Abstract
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.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 4091-4099 |
| Number of pages | 9 |
| Journal | Journal of Immunology |
| Volume | 173 |
| Issue number | 6 |
| State | Published - Sep 15 2004 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Immunology
Cite this
Low-dose Salmonella infection evades activation of flagellin-specific CD4 T cells. / Srinivasan, Aparna; Foley, Joseph; Ravindran, Rajesh; Mcsorley, Stephen J.
In: Journal of Immunology, Vol. 173, No. 6, 15.09.2004, p. 4091-4099.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Low-dose Salmonella infection evades activation of flagellin-specific CD4 T cells
AU - Srinivasan, Aparna
AU - Foley, Joseph
AU - Ravindran, Rajesh
AU - Mcsorley, Stephen J
PY - 2004/9/15
Y1 - 2004/9/15
N2 - 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.
AB - 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.
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M3 - Article
C2 - 15356159
AN - SCOPUS:4644327988
VL - 173
SP - 4091
EP - 4099
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 6
ER -