Frontline: An in-depth evaluation of the production of IL-2 by antigen-specific CD8 T cells in vivo.
IL-2 is an important cytokine that is capable of inducing both proliferation and apoptosis of activated T cells. CD4 T cells are thought to be the major producers of IL-2, but CD8 T cells also produce copious amounts of this cytokine. However, our current understanding regarding the kinetics of IL-2 production by antigen-specific CD8 T cells, and the proportion of these cells that produce IL-2 in vivo, is extremely limited. We now demonstrate that virus-specific CD8 T cells initiate IL-2 production by 6 h post-infection and prior to cell division in vivo. Interestingly, peak levels of IL-2 production were achieved very early during the response and prior to the proliferative peak. We also show -- using transgenic mice expressing herpes simplex virus-1 thymidine kinase under the control of the IL-2 promoter -- that, unlike what has been reported for antigen-specific CD4 T cells, the majority of antigen-specific CD8 T cells produce IL-2 during primary as well as secondary immune responses in vivo.
D'Souza
Warren N
WN
Division of Immunology, Department of Medicine, University of Connecticut Health Center, Farmington, CT 06030-1319, USA.
Lefrançois
Leo
L
D019264:Adoptive Transfer; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology* / Q000378:metabolism* / Q000821:virology; D049109:Cell Proliferation; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D015774:Ganciclovir / Q000494:pharmacology; D006561:Herpes Simplex / Q000276:immunology; D007156:Immunologic Memory / Q000276:immunology; D007376:Interleukin-2 / Q000096:biosynthesis* / Q000276:immunology; D007700:Kinetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D018353:Rhabdoviridae Infections / Q000276:immunology*; D018139:Simplexvirus / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014721:Vesicular stomatitis Indiana virus / Q000276:immunology*
D000998:Antiviral Agents; D018984:Epitopes, T-Lymphocyte; D007376:Interleukin-2; D015774:Ganciclovir