Susceptibility to Cryptosporidium parvum infections in cytokine- and chemokine-receptor knockout mice

J Parasitol. 2002 Oct;88(5):1014-6. doi: 10.1645/0022-3395(2002)088[1014:STCPII]2.0.CO;2.


To determine the role of cytokines and a chemokine receptor in the susceptibility to, and outcome of, infection, 4 different knockout mice (IL-4, IL-10, IL-12, and CCR5) were infected with Cryptosporidium parvum and monitored for infection intensity by collection of fecal pellets from individual mice. Because adult immunocompetent mice are refractory to infection, wild-type mice on the same background as the knockout mice (C57BL/6) were used as a negative control. No infection was detected over a 4-wk time period in IL-4, IL-10, and CCR5 knockout mice inoculated with 106 oocysts. IL-12 knockout mice inoculated with as little as 100 oocysts shed up to 10,000 oocysts/100 microl of feces on the peak infection day (day 8) and were able to fully recover by 2 wk after infection. IL-12 is an important inducer of IFN-gamma, which probably accounted for susceptibility to infection. Previous studies using IFN-gamma knockout mice have shown strain-related differences in infection intensity and outcome, with increased parasite loads and decreased survival among IFN-gamma knockout mice on a C57BL/6 background compared with those on a BALB/c background. Similar results were observed in IL-12 knockout mice on a BALB/c background, which exhibited little or no infection, despite higher levels of inoculation (10(6) oocysts/mouse).

MeSH terms

  • Animals
  • Cryptosporidiosis / immunology*
  • Cryptosporidium parvum / immunology*
  • Cryptosporidium parvum / metabolism
  • Disease Susceptibility / immunology
  • Feces / parasitology
  • Flow Cytometry
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Oocysts / immunology
  • Oocysts / metabolism
  • Receptors, Chemokine / immunology*
  • Receptors, Chemokine / metabolism
  • Receptors, Cytokine / immunology*
  • Receptors, Cytokine / metabolism
  • Specific Pathogen-Free Organisms


  • Receptors, Chemokine
  • Receptors, Cytokine