5-fold or 10- and 25-fold, respectively. Microsoft Excel software was used to determine the amount of Ig based on the standard curve. The lower limit of the Abs assayed in this system was 0.5 Tanespimycin to 1 ng/mL. The SD of the triplicate assay was less than 4% at 12.5 ng/mL and less than 2% at 25 ng/mL. Submandibular lymph node cells, NALT cells or cells from other lymphoid tissues, all of which had been obtained on days 0–14 after an i.n. injection of the allergen, were cultured for 6 days, and the amount of IgE Ab in the culture medium assessed. When standard curves were constructed with fresh culture medium or PBS
containing various amounts of IgE, most of these curves were linear up to 25 ng/mL; but the amounts of IgE in the culture media from NALT were always < 0 (data not shown), suggesting the presence of obstacles to ELISA assay of the medium after the 6 day culture period. Therefore, we cultured untreated cells from NALT, submandibular
lymph nodes or other lymphoid tissues for 6 days, and constructed a standard curve by adding 0–25ng/mL of IgE to the culture media. The amounts of IL-4 in the culture media were assessed by using a Cytoscreen ELISA kit (Biosource International, Camarillo, CA, USA). Fifty μL of standard, control or experimental samples were added to each of several anti-IL-4 Ab-coated wells, and incubation carried out at 37°C for 1 hr. Fifty μL of Dorsomorphin biotin-conjugated monoclonal Ab specific for IL-4 was added to each well, and the plates incubated at 37°C for 1 hr. After four washes with washing buffer, 100 μL of streptavidin-HRP solution was added to each well and incubation continued at room temperature for 30 min. Following four more washes with washing buffer, the antigen-Ab complexes were incubated with 100 μL of tetramethylbenzidine for 30 min at room temperature. The reaction was stopped Resveratrol by the addition of 100 μL of stop solution, after which the absorbance
of each well was read at 450 nm. A standard curve for IL-4 was prepared over the range of 0–1000 pg/mL. Total RNAs were isolated from various kinds of cells by using TRIzol. The total RNAs were reverse transcribed to synthesize first-stranded cDNA by using SuperScriptII reverse transcriptase (Gibco-BRL, Cleveland, OH, USA). A mouse primer set for IL-4 cDNA (forward, 5′-ACG GAG ATG GAT GTG CCA AAC GTC-3′; reverse, 5′-CGA GTA ATC CAT TTG CAT GAT GC-3′; KURABO, Osaka, Japan) was used to amplify a 279 bp fragment; and 30 cycles of PCR were conducted in a GeneAmp PCR System apparatus (9700; PE Applied Biosystems, Foster City, CA, USA). A mouse β-actin primer set (forward, 5′-TGT GAT GGT GGG AAT GGG TCA G-3′; reverse, 5′-TTT GAT GTC ACG CAC GAT TTC C-3′; Kurabo, Osaka, Japan) was used to amplify a 514 bp fragment by 30 cycles of PCR. The PCR products were electrophoresed on 2% agarose gels (Funakoshi, Tokyo, Japan) and analyzed after ethidium bromide staining.