Activated and memory CD8+ T cells can be distinguished by their cytokine profiles and phenotypic markers. Export

@article{citeulike:3438465, abstract = {Dissecting the mechanisms of T cell-mediated immunity requires the identification of functional characteristics and surface markers that distinguish between activated and memory T lymphocytes. In this study, we compared the rates of cytokine production by virus-specific primary and memory CD8+ T cells directly ex vivo. Ag-specific IFN-gamma and TNF-alpha production by both primary and long-term memory T cells was observed in </=60 min after peptide stimulation. Although the on-rate kinetics of cytokine production were nearly identical, activated T cells produced more IFN-gamma, but less TNF-alpha, than memory T cells. Ag-specific cytokine synthesis was not a constitutive process and terminated immediately following disruption of contact with peptide-coated cells, demonstrating that continuous antigenic stimulation was required by both T cell populations to maintain steady-state cytokine production. Upon re-exposure to Ag, activated T cells resumed cytokine production whereas only a subpopulation of memory T cells reinitiated cytokine synthesis. Analysis of cytokine profiles and levels of CD8, LFA-1, and CTLA-4 together revealed a pattern of expression that clearly distinguished in vivo-activated T cells from memory T cells. Surprisingly, CTLA-4 expression was highest at the early stages of the immune response but fell to background levels soon after viral clearance. This study is the first to show that memory T cells have the same Ag-specific on/off regulation of cytokine production as activated T cells and demonstrates that memory T cells can be clearly discriminated from activated T cells directly ex vivo by their cytokine profiles and the differential expression of three well-characterized T cell markers.}, author = {Slifka, M. K. and Whitton, J. L.}, citeulike-article-id = {3438465}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/10605013}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=10605013}, day = {1}, issn = {0022-1767}, journal = {Journal of immunology (Baltimore, Md. : 1950)}, keywords = {activated, cytokines, effector, memory}, month = {January}, number = {1}, pages = {208--216}, posted-at = {2008-10-22 03:55:44}, priority = {2}, title = {Activated and memory CD8+ T cells can be distinguished by their cytokine profiles and phenotypic markers.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/10605013}, volume = {164}, year = {2000} }

TY - JOUR ID - citeulike:3438465 L3 - citeulike-article-id:3438465 N2 - Dissecting the mechanisms of T cell-mediated immunity requires the identification of functional characteristics and surface markers that distinguish between activated and memory T lymphocytes. In this study, we compared the rates of cytokine production by virus-specific primary and memory CD8+ T cells directly ex vivo. Ag-specific IFN-gamma and TNF-alpha production by both primary and long-term memory T cells was observed in </=60 min after peptide stimulation. Although the on-rate kinetics of cytokine production were nearly identical, activated T cells produced more IFN-gamma, but less TNF-alpha, than memory T cells. Ag-specific cytokine synthesis was not a constitutive process and terminated immediately following disruption of contact with peptide-coated cells, demonstrating that continuous antigenic stimulation was required by both T cell populations to maintain steady-state cytokine production. Upon re-exposure to Ag, activated T cells resumed cytokine production whereas only a subpopulation of memory T cells reinitiated cytokine synthesis. Analysis of cytokine profiles and levels of CD8, LFA-1, and CTLA-4 together revealed a pattern of expression that clearly distinguished in vivo-activated T cells from memory T cells. Surprisingly, CTLA-4 expression was highest at the early stages of the immune response but fell to background levels soon after viral clearance. This study is the first to show that memory T cells have the same Ag-specific on/off regulation of cytokine production as activated T cells and demonstrates that memory T cells can be clearly discriminated from activated T cells directly ex vivo by their cytokine profiles and the differential expression of three well-characterized T cell markers. IS - 1 JF - Journal of immunology (Baltimore, Md. : 1950) SN - 0022-1767 EP - 216 TI - Activated and memory CD8+ T cells can be distinguished by their cytokine profiles and phenotypic markers. VL - 164 SP - 208 KW - activated KW - cytokines KW - effector KW - memory AU - Slifka, MK AU - Whitton, JL PY - 2000/01/01/ UR - http://view.ncbi.nlm.nih.gov/pubmed/10605013 ER -