Effect of Interleukin-2 on Peripheral Blood Mononuclear Cell Cytokine Production and the Hepatic Acute Phase Protein Response

This study investigated the ability of recombinant interleukin-2 (IL-2) to modulate the ability of peripheral blood mononuclear cells (PBMCs) to stimulate an acute phase protein response in isolated human hepatocytes. The effect of IL-2 on the production of tumour necrosis factor-α (TNF) and interleukin-6 (IL-6) by PBMCs isolated from patients with gastrointestinal cancer, multiple organ failure, and healthy controls was also studied. The ability of supernatants from IL-2-treated PBMCs to elicit an acute phase response in hepatocytes was then investigated. IL-2 had no effect on IL-6 or TNF production by PBMCs isolated from any group in the presence or absence of bacterial lipopolysaccharide (LPS). Despite this, preincubation of PBMCs with IL-2 significantly reduced the potential of LPS-stimulated PBMC supernatants to stimulate production of α1 antichymotrypsin, α1-acid glycoprotein, and C-reactive protein by hepatocytes. These observations were not due to a direct effect of IL-2 on hepatocyte acute phase protein production. These findings suggest that in this model IL-2 may modulate PBMC-induced acute phase protein production through an IL-6 and TNF-independent pathway.