Functional analysis of human bronchial mucosal T cells extracted with interleukin-2.

Functional analysis of T cells from the bronchial mucosa has been limited by difficulties in extracting T cells from this tissue. Because interleukin-2 (IL-2) is chemotactic for T cells, we determined whether this cytokine could be used to extract T cells from human bronchial wall (BW). Fresh tissue was obtained from 21 patients undergoing surgery for malignancy. Within the BW, 95% of T cells stained for the memory/activation marker CD45RO. When BW sections were incubated with IL-2 for 24 h, 88 to 91% of T cells emigrated into the culture medium. Compared with autologous blood T cells (also exposed to IL-2), these BW T cells expressed CD2 at a greater intensity and showed a fourfold reduction in cloning efficiency in response to phytohemagglutinin, and T-cell clones derived from the BW population displayed a tendency for higher interferon-gamma production. Furthermore, we were also able to extract and clone T cells from bronchoscopic biopsies in four subjects, suggesting that this method will provide a new avenue for examining T-cell function in airway inflammatory diseases.