The present invention may be included in the field of biotechnology and it covers the improved production of recombinant proteins in insect cells or insect larvae as biofactories by a novel expression cassette. This expression cassette comprises nucleic acid sequences such as promoters, homologous regions (hr) as enhancers, and sequences encoding transcriptional regulators, for example, the baculovirus Ac-ie-01 cDNA, or any combination thereof, which are able to increase the quality and production efficiency of the recombinant proteins. Moreover, the present invention is also directed to the vectors themselves comprising the above mentioned nucleic acid sequences of the invention, cells or insects infected, transformed or transfected with those sequences or vectors, and methods for producing the recombinant proteins by using the aforesaid sequences, vectors, cells or insects.

The present invention provides methods of treating, protecting against and inducing an immune response against a tumor or cancer, comprising the step of administering to a subject a recombinant Listeria strain. In one embodiment the present invention relates to a recombinant Listeria strain, said recombinant Listeria strain comprising a recombinant nucleic add, said nucleic add comprising a first open reading frame encoding a recombinant polypeptide comprising a first N-terminal fragment of an LLO protein fused to a heterologous antigen or fragment thereof, and wherein said recombinant nucleic add further comprises a second open reading frame encoding a mutant PrfA protein.

The disclosure relates to a truncated recombinant L1 protein of Human papillomavirus (HPV), a recombinant polynucleotide encoding the protein, a recombinant vector comprising the polynucleotide, an isolated cell comprising the recombinant vector, a composition comprising the protein, and a method for producing the protein. The disclosure also relates to an HPV virus-like particle (VLP) comprising the protein, an immunogenic composition comprising the protein or the VLP, and a method for inducing an immune response to HPV in an individual.