Abstract: The present invention relates fusion partners which act as immunological fusion partners, as expression enhancers, and preferably to fusion partners having both functions. In particular the fusion partners contain a so-called choline binding domain, for example fusions comprising LytA from Streptococcus pneumoniae, or the pneumococcal phage CP1 lysozyme (CPL1) wherein the choline binding domain is modified to include a heterologous T-helper epitope, and are fused to antigens, particularly poorly immunogenic antigens such as self-antigens, eg tumour specific or tissue specific antigens. The invention also relates to fusion proteins containing them, to their manufacture, to their use in immunogenic compositions and vaccines and to their use in medicines.