Abstract: Disclosed are methods and compositions for creating a DNA, RNA or protein molecule with two or more nucleic acid or polypeptide domains, respectively, joined by a linker region. These methods are used to generate random linker libraries of nucleic acids that encode dual-domain or multi-domain polypeptides. The linker regions are characterized by both length and sequence variability.

Abstract: A polypeptide self-antigen useful in a tumor-specific vaccine mimics one or more epitopes of an antigen uniquely expressed by cells of the tumor. The polypeptide is preferably produced in a plant that has been transformed or transfected with nucleic acid encoding the polypeptide and is obtainable from the plant in correctly folded, preferably soluble form without a need for denaturation and renaturation. This plant-produced polypeptide is immunogenic without a need for exogenous adjuvants or other immunostimulatory materials. The polypeptide is preferably an scFv molecule that bears the idiotype of the surface immunoglobulin of a non-Hodgkin's (or B cell) lymphoma. Upon administration to a subject with lymphoma, the plant-produced, tumor-unique scFv polypeptide induces an idiotype-specific antibody or cell-mediated immune response against the lymphoma.

Abstract: A novel method of over expressing genes in plants is provided. This method is based on the RNA amplification properties of plus strand RNA viruses of plants. A chimeric multicistronic gene is constructed containing a plant promoter, viral replication origins, a viral movement protein gene, and one or more foreign genes under control of viral subgenomic promoters. Plants containing one or more of these recombinant RNA transcripts are inoculated with helper virus. In the presence of helper virus recombinant transcripts are replicated producing high levels of foreign gene RNA. Sequences are provided for the high level expression of the enzyme chloramphenicol acetyltransferase in tobacco plants by replicon RNA amplification with helper viruses and movement protein genes derived from the tobamovirus group.

Abstract: The invention relates to ?-galactosidase truncated at the carboxy terminus and the production of enzymatically active recombinant human and animal lysosomal enzymes involving construction and expression of recombinant expression constructs comprising coding sequences of human or animal lysosomal enzymes in a plant expression system. The plant expression system provides for post-translational modification and processing to produce a recombinant gene product exhibiting enzymatic activity. The invention is demonstrated by working examples in which transgenic tobacco plants express recombinant expression constructs comprising human glucocerebrosidase nucleotide sequences. The invention is also demonstrated by working examples in which transfected tobacco plants express recombinant viral expression constructs comprising human ? galactosidase nucleotide sequences.

Abstract: A method for extracting proteins from the intercellular space of plants is provided. The method is applicable to the large scale isolation of many active proteins of interest synthesized by plant cells. The method may be used commercially to recover recombinantly produced proteins from plant hosts thereby making the large scale use of plants as sources for recombinant protein production feasible.