Efficacy and safety of golimumab as add-on therapy to disease-modifying antirheumatic drugs: results of the GO-MORE study.

OBJECTIVES: To evaluate the efficacy and safety of subcutaneous golimumab as add-on therapy in patients with active rheumatoid arthritis (RA) despite disease-modifying antirheumatic drug (DMARD) treatment. To evaluate an intravenous plus subcutaneous (IV+SC) golimumab strategy in patients who had not attained remission. METHODS: GO-MORE was an open-label, multinational, prospective study in patients with active RA in typical clinical practice settings. In part 1, patients received add-on monthly 50-mg subcutaneous golimumab for 6 months. The percentage of patients with good/moderate European League Against Rheumatism (EULAR) 28-joint disease activity score (DAS28)-erythrocyte sedimentation rate (ESR) response was compared in patient subgroups with various concurrent or previous DMARD treatments. In part 2, patients with EULAR responses but not remission were randomly assigned to receive IV+SC or subcutaneous golimumab to month 12; DAS28-ESR remission was measured. RESULTS: 3366 patients were enrolled. At baseline of part 1, 3280 efficacy-evaluable patients had mean disease duration of 7.6 years and mean DAS28-ESR of 5.97 (SD=1.095). At month 6, 82.1% achieved good/moderate EULAR responses and 23.9% attained remission. When EULAR responses were analysed by the number of previously failed DMARD or the concomitant methotrexate dose, DMARD type, or corticosteroid use, no statistically significant differences were observed. Part 2 patients (N=490) who received IV+SC or subcutaneous golimumab achieved similar remission rates (∼25%). Adverse events were consistent with previous reports of golimumab and other tumour necrosis antagonists in this population. CONCLUSIONS: Add-on monthly subcutaneous golimumab resulted in good/moderate EULAR response in most patients; 25% achieved remission after 6 more months of golimumab, but an IV+SC regimen provided no additional efficacy over the subcutaneous regimen.

Granulocyte macrophage-colony stimulating factor reduces the affinity of SHP-2 for the ITIM of CLECSF6 in neutrophils: a new mechanism of action for SHP-2.

Proteins that bear immunoreceptor tyrosine based inhibitory motifs (ITIM) are believed to participate in the repression of cell activation via phosphatases such as SHP-1, SHP-2 and/or SHIP-1. CLECSF6, also called DCIR, is a transmembrane protein expressed on leukocytes and predominantly on neutrophils that bears one ITIM pattern. This feature confers to CLECSF6 a role in the repression of cell activation. In order to better understand its role in neutrophil signalling, we analysed the binding of phosphatases to the ITIM of CLECSF6. We showed that a peptide bearing the ITIM of CLECSF6 in its phosphorylated form associates with both SHP-1 and SHP-2. Phosphorylated SHP-1 binds the ITIM whereas phosphorylated SHP-2 does not. In addition, granulocyte macrophage-colony stimulating factor (GM-CSF) reduces the binding of SHP-2 to the ITIM of CLECSF6 while enhancing the phosphorylation level of SHP-2. GM-CSF is known to recruit SHP-2 to its receptor. These data suggest that the phosphorylation of SHP-2 by GM-CSF promotes the binding of SHP-2 to the GM-CSF receptor to the disadvantage of CLECSF6. Therefore, upon a treatment with GM-CSF, SHP-2 could move from a CLECSF6 associated signalosome with a repressor function to a GM-CSF receptor associated signalosome with an activator function.

The ITIM-bearing CLECSF6 (DCIR) is down-modulated in neutrophils by neutrophil activating agents.

The recently discovered CLECSF6 protein displays the features of a receptor involved in the down-modulation of leukocyte activation. Although CLECSF6 has been the focus of the interest of many researchers lately, a Western blot characterization of the protein is still lacking. This highly reduces our ability to gain full knowledge of the biological relevance of this protein in cell responses. We produced two rabbit polyclonal antisera that detected a glycosylated protein at approximately 35kDa in neutrophils. Four different CLECSF6 mRNA species have been discovered to date. When deglycosylated, the protein displayed the molecular weight expected for the longest CLECSF6 form. Neutrophil membrane fractions were strongly enriched in the protein. We showed a down-modulation of the expression of this protein in neutrophils treated with granulocyte-macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor (TNF-alpha), lipopolysaccharide (LPS), and interleukin (IL)-4. This work supports the hypothesis that CLECSF6 is involved in the control of inflammation in neutrophils.

Human plasma fibronectin potentiates the mitogenic activity of platelet-derived growth factor and complements its wound healing effects.

Integrin-mediated cell adhesion and growth factor stimuli are both required for optimal control of cell proliferation. In the context of skin injury, cell-derived fibronectin and platelet-derived growth factor play important roles in the stimulation of cell proliferation and migration, activities that are crucial to the healing process. To assess the ability of exogenously supplied plasma-derived fibronectin to stimulate wound repair and to study its ability to cooperate with platelet-derived growth factor-BB during healing, we devised a novel topical delivery formulation that allows the controlled release of both molecules to a wound. Using this topical formulation and the rabbit ear model of dermal wound healing, we show that plasma fibronectin is a potent stimulator of the wound healing process. We also show that administration of fibronectin and platelet-derived growth factor-BB in combination has additive wound healing effects. Finally, we report novel findings on the ability of soluble plasma fibronectin to potentiate the mitogenic effects of platelet-derived growth factor-BB in vitro. These findings not only show that optimal concentrations of exogenous fibronectin administered using an effective delivery system stimulate wound healing; they also suggest that PDGF-BB should be administered with fibronectin to achieve optimal therapeutic stimulation of wound healing.

The expression pattern of the ITIM-bearing lectin CLECSF6 in neutrophils suggests a key role in the control of inflammation.

In our study of the modulation of the expression of inflammation-related genes in neutrophils, we have found a gene called CLECSF6 (C-type lectin superfamily 6). CLECSF6 expresses two mRNA species at low levels in resting neutrophils. Here, we describe for the first time the sequence of the short mRNA version. It lacks amino acids that are likely to affect the functionality of its protein product. GM-CSF, IL-3, IL-4, and IL-13 caused an accumulation of the short CLECSF6 mRNA in neutrophils. The surface expression of the CLECSF6 protein was reduced by TNF-alpha, IL-1alpha, LPS, and Matrigel. CLECSF6 bears the immunoreceptor tyrosine-based inhibition motif (ITIM) involved in signal transduction resulting in the inhibition of leukocyte activation. We propose that some neutrophil activators modulate the expression of CLECSF6 at the mRNA (GM-CSF, IL-3, IL-4, and IL-13) or protein (TNF-alpha, IL-1alpha, LPS, and Matrigel) levels in ways that block ITIM-based transduction of anti-inflammatory signals and therefore promote inflammation.