RTX Toxin Determined Virulence of Pasteurellaceae
from: Pasteurellaceae: Biology, Genomics and Molecular Aspects (Edited by: Peter Kuhnert and Henrik Christensen). Caister Academic Press, U.K. (2008)
RTX toxins are bacterial pore forming toxins that are particularly abundant among pathogenic species of Pasteurellaceae where they play a major role in virulence. RTX toxins of several primary pathogens of the family of Pasteurellaceae are directly involved in causing necrotic lesions of the target organs. Many RTX toxins are mainly known as haemolysins due to their capacity to lyse erythrocytes in vitro, an effect that seems to be non-specific. It is now known for many RTX toxins that their specific targets are leukocytes, where RTX toxins bind to the corresponding β subunit (CD18) of β2 integrons and then cause a cytotoxic effect. For several RTX toxins the binding to CD18 was shown to be host specific and seems to be the basis determining the host range of a given RTX toxin. Observations on very closely related species of the Pasteurellaceae family with different RTX toxins indicate that these latter contribute to a significant part to the host specificity of the pathogen itself. RTX toxins induce a strong immunologic response generating neutralizing antibodies. They therefore constitute important antigens in modern subunit vaccines read more ...