TY - JOUR
T1 - Culling of activated CD4 T cells during typhoid is driven by Salmonella virulence genes
AU - Srinivasan, Aparna
AU - Nanton, Minelva R
AU - Griffin, Amanda
AU - McSorley, Stephen J.
PY - 2009/6/15
Y1 - 2009/6/15
N2 - Pathogen-specific CD4 T cells are activated within a few hours of oral Salmonella infection and are essential for protective immunity. However, CD4 T cells do not participate in bacterial clearance until several weeks after infection, suggesting that Salmonella can inhibit or evade CD4 T cells that are activated at early time points. Here, we describe the progressive culling of initially activated CD4 T cells in Salmonella-infected mice. Loss of activated CD4 T cells was independent of early instructional programming, T cell precursor frequency, and Ag availability. In contrast, apoptosis of Ag-specific CD4 T cells was actively induced by live bacteria in a process that required Salmonella pathogenicity island-2 and correlated with increased expression of PD-L1. These data demonstrate efficient culling of initially activated Ag-specific CD4 cells by a microbial pathogen and document a novel strategy for bacterial immune evasion.
AB - Pathogen-specific CD4 T cells are activated within a few hours of oral Salmonella infection and are essential for protective immunity. However, CD4 T cells do not participate in bacterial clearance until several weeks after infection, suggesting that Salmonella can inhibit or evade CD4 T cells that are activated at early time points. Here, we describe the progressive culling of initially activated CD4 T cells in Salmonella-infected mice. Loss of activated CD4 T cells was independent of early instructional programming, T cell precursor frequency, and Ag availability. In contrast, apoptosis of Ag-specific CD4 T cells was actively induced by live bacteria in a process that required Salmonella pathogenicity island-2 and correlated with increased expression of PD-L1. These data demonstrate efficient culling of initially activated Ag-specific CD4 cells by a microbial pathogen and document a novel strategy for bacterial immune evasion.
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U2 - 10.4049/jimmunol.0900382
DO - 10.4049/jimmunol.0900382
M3 - Article
C2 - 19494308
AN - SCOPUS:67649232597
SN - 0022-1767
VL - 182
SP - 7838
EP - 7845
JO - Journal of Immunology
JF - Journal of Immunology
IS - 12
ER -