IL-4 responsive CD4+ T cells specific for myelin basic protein: IL-2 confers a prolonged postactivation refractory phase.
This study compared myelin basic protein-specific T cells from Lewis rats that were derived in the presence of either rat IL-4 or IL-2. Interleukin-4 was a maintenance factor that enabled derivation of long-term T cell lines. When activated, IL-4 dependent lines were lacking in IL-2 production capacity but maintained high levels of responsiveness to IL-2 and recognized IL-2 as a dominant growth factor. Activated IL-4 dependent T cells rapidly reverted to a quiescent phenotype in the presence of IL-4 and rapidly regained myelin basic protein reactivity. In contrast, activated IL-2 dependent T cells that were propagated in IL-2 had a more persistent blastogenic phenotype and a prolonged refractory phase. Interleukin-4 dependent lines that were propagated in IL-2 up-regulated the capacity to produce IL-2 and also acquired prolonged postactivation refractoriness. Thus, IL-2 was a dominant growth factor that conferred prolonged activation-dependent non-responsiveness. The coupling of dominant growth factor activity with prolonged postactivation refractoriness may be associated with the requisite role of IL-2 in homeostatic self-tolerance.
Mannie
Mark D
MD
Department of Microbiology and Immunology, East Carolina University School of Medicine, Greenville, North Carolina 27858, USA.
Fraser
Dana J
DJ
McConnell
Thomas J
TJ
D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism*; D007376:Interleukin-2 / Q000378:metabolism*; D015847:Interleukin-4 / Q000378:metabolism*; D004676:Myelin Basic Protein / Q000276:immunology*; D051381:Rats; D011917:Rats, Inbred Lew; D018418:Th2 Cells
D007376:Interleukin-2; D004676:Myelin Basic Protein; D015847:Interleukin-4