title: Potential non-T cells source of interleukin-4 in food allergy.
abstract: BACKGROUND
  Recently, a study from the Consortium of Food Allergy Research (CoFAR) showed that allergen-induced IL-4 expression in CD25(+) mononuclear cells was increased in allergic patients. However, they did not find the expected increase in GATA-3 expression, suggesting that allergen-induced IL-4 might not be of T-cell origin. We sought to determine whether other cell types were responsible for the increased IL-4 expression in the CD25(+) cell population.
  
  
  METHODS
  Comparing six allergic patients and six healthy controls, we analyzed the CD25(+) isolated population from PBMC for the presence of potential IL-4-expressing non-T cells. We also compared spontaneous expression levels of surface markers (CD203c, CD63, CD25, and HLA-DR) on basophils from whole blood of 42 peanut-allergic patients and from 12 non-atopic controls. Expression of these markers was also evaluated following basophil activation in eight peanut-allergic patients selected from the previous cohort.
  
  
  RESULTS
  In addition to CD4(+) T cells, a substantial proportion of non-T cells were found in the CD25(+) -isolated cell population: basophils, NK, and NK-T cells with a mean percentage ± s.e.m. of 5.24 ± 0.63%, 6.65 ± 1.01%, and 6.01 ± 1.04%, respectively. The majority of these cells exhibited positive intracytoplasmic staining for IL-4. Expression of CD63 and CD25 was significantly higher in allergic patients compared with controls (p < 0.05). Interestingly, we found a significantly higher proportion of activated basophils expressing HLA-DR, compared with non-activated basophils (p < 0.05).
  
  
  CONCLUSIONS
  Our results support the suggested key role of non-T cells secreting IL-4 in food allergy, particularly basophils, which may also play a central role in antigen presentation.
authors.affiliation: Division of Allergy and Immunology, Department of Pediatrics and Medicine, Icahn School of Medicine at Mount Sinai, New York City, NY, USA.
authors.forename: Jean-Christoph
authors.initials: JC
authors.lastname: Caubet
authors.forename: Madhan
authors.initials: M
authors.lastname: Masilamani
authors.forename: Neisha A
authors.initials: NA
authors.lastname: Rivers
authors.forename: Lloyd
authors.initials: L
authors.lastname: Mayer
authors.forename: Hugh A
authors.initials: HA
authors.lastname: Sampson
mesh_terms: D000293:Adolescent; D000328:Adult; D017951:Antigen Presentation; D001491:Basophils / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005512:Food Hypersensitivity / Q000276:immunology*; D006801:Humans; D007223:Infant; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis; D015847:Interleukin-4 / Q000096:biosynthesis*; D008297:Male; D060149:Tetraspanin 30 / Q000032:analysis
chemical_list: C554586:CD63 protein, human; C508017:IL2RA protein, human; C508598:IL4 protein, human; D053645:Interleukin-2 Receptor alpha Subunit; D060149:Tetraspanin 30; D015847:Interleukin-4
keywords: NK cells; NK-T cells; TH2 response; basophils; food allergy; interleukin-4