Methods of Eliciting Broadly Neutralizing Antibodies Targeting HIV-1 GP41

Abstract

The present invention is directed to the induction and characterization of a humoral immune response targeting “entry-relevant” gp41 structures. In its broadest aspect, the present invention is directed to methods of raising a neutralizing antibody response to a broad spectrum of HIV strains and isolates. The present invention targets particular molecular conformations or structures that occur at the cell surface of HIV during viral entry into host cells. Such a humoral response can be generated in vivo as a prophylactic measure in individuals to reduce or inhibit the ability of HIV to infect uninfected cells in the individual's body. Such a response can also be employed to raise antibodies against “entry relevant” gp41 structures. These antibodies can be employed for therapeutic uses, and as tools for further illuminating the mechanism of HIV cell entry.

1 - 14 . (canceled) 
     
     
         15 . A method of raising a broadly neutralizing antibody response to HIV, comprising:
 administering to a mammal a composition including one or more peptides or polypeptides which comprise amino acid sequences that are capable of forming solution stable structures that correspond to, or mimic, the gp41 core six helix bundle.   
     
     
         16 . The method of  claim 15 , wherein said one or more peptides or polypeptides comprise a mixture of C-helical peptide or polypeptide and N-helical peptide or polypeptide. 
     
     
         17 . The method of  claim 15 , wherein at least one of said peptides or polypeptides is multimeric, or is a conjugate structure comprised of an N-helical domain amino acid sequence and a C-helical domain amino acid sequence. 
     
     
         18 . The method of  claim 15 , wherein said mixture of C-helical peptide or polypeptide and N-helical peptide or polypeptide forms a stable core helix solution structure. 
     
     
         19 . The method of  claim 15 , wherein said mixture comprises:
 P-17 and P-18,   P-15 and P-16,   P-17 and P-16 or   P-15 and P-18.   
     
     
         20 - 32 . (canceled) 
     
     
         33 . A composition comprising polyclonal or monoclonal antibodies that specifically bind to a polypeptide comprising:
 (a) one or more amino acid sequences that are capable of forming a stable coiled-coil solution structure corresponding to or mimicking the heptad repeat region of gp41 (N-helical domain); and   (b) one or more amino acid sequences that correspond to, or mimic, an amino acid sequence of the transmembrane-proximal amphipathic α-helical segment of gp41 (C-helical domain);   
       wherein
 said one or more sequences (a) and (b) are alternately linked to one another via a bond, such as a peptide bond (amide linkage) or by an amino acid linking sequence consisting of about 2 to about 25 amino acids. 
 
     
     
         34 . A method of treatment, comprising:
 administering to an individual a composition comprising polyclonal or monoclonal antibodies as claimed in  claim 33  in an amount effective to reduce HIV infection of uninfected cells.   
     
     
         35 . An isolated nucleic acid molecule comprising a polynucleotide having a nucleotide sequence at least 95% identical to a sequence encoding a peptide or polypeptide conjugate comprising (a)one or more amino acid sequences that are capable of forming a stable coiled-coil solution structure corresponding to or mimicking the heptad repeat region of gp41 (N-helical domain); and
 (b) one or more amino acid sequences that correspond to, or mimic, an amino acid sequence of the transmembrane-proximal amphipathic α-helical segment of gp41 (C-helical domain);   
       wherein said one or more sequences (a) and (b) are alternately linked to one another via a bond, such as a peptide bond (amide linkage) or by an amino acid linking sequence consisting of about 2 to about 25 amino acids. 
     
     
         36 . The nucleic acid molecule of  claim 35 , wherein said polynucleotide has the nucleotide sequence in  FIG. 7 . 
     
     
         37 . (canceled) 
     
     
         38 . A recombinant vector comprising the nucleic acid molecule of  claim 35 . 
     
     
         39 . (canceled) 
     
     
         40 . A recombinant host cell comprising the vector of  claim 38 . 
     
     
         41 . A recombinant method for producing a conjugate peptide or polypeptide, comprising culturing the recombinant host cell of  claim 40  under conditions such that said polypeptide is expressed and recovering said polypeptide. 
     
     
         42 . The method of  claim 15  wherein said administering is provided in advance of any symptoms of HIV infection, or in advance of any known exposure to HIV. 
     
     
         43 . The method of  claim 15  wherein said administering is provided upon or after the detection of symptoms which indicate that an animal may be infected with HIV, or upon or after exposure to the virus.