TABLE 1.

E. chaffeensis infection in mice lacking MHC-II genes results in persistent infectiona

DayNo. positive/no. tested (%)Pb
MHC-II+/+ miceMHC-II−/− mice
84/4 (100)7/7 (100)NS
164/8 (50)12/12 (100)0.004
232/5 (40)11/12 (92)0.007
302/7 (29)8/11 (73)0.04
500/8 (0)10/12 (83)0.0002
920/8 (0)7/8 (88)0.0004
  • a Peritoneal exudate cells were recovered from mice at the indicated times after i.p. infection with E. chaffeensis and were used to recover E. chaffeensis by culture in DH82 cells. Cultures were maintained for up to 8 weeks and examined twice a week for the presence of organisms. Cultures were monitored for growth every three to four days until the recovery of viable organisms. Note: MHC-II+/+ mice included both the tlr4n/n and tlr4d/d mice.

  • b Statistical analysis was performed by the chi-square test. NS, not statistically significant.