“…IL-6 stimulates the polarization of naive T cells (Th0 cells) to Th2 cells via induction of IL-4 gene expression (Rincon et al, 1997) and in uences IgE synthesis (Vercelli et al, 1989). TNF-a stimulates B lymphocyte activity (Kehrl et al, 1987) and is increased in the lungs of asthmatics (Casale et al, 1996), where it facilitates extravasation of leukocytes into the tissue via upregulation of vascular cell adhesion molecule 1 (VCAM-1) (Klein et al, 1989;Moser et al, 1992). In addition to the activation processes just described, pulmonary in ammation also features edema from epithelial damage, which may result in a loss of barrier function and enhanced translocation of inhaled antigen to the submucosa (Matsamura, 1970).…”