Table 3.

Mechanism of CpG ODN 1826-induced protective immunity

ExptODN treatmentaTreatmentNo. infected/ total% ProtectionP valuef
1CpG ODN 18260/10100
CpG ODN 1826Control Ig0/10100
CpG ODN 1826Anti-IFN-γb 2/10800.474
CpG ODN 1826Anti-IL-1210/1000.000008
Control ODN 198210/100
None18/180
2CpG ODN 18260/10100
CpG ODN 1826Control Ig0/10100
CpG ODN 1826Anti-IFN-γc 8/10200.0007
Control ODN 19828/1020
None6/60
3CpG ODN 1826Control Ig0/9100
CpG ODN 1826Anti-iNOSd 1/9890.999
CpG ODN 1826Anti-NK cells2/9780.474
Control ODN 1982Control Ig8/80
None9/90
4CpG ODN 1826Control Ig2/1080
CpG ODN 1826Anti-iNOSe 0/101000.474
CpG ODN 1826Anti-CD8+ T cells1/9890.999
CpG ODN 1826Anti-CD4+ T cells0/101000.474
Control ODN 1982Control Igntg nt
None5/1050
  • a CpG ODN (50 μg) was administered i.m. in the tibialis anterior muscle on day −2 relative to i.v. inoculation of sporozoites on day 0.

  • b One milligram of anti-IFN-γ MAb was administered i.p. on days −2, −1, and 0 relative to challenge.

  • c One milligram of anti-IFN-γ MAb was administered on each of days −3 (i.v.), −2 (i.p.), 0 (i.v.), and +2 (i.v.) relative to challenge.

  • d Aminoguanidine (50 mg/kg of body weight) was administered twice daily by gastric lavage, commencing 24 h before ODN administration and continuing until 72 h postchallenge.

  • e Aminoguanidine (50 mg/kg of body weight) was administered twice daily by gastric lavage, commencing 48 h before ODN administration and continuing until 96 h post challenge.

  • f P values were calculated by comparing protection induced by MAb treatment versus control Ig treatment for each treatment group using the chi-square test (uncorrected) or Fisher's exact test (two-tailed) (if the expected cell value was less than five). P values of <0.05 were considered significant.

  • g nt, not tested.