Science and Research

alpha-Linoleic acid enhances the capacity of alpha-1 antitrypsin to inhibit lipopolysaccharide induced IL-1beta in human blood neutrophils

Alpha1-antitrypsin (A1AT, SERPINA1), a major circulating inhibitor of neutrophil elastase (NE) and proteinase-3 (PR3), has been proposed to reduce the processing and release of IL-1beta. Since the anti-inflammatory properties of A1AT are influenced by the presence of polyunsaturated fatty acids, we compared effects of fatty acid-free (A1AT-0) and alpha-linoleic acid bound (A1AT-LA) forms of A1AT on lipopolysaccharide (LPS)-induced synthesis of IL-1beta precursor and the release of IL-1beta from human blood neutrophils. The presence of A1AT-LA or A1AT-0 significantly reduced LPS induced release of mature IL-1beta. However, only A1AT-LA reduced both steady state mRNA levels of IL-1beta and the secretion of mature IL-1beta. In LPS-stimulated neutrophils, mRNA levels of TLR2/4, NFKBIA, P2RX7, NLRP3, and CASP1 decreased significantly in the presence of A1AT-LA but not A1AT-0. A1AT-0 and A1AT-LA did not inhibit the direct enzymatic activity of caspase-1, but we observed complexes of either form of A1AT with NE and PR3. Consistent with the effect on TLR and IL-1beta gene expression, only A1AT-LA inhibited LPS-induced gene expression of NE and PR3. Increased gene expression of PPAR-gamma was observed in A1AT-LA treated neutrophils without of LPS stimulation, and the selective PPAR-gamma antagonist (GW9662) prevented the reduction in IL-1beta by A1AT-LA. We conclude from our data, that the ability of A1AT to reduce TLR and IL-1beta gene expression depends on its association with LA. Moreover, the anti-inflammatory properties of A1AT-LA are likely to be mediated by the activation of PPAR-gamma.

  • Aggarwal, N.
  • Korenbaum, E.
  • Mahadeva, R.
  • Immenschuh, S.
  • Grau, V.
  • Dinarello, C. A.
  • Welte, T.
  • Janciauskiene, S.


  • Lps
  • Serpina1
  • alpha1 antitrypsin
  • fatty acids
  • human neutrophils
  • inflammasome
  • alpha-linoleic acid
Publication details
DOI: 10.2119/molmed.2016.00119
Journal: Molecular medicine (Cambridge, Mass.)
Pages: 680-693 
Work Type: Original
Disease Area: ROR
Partner / Member: JLU, MHH
Access-Number: 27452044
See publication on PubMed

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