Table 1.
Six-week-old male C57BL/6 and CD8 knockout (CD8 KO) mice were orally immunized with 1011 WR201 and eight weeks later challenged with 104 B. melitensis 16 M. Figures at 1 day and 2 weeks after challenge, when most or all animals were infected, are mean CFU ± SD. At 4 and 8 weeks, when many animals had cleared the infection and mean CFU counts became less meaningful, figures are shown as ratio of cleared/total. At day 1, n = 5 for C57BL/6 and n = 4 for CD8 KO; at 2 weeks n = 10 for all groups. CFU comparisons utilized Student's t-test while clearance comparisons utilized Fisher's exact test.
| Organ | Time after challenge | C57BL/6 immunized | C57BL/6 naive |
P value C57BL/6 immunized versus naive |
CD8 KO immunized | CD8 KO naïve |
P value CD8 KO immunized versus naive |
P value immunized versus immunized | P value naïve versus naive |
|---|---|---|---|---|---|---|---|---|---|
| Liver | 2 wks | 1.53 ± 0.840 | 2.91 ± 0.646 | <0.01 | 1.58 ± 0.887 | 2.88 ± 0.646 | <0.05 | >0.05 | >0.05 |
| 4 wks | 9/10 | 1/10 | <0.001 | 7/10 | 0/10 | <0.01 | >0.05 | >0.05 | |
| 8 wks | 17/18 | 11/19 | <0.05 | 20/23 | 14/20 | >0.05 | >0.05 | >0.05 | |
|
| |||||||||
| Spleen | 2 wks | 1.29 ± 0.676 | 2.46 ± 1.22 | <0.05 | 1.59 ± 0.227 | 1.62 ± 0.662 | >0.05 | >0.05 | >0.05 |
| 4 wks | 6/10 | 1/10 | <0.05 | 6/10 | 0/10 | <0.01 | >0.05 | >0.05 | |
| 8 wks | 12/18 | 1/19 | <0.001 | 12/23 | 1/20 | <0.001 | >0.05 | >0.05 | |
|
| |||||||||
| Lung | 1 day | 3.38 ± 0.66 | 3.32 ± 0.18 | >0.05 | 3.48 ± 0.21 | 3.81 ± 0.14 | >0.05 | >0.05 | >0.05 |
| 2 wks | 2.2 ± 0.89 | 2.03 ± 1.17 | >0.05 | 2.32 ± 0.82 | 3.08 ± 0.66 | >0.05 | >0.05 | 0.048 | |
| 4 wks | 8/10 | 4/10 | >0.05 | 4/8 | 1/10 | >0.05 | >0.05 | >0.05 | |
| 8 wks | 11/16 | 11/19 | >0.05 | 10/23 | 10/20 | >0.05 | >0.05 | >0.05 | |