Method of inducing an antiviral immune response against HIV-1 utilizing chimeric HIV Env proteins comprising CD4 mini-proteins or CD4 mimetics
Env-CD4 polypeptide complexes and hybrids that expose cryptic epitopes important in virus neutralization are disclosed. Methods of diagnosis, treatment and prevention using the polypeptides are also provided.
1. A method of inducing an immune response in a subject, comprising:
administering a first composition comprising a polynucleotide encoding a hybrid human immunodeficiency virus (HIV) envelope (Env)-CD4 protein; and
administering a second composition comprising the hybrid human HIV Env-CD4 protein in an amount sufficient to induce an immune response in the subject,
wherein the hybrid HIV Env-CD4 protein comprises: (1) an HIV Env polypeptide which comprises a CD4-binding site and a deletion region from which one or more variable (V) regions are deleted; and (2) a CD4 mini-protein or a CD4-mimetic inserted into the deletion region, wherein the CD4 mini-protein or CD4-mimetic maintains the structural conformation of a CDR2-like loop; and wherein the insertion of the CD4 mini-protein or the CD4 mimetic leads to exposure of a cryptic HIV envelope epitope in or near the CD4-binding site or in or near the chemokine receptor-binding site.
2. The method of claim 1 , wherein the hybrid Env-CD4 protein comprises the CD4 mini-protein.
3. The method of claim 1 , wherein the hybrid Env-CD4 protein comprises the CD4 mimetic.
4. The method of claim 1 , wherein the deletion region comprises a deletion in V1.
5. The method of claim 1 , wherein the deletion region comprises a deletion in V2.
6. The method of claim 1 , further comprising one or more linker sequences.
7. The method of claim 6 , wherein the one or more linker sequences flank the CD4 mini-protein or the CD4 mimetic.
8. The method of claim 1 , wherein the CD4 mini-protein comprises the amino acid sequence SEQ ID NO:1.
9. The method of claim 1 , wherein the CD4 mini-protein comprises the amino acid sequence SEQ ID NO:2.
10. The method of claim 1 , wherein the CD4 mini-protein comprises the amino acid sequence SEQ ID NO:3.
11. The method of claim 1 , wherein the CD4 mini-protein comprises the amino acid sequence SEQ ID NO:4.
12. The method of claim 1 , wherein the HIV Env polypeptide comprises gp140.
13. The method of claim 1 , wherein the first composition comprises a vector encoding the polynucleotide.
14. The method of claim 13 , wherein the vector is a nonviral vector.
15. The method of claim 13 , wherein the vector is a recombinant viral vector.
16. The method of claim 15 , wherein the viral vector is a retroviral vector.
17. The method of claim 15 , wherein the viral vector is an alphaviral vector.
18. The method of claim 15 , wherein the viral vector is an adenoviral vector.
19. The method of claim 15 , wherein the viral vector is an adeno-associated viral vector.
20. The method of claim 15 , wherein the viral vector is a pox viral vector.
21. The method of claim 15 , wherein the viral vector is an avipox viral vector.
22. The method of claim 1 , wherein the polynucleotide is delivered using a particulate carrier.
23. The method of claim 22 , wherein the polynucleotide is coated on a gold or tungsten particle and the coated particle is delivered to the subject using a gene gun.
24. The method of claim 1 , wherein the polynucleotide is encapsulated in a liposome preparation.
25. The method of claim 1 , wherein the subject is a mammal.
26. The method of claim 1 , wherein the mammal is a human.
27. The method of claim 1 , wherein the first composition further comprises an adjuvant.
28. The method of claim 1 , wherein the second composition further comprises an adjuvant.