Systemic treatment with CpG-B after sublethal rickettsial infection induces mouse death through indoleamine 2,3-dioxygenase (IDO).

ABSTRACT: Due to its strong immune stimulatory effects through TLR9, CpG-containing oligodeoxynucleotides (CpG ODN) have been tested in multiple clinical trials as vaccine adjuvant for infectious diseases and cancer. However, immune suppression induced by systemic administration of CpGs has been reported recently. In this study, we evaluated the impact of CpGs in an acute rickettsiosis model. We found that systemic treatment with type B CpG (CpG-B), but not type A CpG (CpG-A), at 2 days after sublethal R. australis infection induced mouse death. Although wild-type (WT) B6 and IDO(-/-) mice showed similar survival rates with three different doses of R. australis infection, treatment with CpG-B after sublethal infection consistently induced higher mortality with greater tissue bacterial loads in WT bu

SUBMITTER: Xin L 

PROVIDER: S-EPMC3314704 | biostudies-literature | 2012

REPOSITORIES: biostudies-literature