Rantes mutants and therapeutic applications thereof

A RANTES mutant wherein, as compared to human wild-type RANTES, at least one amino acid is mutated in the N-terminal region, in the N-loop region, in the 40's-loop region or in all the three regions, said mutant having the capability to competitively antagonize wild-type RANTES, MIP-1α or MIP-1β, or to antagonize the interaction between HIV virus and a chemokine receptor, wherein said mutation is selected from the group consisting of:

• a) Ser1 with Cys;
• b) Ser4 with Cys;
• c) Ser5 with Cys;
• d) Tyr3 with Ala;
• e) Tyr14 with Phe;
• f) Asp6 with Arg;
• g) Arg17 with Ala;
• h) Arg44 with Glu or Ala;
• and
• i) Lys45 with Glu or Ala;
• with the proviso that when either Tyr3 or Arg17 is substituted with alanine, the mutant must comprise at least another one of the mutations a) to c), e), f), h) or i).