The Local Inflammatory Responses to Infection of the Peritoneal Cavity in Humans: Their Regulation by Cytokines, Macrophages, and Other Leukocytes
Figure 2
Peritoneal macrophages (pM) were isolated from CAPD patients who were at least 3 months infection free (IF), or during an episode of infectious peritonitis (P), prior to the start of treatment with antibiotics. 1.106 Cells were incubated ex vivo during 24 h in medium or 5 /mL of LPS. Cytokines were determined in supernatants or cell lysates using ELISA. (a) Pro-IL-1β production and processing and mIL-1β release. Quantities of pro-IL-1β (black bars) and mature IL-1β (mIL-1β) (white bars), expressed in pg/106 cells/24 h, using ELISA specific for either form of IL-1β (), in supernatants and cell lysates from pM isolated during IF-period () or P () and incubated in medium alone (a) or 5 /mL of LPS (b). Values are expressed as (M ± SEM). mIL-1β levels in supernatants from LPS-stimulated pMs were significantly higher when cells were isolated during P (), while pro-IL-1β in cell lysates was decreased (). (c) total IL-1β production (= pro-IL-1β + mIL-1β in supernatants + cell lysates) expressed in pmol/106 cells/24 h for each IF-period (circles) and P episode (triangles) in LPS stimulated pM. Difference between total IL-1β production from IF and P pM was not statistically significant. fraction of total IL-1β that is released in supernatant as mIL-1β, expressed as percentage. Fractional release from peritonitis pM was significantly higher (). (d) total IL-1β production and fractional mIL-1β release in response to increasing doses of LPS in pM isolated during 3 episodes of peritonitis, expressed in pmol/106 cells/24 h. Total IL-1β production increased in a dose-dependent fashion. Within the range of 5.10−9–5.10−6 g/mL, LPS induced a dose-related increase in fractional IL-1β release. (e) release of IL-1β and IL-1ra in supernatants from infection-free () and peritonitis pM () stimulated with and without 5 g/mL of LPS. Substantial amounts of IL-1ra were released in unstimulated cells. LPS-stimulated peritonitis pM released similar quantities of IL-1β and IL-1ra.
