Phenylacetic acid regioisomers possessing a N-difluoromethyl-1,2-dihydropyrid-2-one pharmacophore: evaluation as dual inhibitors of cyclooxygenases and 5-lipoxygenase with anti-inflammatory activity.

A novel class of phenylacetic acid regioisomers possessing a N-difluoromethyl-1,2-dihydropyrid-2-one pharmacophore attached to its C-2, C-3 or C-4 position was designed for evaluation as anti-inflammatory (AI) agents. A number of compounds exhibited a combination of potent in vitro cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LOX) inhibitory activities. 2-(1-Difluoromethyl-2-oxo-1,2-dihydropyridin-4-yl)phenylacetic acid (9a) exerted the most potent AI activity among this group of compounds. Molecular modeling studies showed that the N-difluoromethyl-1,2-dihydropyridin-2-one moiety present in 9a inserts into the secondary pocket present in COX-2 to confer COX-2 selectivity, and that the N-difluoromethyl-1,2-dihydropyrid-2-one group (9a) binds close to the region of the 15-LOX enzyme containing catalytic iron (His361, His366). Accordingly, the N-difluoromethyl-1,2-dihyrdopyrid-2-one moiety possesses properties that make it an attractive pharmacophore suitable for the design of dual COX-2/5-LOX inhibitory AI drugs.

Synthesis of celecoxib analogues possessing a N-difluoromethyl-1,2-dihydropyrid-2-one 5-lipoxygenase pharmacophore: biological evaluation as dual inhibitors of cyclooxygenases and 5-lipoxygenase with anti-inflammatory activity.

A novel class of 1-(4-methanesulfonylphenyl and 4-aminosulfonylphenyl)-5-[4-(1-difluoromethyl-1,2-dihydropyrid-2-one)]-3-trifluoromethyl-1H-pyrazole hybrid cyclooxygenase-2 (COX-2)/5-lipoxygenase (5-LOX) inhibitory anti-inflammatory agents was designed. Replacement of the tolyl ring present in celecoxib by the N-difluoromethyl-1,2-dihydropyrid-2-one moiety provided compounds showing dual selective COX-2/5-LOX inhibitory activities. 1-(4-Aminosulfonylphenyl)-5-[4-(1-difluoromethyl-1,2-dihydropyrid-2-one)]-3-trifluoromethyl-1H-pyrazole exhibited good anti-inflammatory (AI) activity (ED(50) = 27.7 mg/kg po) that compares favorably with the reference drugs celecoxib (ED(50) = 10.8 mg/kg po) and ibuprofen (ED(50) = 67.4 mg/kg po). The N-difluoromethyl-1,2-dihydropyridin-2-one moiety provides a novel 5-LOX pharmacophore for the design of cyclic hydroxamic mimetics for exploitation in the development of COX-2/5-LOX inhibitory AI drugs.

Antigen targeting to dendritic cells with bispecific antibodies.

We have developed a universal DC targeting vehicle that could be a convenient method to deliver any type of antigen to DC. P125, a quadroma (hybrid-hybridoma) secreting bispecific monoclonal antibodies (bsmAb), with one paratope specific for mouse DC DEC-205 and another paratope specific for biotin, was developed by PEG-fusion of the two parental hybridomas and selected by a fluorescence activated cell sorter. The bsmAb were purified using a biotin-Agarose column and the bsmAb activity was demonstrated using ELISA method employing mouse bone marrow DC and biotinylated BSA. Both confocal microscopy and ELISA studies have shown enhanced binding and internalization of biotinylated and FITC-labelled M13 to DC cell in the presence of bsmAb. In vivo studies in mice with biotinylated OVA has shown that in the presence of bsmAb and anti-CD40 mAb, both humoral and cell-mediated responses can be augmented. In addition, only a low concentration of antigen (500 fold less) is required using bsmAb to achieve a similar immune response in mice that were immunized using complete Freund's adjuvant. In the absence of traditional adjuvants, bsmAb targeting of biotinylated antigens to DC could be an alternative, convenient method to deliver antigens to DC. Moreover, this method could be an alternative method to ex vivo stimulation of DC to overcome DC defects and for treatment of cancer.