The present invention provides optimized nucleic acid molecules, methods for optimization of nucleic acid molecules and uses of optimized nucleic acid molecules. A modular design principle is provided that is suitable to generate a nucleic acid, particularly mRNA, which is tailored for a respective application. The nucleic acid molecules of the present invention can be obtained by the versatile combination of multiple modules on nucleic acid level. Such nucleic acid, e.g. mRNA, can be tailored by combining one or more modules, comprising (i) a nucleic acid moiety encoding a polypeptide of interest (e.g. a protein potentially producing a therapeutic outcome) and (ii) at least one further coding or non-coding nucleic acid moiety, e.g. selected among nucleic acid moieties encoding a polypeptide element, such as a secretory signal peptide (SSP), a multimerization element (dimerization, trimerization, tetramerization and oligomerization), a virus like particle (VLP) forming element, a transmembrane element, a dendritic cell targeting element, an immunological adjuvant element, an element promoting antigen presentation； a 2A peptide； a peptide linker element, elements that extend protein half-life, and/or any other polypeptide or protein. Non-coding nucleic acid moieties may be selected e.g. from the group comprising 3′-UTR, 5′-UTR, IRES element, miRNA moiety, histone stem loop, poly(C) sequence, polyadenylation signal, polyA-sequence. The optimized nucleic acid molecule can further be characterized by the presence of at least one modified nucleoside. The versatility of the present invention allows for rational design of a large variety of different nucleic acid molecules with desired properties.La présente invention concerne des molécules d'acide nucléique optimisées, des procédés d'optimisation de molécules d'acide nucléique et des utilisations de molécules d'acide nucléique optimisées. L'invention concerne un principe de construction modulaire permettant de générer u
