The present invention relates to novel isolated antibodies, or the derivatives or antigen binding fragments of same, capable of binding to CXCR4 but also of inducing conformational changes of the CXCR4 homodimers and able to inhibit HIV-1 primary isolate replication in PBMC. More particularly, the present invention relates to the 515H7 and 301aE5 monoclonal antibodies, specific to the CXCR4 protein, as well as their use for the treatment of HIV infection. Pharmaceutical compositions comprising such antibodies and a process for the selection of such antibodies are also covered.
