Expression of two immunoglobulin binding proteins is necessary for S. aureus to avoid host mediated innate and adaptive immune systems (P3138)

• Published in: The Journal of immunology (1950) 2013-05, Vol.190 (1_Supplement), p.186-186.16
• Main Authors: Kim, Hwan Keun, Falugi, Fabiana, Missiakas, Dominique, Schneewind, Olaf
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.190.Supp.186.16

Human or animal infections with S. aureus do not elicit protective immunity against staphylococcal diseases. Staphylococci are notorious to deploy a wide spectrum of strategies to avoid host immune system. Previous work revealed that both innate and adaptive immune systems are hampered by the expression of two immunoglobulin binding proteins; staphylococcal protein A (SpA) and staphylococcal binder of immunoglobulins (Sbi). Staphylococcal protein A, a molecule that associates with both Fc and Fab portions of immunoglobulins, is necessary 1) to neutralize the antibody mediated opsonophagocytosis and 2) to trigger the expansion and apoptotic demise of B cell populations. The second immunoglobulin binding protein, Sbi, can associate with Fc portion of immunoglobulin and complement factor C3 to disable a critical juncture between the innate and adaptive immunity. Although much of biochemical analysis revealed how the two staphylococcal proteins engage with immunoglobulins for many years, their role as immuno modulatory virulence factors in vivo has not been fully understood. We have investigated the significance of immunoglobulin association with staphylococci during acute and chronic infection in animal model and characterized the molecular mechanisms to avert host immune defense system. Strategies are also discussed on how the two secreted products of staphylococci may be exploited for the development of vaccines and therapeutics.