Immunogenic compositions comprising soluble, non-cleavable, chimeric HIV-1 gp160-variants

An immunogenic composition capable of eliciting human immunodeficiency virus type 1 (HIV-1) gp160-specific antibodies in a mammal comprising a soluble, non-cleavable, chimeric HIV-1 gp160 variant, said variant comprising the following regions:

• i) a first region derived from the gp160 of a first strain of HIV-1 consisting of amino acids X to Y, wherein X is a number from 1 to 271 and Y is a number from 306 to 482;
• ii) a second region derived from the gp160 of a second strain of HIV-1 consisting of amino acids Y+1 to the carboxyl terminus of the envelope, wherein said second region fails to contain functional major and minor proteolytic cleavage sites (amino acids 483-486 and 475-479, respectively) and functional major and minor hydrophobic domains (amino acids 487-516 and 659-680, respectively);
• and
• iii) an optional third region, present when X is greater than 1, said region derived from the gp160 of said second strain of HIV-1 and consisting of amino acids 1 to X−1,
• wherein the numbering scheme of X and Y is based upon the numbering scheme of the HIV-1 isolate BRU.