related 30-kDa protein of Mycoplasma pneumoniae exhibits size and antigen variability.

Mycoplasma pneumoniae is a pathogenic bacterium colonizing epithelial cells of the human respirator tract. Using an erythrocyte binding assay we isolated a cytadsorption negative mutant designated M7 which has lost 12 of a total of 13 repetitive sequences of a proline rich C-terminal region of the adhesin related 30-kDa protein. The truncated adhesin related protein of 22 kDa showed reduced antigenicity compared to the corresponding wild-type protein.

The proline-rich P65 protein of Mycoplasma pneumoniae is a component of the Triton X-100-insoluble fraction and exhibits size polymorphism in the strains M129 and FH.

Previously, we described the identification of a novel Mycoplasma pneumoniae M129 protein, named P65 because of its apparent molecular mass of 65 kDa estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (T. Proft and R. Herrmann, Mol.

A spontaneous hemadsorption-negative mutant of Mycoplasma pneumoniae exhibits a truncated adhesin-related 30-kilodalton protein and lacks the cytadherence-accessory protein HMW1.

A spontaneous, hemadsorption-negative mutant of Mycoplasma pneumoniae lacks the cytoskeleton-forming HMW1 protein and exhibits a truncated adhesin-related 30-kDa protein. Genetic analyses revealed deletion of one nucleotide in the hmw1 gene and loss of eight repeated sequences comprising 144 nucleotides in the gene for the adhesin-related 30-kDa protein.

Spatial arrangement of gene products of the P1 operon in the membrane of Mycoplasma pneumoniae.

The spatial arrangement of three P1 operon-encoded proteins--attachment protein P1 (ORF5 gene product) and the ORF6-derived proteins of 40 and 90 kDa--in the membrane of Mycoplasma pneumoniae M129 was investigated by nearest-neighbor analysis. For these studies, the homobivalent, thiol-cleavable, and nonmembrane-permeating cross-linking reagent 3,3'-dithiobis(sulfosuccinimidylpropionate) (DTSSP) was used. The cross-linked proteins were isolated by immunoprecipitation with antibodies directed against fusion proteins of selected regions of the 40-kDa, the 90-kDa, or the P1 protein.

The ORF6 gene product of the P1 operon of Mycoplasma pneumoniae.

The P1 attachment protein gene of Mycoplasma pneumoniae is flanked by two open reading frames with a coding capacity for two proteins of 28 kDa (ORF4) and 130 kDa (ORF6), respectively. An operon-like organization in the order ORF4-P1-ORF6 was proposed by Inamine et al. (11).