TY - JOUR
T1 - Early self-regulatory mechanisms control the magnitude of CD8+ T cell responses against liver stages of murine malaria
AU - Hafalla, Julius C.R.
AU - Morrot, Alexandre
AU - Sano, Gen Ichiro
AU - Milon, Geneviève
AU - Lafaille, Juan J.
AU - Zavala, Fidel
PY - 2003/7/15
Y1 - 2003/7/15
N2 - Following immunization with Plasmodium yoelii sporozoites, the CD8+ T cell population specific for the SYVPSAEQI epitope expressed in sporozoite and liver stages of this malaria parasite revealed the existence of a short term Ag presentation process that translated into a single clonal burst. Further expansion of this CD8+ T cell population in conditions of sustained Ag exposure and additional supply of naive cells was inhibited by regulatory mechanisms that were developed as early as 24-48 h after priming. Studies using mouse models for Plasmodium or influenza virus infections revealed that this mechanism is Ag specific and is mediated by activated CD8+ T cells that inhibit the priming of naive cells. This interference of the priming of naive cells appeared to result from limited access to Ag-presenting dendritic cells, which become disabled or are eliminated after contact with activated cells. Thus, concomitantly with the development of their effector antimicrobial capacity, CD8+ T cells also acquire a self-regulatory role that is likely to represent one of the earliest mechanisms induced in the course of an immune response and that limits the magnitude of the early expansion of CD8+ T lymphocytes reactive to microorganisms.
AB - Following immunization with Plasmodium yoelii sporozoites, the CD8+ T cell population specific for the SYVPSAEQI epitope expressed in sporozoite and liver stages of this malaria parasite revealed the existence of a short term Ag presentation process that translated into a single clonal burst. Further expansion of this CD8+ T cell population in conditions of sustained Ag exposure and additional supply of naive cells was inhibited by regulatory mechanisms that were developed as early as 24-48 h after priming. Studies using mouse models for Plasmodium or influenza virus infections revealed that this mechanism is Ag specific and is mediated by activated CD8+ T cells that inhibit the priming of naive cells. This interference of the priming of naive cells appeared to result from limited access to Ag-presenting dendritic cells, which become disabled or are eliminated after contact with activated cells. Thus, concomitantly with the development of their effector antimicrobial capacity, CD8+ T cells also acquire a self-regulatory role that is likely to represent one of the earliest mechanisms induced in the course of an immune response and that limits the magnitude of the early expansion of CD8+ T lymphocytes reactive to microorganisms.
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U2 - 10.4049/jimmunol.171.2.964
DO - 10.4049/jimmunol.171.2.964
M3 - Article
C2 - 12847268
AN - SCOPUS:0037768834
SN - 0022-1767
VL - 171
SP - 964
EP - 970
JO - Journal of Immunology
JF - Journal of Immunology
IS - 2
ER -