Constitutive expression of interleukin 4 in vivo does not lead to the development of T helper 2 type CD8+ T cells secreting interleukin 4 or interleukin 5.
Interleukin 4 (IL-4) has been shown to commit CD8+ T cells to a T helper (Th) 2 functional phenotype in vitro. To study the effects of IL-4 on CD8+ T cell development in vivo we analysed the CD8+ T cell phenotype in mice constitutively expressing IL-4. Purified CD8+ T cells from uninfected or flu infected IL-4 transgenic (tg) animals produced no detectable IL-4 or IL-5 after in vitro stimulation on anti-CD3 coated plates. However, CD8+ T cells from IL-4 tg mice could be converted into IL-4 and IL-5 producers in vitro in the presence of exogenous added IL-4, showing that these cells were still responsive to IL-4. IL-4 tg mice also showed a delay in influenza virus clearance from the lung, which was probably due to the observed reduction of total CD8+ T cell numbers in the IL-4 tg animals since IL-4 tg CD8+ T cells showed normal levels of influenza-specific cytotoxicity in comparison to controls. Taken together these results suggest that CD8+ T cells are not necessarily switched to a Th2 phenotype by the presence of IL-4 and that some other factor(s) may be important in the switch process of CD8+ T cells in vivo, since the addition of IL-4 during CD8+ T cell activation in vitro leads to Th2 type CD8+ T cells secreting IL-4 and IL-5.
Erb
K J
KJ
Zentrum für Infektionsforschung, Universität Würzburg, Germany.
Hou
S
S
Hyland
L
L
Kirman
J
J
Moll
H
H
Le Gros
G
G
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D005260:Female; D009980:Influenza A virus / Q000276:immunology; D015847:Interleukin-4 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism*; D015848:Interleukin-5 / Q000378:metabolism*; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D009976:Orthomyxoviridae Infections / Q000276:immunology; D019948:Receptors, Interleukin-4 / Q000096:biosynthesis; D013602:T-Lymphocytes, Cytotoxic; D018418:Th2 Cells / Q000276:immunology*
D015848:Interleukin-5; D019948:Receptors, Interleukin-4; D015847:Interleukin-4