Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024141 (systemic lupus erythematosus)
 44,322 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using phage display, we generated a panel of optimized neutralizing antibodies against the human and mouse receptors for interleukin 21 (IL-21), a cytokine that is implicated in the pathogenesis of many types of autoimmune disease. Two antibodies, Ab-01 and Ab-02, which differed by only four amino acids in V(L) CDR3, showed potent inhibition of human and mouse IL-21R in cell-based assays and were evaluated for their pharmacological and pharmacodynamic properties. Ab-01, but not Ab-02, significantly reduced a biomarker of disease (anti-dsDNA antibodies) and IgG deposits in the kidney in the MRL-Fas(lpr) mouse model of lupus, suggesting that anti-IL-21R antibodies may prove useful in the treatment of lupus. Ab-01 also had a consistently higher exposure (AUC(0-infinity)) than Ab-02 following a single dose in rodents or cynomolgus monkeys (2-3-fold or 4-7-fold, respectively). Our data demonstrate that small differences in CDR3 sequences of optimized antibodies can lead to profound differences in in vitro and in vivo properties, including differences in pharmacological activity and pharmacokinetic profiles. The lack of persistent activity of Ab-02 in the MRL-Fas(lpr) mouse lupus model may have been a consequence of faster elimination, reduced potency in blocking the effects of mouse IL-21R, and more potent/earlier onset of the anti-product response relative to Ab-01.
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PMID:In vitro potency, pharmacokinetic profiles, and pharmacological activity of optimized anti-IL-21R antibodies in a mouse model of lupus. 2042 14

Aberrant expression of CXCR4 has been indicated to play a role in the pathogenesis of systemic lupus erythematosus (SLE), but the mechanism of CXCR4 dysregulation in SLE is unclear. This study is aimed to explore the clinical significance and possible mechanisms of abnormal CXCR4 expression on B cells from patients with untreated SLE. Expression of CXCR4 on peripheral B cells was determined by flow cytometry and western blotting. Freshly isolated B cells were cultured with exogenous interleukin 21(IL-21) in the presence or absence of CD40 ligand (CD40L) plus anti-IgM antibody (aIgM), and changes in CXCR4 expression were detected. Involvement of phosphatidylinositol 3 kinase (PI3K)/Akt and Janus kinase/Signal transducer and activator of transcription (JAK/STAT) signaling pathways was assessed by adding blocking agents Ly294002 and AG490. Since CD63 is reported to mediate endosomal recruitment of CXCR4 and BCL6 is capable of silencing CD63 gene transcription, we also measured BCL6 and CD63 gene transcription with real-time PCR. It was shown that CXCR4 expression on B cells was significantly upregulated in SLE patients, especially in those with lupus nephritis, and was positively correlated with SLE Disease Activity Index scores and negatively with the serum complement 3 levels (P<0.05). Downregulation of CXCR4 by IL-21 was intact. In contrast, a similar effect of aIgM plus CD40L in downregulating CXCR4 expression was defective in SLE patients but was restored by co-stimulation with IL-21 in vitro. Both Ly294002 and AG490 promoted downregulation of surface CXCR4 expression on B cells from SLE patients (P=0.078 and P=0.064). Furthermore, B cells from SLE patients exhibited diminished CD63 mRNA and enhanced BCL6 mRNA expression (both P<0.05). To sum up, CXCR4 was overexpressed on SLE B cells, positively correlating with disease activity and kidney involvement. Overactivation of the PI3K/Akt and JAK/STAT pathways as well as defective CD63 synthesis may contribute to CXCR4 dysregulation in SLE.
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PMID:Contribution and underlying mechanisms of CXCR4 overexpression in patients with systemic lupus erythematosus. 2766 47