Tumor necrosis factor α induction in human monocytes

The present study was undertaken to assess the presence of tumor necrosis factor (TNF)-α mRNA and protein in circulating human blood monocytes and to study the TNF-α gene expression in human monocytes isolated by continuous Percoll gradient fractionation. The technique of RNA isolation directly from the blood samples was used to study TNF-α mRNA expression in circulating human blood leukocytes. It was shown that human blood leukocytes of healthy donors contained no presynthesized pool of TNF-α mRNA as well as no TNF-α protein. It was found that early pretreatment with cycloheximide interfers with TNF-α mRNA induction by Staphylococcus aureus.