The invention relates to a fusion protein comprising a polypeptide of interest, a transmembrane domain and an HIV gag polypeptide, or their functionally equivalent variants. The invention also relates to the polynucleotides, vectors, host cells and virus-like particles expressing or presenting said fusion proteins and to the pharmaceutical, immunogenic or vaccines composition containing said fusion proteins, polynucleotides, vectors, host cells and virus-like particles and their use in human and veterinary medicine.