Macrophage-mediated killing of opsonized Treponema pallidum

J Infect Dis. 1992 Jan;165(1):69-74. doi: 10.1093/infdis/165.1.69.


The ability of proteose peptone-induced normal rabbit peritoneal macrophages to kill Treponema pallidum subspecies pallidum in vitro is demonstrated. Treponemes and 10% heated immune or normal sera were incubated with macrophages at a ratio of 1:200. After 2-10 h of incubation, these mixtures were injected intradermally at duplicate sites on normal rabbits. Maximal killing (failure to develop lesions) was seen at 10 h of incubation with immune serum: Only 7% (1/14) of lesions developed compared with 90% (9/10) after incubation in the presence of normal serum (P less than .001). Maximal phagocytosis (detected by immunofluorescence) occurred by 8 h in the presence of immune serum, when 90% of macrophages had ingested treponemes. At this point, however, 70% of lesion sites from macrophages incubated with treponemes and immune serum still developed, suggesting that effective killing may require at least 2 h after phagocytosis.

Publication types

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

MeSH terms

  • Animals
  • Cells, Cultured
  • Fluorescent Antibody Technique
  • Humans
  • Immune Sera / immunology
  • Immunoblotting
  • Macrophages / immunology*
  • Male
  • Opsonin Proteins / immunology*
  • Phagocytosis*
  • Rabbits
  • Treponema pallidum / immunology*


  • Immune Sera
  • Opsonin Proteins