TNF and infection: Moreover, pharmacological agents such as forskolin and a β2 agonist, procaterol, increased the intracellular levels of cAMP, which inhibited TNF-α, interleukin-1 beta (IL-1β), and RV14 infection-induced ICAM-1 expression in cultured human smooth muscle cells [33] and bronchial epithelial cells [34], respectively.