Application of phage display to high throughput antibody generation and characterization

We have created a high quality phage display library containing over 10¹⁰ human antibodies and describe its use in the generation of antibodies on an unprecedented scale. We have selected, screened and sequenced over 38,000 recombinant antibodies to 292 antigens, yielding over 7,200 unique clones. 4,400 antibodies were characterized by specificity testing and detailed sequence analysis and the data/clones are available online. Sensitive detection was demonstrated in a bead based flow cytometry assay. Furthermore, positive staining by immunohistochemistry on tissue microarrays was found for 37% (143/381) of antibodies. Thus, we have demonstrated the potential of and illuminated the issues associated with genome-wide monoclonal antibody generation.     

Culture of a prostatic cell line in basement membrane gels results in an enhancement of malignant properties and constitutive alterations in gene expression

Interaction of a transformed rat prostate epithelial cell (NbMC-2) with basement membrane gels (Matrigel) has been evaluated using a long-term matrix culture system. NbMC-2 cells, and single-cell clonal derivatives, formed spheroidal multicellular structures (aggregates) on Matrigel surfaces and were weakly invasive or noninvasive during a 1 week period. During subsequent 2–4 week periods, invasive cells originating from the aggregates and exhibiting a fusiform morphology became evident and increased in number in the matrix cultures. This biphasic pattern of behavior did not occur on laminin, type I or type IV collagen, or fibronectin substrates, but it did occur on Matrigel in serum-free medium. Characterization of sublines enriched in fusiform cells indicated that they maintained their distinct morphology with continuous culture. Further, they exhibited significantly greater invasive potential, saturation density, and random motility (chemokinesis) than the parent cell line. Steady-state levels of fibronectin mRNA were highly elevated in the tusiform variants, demonstrating a constitutive alteration in patterns of gene expression coinciding with the altered morphology. These results indicate that clonal NbMC-2 cells differentiate at a reproducible frequency into a more aggressive cell type in response to culture in the basement membrane–-like matrix. The altered phenotypic properties appear to be stable since they can be inherited by daughter cells and because they are evident in the absence or matrix. These observations suggest a cell-specific mechanism for promotion of malignant growth by matrix-mediated induction of novel cell properties. © 1994 Wiley-Liss, Inc.     

Prostaglandin VIII — Synthesis of some 9-oxoprostynoic acids

The communication describes the synthesis of (±) 13-dehydro-11-deoxy-PGE₁, 9-oxo-13-hydroxyprost-14-ynoic acid, and (14z)-9-oxo-13-hydroxy-prost-14-enoic acid.     

Short chain oligogalacturonides induce ethylene production and expression of the gene encoding aminocyclopropane 1-carboxylic acid oxidase in tomato plants

Oligogalacturonic acids (OGAs), derived from plant cell wall pectin, have been implicated in a number of signal transduction pathways involved in growth, development and defense responses of higher plants. This study investigates the size range of OGAs capable of inducing ethylene synthesis in tomato plants, and demonstrates that in contrast with many other effects, only short chain OGAs are active. Oligomers across a range of DP from 2-15 were separated and purified to homogeneity by QAE-Sephadex anion exchange chromatography using a novel elution system. The OGAs were applied to tomato plants and assayed for their ability to induce ethylene gas release and changes in steady state levels of mRNA encoding the ethylene forming enzyme aminocyclopropane-1-carboxylic acid oxidase (ACO). The study demonstrated that only OGAs in the size range of DP4-6 were active both in eliciting ACO expression and in the production of ethylene.