The present invention relates, in general, to an immunogen and, in particular, to an immunogen for inducing antibodies that neutralizes a wide spectrum of HIV primary isolates and/or to an immunogen that induces a T cell immune response. The invention also relates to a method of inducing anti-HIV antibodies, and/or to a method of inducing a T cell immune response, using such an immunogen. The invention further relates to nucleic acid sequences encoding the present immunogens.