The present invention relates to protein constructs that comprise one or more peptides, proteins, factors, compounds or other components as further described herein that are linked to and/or are linked to each other via a helical polymeric backbone. The constructs of the invention are suitable for administration to a human or animal body and can be used for pharmaceutical purposes, for example for immunotherapy such as for treating cancer and for other immunological applications, as well as for other therapeutic, prophylactic and/or diagnostic purposes.