IgG Fc Receptors: Role in phagocytosis & Staphyloccal evasion

IgG mediates protection against bacterial infection by activating further opsonization by complement, and via direct tagging of bacteria for destruction through zspecific interaction with phagocyte IgG receptors. The studies presented in this thesis focus on exploring features of IgG-FcR interactions in phagocytosis: • Chapter 2 addresses the expression and function of a novel phagocyte IgG receptor in neutrophils. • The roles of different immunoglobulin heavy chain subclasses (Chapter 3) and light chain isotypes (Chapter 4) were investigated, in the light of differential interaction of IgG with FcRn- and FcR- mediated effector functions, including phagocytosis. • In Chapter 5 we investigated whether S. aureus can express FcR antagonists. • The mechanisms used by S. aureus to escape IgG-mediated immune responses like opsonophagocytosis are studied in Chapter 6. Chapter 7 contains summarizing conclusions and addresses implications of the findings in this thesis for our understanding of immune biology and staphylococcal evasion of IgG receptor-mediated phagocytosis.