In vitro screening for putative psoriasis-specific antigens among wheat proteins and peptides

Br J Dermatol. 2012 Jan;166(1):67-73. doi: 10.1111/j.1365-2133.2011.10608.x. Epub 2011 Dec 9.


Background: Patients with psoriasis who had raised IgG and/or IgA antigliadin antibodies showed clinical improvement in a trial with a gluten-free diet. The selection of patients for the diet treatment was based on the presence of specific antibodies, i.e. the result of humoral immunity.

Objectives: As psoriasis is now considered to be a T cell-mediated disease we decided to challenge peripheral blood mononuclear cells (PBMCs) in vitro from randomly selected patients with well-defined wheat proteins/peptides to explore the possibility of identifying a specific antigen with T cell activating properties in a subgroup of patients.

Methods: PBMCs from 37 patients (20 female and 17 male; mean age 49years) and 37 healthy controls (12 female and 25 male; mean age 57years) were included. Not all patients participated in all experiments. The PBMCs were exposed in vitro with the following wheat proteins/peptides in various concentrations: total albumins, 0·28 α-amylase inhibitor and the synthetic peptides, p31-43, p57-68 and p62-75, based on coeliac-active sequences of α-gliadin. The proliferative response was measured as counts per minute after the cells had been pulsed with methyl-(3) H-thymidine.

Results: Albumin, α-amylase inhibitor, p31-43 and p57-68 elicited a significant response in both patients and controls but showed no differences between the groups. The response induced by the α-amylase inhibitor was higher than that induced by the albumin fraction and the p31-43 and p57-68 peptides. At a concentration of 25μgmL(-1) , five of 36 patients with psoriasis responded positively to the p62-75 peptide and none of the 33 controls, using a stimulation index of 2·4 as the cut-off level (P<0·05). These five patients did not show clinical features that differed from the remaining patients. Among the responding patients the relative number of CD4+ cells increased in some but not all after in vitro challenge with the albumins, 0·28 α-amylase inhibitor, and p62-75. These antigens could also induce in vitro the expression of the homing antigen cutaneous lymphocyte antigen (CLA) in a few patients and controls.

Conclusions: The wheat protein antigens, especially the p62-75 peptide, might be of interest in a subgroup of patients with psoriasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antigens / metabolism*
  • Antigens, Differentiation, T-Lymphocyte / metabolism
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Dietary Proteins / immunology*
  • Female
  • Humans
  • Leukocytes, Mononuclear / immunology
  • Male
  • Membrane Glycoproteins / metabolism
  • Middle Aged
  • Peptides / immunology*
  • Pilot Projects
  • Plant Proteins / immunology*
  • Psoriasis / immunology*
  • Triticum / immunology*


  • Antigens
  • Antigens, Differentiation, T-Lymphocyte
  • CTAGE1 protein, human
  • Dietary Proteins
  • Membrane Glycoproteins
  • Peptides
  • Plant Proteins