Determinants of Staphylococcus aureus colonization and infection: Characterization of interaction between serine-aspartate containing protein D and human Siglec11 and Siglec16

Abstract

<p><i>Staphylococcus aureus</i> is a Gram-positive opportunistic pathogen responsible for a range of infections that can lead to fatal invasive diseases such as pneumonia or osteomyelitis. Approximately 30% of the healthy adult population are persistently colonized by <i>S. aureus</i> strains in their anterior nares. The molecular mechanism underlying <i>S. aureus</i> colonization and infection during its interaction with the host is not fully understood. <p><i>S. aureus</i> can express several virulence determinants during its interaction with the host and/or host components. One of these virulence determinants is the serine-aspartate containing protein D (SdrD). It can increase <i>S. aureus</i> ability to survive in the blood and during systemic infections. SdrD is important for <i>S. aureus</i> colonization, survival, and infection of the host. <p>Unpublished results have demonstrated a possible interaction between SdrD and various proteins in human blood plasma. One of these proteins was identified as the human protein Siglec16. The biological functions of Siglec16 are mostly unknown however, studies show high identity between extracellular regions of Siglec11 and 16. Therefore, this study also includes the Siglec11 as a possible binding partner of the SdrD in the plasma. <p>The aim of this thesis was to develop the biological tools which will facilitate the characterization of the biological implications of the possible interaction between SdrD and Siglec16 and/or Siglec11. The overall results show a slight progress in obtaining the tools to help in further research in characterizing the biological functions of the proteins Siglec16 and Siglec11. However, some results remain unclear and inconclusive in demonstrating a possible or significant interaction between SdrD and the Siglec proteins 11 and 16.