Eosinophils are the major effector cells of immunity to microfilariae in a mouse model of onchocerciasis

Parasitology. 1996 Mar;112 ( Pt 3):323-9. doi: 10.1017/s0031182000065847.


Mice inoculated with microfilariae of the filarial nematode Onchocerca lienalis clear their parasites over a period of 3-4 months and are highly resistant to re-infection. We have investigated the comparative roles of the eosinophil, macrophage and neutrophil in effecting this parasite clearance, employing agents specifically to perturb cell function in vivo. Using the anti-IL-5 monoclonal antibody TRFK-5, we show that eosinophils are of primary importance in effecting resistance to re-infection. Ablation of macrophages (with carbon) and neutrophils (with the monoclonal antibody NIMP-R14) had no effect on parasite clearance following re-infection. Neutralization of these 3 cell types during a primary infection showed that while the removal of both eosinophils and macrophages caused a small but significant delay in parasite clearance, the depletion of neutrophils had no effect. This report describes the first direct evidence for eosinophil-mediated killing of microfilariae in vivo, and is consistent with Th-2 cell responses previously described in this model.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Cattle
  • Cattle Diseases
  • Chi-Square Distribution
  • Disease Models, Animal
  • Eosinophils / immunology*
  • Immunity, Innate
  • Interleukin-5 / immunology
  • Macrophages / immunology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred CBA
  • Neutrophils / immunology
  • Onchocerciasis / blood
  • Onchocerciasis / immunology*
  • Onchocerciasis / veterinary
  • Rats
  • Recurrence


  • Antibodies, Monoclonal
  • Interleukin-5