Polymerase chain reaction amplification of messages for growth factors in cells from human bronchoalveolar lavage fluids

Abstract

Genetic messages for polypeptide growth factors were assessed in human alveolar macrophages, obtained by bronchoalveolar lavage (BAL) from normal subjects (N = 3) and from patients with pneumonia (N = 3), pulmonary lymphoma (N = 3), and idiopathic pulmonary fibrosis (N = 3). Complementary DNAs (cDNAs) were prepared by reverse transcription of the RNA extracted from alveolar macrophages before and after culture on a plastic surface. The cDNAs encoding 10 different growth factors were amplified for electrophoretic analysis by polymerase chain reaction with a pair of 3' and 5' primers specific for each factor. Alveolar macrophages from all normal subjects and patients expressed the messages for interleukin-1 beta and transforming growth factor-beta. Alveolar macrophages from some normal subjects also contained message for insulin-like growth factor-1. Alveolar macrophages from six of nine patients with lung diseases also expressed messages for one or more additional growth factors, including epidermal growth factor, transforming growth factor-alpha, interleukin-1 alpha, and platelet-derived growth factor. The polymerase chain reaction technique thus permits determination of the profile of growth factors contributed to pulmonary reactions by alveolar macrophages, which may be important in pulmonary healing and fibrosis.