Involvement of TLR6/1 in rLcrV-mediated immunomodulation of murine peritoneal macrophages in vitro.

LcrV of Yersinia pestis is an enigmatic antigenic protein having multiple functions such as effector, translocator and regulator in Type III secretion system. In present study, it is reported that rLcrV causes subversion of macrophage-mediated immune functions. rLcrV treatment down regulated the transcription of IL-12, IRAK-1, MHC-II, phosho-STAT1 and adhesion molecule CD18 in LPS stimulated macrophages. rLcrV induced up regulation of phospho-STAT3 expression, while had no effect on expression of phospho-STAT6. Neutralization and immunoprecipitation experiments suggest the probable involvement of TLR2 and TLR6 heterodimer in rLcrV-mediated immunomodulation of macrophages. Adaptor molecule MyD88, CD11b, and MHC-I expression did not modulate upon treatment with rLcrV.