Structure of the DNA (6-4) photoproduct dTT(6-4)TT in complex with the 64M-2 antibody Fab fragment implies increased antibody-binding affinity by the flanking nucleotides.

Pyrimidine (6-4) pyrimidone DNA photoproducts produced by ultraviolet light are highly mutagenic and carcinogenic. The crystal structure of the dTT(6-4)TT photoproduct in complex with the Fab fragment of the antibody 64M-2 that is specific for (6-4) photoproducts was determined at 2.4 Šresolution. The dT(6-4)T segment is fully accommodated in the concave binding pocket of the Fab, as observed in the complex of dT(6-4)T with the Fab. The pyrimidine and pyrimidone bases of the dT(6-4)T segment are positioned nearly perpendicularly to each other. The thymidine segments flanking both ends extend away from the dT(6-4)T segment. The 5'-side thymine base is parallel to the side chain of Tyr100iH of the antibody heavy chain and is also involved in electrostatic interactions with Asn30L, Tyr32L and Lys50L of the antibody light chain. The 5'-side and 3'-side phosphate groups exhibit electrostatic interactions with Asn28L and Ser58H, respectively. These interactions with the flanking nucleotides explain why longer oligonucleotides containing dT(6-4)T segments in the centre show higher antibody-binding affinities than the dT(6-4)T ligand.

Human interleukin 10 receptor 1/IgG1-Fc fusion proteins: immunoadhesins for human IL-10 with therapeutic potential.

Interleukin 10 (IL-10) is produced by various types of human cancer, including malignant melanoma, and plays an important role in negative regulation of cell-mediated immune responses against tumors. We have developed chimeric molecules (immunoadhesins), combining the extracellular domain of human interleukin 10 receptor 1 (IL-10R1) with the Fc regions of human IgG1 heavy chain and investigated their capability of blocking the biological activities of human IL-10. Monomeric and dimeric immunoadhesins (IL-10R1/IgG1) constructs were tested for capturing human IL-10 and blocking its biological activities. Plasmid vectors that contained the IL-10 immunoadhesin constructs were directly transfected into human melanoma cell lines. Transfection of plasmid vectors into melanoma cell lines resulted in capturing of exogenously added as well as endogeneously produced IL-10. The supernatants obtained from an IL-10 non-producing melanoma cell line transfected with monomeric IL-10 immunoadhesin plasmids most efficiently captured exogenously added IL-10, compared to those obtained with the dimeric IL-10R1/IgG1 plasmid vector. Transfection of IL-10-producing melanoma cells with the monomeric IL-10 immunoadhesin plasmids totally captured endogenously produced IL-10 and enhanced T cell responses against allogeneic melanoma cells. Furthermore, purified monomeric IL-10 immunoadhesin protein showed IL-10 capturing efficacy compatible with that of IL-10-specific monoclonal antibodies. Collectively, these studies indicate that IL-10 immunoadhesins, especially in monomeric form, are potent inhibitors of biological activities of IL-10 and suggest that these molecules, alone or in conjunctions with other immunotherapeutic approaches, can be utilized for the immuno-targeting of IL-10 producing tumors.

Novel amino linkers enabling efficient labeling and convenient purification of amino-modified oligonucleotides.

We developed new amino linker reagents for an oligonucleotide (ONT) terminus. These reagents consist of an aminoethyl carbamate main linkage and a side-chain residue, which was a naphthylmethoxymethyl, methoxymethyl, or methyl group or a hydrogen atom. The primary amine was protected with a monomethoxytrityl (MMT) group. The chemical properties of ONTs containing these amino-modifications were investigated. The MMT group of these amino-modifications could be quite rapidly removed from the amine under very mild acidic conditions, which are not strong enough for the deprotection of a conventional aliphatic amine. This significant feature enabled the amino-modified ONTs to be conveniently purified with a reverse phase column. Furthermore, the amino-modifications efficiently reacted to active esters, as compared with other amino-modifications. We also found that the pK(a) values of the amino-modifications were lower than that of the aliphatic amine. All of the experimental results showed that these chemical properties are closely related to their structures. We report here the chemical properties and the availability of the new amino linker reagents.

Pathological study of bronchospasms/tracheomalasia in patients with severe motor and intellectual disabilities.

This report concerns two autopsy cases of severe motor and intellectual disabilities (SMID) who died of bronchospasms or tracheomalasia. One case had no anatomical change in the tracheal wall except for an endotracheal granuloma, while the other showed softening of the tracheal wall. Since patients with SMID have risk factors for bronchospasms and tracheomalasia, such as gastro-esophageal reflux, aspiration, and thoracic deformities, it is important that we suspect the possibility of these conditions, when we see the respiratory distress in cases of SMID.