IL-4 inhibits the expression of mouse formyl peptide receptor 2, a receptor for amyloid beta1-42, in TNF-alpha-activated microglia.

IRIBARREN P; CHEN, K.; HU, J.; ZHANG, X.; GONG, W.; WANG, J. M.

JOURNAL OF IMMUNOLOGY

Año: 2005 vol. 175 p. 6100 - 6100

0022-1767

p class="abstract">Microglia are phagocytic cells in the CNS and actively participate in proinflammatory responses in neurodegenerative diseases. We have previously shown that TNF-alpha up-regulated the expression of formyl peptide receptor 2 (mFPR2) in mouse microglial cells, resulting in increased chemotactic responses of such cells to mFPR2 agonists, including amyloid beta1-42 (Abeta42), a critical pathogenic agent in Alzheimer´s disease. In the present study, we found that IL-4, a Th2-type cytokine, markedly inhibited TNF-alpha-induced expression of mFPR2 in microglial cells by attenuating activation of ERK and p38 MAPK as well as NF-kappaB. The effect of IL-4 was not dependent on Stat6 but rather required the protein phosphatase 2A (PP2A) as demonstrated by the capacity of PP2A small interfering RNA to reverse the effect of IL-4 in TNF-alpha-activated microglia. Since both IL-4 and TNF-alpha are produced in the CNS under pathophysiological conditions, our results suggest that IL-