Computational Discovery and Experimental Confirmation of TLR9 Receptor Antagonist Leads.

Toll-like receptors (TLR) are receptors of innate immunity that recognize pathogen associated molecular patterns. They play a critical role in many pathological states, in acute and chronic inflammatory processes. TLR9 is a promising target for drug discovery, since it has been implicated in several pathologies, including defense against viral infections and psoriasis. Immune-modulators are promising molecules for therapeutic intervention in these indications. TLR9 is located in the endosome and activated by dsDNA with CpG motives encountered in microbial DNA. Here we report on a combined approach to discover new TLR9 antagonists by computational chemistry and cell based assays. We used our in-house iterative stochastic elimination (ISE) algorithm to create models that distinguish between TLR9 antagonists ("actives") and other molecules ("inactives"), based on molecular physicochemical properties. Subsequent screening and scoring of a data set of 1.8 million commercially available molecules led to the purchasing of top scored molecules, which were tested in a new cell based system based on human pattern recognition receptors (PRRs) stably expressed in NIH3T3 fibroblasts. As described previously, this cell line shows a very low endogenous PRR-activity and contains a reporter gene which is selectively activated by the integrated human PRR enabling rapid screening of potential ligands. IC50 values of each of these top scored molecules were determined. Out of 60 molecules tested, 56 showed antagonistic activity. We discovered 21 new highly potential antagonists with IC50 values lower than 10 µM, with 5 of them having IC50 values under 1 µM.

Functional outcome of anatomic correction of corrected transposition of the great arteries.

OBJECTIVE: Anatomic correction of corrected transposition of the great arteries, utilizing the morphologic left ventricle as a systemic pumping chamber, is considered the preferred method. The purpose of the study was to analyze the intermediate functional outcome following anatomical correction. METHODS: Between 1997 and 6/2010, 23 patients with corrected transposition of the great arteries and associated lesions underwent anatomical correction. Seventeen (74%) and six patients (26%) had situs solitus {S,L,L} and situs invs {I,D,D}, respectively. Fifteen patients (65%) had undergone 18 palliations before the corrective operation. The median age at palliation was 0.23 years, with a range of 0.016-8.4 years. A corrective, modified Senning-arterial switch procedure was performed in nine patients, 13 patients underwent a modified Senning-Rastelli procedure, and in one patient a combination of modified Senning and aortic translocation (Bex/Nikaidoh) was used. The median age at the corrective operation was 2 years (from 0.3 to 15.7 years). RESULTS: There was no mortality or heart transplant within the mean follow-up of 3.4 years. Freedom from reintervention was 77% at 5 years. There were no signs of obstruction of the systemic and pulmonary venous tunnels. The function of both ventricles was normal in all patients, even in the four patients who required retraining of the left ventricle. Mild aortic regurgitation was noticed in three patients. Preoperatively detected significant tricuspid regurgitation either disappeared or became trivial after the operation in all the six patients. All patients except two are in sinus rhythm; one patient is pacemaker-dependent preoperatively and one is pacemaker-dependent postoperatively. There were no clinically apparent neurological problems. All patients, but one, are in the New York Heart Association (NYHA) class I. CONCLUSIONS: Anatomic correction of corrected transposition of the great arteries can be performed in selected patients without mortality and with acceptable morbidity. The mid-term functional outcome is excellent, resulting in normal ventricular function, even in retrained left ventricles, and minimal incidence of complete heart block. The long-term function of the aortic valve, intraventricular tunnels, conduits, and ventricles requires close surveillance.