Abstract: This invention relates generally to the field of growth factor. In particular, the invention provides an isolated nucleic acid fragment, comprising a sequence of nucleotides encoding a Kringle domain 1 of human hepatocyte growth factor (HGFK1). Proteins or peptides encoded by the HGFK1 nucleic acids are also provided. Compositions comprising HGFK1 nucleic acids, proteins, or functional derivatives or fragments are also provided. Methods for producing and/or using HGFK1 nucleic acids, proteins, or functional derivatives or fragments are further provided.

Abstract: A recombinant vaccinia virus, effective in combatting hepatitis B infections in humans, is provided. The virus has incorporated therein the entire HBsAg gene, and is capable of expressing in and secreting from animal (including human) cells, in particulate form, all three of the constituent protein epitopes S, preS2 and preS1 constituting the proteinaceous surface antigen of hepatitis B virus. The recombinant vaccinia virus is prepared by recombination of a selected vaccinia virus strain of very low toxicity towards mammals with an expression plasmid containing the HBsAg sequence and the promoter sequence thereof in operative registry therewith, this sequence being provided at a location interposed within a gene sequence common to the expression plasmid and the vaccinia viral genome. This recombinant virus can be used as a novel live vaccine of low toxicity and also as a system for the production of secretable HBsAg particles with all of the three components, which can be applied as a novel sub-unit vaccine.