TABLE 2.

Induction of LPS-mediated hyporesponsiveness in THP-1 cells to a subsequent challenge with rFimA depends on TLRsa

THP-1 pretreatmentAmt (pg/ml) of cytokine measured (mean ± SD) (n = 3)
TNF-αIL-1β
Medium only2,418 ± 237352 ± 68
Ec-LPS49 ± 1131 ± 12
Ec-LPS + anti-TLR276 ± 2648 ± 16
Ec-LPS + anti-TLR42,159 ± 183*309 ± 44*
Pg-LPSNDb98 ± 21
Pg-LPS + anti-TLR2ND317 ± 55*
Pg-LPS + anti-TLR4ND112 ± 36
  • a THP-1 cells were exposed for 30 min to 10 μg of anti-TLR MAbs per ml prior to incubation with 1μg of Ec-LPS or Pg-LPS per ml. After 24 h, the cells were washed and challenged with 1 μg of rFimA per ml. Culture supernatants were collected after overnight incubation and assayed for cytokine responses. Asterisks * indicate groups for which the MAb treatment significantly (P < 0.05) impaired the ability of LPS to induce hyporesponsiveness in THP-1 cells to an ensuing challenge with rFimA.

  • b ND, not determined, as previous experiments showed that Pg-LPS does not cause significant hyporesponsiveness to TNF-α induction by rFimA.