RANTES production by memory phenotype T cells is controlled by a posttranscriptional, TCR-dependent process.
An examination of differences in gene expression between memory and naive phenotype T cells revealed elevated levels of mRNA for several chemokines, especially RANTES, in memory phenotype T cells. Although RANTES mRNA is spliced and cytoplasmic, these cells do not contain or secrete significant amounts of RANTES protein without TCR stimulation. This secretion is independent of transcription, but requires translation. In vivo, CD8+ memory T cells proliferate continuously and slowly in response to IL-15; however, IL-15 does not stimulate RANTES secretion. These results show that memory phenotype CD8+ T cells use preexisting mRNA to produce and secrete RANTES rapidly following TCR stimulation. Such storage of preformed mRNAs for important inflammatory mediators may contribute to the speed of secondary immune responses.
Swanson
Bradley J
BJ
Howard Hughes Medical Institute, Denver, CO 80206, USA.
Murakami
Masaaki
M
Mitchell
Thomas C
TC
Kappler
John
J
Marrack
Philippa
P
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D018946:Chemokine CCL5 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D005260:Female; D007156:Immunologic Memory / Q000235:genetics; D008213:Lymphocyte Activation / Q000235:genetics / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D012323:RNA Processing, Post-Transcriptional / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics / Q000276:immunology; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology*
D018946:Chemokine CCL5; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell