HIV-1 Peptides, Nucleic Acids, and Compositions and Uses Thereof
This invention features polypeptides, variants thereof, and fragments thereof useful in eliciting an immune response (e.g., neutralizing antibodies) against abroad spectrum of HIV-I isolates. The polypeptides, variants, and fragments include a portion of the gp120 V2 domain of HIV-I. The polypeptides, variants, and fragments display an epitope that is recognized by at least one antibody which neutralizes at least one HIV-I primary isolate. This invention also features nucleic acid sequences encoding those polypeptides. In addition, the invention provides methods of screening for inhibitors of HIV-I entry into cells, as well as methods of treatment using the inhibitors.
1 . An isolated polypeptide, consisting of:
(a) an amino acid sequence EIKNC SFNXT TXXRD KXXXX YXLFY XLDXV (SEQ ID NO:1); or
(b) a fragment of the sequence, wherein the fragment comprises amino acids 14-20 of SEQ ID NO:1; or
(c) a fragment of the sequence, wherein the fragment comprises at least six consecutive amino acids of SEQ ID NO:1 and includes at least two of the residues at positions 14-16 and at least two of the X residues at positions 17-20,
wherein the X at position 9 of SEQ ID NO:1 is M or I;
the X at position 12 of SEQ ID NO:1 is S, E, G, or N;
the X at position 13 is L, I, or M;
the X at position 17 of SEQ ID NO:1 is K, R or Q;
the X at position 18 of SEQ ID NO:1 is K, R, or Q;
the X at position 19 of SEQ ID NO:1 is K, R or Q;
the X at position 20 of SEQ ID NO:1 is E or V;
the X at position 22 of SEQ ID NO:1 is S or A;
the X at position 26 of SEQ ID NO:1 is K or R; and
the X at position 29 of SEQ ID NO:1 is I or V.
2 . The polypeptide of claim 1 , selected from the group of
a) wherein the X at position 17 is K; the X at position 18 is Q; the X at position 19 is K; and the X at position 20 is V (KQKV, SEQ ID NO:3);
b) wherein the X at position 17 is K; the X at position 18 is Q; the X at position 19 is K; and the X at position 20 is E (KQKE, SEQ ID NO:4);
c) wherein the X at position 17 is K; the X at position 18 is K; and the X at position 19 is K (KKK);
d) wherein the X at position 17 is K; the X at position 18 is R; and the X at position 19 is Q (KRQ);
e) wherein the X at position 17 is K; the X at position 18 is K; and the X at position 19 is Q (KKQ); or
f) wherein the X at position 17 is K; the X at position 18 is Q; and the X at position 19 is Q (KQQ).
3 . An isolated protein comprising the polypeptide of claim 1 , and flanked at either end, or both ends, by a heterologous amino acid sequence.
4 . The isolated polypeptide of claim 1 , wherein the polypeptide is glycosylated.
5 . (canceled)
6 . A pharmaceutical composition comprising the polypeptide of claim 1 and a pharmaceutically acceptable carrier.
7 . An isolated antibody, or antigen-binding fragment thereof, that specifically binds to a polypeptide consisting of SEQ ID NO:6 at an epitope comprising one or more of the amino acid residues at positions 14-19 of SEQ ID NO:1.
8 . The isolated antibody of claim 7 , wherein the residues at positions 17-20 of SEQ ID NO:1 are selected from of KQKE (SEQ ID NO:4) or KQKV (SEQ ID NO:3).
9 . An isolated antibody that crossblocks the binding of the antibody of claim 7 .
10 . The isolated polypeptide of claim 1 , wherein the polypeptide, when administered to a mammalian subject, elicits the production by the subject of an antibody that has cross-neutralizing activity against HIV-1.
11 . An isolated nucleic acid encoding the polypeptide of claim 1 .
12 . A vector comprising the nucleic acid sequence of claim 11 .
13 . (canceled)
14 . A method of stimulating the production of an antibody in a mammalian subject, the method comprising
delivering to a mammalian subject a composition comprising the polypeptide of claim 1 .
15 - 19 . (canceled)
20 . The method of claim 14 , further comprising delivering one or more additional polypeptides to the subject, wherein each of the one or more additional polypeptides is a polypeptide consisting of:
(a) an amino acid sequence EIKNC SFNXT TXXRD KXXXX YXLFY XLDXV (SEQ ID NO:1); or
(b) a fragment of the sequence, wherein the fragment comprises amino acids 14-20 of SEQ ID NO:1; or
(c) a fragment of the sequence, wherein the fragment comprises at least six consecutive amino acids of SEQ ID NO:1 and includes at least two of the residues at positions 14-16 and at least two of the X residues at positions 17-20, wherein
the X at position 9 of SEQ ID NO:1 is M or I;
the X at position 12 of SEQ ID NO: 1 is S, E, G, or N;
the X at position 13 is L, I, or M;
the X at position 17 of SEQ ID NO: 1 is K, R or Q;
the X at position 18 of SEQ ID NO: 1 is K, R, or Q;
the X at position 19 of SEQ ID NO: 1 is K, R or Q;
the X at position 20 of SEQ ID NO: 1 is E or V;
the X at position 22 of SEQ ID NO: 1 is S or A;
the X at position 26 of SEQ ID NO: 1 is K or R; and
the X at position 29 of SEQ ID NO:1 is I or V.
21 . The method of claim 1 , wherein the mammalian subject is a human.
22 . The method of claim 14 , wherein the polypeptide comprises a single-chain epitope fused to a T-helper amino acid sequence.
23 - 24 . (canceled)
25 . A method of inhibiting infection of a cell by HIV-1, the method comprising contacting a cell or an HIV-1 virus with the polypeptide of claim 1 .
26 . (canceled)
27 . A method of treating a subject that is infected, is suspected of being infected, or is likely to be infected with HIV-1, the method comprising delivering to a subject the pharmaceutical composition of claim 6 .
28 - 29 . (canceled)
30 . A method of immunizing a human subject with an immunogen consisting or containing the polypeptides of claim 1 , together with appropriate adjuvants and carriers, in order to induce an antibody response that protects against infection by HIV.
31 . A method of immunizing a human subject with an immunogen consisting or containing the polypeptides of claim 1 , together with appropriate adjuvants and carriers, where the specific sequence of the V2-CND polypeptide is identical or highly related to the sequence of the corresponding region in a virus or HIV-1 Env gene isolated directly from the same patient.
32 . An isolated protein comprising the polypeptide of claim 1 , and flanked at either end, or both ends, by additional gp120-derived amino acid sequences that normally flank this region in one or more viral isolates.