TABLE 4.
EPEC derivatives and their effect on caspase-8 activation during EPEC infection
| EPEC strain genotypea | Pentapeptide insertion sequence | Caspase-8 activationb |
|---|---|---|
| Wild type | − | − |
| ΔnleB1 | − | +++ |
| ΔnleB1(pNleB1) | − | − |
| ΔnleB1(pNleB1Tn68) | NAAAT | NTc |
| ΔnleB1(pNleB1Tn79) | AAAAN | NT |
| ΔnleB1(pNleB1Tn92) | VAAAL | NT |
| ΔnleB1(pNleB1Tn120) | AAAAR | NT |
| ΔnleB1(pNleB1Tn127) | YAAAM | NT |
| ΔnleB1(pNleB1Tn142) | CGRNK | +++ |
| ΔnleB1(pNleB1Tn156) | GAAAL | +++ |
| ΔnleB1(pNleB1Tn157) | CGRIG | +++ |
| ΔnleB1(pNleB1Tn198) | CGRTG | +++ |
| ΔnleB1(pNleB1Tn205) | CGRTG | + |
| ΔnleB1(pNleB1Tn221) | DAAAL | +++ |
| ΔnleB1(pNleB1Tn228) | DAAAT | +++ |
| ΔnleB1(pNleB1Tn230) | CGRNK | +++ |
| ΔnleB1(pNleB1Tn237) | DAAAP | +++ |
| ΔnleB1(pNleB1Tn248) | CGRND | − |
| ΔnleB1(pNleB1Tn262) | MRPHR | +++ |
| ΔnleB1(pNleB1Tn262) | SAAAR | +++ |
| ΔnleB1(pNleB1Tn267) | CGRTA | + |
| ΔnleB1(pNleB1Tn269) | AAAAL | +++ |
| ΔnleB1(pNleB1Tn277) | CGRKS | +++ |
| ΔnleB1(pNleB1Tn278) | CGRSK | ++ |
| ΔnleB1(pNleB1Tn286) | CGRND | + |
| ΔnleB1(pNleB1Tn291) | IAAAG | +++ |
| ΔnleB1(pNleB1Tn303) | CGRNN | − |
| ΔnleB1(pNleB1Tn324) | CGRSM | + |
| ΔnleB1(pNleB1Tn326) | SAAAT | − |
| ΔnleB1(pNleB1Tn329) | LRPHS | + |
a
The number after Tn indicates the position of the insertion.
b
HeLa cell lysates were examined for caspase-8 activation levels after EPEC infection and FasL stimulation; +, ++, and +++, increasing levels of caspase-8 cleavage, with +++ indicating levels of caspase-8 cleavage comparable to that of uninfected HeLa cells stimulated with FasL; −, the absence of caspase-8 cleavage comparable to the inhibition observed in the presence of wild-type NleB1.
c
NT, not tested.