DNA VACCINES FOR BACTERIAL-INFECTIONS

DNA vaccines are an exciting development in vaccine technology which m ay have a special role in preventing viral infections and as 'theracin es' for cancer. Their use in preventing bacterial infections has, by c omparison, been less well documented, While it is unlikely that tradit ional, highly successful and cheap vaccines for diseases such as dipht heria will be replaced by DNA vaccines, naked DNA may be particularly appropriate for preventing bacterial infections where cytotoxic T cell s confer protection, or where a Th1 type T cell response mediates resi stance, For example, DNA vaccines containing different mycobacterial a ntigens have been shown to inhibit overt infections by Mycobacterium t uberculosis in rodent models. The use of DNA vaccines In bacterial inf ections may be complicated by fundamental differences between prokaryo tic and eukaryotic genes and gene products, including mRNA stability, codon bias, secondary structures surrounding native start sequences an d glycosylation. These problems can be solved by re-synthesis of bacte rial genes to produce 'new' sequences which are more highly expressed by eukaryotic cells.