Type V Secretion System Exoproteins and their Roles in the Adherence of the Gram-Negative Bacterial Pathogens Moraxella catarrhalis, Burkholderia pseudomallei and Burkholderia mallei
Type V secretion systems are responsible for secretion of large molecular weight virulence factors in a wide variety of Gram-negative pathogens. The type V secretion system family consists of Two Partner Secretion (TPS) systems and autotransporter proteins. These systems are responsible for the export of a large number adherence factors which are important for the pathogenesis of the organism possessing these systems. In these studies, we have identified several type V secretion systems which appear to be important for adherence of the Gram-negative pathogens Moraxella catarrhalis, Burkholderia pseudomallei, and Burkholderia mallei. More specifically, we identified three proteins, MhaB1, MhaB2, and MhaC, which make up a TPS system in M. catarrhalis that is wellconserved and is important for adherence of the organism to human epithelial cells. In B. pseudomallei, two autotransporter proteins, namely BocA1 and BocA2, were also shown to be important for attachment of this organism to human respiratory cells and appear to be well conserved. A well-conserved homolog of BocA1 was also identified in B. mallei and was demonstrated to be important for the binding of this organism to cells derived from the human respiratory tract as well. Taken together, these data reveal the identification and characterization of six novel proteins which appear to be important for the pathogenesis of these organisms and may be attractive targets for the highly desired vaccines protecting against infection by these pathogens.
School:University of Toledo Health Science Campus
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:bacterial adherence moraxella catarrhalis burkholderia mallei pseudomallei type v secretion
Date of Publication:01/01/2007