Interleukin‐16 stimulates the expression and production of pro‐inflammatory cytokines by human monocytes

NL Mathy, W Scheuer, M Lanzendörfer, K Honold… - …, 2000 - Wiley Online Library
NL Mathy, W Scheuer, M Lanzendörfer, K Honold, D Ambrosius, S Norley, R Kurth
Immunology, 2000Wiley Online Library
Summary Interleukin‐16 (IL‐16) acts as a chemoattractant for CD4+ cells, as a modulator of
T‐cell activation, and plays a key role in asthma. This report describes the cytokine‐inducing
effects of IL‐16 on total peripheral blood mononuclear cells (PBMC) and PBMC
subpopulations. While CD4+ T lymphocytes did not secrete cytokines in response to rhIL‐
16, CD14+ CD4+ monocytes and maturing macrophages secrete IL‐1β, IL‐6, IL‐15 and
tumour necrosis factor‐α (TNF‐α) upon rhIL‐16 stimulation. The mRNA species for these …
Summary
Interleukin‐16 (IL‐16) acts as a chemoattractant for CD4+ cells, as a modulator of T‐cell activation, and plays a key role in asthma. This report describes the cytokine‐inducing effects of IL‐16 on total peripheral blood mononuclear cells (PBMC) and PBMC subpopulations. While CD4+ T lymphocytes did not secrete cytokines in response to rhIL‐16, CD14+ CD4+ monocytes and maturing macrophages secrete IL‐1β, IL‐6, IL‐15 and tumour necrosis factor‐α (TNF‐α) upon rhIL‐16 stimulation. The mRNA species for these four cytokines were detected as early as 4 hr post‐stimulation, with protein being secreted by 24 hr. Secretion of IL‐1β and IL‐6 by total PBMC was dose dependent, with maximal secretion being observed using 50 ng/ml rhIL‐16. However, for IL‐15 or TNF‐α maximal secretion by total PBMC occurred with all concentrations between 5 ng/ml to 500 ng/ml rhIL‐16. Purified monocytes/macrophages secreted maximal concentrations of all four cytokines in the presence of 500 ng/ml rhIL‐16, except for monocytes where maximal secretion of IL‐15 was, interestingly, observed with only 50 ng/ml rhIL‐16. The use of higher concentrations of rhIL‐16 (1000 ng/ml) inhibited secretion of all four cytokines. While these IL‐16‐induced cytokines are likely to be involved in the immune system's response to antigen, the data suggest that IL‐16 may play a key role in initiating and/or sustaining an inflammatory response.
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