Eagle’s minimum essential medium (MEM), Dulbecco’s modified
Eagle’s medium (DMEM), and trypsin (0.25%) were obtained from the
Research Foundation for Microbial Diseases of Osaka University (Suita,
Osaka, Japan); fetal bovine serum from Flow Laboratories (North Ryde,
Australia); tissue culture dishes and four-chamber, polystyrene-vessel,
glass culture slides from Becton Dickinson (Franklin Lakes, NJ); HEPES,
RPMI 1640 medium, and nonenzymatic cell dissociation solution from
Gibco BRL (Grand Island, NY); bovine serum albumin (BSA),
phytohemagglutinin (PHA), and cycloheximide from Sigma (St. Louis, MO);
and human recombinant tumor necrosis factor (TNF)-α and IL-4 from
Genzyme (Cambridge, MA). A mouse monoclonal antibody to human IL-4Rα
was obtained from Beckman Coulter (Fullerton, CA), and a neutralizing
mouse monoclonal antibody to the IL-4R complex as well as normal mouse
IgG2A, mouse IgG1, and
normal rabbit IgG were from R&D Systems (Minneapolis, MN). A rat
monoclonal antibody to human IL-2Rγc was obtained from Sumitomo
Electric (Osaka, Japan), and normal rat IgG, fluorescein isothiocyanate
(FITC)–conjugated goat antibodies to mouse IgG, FITC-conjugated goat
antibodies to rat IgG, and FITC-conjugated goat antibodies to rabbit
IgG were from ICN Pharmaceuticals (Aurora, OH). Rabbit polyclonal
antibodies to STAT6 and horseradish peroxidase (HRP)–conjugated goat
antibodies to rabbit IgG were from Santa Cruz Biotechnology (Santa
Cruz, CA), and an HRP-conjugated mouse monoclonal antibody to
phosphotyrosine was from Transduction Laboratories (Lexington, KY). 125I-labeled IL-4 was from DuPont NEN (Boston,
MA), and protein G-Sepharose gel (4 Fast Flow), enhanced
chemiluminescence (ECL) immunoblot detection reagents, and
autoradiography film (Hyperfilm) were from Amersham Pharmacia Biotech
(Little Chalfont, UK). Biotinylated protein size markers were obtained
from New England Biolabs (Beverly, MA); polyacrylamide gels (7.5%)
from Daiichi Pure Chemicals (Tokyo, Japan); polyvinylidene difluoride
membranes from Millipore (Bedford, MA); protein assay reagent from
Bio-Rad (Hercules, CA); nonfat blocking solution (Block Ace)
from Dainippon Pharmaceutical (Osaka, Japan); and mounting medium
(Vectashield) from Vector Laboratories (Burlingame, CA).