Targeting Surface Protein SasX by Active and Passive Vaccination To Reduce Staphylococcus aureus Colonization and Infection

Qian Liu; Xin Du; Xufen Hong; Tianming Li; Bing Zheng; Lei He; Yanan Wang; Michael Otto; Min Li

doi:10.1128/IAI.02951-14

Targeting Surface Protein SasX by Active and Passive Vaccination To Reduce Staphylococcus aureus Colonization and Infection

^aDepartment of Laboratory Medicine, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
^bDepartment of Laboratory Medicine, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China
^cPathogen Molecular Genetics Section, Laboratory of Human Bacterial Pathogenesis, National Institute of Allergy and Infectious Diseases, The National Institutes of Health, Bethesda, Maryland, USA

A. Camilli, Editor

ABSTRACT

SasX is a recently described surface protein of Staphylococcus aureus that is linked to the epidemic success of hospital-associated methicillin-resistant clones, in particular in Asia. It enhances nasal colonization and virulence in skin and lung infection models. Here, we evaluated the potential of SasX as a vaccine component in passive and active immunization efforts using mouse infection models. We found that SasX induced a specific immune response predominantly based on IgG1 antibodies. Active immunization with recombinant SasX or passive immunization with rabbit polyclonal anti-SasX IgG significantly decreased the size of lesions caused by S. aureus in a skin infection model. Furthermore, active immunization reduced acute lung injury in a lung infection model. Moreover, active or passive immunization significantly reduced S. aureus colonization in a nasal colonization model. Finally, anti-SasX IgG enhanced the susceptibility of S. aureus to killing by human neutrophils. We conclude that SasX is a potential target for therapeutics or vaccines designed to moderate colonization and infection by sasX-positive epidemic strains of S. aureus.

FOOTNOTES

Received 19 November 2014.
Returned for modification 8 January 2015.
Accepted 7 March 2015.
Accepted manuscript posted online 16 March 2015.

Address correspondence to Michael Otto, motto{at}niaid.nih.gov, or Min Li, ruth_limin{at}126.com.
Q.L. and X.D. contributed equally to this work.
Citation Liu Q, Du X, Hong X, Li T, Zheng B, He L, Wang Y, Otto M, Li M. 2015. Targeting surface protein SasX by active and passive vaccination to reduce Staphylococcus aureus colonization and infection. Infect Immun 83:2168–2174. doi:10.1128/IAI.02951-14.