title: In vitro kinetics of allergen- and microbe-induced IL-4 and IFN-gamma mRNA expression in PBMC of pollen-allergic patients.
abstract: BACKGROUND
  According to a hypothesis allergens induce Th2 responses in allergic patients, and microbes induce Th1 responses. We studied the kinetics of in vitro allergen-, tuberculin (PPD)- and tetanus toxin (TT)-induced IFN-gamma and IL-4 mRNA expression in peripheral blood mononuclear cell (PBMC) cultures of pollen-allergic patients and healthy controls.
  
  
  METHODS
  PBMC of 10 birch or timothy pollen-allergic patients and of 13 healthy controls were stimulated in vitro with allergen (birch or timothy), PPD or TT. Pellets and supernatants were collected at 24, 48, 72 and 96 h after stimulation. IFN-gamma and IL-4 production was measured by enzyme linked immunosorbent assay and mRNA expression using RT-PCR and time-resolved fluorometry.
  
  
  RESULTS
  Allergen induced IFN-gamma production and mRNA expression in PBMC more in allergic patients than in healthy controls. Also allergen induced IL-4 mRNA expression more in allergic patients than in healthy controls. PPD induced IFN-gamma mRNA expression both in allergic patients and healthy controls, whereas IFN-gamma production was induced only in healthy controls and IL-4 was not induced at all. TT induced IFN-gamma mRNA expression in both groups, IFN-gamma production in allergic patients, and IL-4 mRNA expression in both allergic patients and healthy controls.
  
  
  CONCLUSIONS
  In vitro stimulation with allergen induced both IFN-gamma and IL-4 mRNA expression of PBMC in allergic patients. These observations challenge the clearcut division of microbe-specific Th1 and allergen-specific Th2 responses in peripheral blood.
authors.affiliation: Department of Pulmonary Diseases and Clinical Allergology, University of Turku, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Laaksonen
authors.forename: M
authors.initials: M
authors.lastname: Waris
authors.forename: M J
authors.initials: MJ
authors.lastname: Mäkelä
authors.forename: E O
authors.initials: EO
authors.lastname: Terho
authors.forename: J
authors.initials: J
authors.lastname: Savolainen
mesh_terms: D000328:Adult; D000485:Allergens / Q000009:adverse effects* / Q000097:blood / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000097:blood / Q000209:etiology* / Q000378:metabolism*; D007114:Immunization; D007371:Interferon-gamma / Q000096:biosynthesis* / Q000187:drug effects*; D015847:Interleukin-4 / Q000096:biosynthesis*; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000187:drug effects* / Q000378:metabolism*; D008297:Male; D011058:Pollen / Q000009:adverse effects*; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000485:Allergens; D012333:RNA, Messenger; D015847:Interleukin-4; D007371:Interferon-gamma