Rat Anti-Mouse CD40 Monoclonal antibody, clone FGK4.5/ FGK45 Functional Grade

CD40 and its ligand CD40L (CD154) belong to the tumor necrosis factor receptor superfamily and are expressed by a variety of immune and non-immune cells. CD40L plays a central role in co-stimulation and regulation of the immune response via activation of cells expressing CD40. Imbalance of the CD40-CD40L co-stimulatory pathway has been reported in many autoimmune diseases, including systemic lupus erythematosus, rheumatoid arthritis, and S Ogren' s syndrome, thus supporting its role in the breach of immune tolerance that is typical of these diseases. Targeting CD40-CD40L signalling might represent a novel therapeutic option for several autoimmune disorders.

Background Chronic kidney disease (CKD) is associated with endothelial dysfunctions thus prompting links between microcirculation (MC), inflammation and major cardiovascular risk factors. Purpose of the study We have previously reported that siRNA-silencing of CD40 (siCD40) reduced atherosclerosis (ATH) progression. Here, we have deepened on the effects of the siCD40 treatment by evaluating retrospectively, in stored kidneys from the siCD40 treated ApoE(-/-) mice, the renal microcirculation (measured as the density of peritubular capillaries), macrophage infiltration and NF-kappa B activation. Methods Kidneys were isolated after 16 weeks of treatment with the anti-CD40 siRNA (siCD40), with a scrambled control siRNA (siSC) or with PBS (Veh. group). Renal endothelium, infiltrating macrophages and activated NF-kappa B in endothelium were identified by immunohistochemistry, while the density of stained peritubular capillaries was quantified by image analysis. Results ATH was associated with a reduction in renal MC, an effect reversed by the anti-CD40 siRNA treatment (3.8 +/- 2.7% in siCD40; vs. 1.8 +/- 0.1% in siSC; or 1.9 +/- 1.6% in Veh.; p < 0.0001). Furthermore, siCD40 treatment reduced the number of infiltrating macrophages compared to the SC group (14.1 +/- 5.9 cells/field in siCD40; vs. 37.1 +/- 17.8 cells/field in siSC; and 1.3 +/- 1.7 cells/field in Veh.; p = 0.001). NF-kappa B activation also peaked in the siSC group, showing lower levels in the siCD40 and Veh. groups (63 +/- 60 positive cells/section in siCD40; vs. 152 +/- 44 positive cells/section in siSC; or 26 +/- 29 positive cells/section in veh.; p = 0.014). Lastly, serum creatinine was also increased in the siCD40 (3.4 +/- 3.3 mg/dL) and siSC (4.6 +/- 3.0 mg/dL) groups when compared with Veh. (1.1 +/- 0.9 mg/dL, p = 0.1). Conclusions Anti-CD40 siRNA therapy significantly increased the density of peritubular capillaries and decreased renal inflammation in the ATH model. These data provide a physiological basis for the development of renal diseases in patients with ATH. Furthermore, our results also highligth renal off-target effects of the siRNA treatment which are discussed.