Analysis of interleukin 12 protein production and mRNA expression in mice exposed topically to chemical allergens.
Interleukin (IL) 12 is a heterodimeric cytokine which stimulates IFN-gamma production and promotes the development of type 1 T helper cells and T cytotoxic cells from their respective precursors. We have described previously that contact allergens such as 2,4-dinitrochlorobenzene (DNCB), and respiratory allergens such as trimellitic anhydride (TMA) induce discrete type 1 and type 2 cytokine secretion patterns, respectively, following repeated topical exposure of BALB/c strain mice. Under such conditions, we have now examined production by draining LNC of the inducible subunit of IL-12 (p40) and p40 and p35 subunit mRNA expression. Cultured LNC prepared from mice treated with DNCB secreted significantly more IL-12 p40 protein than did TMA- or vehicle-activated LNC, such differences becoming more pronounced as the duration of culture increased. Maximal levels of mRNA expression of the IL-12 p40 subunit were observed after 6-24 h of culture in all treatment groups and declined thereafter. Somewhat higher levels were induced following exposure to DNCB, these differences only reached statistical significance at 24 h of culture. Expression of this subunit by LNC from all treatment groups declined with time in culture. Levels of IL-12 p35 mRNA expression were comparable in cultured LNC prepared from allergen and vehicle treated mice and remained constant throughout the entire culture period. These data indicate that the divergent T cell cytokine responses seen in response to contact and respiratory allergens are associated with differential production of IL-12 p40 protein in the absence of substantial changes in the expression of mRNA for either subunit.
Warbrick
E V
EV
Zeneca Central Toxicology Laboratory, Alderley Park, Macclesfield, Cheshire, UK. vicky.warbrick@ctl.zeneca.com
Dearman
R J
RJ
Basketter
D A
DA
Kimber
I
I
D000096:Acetone / Q000494:pharmacology; D000287:Administration, Topical; D000485:Allergens / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D017931:DNA Primers / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000378:metabolism; D004137:Dinitrochlorobenzene / Q000494:pharmacology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D018664:Interleukin-12 / Q000096:biosynthesis* / Q000235:genetics; D008198:Lymph Nodes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D019255:NADPH Oxidases; D000069463:Olive Oil; D010796:Phthalic Anhydrides / Q000494:pharmacology; D010938:Plant Oils / Q000494:pharmacology; D011506:Proteins; D012333:RNA, Messenger / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D000485:Allergens; D017931:DNA Primers; D004268:DNA-Binding Proteins; D004137:Dinitrochlorobenzene; D000069463:Olive Oil; D010796:Phthalic Anhydrides; D010938:Plant Oils; D011506:Proteins; D012333:RNA, Messenger; D000096:Acetone; D018664:Interleukin-12; C015559:trimellitic anhydride; D019255:NADPH Oxidases; C113333:NCF4 protein, human