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dc.contributor.authorLi, Jinquan
dc.contributor.authorZhu, Hui
dc.contributor.authorFeng, Wenchao
dc.contributor.authorLiu, Mengyao
dc.contributor.authorSong, Y.
dc.contributor.authorZhang, Xiaolan
dc.contributor.authorZhou, Yang
dc.contributor.authorBei, W.
dc.contributor.authorLei, Benfang
dc.identifier.citationLi J, Zhu H, Feng W, Liu M, Song Y, Zhang X, Zhou Y, Bei W, Lei B. 2013. Regulation of Inhibition of Neutrophil Infiltration by the Two-Component Regulatory System CovRS in Subcutaneous Murine Infection with Group A Streptococcus. Infection and Immunity 81:974-983.en_US
dc.description.abstractHypervirulent invasive group A streptococcus (GAS) isolates inhibit neutrophil infiltration more than pharyngitis isolates do, and the molecular basis of this difference is not well understood. This study was designed to first determine whether natural null mutation of the two-component regulatory system CovRS is responsible for the enhancement of the inhibition of neutrophil recruitment seen in hypervirulent GAS. Next, we examined the role of CovRS-regulated interleukin-8/CXC chemokine peptidase (SpyCEP), C5a peptidase (ScpA), and platelet-activating factor acetylhydrolase (SsE) in the enhanced innate immune evasion. Invasive isolate MGAS5005 induces less neutrophil infiltration and produced a greater lesion area than pharyngitis isolate MGAS2221 in subcutaneous infections of mice. It is known that MGAS5005, but not MGAS2221, has a natural 1-bp deletion in the covS gene. Replacement of covSΔ1bp in MGAS5005 with wild-type covS resulted in the MGAS2221 phenotype. Deletion of covS from MGAS2221 resulted in the MGAS5005 phenotype. Tests of single, double, and triple deletion mutants of the MGAS5005 sse, spyCEP, and scpA genes found that SsE plays a more important role than SpyCEP and ScpA in the inhibition of neutrophil recruitment and that SsE, SpyCEP, and ScpA do not have synergistic effects on innate immune evasion by MGAS5005. Deletion of sse, but not spyCEP or scpA, of MGAS2221 enhances neutrophil recruitment. Thus, covS null mutations can cause substantial inhibition of neutrophil recruitment by enhancing the expression of the chemoattractant-degrading virulence factors, and SsE, but not SpyCEP or ScpA, is required for CovRS-regulated GAS inhibition of neutrophil infiltration.en_US
dc.description.sponsorshipThis work was supported in part by grants AI095704, AI097703, and GM103500-09 from the National Institutes of Health and the Montana State Agricultural Experimental Station. J.L. was supported by a Ph.D. student exchange scholarship from the Ministry of Education, China. The work done at Harbin Medical University was supported by grant LC2011C02 from the Natural Science Foundation of Heilongjiang Province and a grant from the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State of Education Ministry, China.en_US
dc.titleRegulation of Inhibition of Neutrophil Infiltration by the Two-Component Regulatory System CovRS in Subcutaneous Murine Infection with GroupA Streptococcusen_US
mus.citation.journaltitleInfection and Immunityen_US
mus.identifier.categoryHealth & Medical Sciencesen_US
mus.relation.collegeCollege of Agricultureen_US
mus.relation.collegeCollege of Letters & Scienceen_US
mus.relation.departmentMicrobiology & Immunology.en_US
mus.relation.universityMontana State University - Bozemanen_US

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