Two distinct stages in the transition from naive CD4 T cells to effectors, early antigen-dependent and late cytokine-driven expansion and differentiation.
Efficient peptide presentation by professional APC to naive and effector CD4 T cells in vitro is limited to the first 1-2 days of culture, but is nonetheless optimum for effector expansion and cytokine production. In fact, prolonging Ag presentation leads to high levels of T cell death, decreased effector expansion, and decreased cytokine production by recovered effectors. Despite the absence of Ag presentation beyond day 2, T cell division continues at a constant rate throughout the 4-day culture. The Ag-independent later stage depends on the presence of IL-2, and we conclude optimum effector generation depends on an initial 2 days of TCR stimulation followed by an additional 2 days of Ag-independent, cytokine driven T cell expansion and differentiation.
Jelley-Gibbs
D M
DM
Trudeau Institute, Saranac Lake, NY 12983, USA.
Lepak
N M
NM
Yen
M
M
Swain
S L
SL
D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000378:metabolism; D000941:Antigens / Q000502:physiology*; D000955:Antigens, T-Independent / Q000502:physiology; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D002453:Cell Cycle / Q000276:immunology*; D002454:Cell Differentiation / Q000276:immunology; D002455:Cell Division / Q000276:immunology; D002460:Cell Line; D002478:Cells, Cultured; D010856:Columbidae; D003574:Cytochrome c Group / Q000276:immunology; D016207:Cytokines / Q000502:physiology*; D004306:Dose-Response Relationship, Immunologic; D007156:Immunologic Memory; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D013997:Time Factors
D000941:Antigens; D000955:Antigens, T-Independent; D003574:Cytochrome c Group; D016207:Cytokines