POLYPEPTIDES MODULATING SIGLEC DEPENDENT IMMUNE RESPONSES

The invention relates to a fusion protein comprising a main protein and one or more extension peptides, wherein the amino acid sequence of the main protein is identical or similar to the amino acid sequence of a mammalian protein or a fragment thereof, and said extension peptide comprises a cluster of O-glycosylated amino acids. The extension peptide is identical to a non-repeated sequence of the mammalian protein and/or identical or similar to SEQ ID NO: 1. The main protein is preferably VWF. The fusion protein has an increased half life as compared to the main protein and may be used to increase the half-life of a binding partner, e.g. FVIII. The invention further relates to the complex formed by the fusion protein, a polynucleotide encoding the fusion protein as well as a vector and host cell comprising the polynucleotide.