Abstract: The invention concerns CD40 skipping 5 nucleic acid sequences and amino acid sequences obtained by alternative splicing of CD40, pharmaceutical compositions comprising said sequences and methods for treatment of a disease, wherein a beneficial therapeutic effect is achieved by the up regulation of the CD40-R-CD40-L interaction. An antibody capable of selectively binding to the amino acid of CD40 skipping 5 and pharmaceutical composition comprising the above antibody and methods for detecting the presence of exon 5 skipping expression in a sample are also within the scope of the invention.

Abstract: Provided are substantially pure CD40 splice variants that include altered internal sequences and unique tail sequences relative to previously described CD40 protein sequences. Also provided are fragments of the CD40 splice variants comprising at least 10 amino acids including at least 4 amino acids of the unique tail sequence; the unique tail sequences, and homologues thereof having at least 10 amino acids and 90% identity and antibodies which bind to an epitope on such proteins are disclosed. Pharmaceutical compositions comprising the protein, antibodies, isolated nucleic acid molecule that encode such proteins and pharmaceutical composition comprising such nucleic acid molecules are also disclosed. The present invention additionally relates to recombinant expression vectors that include the nucleic acid molecules and host cells which comprise such recombinant expression vectors are disclosed.