In vivo studies fail to reveal a role for IL-4 or STAT6 signaling in Th2 lymphocyte differentiation.
The expression of interleukin-4 (IL-4) is viewed as the hallmark of a Th2 lymphocyte, whereas the subsequent action of IL-4 and IL-13, mediated through the STAT6 signaling pathway, is seen as a prerequisite for the full development of Th2 immune responses to parasites and allergens. G4 mice, whose IL-4 gene locus contains the fluorescent reporter eGFP, were used to quantify the number of Th2 cells that develop during Nippostrongylus brasiliensis- or allergen-induced immune responses under conditions where IL-4 or STAT6 was absent. Here, we show that deletion of IL-4 or STAT6 had little impact on the number or timing of appearance of IL-4-producing Th2 cells. These data indicate that in vivo differentiation of naïve CD4 T cells to Th2 status often occurs independently of IL-4 and STAT6 and that recently described pathways of Th2 cell differentiation may explain how allergens and parasites selectively induce Th2-mediated immunity.
van Panhuys
Nicholas
N
Malaghan Institute of Medical Research, P. O. Box 7060, Wellington South, New Zealand.
Tang
Shiau-Choot
SC
Prout
Melanie
M
Camberis
Mali
M
Scarlett
Debbie
D
Roberts
Joanna
J
Hu-Li
Jane
J
Paul
William E
WE
Le Gros
Graham
G
D000485:Allergens / Q000276:immunology; D000818:Animals; D002454:Cell Differentiation; D007109:Immunity; D015847:Interleukin-4 / Q000502:physiology*; D051379:Mice; D008817:Mice, Mutant Strains; D009559:Nippostrongylus / Q000276:immunology; D010271:Parasites / Q000276:immunology; D050800:STAT6 Transcription Factor / Q000502:physiology*; D015398:Signal Transduction; D018418:Th2 Cells / Q000166:cytology*
D000485:Allergens; D050800:STAT6 Transcription Factor; C494100:Stat6 protein, mouse; D015847:Interleukin-4