Virulent Treponema pallidum, lipoprotein, and synthetic lipopeptides induce CCR5 on human monocytes and enhance their susceptibility to infection by human immunodeficiency virus type 1

J Infect Dis. 2000 Jan;181(1):283-93. doi: 10.1086/315209.


Treponema pallidum, its membrane lipoproteins, and synthetic lipoprotein analogues (lipopeptides) were each examined to determine whether they induced CCR5 expression on human peripheral blood mononuclear cells (PBMC). Reverse transcription-polymerase chain reaction for CCR5 gene transcripts, macrophage inflammatory protein (MIP)-1beta binding assays, and flow cytometry revealed that either T. pallidum, a representative treponemal lipoprotein, or a corresponding synthetic lipopeptide induced CCR5 on CD14 monocytes but not on CD3 lymphocytes. CXCR4, the coreceptor for T cell-tropic strains of human immunodeficiency virus type 1 (HIV-1), was not induced on PBMC by treponemes or by lipoproteins or lipopeptides. Consistent with these findings, T. pallidum, lipoprotein, and synthetic lipopeptide all promoted the entry of a macrophage-tropic, but not a T cell-tropic, strain of HIV-1 into monocytes. These combined results imply that T. pallidum and its constituent lipoproteins likely induce the expression of CCR5 on macrophages in syphilitic lesions, thereby enhancing transmission of macrophage-tropic HIV-1.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Chemokine CCL4
  • Chemokines / metabolism
  • HIV Infections / etiology
  • HIV-1 / growth & development*
  • Humans
  • Lipoproteins / pharmacology*
  • Macrophage Inflammatory Proteins / metabolism
  • Monocytes / drug effects*
  • Monocytes / virology
  • Protein Binding / drug effects
  • Receptors, CCR5 / biosynthesis*
  • Receptors, CXCR4 / biosynthesis
  • Syphilis / complications
  • Treponema pallidum / chemistry*
  • Treponema pallidum / pathogenicity


  • Chemokine CCL4
  • Chemokines
  • Lipoproteins
  • Macrophage Inflammatory Proteins
  • Receptors, CCR5
  • Receptors, CXCR4