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Compound
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Query: UMLS:C1832526 (
PCC
)
5,967
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We have utilized the sensitive polymerase chain reaction (PCR) to determine whether cytotoxic T lymphocyte (CTL) hybridomas generated from peritoneal exudate lymphocytes (PEL) and mixed lymphocyte cultures (MLC) express transcripts for perforin and the cytotoxic cell proteinases CCP1 to CCP5. We could readily detect less than one transcript per cell using this methodology. Cytolytic activity could be induced to varying levels in four of the five hybridoma clones tested. With the exception of low level
CCP2
expression in the MLC hybridoma MD45 following antigen stimulation, all of the hybridomas could be stimulated to function as potent cytolytic cells in the complete absence of perforin or
CCP
transcripts. PCR analysis utilizing actin primers indicated that all samples contained material which could be reverse transcribed and PCR-amplified. These results support the argument that populations of lymphocytes do exist that are capable of target cell lysis by an alternative mechanism not involving perforin and
CCP
.
...
PMID:Peritoneal exudate lymphocyte and mixed lymphocyte culture hybridomas are cytolytic in the absence of cytotoxic cell proteinases and perforin. 144 10
C1s is the highly specific modular serine protease that mediates the proteolytic activity of the C1 complex and thereby triggers activation of the complement cascade. The crystal structure of a catalytic fragment from human C1s comprising the second complement control protein (
CCP2
) module and the chymotrypsin-like serine protease (SP) domain has been determined and refined to 1.7 A resolution. In the areas surrounding the active site, the SP structure reveals a restricted access to subsidiary substrate binding sites that could be responsible for the narrow specificity of C1s. The ellipsoidal
CCP2
module is oriented perpendicularly to the surface of the SP domain. This arrangement is maintained through a rigid module-domain interface involving intertwined proline- and tyrosine-rich polypeptide segments. The relative orientation of SP and
CCP2
is consistent with the fact that the latter provides additional substrate recognition sites for the C4 substrate. This structure provides a first example of a
CCP
-SP assembly that is conserved in diverse extracellular proteins. Its implications in the activation mechanism of C1 are discussed.
...
PMID:Crystal structure of the catalytic domain of human complement c1s: a serine protease with a handle. 1077 60
This study was performed to assess the utility of anti-cyclic citrullinated peptide (anti-CCP) antibodies in distinguishing between patients with rheumatoid arthritis (RA) and patients with polyarticular involvement associated with chronic hepatitis C virus (HCV) infection. Serum anti-
CCP
antibodies and rheumatoid factor (RF) were evaluated in 30 patients with RA, 8 patients with chronic HCV infection and associated articular involvement and 31 patients with chronic HCV infection without any joint involvement. In addition, we retrospectively analysed sera collected at the time of first visit in 10 patients originally presenting with symmetric polyarthritis and HCV and subsequently developing well-established RA. Anti-
CCP
antibodies and RF were detected by commercial second-generation anti-
CCP2
enzyme-linked immunosorbent assay and immunonephelometry respectively. Anti-
CCP
antibodies were detected in 23 of 30 (76.6%) patients with RA but not in patients with chronic HCV infection irrespective of the presence of articular involvement. Conversely, RF was detected in 27 of 30 (90%) patients with RA, 3 of 8 (37.5%) patients with HCV-related arthropathy and 3 of 31 (9.7%) patients with HCV infection without joint involvement. Finally, anti-
CCP
antibodies were retrospectively detected in 6 of 10 (60%) patients with RA and HCV. This indicates that anti-
CCP
antibodies can be useful in discriminating patients with RA from patients with HCV-associated arthropathy.
...
PMID:Role of anti-cyclic citrullinated peptide antibodies in discriminating patients with rheumatoid arthritis from patients with chronic hepatitis C infection-associated polyarticular involvement. 1505 77
A family of serine proteases mediates the proteolytic cascades of several defense mechanisms in vertebrates, such as the complement system, blood coagulation and fibrinolysis. These proteases usually form large complexes with other glycoproteins. Their common features are their modular structures and restricted substrate specificities. The lectin pathway of complement, where mannose-binding lectin (MBL) recognizes the carbohydrate structures on pathogens, is activated by mannose-binding lectin-associated serine protease-2 (MASP-2). We present the 2.25A resolution structure of the catalytic fragment of MASP-2 encompassing the second complement control protein module (
CCP2
) and the serine protease (SP) domain. The
CCP2
module stabilizes the structure of the SP domain as demonstrated by differential scanning calorimetry measurements. The asymmetric unit contains two molecules with different
CCP
-SP domain orientations, reflecting increased modular flexibility at the
CCP2
/SP joint. This flexibility may partly explain the ability of the MASP-2 dimer to perform all of its functions alone, whereas the same functions are mediated by the much larger C1r2-C1s2 tetramer in the C1 complex of the classical pathway. The main scaffold of the MASP-2 SP domain is chymotrypsin-like. Eight surface loops determine the S1 and other subsite specificities. Surprisingly, some surface loops of MASP-2, e.g. loop 1 and loop 2, which form the S1 pocket are similar to those of trypsin, and show significant differences if compared with those of C1s, indicating that the nearly identical substrate specificities of C1s and MASP-2 are realized through different sets of enzyme-substrate interactions.
...
PMID:The structure of MBL-associated serine protease-2 reveals that identical substrate specificities of C1s and MASP-2 are realized through different sets of enzyme-substrate interactions. 1536 79
Antibodies directed to cyclic citrullinated peptides (anti-CCP) are highly specific for rheumatoid arthritis (RA) and can easily be detected in sera by using commercially available immunoassays. The second version of the anti-
CCP
test (anti-
CCP2
) demonstrated high specificity (89-98%) and good sensitivity (41-88%) for RA. Commercially available ELISA methods from three different companies are on the market. All three
CCP2
assays show similar results as all
CCP2
assays use the same antigen-coated plates. This study was an evaluation of a new automated method for the determination of anti-
CCP2
in a routine laboratory setting. Five hundred and forty three serum samples were tested for anti-
CCP2
within normal routine diagnostic using a commercially available ELISA and retested with a prelaunch version of a new and fully-automated method (EliA). The results were comparable. The new automated assay is easy to use and demonstrated a diagnostic sensitivity of 80% and specificity of 97%.
...
PMID:Anti-CCP: history and its usefulness. 1605 Jan 44
In the past decade significant advantages have been made in the treatment of rheumatoid arthritis (RA) and therapeutic strategies have changed a lot. These days, highly effective disease modifying anti-rheumatic drugs enable intervention early in the disease process, in order to prevent major joint damage. For years, serological support in the diagnosis of RA has been limited to the presence of rheumatoid factors, although not very specific for RA. During the last years a variety of circulating non-RF antibodies have been discovered and reported to be of potential diagnostic value.
CCP2
proved to be a very disease-specific and even sensitive marker for RA. In addition to the diagnostic properties,
CCP
showed to be a good prognostic marker,
CCP
helps to predict the erosive or nonerosive progression of the disease, and
CCP
is already present early in the disease. This diagnostic tool enables the clinician to choose the optimal therapeutic management for each single RA patient.
...
PMID:Additional diagnostic and clinical value of anti-cyclic citrullinated peptide antibodies compared with rheumatoid factor isotypes in rheumatoid arthritis. 1608 Oct 30
Our aim is to assess the prevalence and associated clinical features of anti-
CCP
(cyclic citrullinated peptide) antibodies for RF (rheumatoid factor)-positive and RF-negative rheumatoid arthritis (RA) and psoriatic arthritis (PsA). In a prospective, cross-sectional, multi-centre study, we determined the titres of anti-
CCP
antibodies in 208 RA patients (129 RF-positive, 79 RF-negative), 56 PsA patients and 39 healthy controls (HC). Clinical parameters including disease activity (disease activity score 28-DAS28), physical disability (health assessment questionnaire-HAQ), functional capacity (functional class) and radiological erosions were investigated in patients with RA. In PsA patients, clinical and radiological features were determined. Anti-
CCP2
antibodies were measured using a second-generation anti-
CCP
enzyme-linked immunosorbent assay (Euro-Diagnostica, Netherlands). One-hundred four of 129 RF-positive RA (81%), 16 of 79 RF-negative RA (20%), seven of 56 PsA patients (12.5%) and none of the HC had anti-
CCP
antibodies. RA patients with anti-
CCP
antibodies had significantly higher disease activity, greater loss of function and more frequent erosive disease than anti-
CCP
antibody-negative group. In subgroup analysis, anti-
CCP
antibodies in RF-negative patients were also associated with erosive disease. All PsA patients with anti-
CCP
antibodies had symmetric arthritis with higher number of swollen joints. The prevalence of anti-
CCP
antibodies in RF-positive RA patients was significantly higher than in RF-negative RA and PsA patients. Anti-
CCP
antibodies were also associated with erosive disease in RF-negative RA patients. Both anti-
CCP
and RF tests were negative in 30% of the patients. Anti-
CCP
positivity was a frequent finding in PsA and associated with symmetrical polyarthritis.
...
PMID:Anti-CCP antibodies in rheumatoid arthritis and psoriatic arthritis. 1653 91
Antibodies directed against citrullinated vimentin are members of the family of autoantibodies reactive with citrullinated proteins and are among the most specific serological markers for the diagnosis of rheumatoid arthritis (RA). This study was performed to test the diagnostic value of a newly developed enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies against a genetically modified citrullinated vimentin (anti-MCV) in comparison with a second-generation anti-cyclic citrullinated peptides (anti-
CCP2
) ELISA test system. Blinded sera from 631 patients (409 consecutive out-patients and 222 randomly selected stored sera) with RA (n = 164) and non-RA (osteoarthritis [n = 120], polymyalgia rheumatica/giant cell arteritis [n = 80], spondyloarthritis [n = 36], and other inflammatory rheumatic or non-inflammatory disease [n = 67]) were tested for the presence of anti-MCV and anti-
CCP2
antibodies according to the manufacturers' instructions. The diagnostic performance of the anti-MCV was comparable with the anti-
CCP2
assay for the diagnosis of RA according to the calculated area under the curve (0.824; 95% confidence interval (CI) 0.778-0.870 versus 0.818; 95% CI 0.767-0.869) as analysed by receiving operating characteristic curve. When categorised with a cutoff value of 20.0 U/ml (as recommended by the manufacturer), sensitivity and specificity of the anti-MCV ELISA were 69.5% (95% CI 61.9%-76.5%) and 90.8% (86.9%-93.8%), respectively, compared with 70.1% (62.5%-77.0%) and 98.7% (96.7%-99.6%) of the anti-
CCP2
assay. Using the cutoff values of 19.0 U/ml and 81.5 U/ml for the anti-MCV test to obtain a sensitivity and specificity identical to the anti-
CCP2
assay, showed a reduced specificity (89.8%; 85.8%-92.9%) and sensitivity (53.7%; 45.7%-61.5%), respectively, of the anti-MCV ELISA compared with the anti-
CCP2
test. In conclusion, the serum ELISA testing for anti-MCV antibodies as well as the anti-
CCP
-2 assay perform comparably well in the diagnosis of RA. In the high-specificity range, however, the anti-
CCP2
assay appears to be superior to the anti-MCV test.
...
PMID:Diagnostic value of antibodies against a modified citrullinated vimentin in rheumatoid arthritis. 1685 19
Rheumatoid arthritis (RA) is a common, systemic autoimmune disease characterized by chronic inflammation of the synovium, that can lead to progressive joint destruction and in many cases results in severe disability and poor quality of life. With the availability of more sophisticated and effective therapies and with increasing evidence that the first few months of disease represent an unique therapeutic opportunity and that such early therapeutic intervention is crucial in preventing irreversible joint damage, it is widely accepted that early and accurate diagnosis of RA is critical in disease management. Within the last three years a growing number of publications have reported that the second generation anti-
CCP
(cyclic citrullinated peptide) test may become the marker of choice for diagnosing early RA as it appears to be highly specific for the disease with a sensitivity comparable to the widely used but less specific rheumatoid factor test. Additionally, anti-
CCP2
positivity can predict future development of RA in both asymptomatic individuals and in patients with undifferentiated arthritis. Furthermore, antibody levels at presentation can correlate with progression to erosive disease.
...
PMID:Autoantibodies to citrullinated antigens in (early) rheumatoid arthritis. 1711 Mar 15
To investigate the prevalence of anti-third generation cyclic citrullinated peptide antibodies (anti-CCP3) in patients with systemic connective tissue diseases, we assembled a training set consisting of 115 patients with rheumatoid arthritis (RA), 52 with Calcinosis, Raynaud's phenomenon, oesophageal dysmotility, sclerodactyly, telangiectasia (CREST) syndrome, 21 with scleroderma, 20 with ankylosing spondylitis, 18 with reactive arthritis, 25 with juvenile rheumatoid arthritis (RA), 51 with osteoarthritis, 26 with mixed connective tissue disease, 23 with primary Sjogren's syndrome, 74 with systemic lupus erythematosus, 49 with Polymyalgia rheumatica, and 39 with polymyositis/dermatomyositis. The commercial enzyme-linked immunosorbent assay (ELISA) was used to detect anti-
CCP
antibodies, including anti-
CCP2
(regular, second generation of
CCP
antigen) and anti-CCP3 (third generation of
CCP
antigen) in disease-related specimens and normal controls. These serum samples were also evaluated for anti-centomere antibodies by anti-centromere ELISA kit. The higher frequencies of anti-CCP3 and anti-
CCP2
were detected in 75.6 and 70.4% patients with RA, respectively. At the same time, anti-CCP3 (not anti-
CCP2
) was significantly increased in samples isolated from patients with CREST syndrome. The clinical sensitivity of IgG anti-CCP3 for the patients with CREST syndrome was 29% (15 of 52) and the specificity was 96% (384 of 397), with the exception of the RA group. The anti-centromere antibodies were significantly higher in patients with CREST only. The results of our study suggest that compared to anti-
CCP2
assay, the new anti-CCP3 assay can enhance the clinical sensitivity for diagnosis of RA and, as an associate marker combined with anticentromere, can distinguish CREST syndrome from other systemic connective tissue diseases, especially RA. The clinical specificity of anti-CCP3 was lower than anti-
CCP2
assay in diagnosis of RA because of the crossreaction to the patients with CREST syndrome.
...
PMID:Increased prevalence of anti-third generation cyclic citrullinated peptide antibodies in patients with rheumatoid arthritis and CREST syndrome. 1742 60
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