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PubMed1985

Antibodies to nRNP, Sm, Ro(SSA) and La(SSB) detected by ELISA: their specificity and inter-relations in connective tissue disease sera.

The profile of autoantibodies to four soluble cellular ribonucleoproteins nRNP, Sm Ro(SSA) and La(SSB) was determined using ELISA with immuno-affinity-purified antigens in a connective tissue disease population. Compared with immunodiffusion, results using ELISA showed greater sensitivity but lower specificity and low titres of antibodies were frequently found in the sera of patients with connective tissue diseases other than systemic lupus erythematosus. This was true even for antibodies to Sm which have been considered highly specific for SLE. Antibodies to these antigens were predominantly of the IgG class and were capable of fixing complement irrespective of the clinical context. As previously demonstrated by immunodiffusion strong associations between anti-nRNP and anti-Sm and between anti-Ro(SSA) and anti-La(SSB) were detected by ELISA, while antibodies to nRNP and to Ro(SSA) identify distinctive serological groups. The observation that certain antibodies are closely linked suggests a relationship between the immune responses to particular antigens, and this might be explained by biological links between the antigens.

Antibody Specificity↗
PubMed1997

Anti-Ro (SSA) and anti-La (SSB) antibodies and complete congenital heart block.

Complete congenital heart block (CCHB) is the most severe manifestation of neonatal lupus syndrome, associated with a mortality rate of up to 31%. It is caused by irreversible damage to the cardiac conduction system due to the transplacental passage of maternal antibodies to the fetus. Anti-Ro (SSA) and anti-La (SSB) antibodies are usually detected in sera of mothers of children with prenatally diagnosed CCHB and in cardiac tissues of affected newborns. Their pathogeneic role in the development of CCHB has been established in several studies. When CCHB is detected during pregnancy, careful monitoring and delivery are needed before heart failure is developed. Treatment strategies are debatable and may include prophylactic therapy for high-risk pregnant women and a combination of intrauterine plasmapheresis with plasma exchange or with corticosteroids. Pacemaker insertion is required in most infants during the first three months of life. Assays for anti-Ro (SSA) and anti-La (SSB) antibodies should be performed on sera of pregnant women with SLE and newborns with CCHB.

Antibodies↗
PubMed1992

Conjunctival epithelial cells from patients with Sjögren's syndrome inappropriately express major histocompatibility complex molecules, La(SSB) antigen, and heat-shock proteins.

The La(SSB) antigen has been detected within the cytoplasm and on the membrane of conjunctival cells (CC) from patients with Sjögren's syndrome, whereas it was weakly expressed in the nucleus of normal cells. The diseased CC were shown to overproduce major histocompatibility complex (MHC) class I antigens and express MHC class II antigens. Anti-heat-shock protein monoclonal antibody bound to the cell membrane in patients but not in normal controls.

Autoantigens↗
PubMed1999

Regulation of divergent transcription from the uvrA-ssb promoters in Sinorhizobium meliloti.

The Sinorhizobium meliloti uvrA gene was isolated by complementation of a Rhodobacter sphaeroides UvrA- mutant. DNA sequencing of the region upstream of the S. meliloti uvrA gene reveals the presence of the ssb gene in the opposite transcriptional orientation. PCR-mediated mutagenesis demonstrated that expression of these two genes is inducible by DNA damage, and depends, in both cases, on the direct repeat GTTCN7GTTC (cited according to the direction of uvrA transcription). Comparison of the sequences of recA and uvrA promoters from different bacterial species of the alpha group of the Proteobacteria has identified the direct repeat GTTCYYKTTTTGTTC as the SOS box in this phylogenetic group.

Adenosine Triphosphatases↗
PubMed2005

Application of SSB-like protein from Thermus aquaticus in multiplex PCR of human Y-STR markers identification.

Here, we demonstrate the application of SSB-like protein from Thermus aquaticus (TaqSSB) in multiplex PCR of human Y-STR markers identification. The use of thermostable TaqSSB prevents or reduces primer dimmer formation, one of the particular problems known to cause inhibition of primer hybridization to the template and reduction of a number of primers available for annealing in PCR reaction.

Bacterial Proteins↗
PubMed1981

Antinuclear antibody-negative systemic lupus erythematosus. I. Anti-Ro(SSA) and anti-La(SSB) antibodies.

Anti-Ro(SSA) and anti-La(SSB) antibodies are found in approximately 25% of systemic lupus erythematosus patients. These antibodies are also detected in lupus patients who fail to demonstrate a significant antinuclear antibody (ANA) titer when mouse liver is employed as the substrate. Approximately 5% to 10% of systemic lupus patients are in this category. These ANA-negative, Ro(SSA)-positive lupus patients generally demonstrate a prominent widespread photosensitive dermatitis and are frequently initially seen and evaluated by a dermatologist.

Antibodies, Antinuclear↗
PubMed2006

Improvements of rolling circle amplification (RCA) efficiency and accuracy using Thermus thermophilus SSB mutant protein.

Rolling circle amplification (RCA) of plasmid or genomic DNA using random hexamers and bacteriophage phi29 DNA polymerase has become increasingly popular in the amplification of template DNA in DNA sequencing. We have found that the mutant protein of single-stranded DNA binding protein (SSB) from Thermus thermophilus (Tth) HB8 enhances the efficiency of amplification of DNA templates. In addition, the TthSSB mutant protein increased the specificity of phi29 DNA polymerase. We have overexpressed the native and mutant forms of TthSSB protein in Escherichia coli and purified them to homogeneity. In vitro, these proteins were found to bind specifically to single-stranded DNA. Addition of TthSSB mutant protein to RCA halved the elongation time required for phi29 DNA polymerase to synthesize DNA fragments in RCA. Furthermore, the presence of the TthSSB mutant protein essentially eliminates nonspecific DNA products in RCA reactions.

Bacillus Phages↗
PubMed1988

Anti La(SSB) identifies a distinctive subgroup of systemic lupus erythematosus.

The relevance of antibodies for La(SSB) as a marker of a distinctive systemic lupus erythematosus (SLE) subset was studied in 185 lupus patients. Anti La was detected in 39 (21%) and was accompanied invariably by anti Ro. Clinically, anti La-positive patients were distinguished by a later age of disease onset, and a low frequency of lupus nephritis. In common with other anti Ro-positive patients they showed a high frequency of keratoconjunctivitis sicca. Anti La identified patients with higher titres of anti Ro antibodies and was significantly associated with HLA-DR3. Serological markers such as these are useful for identifying more homogeneous populations of SLE patients for studies of aetiology and pathogenesis.

Adult↗
PubMed1998

RecQ helicase, in concert with RecA and SSB proteins, initiates and disrupts DNA recombination.

RecQ helicase is important to homologous recombination and DNA repair in Escherichia coli. We demonstrate that RecQ helicase, in conjunction with RecA and SSB proteins, can initiate recombination events in vitro. In addition, RecQ protein is capable of unwinding a wide variety of DNA substrates, including joint molecules formed by RecA protein. These data are consistent with RecQ helicase assuming two roles in the cell; it can be (1) an initiator of homologous recombination, or (2) a disrupter of joint molecules formed by aberrant recombination. These findings also shed light on the function of the eukaryotic homologs of RecQ helicase, the Sgs1, Blm, and Wrn helicases.

Adenosine Triphosphatases↗
PubMed1993

Isolation of Brucella abortus ssb and uvrA genes from a genomic library by use of lymphocytes as probes.

Brucella abortus proteins from virulent S2308 expressed from a pBluescript II SK- genomic library stimulated peripheral blood mononuclear (PBM) cell proliferation from cattle vaccinated with B. abortus S19. The method described here permits a rapid and directed approach to isolate genes encoding antigens of B. abortus that interact with lymphocytes primed to the living bacterium. The supernatants from the bacterial host JM109 (DE3) were cultured with freshly isolated bovine PBM cells. A total of 300 clones were evaluated. Ten clones were identified that stimulated T-lymphocyte proliferation. Among them, one clone with a 2.5-kb insert stimulated T-lymphocyte proliferation in all three animals, suggesting that the proteins encoded by genes within this fragment may represent immunodominant antigens. DNA sequencing of this clone reveals two large open reading frames (ORFs). ORF II has a high degree of similarity to the Escherichia coli ssb gene, which codes for the single-stranded DNA binding protein. ORF I, in the opposite direction to ORF II, shows similarity to the N terminus of the E. coli uvrA gene, which codes for one of the three subunits of the E. coli ABC excision nuclease. The observation that the PBM cells recognized and proliferated in response to proteins expressed from single clones provides a novel strategy to select bacterial antigens that may prove useful in designing alternative vaccines against brucellosis.

Amino Acid Sequence↗
PubMed1992

Damage to the endothelium in Sjögren's syndrome: lack of correlation with antinuclear antibody titre and presence of antibodies to SSA or SSB autoantigens.

Serum levels of von Willebrand factor antigen (as an index of damage to the endothelium) and tissue antinuclear antibodies and antibodies to SSA (Ro) (which have been associated with vasculitis) and SSB (La) autoantigens were measured in patients with Sjögren's syndrome. Although high levels of all indices were recorded, there were no intercorrelations. This provides evidence that although tissue autoantibodies may be useful in confirming a diagnosis, they have no place in the pathological course of the disease and so may be an epiphenomenon.

Antibodies, Antinuclear↗
PubMed2004

Divergence of the mRNA targets for the Ssb proteins of bacteriophages T4 and RB69.

The single-strand binding (Ssb) protein of phage T4 (T4 gp32, product of gene 32) is a mRNA-specific autogenous translational repressor, in addition to being a sequence-independent ssDNA-binding protein that participates in phage DNA replication, repair and recombination. It is not clear how this physiologically essential protein distinguishes between specific RNA and nonspecific nucleic acid targets. Here, we present phylogenetic evidence suggesting that ssDNA and specific RNA bind the same gp32 domain and that plasticity of this domain underlies its ability to configure certain RNA structures for specific binding. We have cloned and characterized gene 32 of phage RB69, a relative of T4 We observed that RB69 gp32 and T4 gp32 have nearly identical ssDNA binding domains, but diverge in their C-terminal domains. In T4 gp32, it is known that the C-terminal domain interacts with the ssDNA-binding domain and with other phage-induced proteins. In translation assays, we show that RB69 gp32 is, like T4 gp32, an autogenous translational repressor. We also show that the natural mRNA targets (translational operators) for the 2 proteins are diverged in sequence from each other and yet can be repressed by either gp32. Results of chemical and RNase sensitivity assays indicate that the gp32 mRNA targets from the 2 related phages have similar structures, but differ in their patterns of contact with the 2 repressors. These and other observations suggest that a range of gp32-RNA binding specificities may evolve in nature due to plasticity of the protein-nucleic acid interaction and its response to modulation by the C-terminal domain of this translational repressor.

Amino Acid Sequence↗
PubMed1987

Fetal heart block, anti-SSA and anti-SSB antibodies. Association with intra-uterine growth retardation, fetal death and lupus anticoagulant.

A case of complete fetal heart block associated with intra-uterine growth retardation, SSA- and SSB-antibodies is presented. The fetus died in utero. Autopsy revealed damage to the fetal cardiac conducting system together with severe placental fibrosis and recent infarctions. These findings and a slightly prolonged activated partial thromboplastin time indicated also the presence of the lupus anticoagulant.

Adult↗
PubMed2000

Relationship between the occurrence of anti-SSA, anti-SSB autoantibodies and HLA class II alleles from the aspect of in vitro inhibitory effect of glucocorticosteroid on the antibody-dependent cellular cytotoxicity in patients with primary Sjögren's syndrome.

Though at present there is no evidence-based algorithm for the treatment of primary Sjögren's syndrome, it is generally accepted that glucocorticosteroid (GS) therapy must be introduced in cases with severe systemic manifestations. As the side-effects of the GSs are well known, it would be useful to know in advance how the patients will respond to this type of treatment. For this reason we measured the in vitro steroid sensitivity of 29 SS patients using inhibition of antibody dependent cellular cytotoxicity (ADCC) test by methylprednisolone compared to that of 28 controls. SS patients proved to be significantly less sensitive to GSs than controls (inhibition of ADCC reaction: 42.4 vs 53.1%; p < 0.01). This was especially true in SS patients with anti-SSA and/or SSB autoantibody positivity and with HLA-DR2 and/or -DR3 alleles. Comparing the results of the in vitro GS sensitivity and the clinical effectiveness of the previously applied corticosteroid therapy it seems that steroid inhibition of ADCC reaction has a predictive value in determination of in vivo sensitivity to GSs. However, in patients with decreased in vitro GS sensitivity a more expressed in vivo steroid sensitivity cannot be excluded.

Adult↗
PubMed2002

[Anti-SSA/Ro and anti-SSB/La antibodies. What's new?].

Anti-SSA/Ro and anti-SSB/La autoantibodies recognize different epitopes on polypeptides associated with small RNAs called scYRNA situated mostly in the cytoplasmic compartment (70%) and few in the nuclear compartment (30%). These hYRNPs (h=human) can be found on the cytoplasmic membrane or in small blebs during apoptosis after various stimuli such as UVB, 17-beta-estradiol, viral infection, TNF alpha and other cellular apoptosis inducing molecules. At least two major different proteins are called SSA/Ro: a 52 kDa Ro (with two subtypes alpha and beta) and a 60 kDa Ro. There is only one SSB/La protein of 48 kDa. In some circumstances, other proteins such as calreticuline (MW 57 kDa) join Ro/SSA proteins on some YRNAs. Anti-SSA/Ro antibodies are detected in the sera of 30% of patients with SLE, even during preclinical setting; anti-Ro/SSA are strongly associated (90%) with some subtypes of SLE such as old-onset (>50 y) SLE, subacute lupus erythematosus, drug-induced subacute lupus erythematosus and in patients with hereditary C2 or C4 or C1q deficiency with lupus or lupus-like disease. Anti-SSA/Ro are also associated with primary Sjögren syndrome (50% to 60%) and with undifferenciated connective tissue disease (UCTD). Anti-SSA/Ro antibodies are almost always present in sera of mothers with babies with neonatal lupus syndrome (NNL) and with complete congenital heart block (CCHB). This last event is very unusual in pregnant patients with anti-Ro/SSA antibodies (1% to 2% of primigeste women). Some good evidences such as experimental models in vitro or ex-vivo, argue for the responsibility of maternal anti-Ro/SSA 52 kDa and/or anti-La/SSB antibodies (or associated IgG antibodies) as major etiologic factor of CCHB and NNL. IgG anti-Ro 52 beta kDa has been shown able to interrupt the atrioventricular conduction as well as the L calcium channel influx of fetal cardiocytes. Other factors must be taken into account to explain discordant twins (with and without CCHB). More recently anti-Ro/SSA antibodies were associated with QT interval prolongation in newborns without CCHB.

Animals↗
PubMed2002

Analysis of common k-mers for whole genome sequences using SSB-tree.

As sequenced genomes become larger and sequencing process becomes faster, there is a need to develop a tool to analyze sequences in the whole genomic scale. However, on-memory algorithms such as suffix tree and suffix array are not applicable to the analysis of whole genome sequence set, since the size of individual whole genome ranges from several million base pairs to hundreds billion base pairs. In order to effectively manipulate the huge sequence data, it is necessary to use the indexed data structure for external memory. In this paper, we introduce a workbench called SequeX for the analysis and visualization of whole genome sequences using SSB-tree (Static SB-tree). It consists of two parts: the analysis query subsystem and the visualization subsystem. The query subsystem supports various transactions such as pattern matching, k-occurrence, and k-mer analysis. The visualization subsystem helps biologists to easily understand whole genome structure and feature by sequence viewer, annotation viewer, CGR (Chaos Game Representation) viewer, and k-mer viewer. The system also supports a user-friendly programming interface based on Java script for batch processing and the extension for a specific purpose of a user. SequeX can be used to identify conserved genes or sequences by the analysis of the common k-mers and annotation. We analyze the common k-mer for 72 microbial genomes announced by Entrez, and find an interesting biological fact that the longest common k-mer for 72 sequences is 11-mer, and only 11 such sequences exist. Finally we note that many common k-mers occur in conserved region such as CDS, rRNA, and tRNA.

Archaea↗
PubMed1991

The occurrence of antinuclear, anti-SSA/Ro and anti-SSB/La antibodies in patients with polymorphous light eruption.

Serological features were investigated in 22 patients with polymorphous light eruption. The diagnosis was made from the history and clinical patterns and confirmed by phototesting and histological examinations. In 4 patients with polymorphous light eruption, anti-RNP antibodies were detected in the serum despite the fact that the antinuclear antibody tests were negative in all cases. The serum levels of anti-SSA/Ro antibodies in the patients were mildly but significantly elevated (p less than 0.001) as compared with healthy controls. No difference was found between the patients and controls regarding the serum concentrations of anti-SSB/La antibodies. The conclusion is drawn that it is necessary to examine patients with polymorphous light eruption with regard to a 'late autoimmune course' and it is worthwhile to study the relationship between the photosensitivity and the occurrence of anti-SSA/Ro antibodies.

Adult↗