TABLE 1.

Induction of hyporesponsiveness in THP-1 cells to a secondary challenge with rFimA depends on CD14 and TLR4a

THP-1 pretreatmentAmt (pg/ml) of cytokine measured (mean ± SD) (n = 3)
TNF-αIL-1β
Medium only2,108 ± 197297 ± 42
rFimA365 ± 2857 ± 19
rFimA + IgG1 control381 ± 3446 ± 16
rFimA + IgG2a control341 ± 5473 ± 37
rFimA + anti-CD141,920 ± 134*218 ± 29*
rFimA + anti-TLR2423 ± 4669 ± 34
rFimA + anti-TLR41,432 ± 158*167 ± 28*
  • a THP-1 cells were exposed for 30 min to 10 μg of immunoglobulin isotype controls per ml or anti-CD14, anti-TLR2, or anti-TLR4 MAb prior to incubation with 1 μg of rFimA 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 rFimA to induce hyporesponsiveness in THP-1 cells to a secondary challenge with rFimA.