title: Diminished bacterial clearance is associated with decreased IL-12 and interferon-gamma production but a sustained proinflammatory response in a murine model of postseptic immunosuppression.
abstract: After a major illness or injury, immune status in critically ill patients may fluctuate between a marked proinflammatory response and an immunosuppressed state. Postinflammatory immunosuppression can result in increased susceptibility to infection. Alterations of cytokine production, such as suppression of IFNgamma and elevation of the anti-inflammatory cytokine IL-10, are believed to contribute to postinflammatory immunosuppression. We examined antimicrobial immunity in mice that had previously been subjected to a sublethal cecal ligation and puncture (CLP) as a model of major injury. Mice were challenged with Pseudomonas aeruginosa (5 x 10(7) CFU i.v.) on day 5 after CLP or sham surgery. Bacterial clearance in mice after CLP was impaired and associated with decreased production of IFNgamma and increased production of IL-10 in the early response to the Pseudomonas challenge. Pseudomonas-induced production of the IFNgamma-inducing factor IL-12 was also decreased in post-CLP mice. However, splenocytes from post-CLP mice remained responsive to exogenous stimulation with the IFNgamma-inducing cytokines IL-12, IL-15, and IL-18 as well as T-cell receptor activation. Furthermore, production of the proinflammatory cytokines TNF-alpha, IL-1beta, and IL-6 were as high, or higher, in the post-CLP group compared with sham mice after P. aeruginosa challenge. Blockade of IL-10 did not reverse IL-12 and IFNgamma suppression in splenocytes from post-CLP mice. These studies show that suppressed bacterial clearance in post-CLP mice is associated with decreased production of IFNgamma and IL-12 and with increased production of IL-10 and proinflammatory cytokines.
authors.affiliation: Department of Anesthesiology, University of Texas Medical Branch, Galveston, Texas 77555, USA. edmurphe@utmb.edu
authors.forename: E D
authors.initials: ED
authors.lastname: Murphey
authors.forename: Cheng Y
authors.initials: CY
authors.lastname: Lin
authors.forename: Roy W
authors.initials: RW
authors.lastname: McGuire
authors.forename: Tracy
authors.initials: T
authors.lastname: Toliver-Kinsky
authors.forename: David N
authors.initials: DN
authors.lastname: Herndon
authors.forename: Edward R
authors.initials: ER
authors.lastname: Sherwood
mesh_terms: D000818:Animals; D002432:Cecum / Q000293:injuries / Q000601:surgery; D016207:Cytokines / Q000096:biosynthesis / Q000378:metabolism; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007108:Immune Tolerance; D007165:Immunosuppression Therapy; D007166:Immunosuppressive Agents; D007249:Inflammation / Q000473:pathology*; D007371:Interferon-gamma / Q000096:biosynthesis*; D007375:Interleukin-1 / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D018664:Interleukin-12 / Q000096:biosynthesis*; D019409:Interleukin-15 / Q000096:biosynthesis; D020382:Interleukin-18 / Q000096:biosynthesis; D015850:Interleukin-6 / Q000096:biosynthesis; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D018805:Sepsis / Q000378:metabolism / Q000473:pathology*; D013154:Spleen / Q000166:cytology; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D016207:Cytokines; D007166:Immunosuppressive Agents; D007375:Interleukin-1; D019409:Interleukin-15; D020382:Interleukin-18; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D018664:Interleukin-12; D007371:Interferon-gamma; D012260:Ribonucleases