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P Toivanen

Publications and source records attributed to P Toivanen.

At least 127 records · Page 7Linked to original sources
PubMed1993

The putative arthritogenic cationic 19-kilodalton antigen of Yersinia enterocolitica is a urease beta-subunit.

The gene coding for a putative 19-kDa arthritogenic antigen of Yersinia enterocolitica O:3 (A. K. H. Mertz et al., J. Clin. Invest. 87:632-642, 1991) was cloned and sequenced after amplification of part of the gene by the polymerase chain reaction using degenerate primers, inferred from the amino acid sequence. The deduced amino acid sequence of the antigen showed similarity to small subunits of ureases from several different organisms, including the jack bean urease. Screening of a genomic library of Y. enterocolitica O:3 with a 19-kDa-antigen-specific DNA probe allowed recombinant clones containing the entire urease operon to be obtained. These clones expressed urease activity in Escherichia coli.

Amino Acid Sequence↗
PubMed1993

Yersinia associated arthritis in SHR rats: effect of the microbial status of the host.

Following the intravenous injection of live Yersinia enterocolitica O:8, 50-69% of SHR rats developed arthritis; these rats were antibody free against all rat pathogens tested. In contrast, only 20-25% of SHR rats which had serum antibodies against Bacillus piliformis, Kilham rat virus, and Toolan H-1 virus developed arthritis. The results indicate that the microbial load of the host has a profound effect on the susceptibility to experimental arthritis.

Animals↗
PubMed1993

Detection of cytomegalovirus DNA in cells from synovial fluid and peripheral blood of patients with early rheumatoid arthritis.

OBJECTIVE: To study the role of cytomegalovirus (CMV) in the etiology of rheumatoid arthritis (RA). METHODS: Polymerase chain reaction (PCR), immunoperoxidase staining for CMV specific antigens, virus isolation and antibody assays were applied to study samples from patients with RA of less than one year's duration. RESULTS: By PCR, CMV DNA was detected in granulocytes from 3 of 24 synovial fluid (SF) samples and in 10 of 43 peripheral blood samples of patients with RA. These figures are not significantly different from those observed for the control groups (reactive arthritis, other arthropathies, healthy individuals). By immunoperoxidase staining, no evidence for the CMV antigens was observed in the SF cells. All the virus isolations were negative, and the level of CMV specific circulating antibodies in RA was not different from that in the other groups. CONCLUSION: In spite of the negative results, the potential role of CMV in the etiology of RA cannot be totally excluded on the basis of these results; the mutual contribution of the triggering agent and the host response in genetically susceptible individuals is discussed.

Adult↗
PubMed1992

Yersinia-triggered reactive arthritis. Use of polymerase chain reaction and immunocytochemical staining in the detection of bacterial components from synovial specimens.

OBJECTIVE: To investigate whether microbial DNA is present in synovial specimens from patients with Yersinia-triggered reactive arthritis. METHODS: Synovial specimens from 13 patients with Yersinia enterocolitica O:3-triggered reactive arthritis and from 16 control patients were studied using polymerase chain reaction and immunocytochemical staining techniques. RESULTS: Yersinia chromosomal DNA was not found in any of the synovial specimens from Yersinia-triggered arthritis patients or controls, whereas with immunocytochemical techniques, Yersinia antigens were observed in synovial specimens from all of the patients with Yersinia-triggered reactive arthritis. CONCLUSION: Only stable bacterial degradation products, not whole bacteria, are present at the site of inflammation in Yersinia-triggered reactive arthritis.

Adult↗
PubMed1992

Salmonella specific antibodies in serum and synovial fluid in patients with reactive arthritis.

The occurrence of Salmonella specific antibodies was analysed in paired serum and synovial fluid samples from 12 patients with Salmonella triggered reactive arthritis. The antibody concentration of IgA2 subclass in synovial fluid exceeded that of serum in 8 of the 12 pairs studied, compared to 0-3 in the other immunoglobulin classes and subclasses. This finding indicates intra-articular production of IgA2 class antibodies against the triggering microbe.

Adult↗
PubMed1992

Molecular mimicry in the pathogenesis of spondyloarthropathies. A critical appraisal of cross-reactivity between microbial antigens and HLA-B27.

We describe an amino acid homology between a virulence plasmid encoded outer membrane protein of Yersinia, YadA (previously called Yop1) and HLA-B27. This tetrapeptide is also included in the hexapeptide, earlier found to be identical between Klebsiella nitrogenase and HLA-B27. The synthetic peptide based on the HLA-B27 homologous portion of the YadA does not stimulate lymphocytes obtained from HLA-B27+ patients with Yersinia-triggered reactive arthritis or from controls. One-third of the yersiniosis patients have antibodies against the synthetic peptide. Instead of recognizing the HLA-B27 homologous portion, the antibodies are directed against the left flanking sequence of the synthetic peptide. Similar results were obtained regarding antibody response to Klebsiella nitrogenase derived synthetic peptide included in the panel of controls; the response was not restricted to patients with reactive arthritis nor was it specifically directed against the sequence shared by HLA-B27 and Klebsiella pneumoniae nitrogenase. The present results do not support the role of molecular mimicry or cross-reactive antibodies in the pathogenesis of spondyloarthropathies.

Adult↗
PubMed1992

Involvement of the avian mu heavy chain in recolonization of the bursa of Fabricius.

In the chicken, the B cells develop in a specialized organ, the bursa of Fabricius. Earlier it was shown that neonatal bursal cells treated with polyclonal anti-chicken immunoglobulin antibodies are not able to recolonize the bursa when transferred into cyclophosphamide-treated chicks. In this study, 4-day-old bursal cells were treated with different polyclonal and monoclonal anti-immunoglobulin antibodies and transferred into 4-day-old cyclophosphamide-treated chickens. Two monoclonal anti-chicken IgM antibodies, CVI-59.7 and 21-2B2, recognizing distinct epitopes of the mu heavy chain, were inhibitory. Incubation of cells with 21-2B2 antibody caused about 90% inhibition of bursal recolonization. After incubation with CVI-59.7 antibody the inhibition was 50%. The high inhibition by 21-2B2 antibody was also seen when F(ab')2 fragments of the antibody were used. These results suggest that the entry of the cells needed for bursal recolonization is inhibited almost totally by 21-2B2 antibody, or that this antibody blocks further proliferation of the cells in bursal follicles. In conclusion, we have shown that a mu heavy chain epitope is intimately involved in the recolonization of bursal follicles, and distinct epitopes of the mu heavy chain are not equally important in this process.

Animals↗
PubMed1992

Lipopolysaccharide O side chain of Yersinia enterocolitica O:3 is an essential virulence factor in an orally infected murine model.

The rfb gene cluster of Yersinia enterocolitica O:3, responsible for the biosynthesis of the O side chain, was previously cloned, and a Y. enterocolitica O:3 side chain-specific bacteriophage (phi YeO3-12) was isolated (A. Al-Hendy, P. Toivanen, and M. Skurnik, Microb. Pathog. 10:47-59, 1991). This paper describes the isolation and characterization of the bacteriophage phi YeO3-12-resistant mutant of Y. enterocolitica O:3, YeO3-R2. Lipopolysaccharide isolated from YeO3-R2 lacked the O side chain, as evidenced by silver staining and by immunoblots probed with a Y. enterocolitica O:3 O side chain-specific monoclonal antibody. The core was complete, as shown in immunoblots probed with an outer core-specific monoclonal antibody. In Southern blotting with the cloned Y. enterocolitica O:3 rfb region as a probe, there was no detectable difference in the hybridization pattern of chromosomal DNA isolated from YeO3-R2 and that isolated from wild-type Y. enterocolitica O:3. This suggests that a point mutation, rather than a large deletion, was responsible for the rough phenotype of YeO3-R2. The virulence of YeO3-R2 was determined in an orally infected desferal-attenuated murine model. The mutant was approximately 50-fold less virulent than the isogenic wild type. The ability of YeO3-R2 to reexpress O side chain, and hence full virulence, was reconstituted by complementing the chromosomal mutation in trans with the distal 6.5 kb of the Y. enterocolitica O:3 rfb region. This same 6.5-kb fragment transcomplemented a transposon mutation in the same area of the Y. enterocolitica O:3 rfb region when expressed in Escherichia coli. This transcomplementation implies that the rfb region of Y. enterocolitica O:3 is organized into at least two separate operons.

Animals↗
PubMed1992

LcrF is the temperature-regulated activator of the yadA gene of Yersinia enterocolitica and Yersinia pseudotuberculosis.

The virulence plasmid of human pathogenic Yersinia species, pYV, encodes secreted proteins, Yop proteins, and an outer membrane protein, YadA. YadA has been associated with binding to a variety of substrates and with interference with host defense. YadA is regulated by temperature and is expressed only at 37 degrees C. Unlike the yop regulon, the yadA gene is not under Ca2+ regulation. Here, we show that LcrF (VirF), the temperature-regulated activator of the yop regulon, also acts as an activator for yadA.

Bacterial Outer Membrane Proteins↗
PubMed1992

Long term follow up of SHR rats with experimental yersinia associated arthritis.

One hundred and one SHR rats were injected intravenously with live Yersinia enterocolitica O:8. The rats were randomly divided into two groups consisting of 48 and 53 rats. The group of 48 rats was monitored for 245 days to establish the incidence and the clinical features of the arthritis. The remaining 53 rats were killed in groups of three to five rats at intervals from four to 245 days after inoculation to examine the clearance of bacteria and the development of histological changes in the synovial membrane. Arthritis developed in 23/48 (48%) rats at seven to 27 days after inoculation. The arthritis subsided in most rats within four weeks, without leading to ankylosis of the affected joints. The arthritis was prolonged in three rats and recurrent in two. In the group of 53 rats Yersinia enterocolitica O:8 was cleared from most of the internal organs by day 77, but persisted in the inguinal lymph nodes in many of the rats up to day 245. All macroscopically arthritic joints showed clear histological signs of non-suppurative synovitis. No histological synovitis was detected in those joints observed macroscopically to be non-arthritic. Yersinia associated arthritis in SHR rats provides a potential model for reactive arthritis. There are strong similarities in the course of the arthritis and histopathological changes in the synovium between this animal model and reactive arthritis in humans. This study supports the association between poor elimination of the causative agent and the development of arthritis.

Animals↗
PubMed1991

Application of the polymerase chain reaction and immunofluorescence techniques to the detection of bacteria in Yersinia-triggered reactive arthritis.

Leukocytes in synovial fluid and peripheral blood samples from patients with Yersinia-triggered reactive arthritis were analyzed after DNA amplification using the polymerase chain reaction. The primers applied were specific for the virulence plasmid-coded 1crE genes of Yersinia enterocolitica O:3 and Yersinia pseudotuberculosis III. No Yersinia DNA was observed within the synovial fluid cells or peripheral blood cells by polymerase chain reaction techniques. However, Yersinia antigens were detected in the synovial fluid cells by immunofluorescence techniques. These results suggest that only parts of the causative agents, not the entire microbe, can enter the joint and initiate the inflammation that leads to a reactive arthritis.

Adolescent↗
PubMed1991

Antibodies to arthritis-associated microbes in inflammatory joint diseases.

IgM, IgG and IgA class antibodies against Yersinia, Salmonella, Campylobacter and Borrelia were determined by enzyme-linked immunosorbent assay (ELISA) in a group of 340 unselected patients with a recent inflammatory joint disease. The control group consisted of 340 and 100 healthy blood donors using Borrelia-ELISA and other ELISAs, respectively. Of all the patients, 27.4% had increased antibody levels against at least one of the microbes tested. The prevalence of positive antibody levels was highest in Yersinia antibodies (17.9%). The corresponding figures for Salmonella, Campylobacter and Borrelia were 7.0, 6.2 and 1.8%, respectively. Patients with entero-arthritis or clinically typical reactive arthritis who had not had gastrointestinal or urogenital symptoms previously had the highest prevalence of the microbial antibodies (67.6 and 40.7%, respectively). These findings indicate that arthritis may often have a reactive etiopathogenesis without recognized gastrointestinal infection, emphasizing the importance of microbial serology in the differential diagnosis.

Antibodies, Bacterial↗
PubMed1991

Expression cloning of Yersinia enterocolitica O:3 rfb gene cluster in Escherichia coli K12.

The genes of Yersinia enterocolitica serotype O:3 (YeO3) that determine the synthesis of the O-side-chain of the lipopolysaccharide, the rfb region, were cloned into plasmid pBR322. The O-side-chain of YeO3 was expressed by the clone both in Escherichia coli and Salmonella typhimurium indicating that the entire rfb region was included in the clone. It was shown by restriction mapping, deletion analysis and transposition mutagenesis that about 10.4 kilobase pairs of DNA was essential for the synthesis and expression of the O-side-chain. The correct assembly of the O-side-chain on the cell surface of the clone was confirmed by immunofluorescence microscopy and slide agglutination. Immunoblotting using monoclonal antibody specific for the O-side-chain of YeO3 revealed that the O-side-chain material synthesized by the clone in E. coli was similar to that of YeO3. The clone did not show the in vitro temperature variation in O-side-chain expression characteristic of YeO3. Instead analogous O-side-chain was produced both at 25 degrees C and at 37 degrees C. Using transposon Tn2507, which carries a promotorless chloramphenicol acetyltransferase (CAT) gene, transcriptional fusions with the target DNA were generated. When testing the ability of mutated clones to produce CAT, transcription was shown to occur in a uniform direction throughout the whole rfb region. In colony hybridizations, using the cloned insert as a probe, homologous DNA was detected only in pathogenic Y. enterocolitica serotypes.

Agglutination Tests↗
PubMed1991

The effect of growth temperature on the biosynthesis of Yersinia enterocolitica O:3 lipopolysaccharide: temperature regulates the transcription of the rfb but not of the rfa region.

The rfb region of Yersinia enterocolitica O:3 (YeO3) that determines the synthesis of the O-side chain of the lipopolysaccharide was cloned and expressed in Escherichia coli K12 previously. The clone did not show the in vitro temperature variation in O-side chain expression known for YeO3, instead analogous O-side-chain was produced at 25 degrees C and at 37 degrees C and both were similar to that produced by YeO3 at 25 degrees C. In Northern blot analysis marked reduction in the amount of rfb-specific mRNA was observed from YeO3 grown at 37 degrees C when compared with those grown at 25 degrees C. On the other hand, equal amounts of rfb-specific mRNA were detected in the E. coli clone at both growth temperatures. This indicates that the transcription of YeO3 rfb region is dramatically repressed at 37 degrees C. The repressor gene is located outside the rfb region with no analogous locus in E. coli chromosome. We cloned 18.2 kilobase pairs of YeO3 chromosomal DNA that rendered E. coli K12 reactive with 2B5, a YeO3 core-specific monoclonal antibody, in colony blotting, indirect immunofluorescence and immunoblotting. Hence this clone contains the YeO3 rfa region, encompassing the genes involved in the core oligosaccharide biosynthesis. No apparent difference, in the aforementioned tests, was noticed in the expression of the 2B5 epitope at different growth temperatures either in YeO3 or in E. coli. In Northern blot analysis comparable amounts of rfa-specific mRNA were detected at 25 degrees and 37 degrees C. This argues that in YeO3 the core oligosaccharide biosynthesis is not temperature-regulated.

Blotting, Northern↗
PubMed1991

Salmonella-specific antibodies in reactive arthritis.

The development and persistence of Salmonella-specific serum antibodies of different immunoglobulin classes and subclasses were compared between those who developed reactive arthritis (n = 39) and those who did not (n = 58) after Salmonella infection. Antibodies against lipopolysaccharide and SDS-extract antigen were measured by ELISA. A significant difference was seen between the two patient groups after 4-14 months of follow-up; those with reactive arthritis had higher levels of Salmonella-specific IgM, IgG, and IgA class antibodies than those without arthritis. In the increased antibody response, secretory IgA, IgA1, and IgG2 classes were especially well represented. The persisting antibody response is a common feature in reactive arthritis and supports persistence of the pathogen or its components in the host. The differences observed in antibody profiles between Salmonella- and Yersinia-triggered reactive arthritides suggest certain dissimilarities (e.g., in the location of persisting microbes) in the arthritogenic process due to these two microbes.

Adolescent↗
PubMed1991

Rapid method for isolation and staining of bacterial lipopolysaccharide.

Classically bacterial lipopolysaccharide (LPS) purification and silver staining take several days. We designed a simple and fast method for LPS isolation which when combined with silver staining using Pharmacia PhastSystem both can be completed in few hours. The purity of LPS isolated by this simple method may not be comparable to that by the phenol-water method hence we recommend this rapid isolation and staining procedures for simple and fast study of LPS patterns in gels.

Electrophoresis, Polyacrylamide Gel↗