| First Author | Srinivasan A | Year | 2004 |
| Journal | J Immunol | Volume | 173 |
| Issue | 6 | Pages | 4091-9 |
| PubMed ID | 15356159 | Mgi Jnum | J:92748 |
| Mgi Id | MGI:3054467 | Doi | 10.4049/jimmunol.173.6.4091 |
| Citation | Srinivasan A, et al. (2004) Low-dose salmonella infection evades activation of flagellin-specific CD4 T cells. J Immunol 173(6):4091-9 |
| abstractText | Many pathogens can establish a lethal infection from relatively small inocula, yet the effect of infectious dose upon CD4 T cell activation is not clearly understood. This issue was examined by tracking Salmonella flagellin-specific SM1 T cells in vivo, after i.v. and oral challenge of mice with virulent Salmonella typhimurium. SM1 T cells rapidly expressed activation markers and expanded in response to high-dose infection but remained completely unresponsive in mice challenged with low doses of Salmonella. SM1 T cells, in these mice, remained unresponsive, despite massive bacterial replication in vivo. Naive SM1 T cells in low-dose Salmonella-infected mice were activated rapidly after the injection of flagellin peptide, demonstrating that these T cells were fully capable of responding, ruling out the possibility of a bacterial-induced suppressive environment. The inability of flagellin-specific SM1 T cells to respond to low-dose infection was not due to Ag down-regulation, because flagellin expression was detected using a functional assay. Together, these data suggest that low-dose Salmonella infection can evade flagellin-specific CD4 T cell activation in vivo. |
