TABLE 4.
Lymphocyte proliferation responses after challenge with wild-type EPEC strain E2348/69 or an isogenic ΔespB mutant strain (UMD864)
| Antigen | Response rate (%)a
|
|
|---|---|---|
| Recipients of wild-type EPEC | Recipients of ΔespB mutant EPEC | |
| Lymphoproliferative responses | ||
| Recombinant EspB | 4/10 (40) | 0/7 (0)b |
| Wild-type EPEC homogenate | 4/10 (40) | 1/7 (14) |
| ΔespB mutant EPEC homogenate | 3/10 (30) | 1/7 (14) |
| BSA | 0/10 (0) | 0/7 (0) |
| IFN-γ production | ||
| Recombinant EspB | 2/10 (20) | 0/7 (0) |
| Wild-type EPEC homogenate | 2/10 (20) | 0/7 (0) |
| ΔespB mutant EPEC homogenate | 3/10 (30) | 0/7 (0) |
| BSA | 0/10 (0) | 0/7 (0) |
a
Number of individuals affected/total number.
b
Three volunteers had a very high background proliferation in the absence of antigenic stimulation and were excluded from the analysis.