LRG1 downregulation in allergic airway disorders and its expression in peripheral blood and tissue cells

J Transl Med. 2016 Jul 4;14(1):202. doi: 10.1186/s12967-016-0929-2.


Background: Increased leucine-rich α2-glycoprotein-1 (LRG1) has been observed in plasma of individuals with various diseases. However, the role of LRG1 in allergic airway disease has not been investigated.

Objective: To explore the involvement of LRG1 in allergy and its cell origins.

Methods: The expression levels of LRG1 and its receptor transforming growth factor-beta receptor II (TGFBR2) in patients with allergic rhinitis (AR) and asthma (AS) were examined by flow cytometry, and enzyme-linked immunosorbent assay (ELISA).

Results: LRG1 and soluble TGFBR2 expression in plasma of patients with AR and AS were markedly lower than that of healthy control (HC) subjects. Large proportions of CD123 + HLA-DR-, CD16+, CD4+, CD8+, CD14+, and CD19+ cells expressed LRG1, although the percentages of LRG1+ cells in these cell populations were lower in AR and AS patients. Up to 89.8 and 15.5 % of dispersed mast cells expressed LRG1 and TGFBR2. Moreover, allergen extract exposure significantly reduced LRG1 and TGFBR2 expression in the plasma and leukocytes of patients with AR and AS.

Conclusions: Reduced LRG1 and TGFBR2 levels in patients with allergic airway disorders are likely caused by inhibitory actions of allergens in LRG1 producing cells. Thus, LRG1 may be a key regulatory factor of allergic responses.

Keywords: Allergic airway disorder; LRG1; Leukocytes; Mast cells; TGFBR2.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Allergens / immunology
  • Asthma / blood*
  • Case-Control Studies
  • Cell Line
  • Down-Regulation*
  • Female
  • Flow Cytometry
  • Glycoproteins / blood*
  • Humans
  • Male
  • Mast Cells / metabolism
  • Middle Aged
  • Organ Specificity*
  • Peripheral Blood Stem Cells / metabolism*
  • Protein Serine-Threonine Kinases / blood
  • Receptor, Transforming Growth Factor-beta Type II
  • Receptors, Transforming Growth Factor beta / blood
  • Rhinitis, Allergic / blood*
  • Time Factors
  • Tryptases / blood
  • Young Adult


  • Allergens
  • Glycoproteins
  • LRG1 protein, human
  • Receptors, Transforming Growth Factor beta
  • Protein Serine-Threonine Kinases
  • Receptor, Transforming Growth Factor-beta Type II
  • Tryptases