Celltech R&D Ltd.

The integrin CD103 is highly expressed at mucosal sites, but its role in mucosal immune regulation remains poorly understood. We have analyzed the functional role of CD103 in intestinal immune regulation using the T cell transfer model of colitis. Our results show no mandatory role for CD103 expression on T cells for either the development or CD4+CD25+ regulatory T (T reg) cell–mediated control of colitis. However, wild-type CD4+CD25+ T cells were unable to prevent colitis in immune-deficient recipients lacking CD103, demonstrating a nonredundant functional role for CD103 on host cells in T reg cell–mediated intestinal immune regulation. Non–T cell expression of CD103 is restricted primarily to CD11chighMHC class IIhigh dendritic cells (DCs). This DC population is present at a high frequency in the gut-associated lymphoid tissue and appears to mediate a distinct functional role. Thus, CD103+ DCs, but not their CD103− counterparts, promoted expression of the gut-homing receptor CCR9 on T cells. Conversely, CD103− DCs promoted the differentiation of IFN-γ–producing T cells. Collectively, these data suggest that CD103+ and CD103− DCs represent functionally distinct subsets and that CD103 expression on DCs influences the balance between effector and regulatory T cell activity in the intestine.

The scale up and process development for synthesis of the MMP inhibitor CH5902 is described.The first objective was to minimize the number of stages, preferably avoiding the isolation of intermediates that are oils or that are potentially unstable to ambient conditions.The route then naturally simplifies to four discrete stages: formation of the thioacetate, Me 4-(acetylsulfanylmethyl)tetrahydropyran-4-carboxylate (stage 1), oxidation and coupling to form the sulfonamide ester, methyl-[4-[4-(4-chlorophenyl)piperazin-1-yl]sulfonylmethyl]tetrahydropyran-4-carboxylate (stage 2), hydrolysis to the corresponding acid, [4-[4-(4-chlorophenyl)piperazin-1-yl]sulfonylmethyl]tetrahydropyran-4-carboxylic acid (stage 3), and conversion to the hydroxamic acid, [4-[4-(4-chlorophenyl)piperazin-1-yl]sulfonylmethyl]tetrahydropyran-4-carboxylic acid N-hydroxy amide (stage 4).In this approach, the original discovery route was streamlined and telescoped into a four-stage sequence, which was demonstrated on a multikilogram scale.A number of issues arising from both process development and process safety concerns are discussed.

A modified crystallohydrodynamic approach introduced in 2001 is applied to two human IgG4 constructs from mouse IgG1. The constructs were point mutants of the chimeric antibody molecule cB72.3(gamma4): cB72.3(gamma4A), devoid of inter-chain disulfide bridging, and cB72.3(gamma4P), which has full inter-chain bridging. As before, the known crystallographic structures for the Fab and Fc domains were combined with the measured translational frictional ratios to obtain an estimate for the apparent time-averaged hydration of the domains and hence for that of the intact molecule. The original approach was modified with the hydrated dimensions of the domains being applied, rather than the anhydrous crystallographic dimensions, for assessing the inter-domain orientations using the algorithms HYDROSUB and SOLPRO. Both chimeric IgG4 molecules were found to have open, rather than compact, structures, in agreement with the previous study on wild-type human IgG4. The insertion of a frictionless connector between the domains was necessary, however, for representing the cB72.3(gamma4A) chimera. It therefore appears that the inter-chain disulfide bonds act as physical constraints in the cB72.3(gamma4P) chimera, forcing the antibody domains together and producing a less elongated structure than that of cB72.3(gamma4A). The open structures produced for the two IgG4 chimeras showed similarity to those structures identified for murine IgG1 and IgG2a molecules through X-ray crystallography.