Antibodies directed against ribosomal P proteins cross-react with phospholipids

Protein Kinase CK2 Maintains Reciprocal Balance Between Th17 and Treg Cells in the Pathogenesis of UC

BACKGROUND

T helper 17 and regulatory T cells balance have crucial effects on the development of ulcerative colitis (UC). Currently, how to break this balance has not yet been found. Protein kinase CK2 is involved in the pathogenesis of immune-related disorders. However, its effects on the development of UC are obscure.

METHODS

The level of CK2 in the colonic tissues of UC patients was quantified by quantitative real-time polymerase chain reaction (qRT-PCR) and immune-histochemistry. Peripheral blood CD4+ T cells were treated with CK2 inhibitor CX4945 or transfected with Csnk2-interfering lentivirus; the mRNA expression and protein levels of inflammatory cytokines were detected by qRT-PCR, enzyme-linked immunosorbent assay, and flow cytometry. Moreover, CX4945 was administered to trinitrobenzene sulfonic acid (TNBS)-induced colitis mice model for determining the function of CK2 on the regulation of intestinal inflammation.

RESULTS

The CK2 level was markedly increased in inflamed mucosa of UC and highly expressed in CD4+ T cells. Blockade of CK2 by CX4945 inhibited Th17 but promoted regulatory T-cell (Treg) immune responses in CD4+ T cells from patients with UC. Moreover, CK2 blockade alleviated TNBS-induced colitis in mice. Inhibition of CK2 suppressed Th17 but promoted Treg differentiation by decreasing the phosphorylation level of signal transducer and activator of transcription (STAT) 3 and increasing the phosphorylation level of STAT5. The RNA-Seq and co-immunoprecipitation analysis further showed that CK2 could interact with Sirtuin 1 (SIRT1) and downregulate SIRT1 expression, which participated in Th17 inhibition but promoted Treg differentiation. Sirtuin 1 upregulation ameliorated TNBS-induced colitis, whereas SIRT1 blockade aggravated TNBS-induced colitis in mice.

CONCLUSIONS

CK2 have crucial effects on the development of UC by maintaining reciprocal balance between Th17 and Treg cells. Protein kinase CK2 blockade might be considered as a new therapeutic approach for UC treatment.

Association of Antiribosomal P Antibody with Neurological and Systemic Manifestations in Patients with Systemic Lupus Erythematosus in Southwestern Colombia

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by heterogeneous pathogenesis, various clinical manifestations, and a broad spectrum of autoantibodies which recognize different cellular components. This study examines the clinical significance and serological associations of serum antiribosomal P antibodies (anti-P) derived from SLE patients in a population from southwestern Colombia.

METHODS

We performed a cross-sectional study of 66 SLE patients. Serum antiribosomal P0 autoantibodies were detected by line immunoassay using the ANA-LIA MAXX kit and processed on the automated HumaBlot 44FA system (Human Diagnostics, Germany).

RESULTS

Of the 66 SLE patients included in the study, 17 patients (25.76%) showed anti-P positivity by line immunoassay (IA), 47 (71.21%) were negative, and results from 2 patients were indeterminate. We did not find an association with neuropsychiatric SLE (NPSLE), renal, or hepatic disorders (P > 0.05). Laboratory findings indicated that anti-P positivity was significantly associated to anti-Smith (P = 0.001), anti-Ro60/SSA (P = 0.046), and anti-dsDNA antibodies (P = 0.034), the latter being true only when performed using indirect immunofluorescence (IIF).

CONCLUSION

The anti-P antibodies are not associated with clinical manifestations such as NPSLE, lupus nephritis, or hepatic involvement in the southwest Colombian SLE population. Moreover, we confirmed previously reported association between anti-P antibody, serum anti-dsDNA, and anti-Smith.

The Development of CK2 Inhibitors: From Traditional Pharmacology to in Silico Rational Drug Design

Casein kinase II (CK2) is an ubiquitous and pleiotropic serine/threonine protein kinase able to phosphorylate hundreds of substrates. Being implicated in several human diseases, from neurodegeneration to cancer, the biological roles of CK2 have been intensively studied. Upregulation of CK2 has been shown to be critical to tumor progression, making this kinase an attractive target for cancer therapy. Several CK2 inhibitors have been developed so far, the first being discovered by "trial and error testing". In the last decade, the development of in silico rational drug design has prompted the discovery, de novo design and optimization of several CK2 inhibitors, active in the low nanomolar range. The screening of big chemical libraries and the optimization of hit compounds by Structure Based Drug Design (SBDD) provide telling examples of a fruitful application of rational drug design to the development of CK2 inhibitors. Ligand Based Drug Design (LBDD) models have been also applied to CK2 drug discovery, however they were mainly focused on methodology improvements rather than being critical for de novo design and optimization. This manuscript provides detailed description of in silico methodologies whose applications to the design and development of CK2 inhibitors proved successful and promising.

Anti-ribosomal-P antibodies in lupus nephritis, neuropsychiatric lupus, lupus hepatitis, and Chagas' disease: promising yet limited in clinical utility

Anti-P antibodies have been associated with organ involvement in SLE, such as in autoimmune hepatitis, and have been suggested to be directly pathogenic. Neuropsychiatric lupus, lupoid hepatitis, autoimmune hepatitis, lupus nephritis, and Chagas' disease have been associated with the presence of anti-P antibody. This review seeks to look into the current literature on anti-P antibody and the association between SLE and non-SLE autoimmune connective tissue disorder.

Serology of Lupus Erythematosus: Correlation between Immunopathological Features and Clinical Aspects

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the aberrant production of a broad and heterogenous group of autoantibodies. Even though the presence of autoantibodies in SLE has been known, for more than 60 years, still nowadays a great effort is being made to understand the pathogenetic, diagnostic, and prognostic meaning of such autoantibodies. Antibodies to ds-DNA are useful for the diagnosis of SLE, to monitor the disease activity, and correlate with renal and central nervous involvements. Anti-Sm antibodies are highly specific for SLE. Anti-nucleosome antibodies are an excellent marker for SLE and good predictors of flares in quiescent lupus. Anti-histone antibodies characterize drug-induced lupus, while anti-SSA/Ro and anti-SSB/La antibodies are associated with neonatal lupus erythematosus and photosensitivity. Anti-ribosomal P antibodies play a role in neuropsychiatric lupus, but their association with clinical manifestations is still unclear. Anti-phospholipid antibodies are associated with the anti-phospholipid syndrome, cerebral vascular disease, and neuropsychiatric lupus. Anti-C1q antibodies amplify glomerular injury, and the elevation of their titers may predict renal flares. Anti-RNP antibodies are a marker of Sharp's syndrome but can be found in SLE as well. Anti-PCNA antibodies are present in 5–10% of SLE patients especially those with arthritis and hypocomplementemia.

The role of measurement of serum autoantibodies in prediction of pediatric neuropsychiatric systemic lupus erythematosus

Neuropsychiatric systemic lupus erythematosus (NPSLE) is one of the most difficult manifestations of lupus to diagnose. Measurement of serum brain antibodies has contributed to early diagnosis and management of NPSLE before development of a debilitating disease. We aimed to assess the value of serum anti-ganglioside M1 antibodies in prediction of NPSLE, in comparison to other antibodies used in routine laboratory diagnosis of NPSLE. In addition, we are the first to study the relationship between these antibodies and cognitive function in lupus patients. Serum anti-ganglioside M1, anti-ribosomal P protein and anti-cardiolipin antibodies were measured in 30 lupus patients without clinical evidence of NPSLE, aged 8-16 years, and 30 healthy matched-subjects. Patients were followed-up clinically by monthly neuropsychiatric evaluation and assessment of cognitive function for 12 months. Twelve patients developed neuropsychiatric manifestations during follow-up. Of those patients, 83.3%, 50% and 16.7% were seropositive for anti-ganglioside M1, anti-ribosomal P and anti-cardiolipin antibodies, respectively at the time of initial evaluation before clinical presentation of NPSLE. There was a significant positive association between anti-ganglioside seropositivity and cognitive dysfunction (P<0.001). In addition, anti-ganglioside seropositivity had a significant risk for association with cognitive dysfunction (odds ratio: 36; 95% CI: 4.3-302.8).

CONCLUSIONS

Serum anti-ganglioside M1 antibodies had a higher predictive value for NPSLE than other antibodies used in routine laboratory diagnosis of this disease. Thus, they may be reliable parameters for early diagnosis and management of NPSLE before clinical manifestations ensue. In addition, anti-ganglioside M1 antibodies may play a role in cognitive dysfunction found in some lupus patients.

How druggable is protein kinase CK2?

CK2 is a pleiotropic, ubiquitous, and constitutively active protein kinase (PK), with both cytosolic and nuclear localization in most mammalian cells. The holoenzyme is generally composed of two catalytic (alpha and/or alpha') and two regulatory (beta) subunits, but the free alpha/alpha' subunits are catalytically active by themselves and can be present in cells under some circumstances. CK2 catalyzes the phosphorylation of more than 300 substrates characterized by multiple acidic residues surrounding the phosphor-acceptor amino acid, and, consequently, it plays a key role in several physiological and pathological processes. But how can one kinase orchestrate all these tasks faithfully? How is it possible that one kinase can, despite all pleiotropic characteristics of PKs in general, be involved in so many different biochemical events? Is CK2 a druggable target? Several questions are still to be clearly answered, and this review is an occasion for a fruitful discussion.

Antiribosomal-P protein antibodies in a patient with systemic lupus erythematosus and non-Hodgkin's lymphoma: more than coincidental finding?

Patients with systemic lupus erythematosus (SLE) are at an increased risk of lymphomas, but mechanisms underlying this association are obscure. Recently, it has been shown that antiribosomal-P protein (anti-P) antibodies cross-react with phospholipids and enhance the production of cytokines which may influence lymphomagenesis. We report a 46-year-old woman who suffered high grade diffuse large B-cell non-Hodgkin's lymphoma (DLBCL) 28 months after the diagnosis of SLE. Development of lymphoma was associated with occurrence of serum monoclonal IgM, and pronounced prolongation of phospholipid-dependent clotting tests. Anti-P IgG antibodies were highly positive both on HEp-2 cells and in ELISA test. Anticardiolipin, anti-beta2 glycoprotein I, and antiprothrombin IgM antibodies have also been found in high concentrations. Complete remission of DLBCL and SLE, with normalisation of clotting tests, and disappearance of M component was achieved with administration of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone. The progression of SLE to DLBCL associated with presence of anti-P antibodies has not been previously reported. This association may not be coincidental, but further investigations are required to confirm this hypothesis.