Immune responses to DNA vaccines

DNA vaccines, based on plasmid vectors expressing an antigen under the cont rol of a strong promoter, have been shown to induce protective immune respo nses to a number of pathogens, including viruses, bacteria and parasites. T hey have also displayed efficacy in treatment or prevention of cancer, alle rgic diseases and autoimmunity. Immunologically, DNA vaccines induce a full spectrum of immune responses that include cytolytic T cells, T helper cell s and antibodies. The immune response to DNA vaccines can be enhanced by ge netic engineering of the antigen to facilitate its presentation to B and T cells. Furthermore, the immune response can be modulated by genetic adjuvan ts in the form of vectors expressing biologically active determinants or by more traditional adjuvants that facilitate uptake of DNA into cells. The e ase of genetic manipulation of DNA vaccines invites their use not only as v accines but also as research tools for immunologists and microbiologists.