Uses of parasite macrophage migration inhibitory factors
This invention relates to compositions (e.g. vaccine compositions) which can be used to provide a subject with protective immunity against a parasite infection. The compositions comprise: (i) an immunologically effective amount of a nucleic acid (e.g. a nucleic acid-based vaccine) comprising a sequence which encodes a parasite macrophage migration inhibitory factor (MIF) antigen; (ii) a parasite MIF antigen; or (iii) an antibody which specifically binds to a parasite MIF antigen. The compositions may be used to treat infections and diseases caused by parasitic protozoans, such as a Plasmodium parasite, or parasitic helminths.
1. A method for providing protective immunity against a Plasmodium infection in a subject in need thereof, comprising administering an immunologically effective amount of a composition to the subject, wherein the composition is an RNA immunogen comprising an RNA comprising a sequence which encodes a Plasmodium macrophage migration inhibitory factor (MIF) antigen, wherein the RNA immunogen induces protective immunity in the subject that is characterized by protective immunological memory against the Plasmodium and/or an effective Plasmodium parasite-responsive memory T cell population.
2. The method of claim 1 , wherein the RNA-based immunogen comprises a self-replicating RNA molecule.
3. The method of claim 2 , wherein the self-replicating RNA is an alphavirus-derived RNA replicon.
4. The method of claim 1 , wherein the composition further comprises a delivery system selected from the group consisting of a cationic nano-emulsion (CNE) delivery system and a lipid nanoparticle (LNP) delivery system.
5. The method of claim 1 wherein the subject is a vertebrate.
6. The method of claim 1 wherein:
(a) the composition further comprises a nucleic acid sequence which encodes an additional Plasmodium antigen, and/or
(b) the composition further comprises an additional Plasmodium antigen, and/or
(c) the composition is administered to the subject in combination with a further composition which comprises a nucleic acid comprising a sequence which encodes an additional Plasmodium antigen; and/or
(d) the composition is administered to the subject in combination with a further composition which comprises an additional Plasmodium antigen.
7. A method of enhancing an immune response to a non-MIF Plasmodium antigen in a subject, comprising administering a composition to the subject, wherein the composition is an RNA immunogen comprising an RNA comprising a sequence which encodes a Plasmodium macrophage migration inhibitory factor (MIF) antigen, wherein the RNA immunogen induces protective immunity that is characterized by protective immunological memory against the Plasmodium and/or an effective Plasmodium parasite-responsive memory T cell population, and wherein the composition further comprises an effective amount of the non-MIF Plasmodium antigen.
8. The method of claim 1 , wherein the composition is administered to the subject as a prophylactic.