Abstract: A method of releasing an agent for example, a chemotherapeutic, under predetermined conditions by protecting the agent within a lipid structure such as a liposome, causing lipase activity to be constituted by combining two or more components, e.g., recombinant N- or C-terminal Clostridium perfringens alpha-toxin fragments, one of these components being conjugated to a targeting molecule e.g., an antibody which binds to a target such as a tumor antigen. The lipid structure is then exposed to the constituted lipase activity such as to release the agent. Also disclose are materials and kits for use in the method.

Abstract: A method of releasing an agent (e.g. a chemotherapeutic) under predetermined conditions comprising the steps of protecting the agent within a lipid structure (e.g. a liposome), causing lipase activity to be constituted by combining two or more components (e.g. recombinant N- or C-terminal Clostridium perfringens alpha-toxin fragments), one of these components being conjugated to a targeting molecule (e.g. an antibody) which binds to a target (e.g. a tumour antigen) under the predetermined conditions. The lipid structure is then exposed to the constituted lipase activity such as to release the agent. Also disclosed are materials and kits for use in the method.

Abstract: The present invention provides human monoclonal antibodies, derived from the murine mAb NM-01 (PCT/US92/07111), which are specifically reactive with HIV gp120 and have the capacity to neutralize the infection of H9 cells in culture by live HIV-1 strains MN and III.sub.B as shown by reverse transcriptase, p24 and syncytium formation assays. These antibodies were shown to be as or more effective than the parent murine antibody by the aforementioned criteria.