Caveolin-1 is a scaffolding protein that organizes and concentrates specific ligands within the caveolae membranes. We identified a conserved caveolin-1 binding motif in the HIV-1 transmembrane envelope glycoprotein gp41 and designed several synthetic peptides, referred to as CBD1, corresponding to the consensus caveolin-1 binding domain in gp41. In rabbits, these peptides elicit the production of antibodies that inhibit infection of primary CD4(+) T lymphocytes by various primary HIV-1 isolates. Interestingly, gp41 exists as a stable complex with caveolin-1 in HIV-infected cells. Anti-CBD1 peptide antibodies, therefore, might be functional by inhibiting the potential interaction of gp41 with caveolin-1. Because of their capacity to elicit antibodies that inhibit the different clades of HIV-1, CBD1-based peptides may represent a novel synthetic universal B cell epitope vaccine candidate for HIV/AIDS. Moreover, such peptides could also have an application as a therapeutic vaccine since CBD1-specific antibodies are rare in HIV-infected individuals from several geographic origins.