Although, the V3 loop displays high structural conservation, yet the degree of cross reactive anti-V3 antibody response in individuals infected with diverse HIV-1 subtypes varies substantially [39] . This difference in antibody response to V3 loop, has been shown to be primarily determined by the four amino residues in the V3 crown (GPGQ or GPGR), which mostly form a type II β-turn [19, 40] . Interestingly, the anti-V3 monoclonal antibodies (mAbs) isolated from non-clade B infected individuals, bearing GPGQ at the tip of V3 display better neutralization capacity than subtype-B (having GPGR) derived anti-V3 mAbs [19] . Such an observation was substantiated by a study showing a high neutralization potential of the anti-V3 mAbs derived from Cameroon subjects infected with viruses harboring GPGQ (subtype-AG) at the V3 crown [21] . Further, in an immunization study carried out in rabbits with a gp120 DNA prime followed by a boost with various cholera toxin B (CTB) fusion proteins containing the V3 sequences from different HIV-1 subtypes, the CTB fusion protein containing a consensus-C (con-C) V3 sequence (V3C-CTB) (having a GPGQ motif at V3 crown), elicited a highly potent HIV-1 neutralizing response compared to the other V3-CTB constructs [41] .