BigPatents India

The invention provides a linear concatamer of at least two non-identical DNA sequences which, by virtue of third base redundancy of the genetic code of the codons, each encode the same polypeptide of at least 30 amino acids; wherein the concatamer comprises or consists of a nucleic acid sequence which codes for an oligomer of said polypeptides in a continous reading frame. A single invariant cysteine codon may be added to one DNA sequence to encode a polypeptide derivative with a unique unpaired cysteine. The concatamer may be fused to one or more sequences encoding one or more antigens. The DNA sequences in the concatamer may encode the compliment C3 fragment C3d or an analogue thereof. The invention also provides an expression vector comprising the concatamer nucleic acid sequence and regulatory or other sequences for expression of any oligomeric polypeptide encoded thereby, as well as a host cell comprising the expression vector. The invention can also provide a method of inducing an immune response to an antigen in the human or animal by administering a concatamer or administering a vector. Thus the invention can provide a pharmaceutical composition in the form of a DNA vaccine. Drawing: NIL Total Pages: 55 (FIG.-NIL)