This invention discloses immunopotentiating agents which stimulate an immune response. These agents are categorized into single agents that act directly, adjuvants added concurrently with the agents, or heteroconjugates. Heteroconjugate agents elicit or enhance a cellular or humoral immune response which may be specific for an
epitope contained within an
amino acid sequence. Enhanced hematopoieses by
bone marrow stem cell recruitment was also a result of administering some of these agents. Examples of immunopotentiating agents include
monoclonal antibodies and proteins derived from microorganisms (e.g., enterotoxins) which activate T cells. One method of treatment disclosed uses only the immunopotentiating agent to stimulate the
immune system. Another uses adjuvants in combination with the agent. A third method employs heteroconjugates. Heteroconjugates comprise: (a) an immunopotentiating
protein which is characterized as having an ability to stimulate T cells; and (b) a second
protein having an
amino acid sequence which includes an
epitope against which a cellular or humoral response is desired. This invention also relates to a method of preparing the heteroconjugate, and to a method of stimulating the
immune system in vivo in a novel way. One
route of stimulation is to activate T cells, in some instances, specific subsets of T cells, by administering heteroconjugates containing an immunopotentiating
protein and a second protein, to mammals. For this method of treatment, the second protein in the heteroconjugate is derived from abnormal or diseased tissue, or from an
infectious agent; alternatively, the second protein is produced synthetically by
standard methods of
molecular biology. Sources of the second protein include tumors, viruses,
bacteria, fungi, protozoal or metozoal parasites.
Monoclonal antibodies or T cells prepared from mammals whose immune systems have responded to administration of the heteroconjugate may be produced and administered to induce
passive immunity. A method of preparing a hybridoma which secretes said
monoclonal antibodies and use of these
monoclonal antibodies and T cells, are also disclosed. This invention is also directed to a vaccine comprising the heteroconjugate.