Human monocyte-derived type 1 and 2 macrophages recognize Ara h 1, a major peanut allergen, by different mechanisms

Sci Rep. 2021 May 12;11(1):10141. doi: 10.1038/s41598-021-89402-1.

Abstract

Evidence has suggested that major peanut allergen Ara h 1 activates dendritic cells (DCs) via interaction with DC-SIGN (dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin), a C-type lectin receptor, and contributes to development of peanut allergy. Since macrophages, as well as DCs, play a crucial role in innate immunity, we investigated whether natural Ara h 1 (nAra h 1) activates two different subsets of macrophages, human monocyte derived macrophage type 1 (hMDM1: pro-inflammatory model) and type 2 (hMDM2: anti-inflammatory model). hMDM1 and hMDM2 predominantly produced pro-inflammatory cytokines (IL-6 and TNF-α) and an anti-inflammatory cytokine (IL-10) in response to nAra h 1, respectively. hMDM2 took up nAra h 1 and expressed DC-SIGN at higher levels than hMDM1. However, small interfering RNA knockdown of DC-SIGN did not suppress nAra h 1 uptake and nAra h 1-mediated cytokine production in hMDM2. Inhibitors of scavenger receptor class A type I (SR-AI) suppressed the response of hMDM2, but not of hMDM1, suggesting that SR-AI is a major receptor in hMDM2 for nAra h 1 recognition and internalization. nAra h 1 appears to exert stimulatory capacity on DC and macrophages via different receptors. This study advances our understanding how a major peanut allergen interacts with innate immunity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / immunology*
  • Antigens, Plant / immunology*
  • Arachis / immunology*
  • Biomarkers
  • Cell Plasticity / immunology*
  • Disease Susceptibility
  • Humans
  • Immunophenotyping
  • Macrophage Activation / immunology
  • Macrophages / immunology*
  • Macrophages / metabolism
  • Membrane Proteins / immunology*
  • Monocytes / immunology*
  • Monocytes / metabolism
  • Peanut Hypersensitivity / diagnosis
  • Peanut Hypersensitivity / immunology*
  • Peanut Hypersensitivity / metabolism
  • Plant Proteins / immunology*

Substances

  • Allergens
  • Antigens, Plant
  • Ara h 1 protein, Arachis hypogaea
  • Biomarkers
  • Membrane Proteins
  • Plant Proteins