Protection Against Tuberculosis by Plasmid DNA

The availability of cloned mycobacterial genes and suitable vectors for expression in mammalian cells has now opened a new avenue in which individual mycobacterial protein antigens can be tested for their ability to confer protective immunity. Expression of protection against mycobacteria is largely a function of antigen specific CD4 and cytotoxic CD8 T cells. We have found that intramuscular injection of plasmid DNA expressing several mycobacterial immunodominant genes can induce both T cell populations and confer protection equivalent to BCG, suggesting that this approach may lead to a new vaccine.