Reduced expression of the chemokine receptor CCR1 in human macrophages and U-937 cells in vitro infected with Leishmania infantum

Clin Exp Med. 2004 Apr;3(4):225-30. doi: 10.1007/s10238-004-0029-0.

Abstract

Chemokines exert their actions through G-proteinlinked receptors, which are expressed to variable extents by different cell types. In accordance with the chemokine classification, these receptors are designated as CXC, CC, XC, and CX(3)C, followed by R and a number. The purpose of this investigation was to evaluate CCR1 expression in human peripheral blood-derived macrophages and the human monocytic U-937 cell line. Cells in vitro were infected with live Leishmania infantum promastigotes (zymodeme MON1); cell lysates were then subjected to SDS-PAGE and immunoblotting, by using an anti-CCR1 affinity purified polyclonal antibody. The expression of the CCR1 gene was analyzed by RT-PCR, using specific human primers. The results of both immunoblotting and RT-PCR showed that CCR1 expression in Leishmania-infected cells was lower than in uninfected control cells. These results indicate that Leishmania infantum infection causes a down-regulation of the CCR1 gene and protein expression, suggesting that reduced phagocyte recruitment at the inflammation sites could favor parasite progression and the spread of Leishmania infection.

MeSH terms

  • Animals
  • Blotting, Western
  • Densitometry
  • Gene Expression Regulation*
  • Humans
  • Leishmania infantum / physiology*
  • Macrophages / metabolism*
  • Macrophages / parasitology*
  • Receptors, CCR1
  • Receptors, Chemokine / biosynthesis*
  • Receptors, Chemokine / genetics*
  • Reverse Transcriptase Polymerase Chain Reaction
  • U937 Cells

Substances

  • CCR1 protein, human
  • Receptors, CCR1
  • Receptors, Chemokine