Passive immune protection of a Staphylococcus aureus peptidoglycan mimic peptide against Staphylococcus aureus infection
CHEN Yiguo
HOU Xiaorui
ZHU Ping
LIU Beiyi
Abstract：Peptidoglycan (PGN) is a conserved component of the cell wall of Gram-positive bacteria including S.aureus.However,PGN,as a thymus-independent antigen,can't be considered as a vaccine candidate because of its weak immunogenicity.In this study,we modified SP31 peptide (ATWSHHLSSAGLSAGG) mimicing the PGN of S.aureus by online MHC prediction ( and DNAStar,and evaluated its passive protective immunization in mice.The results showed that the modified MAP-P31.1 by adding a-GGAS tail fulfilled a T cell epitope with a higher antigenic index and 10-fold antisera boosted by heat-killed S.aureus than that of the original MAP-P31.In vitro,our results also showed that anti-MAP-P31.1 sera had more potent bactericidal/bacteriostatic activity against MSSA with or without complements than that of anti-MAP-P31 and anti-S,aureus sera.Importantly,anti-MAP-P31.1 sera also had a bactericidal/bacteriostatic activity on MRSA,whereas anti-MAP.P31 sera did not.In addition,anti-MAP-P31.1 sera also increased phagocytosis activity of murine peritoneal macrophage against MSSA and MRSA.Finally,purified anti-MAP-P31.1 sera notably prolonged living time and survival of mice infected with MSSA,and the bacterial loads in the spleens,livers,and kidneys were decreased after administering anti-MAP-P31.1.Our results above showed that the modified MAP-P31.1 mimic peptide induce an improved antibody response to MRSA in vitro,but do not confer an effective protection against MRSA infection in vivo.
Keywords：PGNMimic peptideBactericidal/bacteriostatic activityS.aureusMultiple antigenic peptide
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 661-667 )