A Multiple Antigenic Peptide Mimicking Peptidoglycan Induced T Cell Responses to Protect Mice from Systemic Infection with Staphylococcus aureus: e0136888

• Published in: PloS one 2015-08, Vol.10 (8)
• Main Authors: Wang, Xiang-Yu, Huang, Zhao-Xia, Chen, Yi-Guo, Lu, Xiao, Zhu, Ping, Wen, Kun, Fu, Ning, Liu, Bei-Yi
• Format: Article
• Language: English
• Subjects: Staphylococcus aureus
• ISSN: 1932-6203
• DOI: 10.1371/journal.pone.0136888

Due to the enormous capacity of Staphylococcus aureus to acquire antibiotic resistance, it becomes imperative to develop vaccines for decreasing the risk of its life-threatening infections. Peptidoglycan (PGN) is a conserved and major component of S. aureus cell wall. However, it has not been used as a vaccine candidate since it is a thymus-independent antigen. In this study, we synthesized a multiple antigenic peptide, named MAP27, which comprised four copies of a peptide that mimics the epitope of PGN. After immunization with MAP27 five times and boosting with heat-inactivated bacterium one time, anti-MAP27 serum bound directly to S. aureus or PGN. Immunization with MAP27 decreased the bacterial burden in organs of BALB/c mice and significantly prolonged their survival time after S. aureus lethal-challenge. The percentage of IFN- gamma +CD3+ T cells and IL-17+CD4+ T cells in spleen, as well as the levels of IFN- gamma , IL-17A/F and CCL3 in spleen and lung, significantly increased in the MAP27-immunized mice after infection. Moreover, in vitro incubation of heat-inactivated S. aureus with splenocytes isolated from MAP27-immunized mice stimulated the production of IFN- gamma and IL-17A/F. Our findings demonstrated that MAP27, as a thymus-dependent antigen, is efficient at eliciting T cell-mediated responses to protect mice from S. aureus infection. This study sheds light on a possible strategy to design vaccines against S. aureus.