[Effects of secretory leukocyte protease inhibitor on the production of some cytokines and nitric oxide by murine peritoneal macrophages in response to lipopolysaccharide stimulation and M. avium complex infection].
Secretory leukocyte protease inhibitor (SLPI), a serine protease inhibitor abundantly found in mucous secretions of lung, is thought to serve as an important protective component in the secretory fluids at sites of degenerative and inflammatory diseases. In this study, we examined the effects of SLPI on the production of a proinflammatory cytokine, TNF-alpha, and immunosupressive cytokines, IL-10 and transforming growth factor-beta (TGF-beta) by macrophages (M phi s), in response to lipopolysaccharide (LPS)-mediated stimulation and M. avium complex (MAC) infection, using recombinant half-sized SLPI (1/2 SLPI) consisting of C-terminal domain (Arg55-Ala107) of intact SLPI. In addition, effects of SLPI on the production of nitric oxide radicals (NO), important antimicrobial effectors of M phi s against micro-organisms, by these M phi s were studied. First, when the number of TNF-alpha producing cells in the LPS-stimulated M phi population was counted by the ELISPOT assay, more than half of the M phi s acquired TNF-alpha secreting ability at 24 hr after LPS stimulation. On the other hand, MAC-infected M phi s produced detectable amounts of TNF-alpha into culture fluid during the first 24 hr. In both cases, 1/2 SLPI did not affect the LPS- or MAC-induced TNF-alpha production by M phi s. Second, when the production of IL-10 and TGF-beta by M phi s was determined by measuring the amounts of these cytokines accumulated in M phi culture fluids by ELISA, the following was observed. M phi IL-10 production was rapidly increased in the early phase of cultivation after LPS stimulation or MAC infection, peaking on day 1 and thereafter declining to normal level by day 14. Half-sized SLPI did not affect IL-10 production of LPS-stimulated M phi s, while it caused slight enhancement of IL-10 production by MAC-infected M phi s. M phi TGF-beta production was initiated in the middle phase (day 7) of M phi cultivation and continued until day 14. Notably, 1/2 SLPI markedly potentiated the TGF-beta producing ability of the LPS-stimulated M phi s. Moreover, 1/2 SLPI caused moderate increase in the TGF-beta production by MAC-infected M phi s. Third, significantly potentiated NO production was observed in M phi s during the first 2 days after LPS stimulation and MAC infection. Half-sized SLPI did not affect the NO production by LPS-stimulated or MAC-infected M phi s. These findings indicate that SLPI up-regulates the production of some immunoregulatory cytokines including IL-10 and TGF-beta, particularly the latter, by M phi s in response to LPS stimulation or MAC infection, thereby suggesting the possibility that SLPI may exhibit antiinflammatory effects in vivo, especially patients with bacterial infections including MAC diseases, through the modulation of M phi expression of some immunosuppressive cytokines.
Sano
C
C
Department of Microbiology and Immunology, Shimane Medical University.
Shimizu
T
T
Sato
K
K
Ogasawara
K
K
Tomioka
H
H
D000818:Animals; D002478:Cells, Cultured; D016207:Cytokines / Q000096:biosynthesis*; D005260:Female; D008264:Macrophages / Q000187:drug effects* / Q000382:microbiology / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D015269:Mycobacterium avium Complex / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins / Q000494:pharmacology*; D053481:Secretory Leukocyte Peptidase Inhibitor; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology*
D016207:Cytokines; D053491:Proteinase Inhibitory Proteins, Secretory; D011506:Proteins; D053481:Secretory Leukocyte Peptidase Inhibitor; D015842:Serine Proteinase Inhibitors; C506815:Slpi protein, mouse; D009569:Nitric Oxide