| 摘要 |
<p>Disclosed are bacteria having virulence attenuated by a mutation to the gene poxR and a method of producing them. Such bacteria are useful for inducing an immune response in an animal or human against virulent forms of the bacteria with reduced risk of a virulent infection and as an alternative to normally virulent bacteria as research tools. In a preferred embodiment, poxR attenuated bacteria can be used as a vaccine to induce immunoprotection in an animal against virulent forms of the bacteria. The disclosed bacteria can also be used as hosts for the expression of heterologous genes and proteins, or to deliver DNA for genetic immunization, or to deliver and present heterologous antigens to the immune system of an animal, leading to improved stimulation of an immune response to the antigens. It has been discovered that bacteria harboring a poxR mutation has significantly reduced virulence. Also disclosed is the nucleotide sequence of the poxR gene from Salmonella typhimurium, and the amino acid sequence of the encoded protein. The encoded protein has 325 amino acids and has significant sequence similarity to class-II lysyl-tRNA synthetases.</p> |
