Release of monocyte chemoattractant protein (MCP)-1 by a human alveolar epithelial cell line in response to Mycobacterium avium

Clinical strains of Mycobacterium avium isolated from patients with acquire d immunodeficiency syndrome, brit not a non-clinical laboratory strain (ATC C 25291), were found to stimulate the human alveolar epithelial cell line A 549, to produce monocyte chemoattractant protein (MCP)-1, A549 cells were a lso found to produce elevated levels of MCP-1 in response to sonicates of t hr: clinical strains of M. avium, and surprisingly, the non-clinical strain as well. However, sonic extracts of the clinical strains were found to ind uce significantly higher levels of MCP-1 production compared to extracts of the non-clinical strain (P < 0.001). These data suggest the existence of s train-related differences in antigen expression by M. avium. The clinical a nd non-clinical strains of M. avium were found to attach and invade, but no t replicate in A549 cells indicating that MCP-1 production by A549 cells do es require the presence of viable, replicating organisms. Activation of alv eolar epithelial cells by exposure to nl. avium resulting in the production of chemokines which recruit inflammatory cells to the site of infection ma y be an important regulatory pathway For the activation of pulmonary host d efense. (C) 2000 Federation of European Microbiological Societies. Publishe d by Elsevier Science B.V. All rights reserved.