Title: Persistence of lung CD8 T cell oligoclonal expansions upon smoking cessation in a mouse model of cigarette smoke-induced emphysema.
Authors: Motz, Gregory T; Eppert, Bryan L; Sun, Guangyun; Wesselkamper, Scott C; Linke, Michael J; Deka, Ranjan; Borchers, Michael T
Published In J Immunol, (2008 Dec 01)
Abstract: The role of adaptive immunity in the development or progression of chronic obstructive pulmonary disease (COPD) remains undefined. Recently, the presence of autoantibodies and autoreactive T cells has been demonstrated in COPD patients. In addition, oligoclonal expansions of lung T cells have been observed in COPD patients, but the overlapping incidence of infections, tumors, and cigarette smoke exposure obscures the antigenic stimulus. We analyzed the TCR Vbeta repertoire of CD4 and CD8 T cells purified from the lungs and spleens of mice chronically exposed to cigarette smoke. In a mouse model of COPD, we demonstrate that chronic cigarette smoke exposure causes oligoclonal expansions of T cells isolated from the lungs, but not spleens. TCR Vbeta repertoire analyses revealed oligoclonal expansions predominantly occurred in lung CD8 T cells, with preferential usage of Vbeta7, Vbeta9, Vbeta13, and Vbeta14. Using nucleotide sequence analysis based on Jbeta analyses, we demonstrate selection of CDR3 amino acid motifs, which strongly suggests Ag-driven oligoclonal T cell expansion. Analysis of the lung TCR Vbeta repertoire of mice with cigarette smoke-induced emphysema, which had undergone smoking cessation for 6 mo, revealed that oligoclonal expansions persisted. This study formally demonstrates that chronic cigarette smoke exposure, alone, causes a persistent adaptive T cell immune response. These findings have important implications for therapeutic approaches in the treatment of COPD, and provide insight into potential mechanisms involved in disease pathogenesis.
PubMed ID: 19017996
MeSH Terms: Amino Acid Motifs/genetics; Amino Acid Motifs/immunology; Animals; Autoantibodies/immunology; Autoimmune Diseases/chemically induced; Autoimmune Diseases/genetics*; Autoimmune Diseases/immunology; CD4-Positive T-Lymphocytes/immunology*; CD8-Positive T-Lymphocytes/immunology*; Disease Models, Animal; Female; Genes, T-Cell Receptor beta/genetics*; Genes, T-Cell Receptor beta/immunology; Humans; Lung/immunology; Mice; Mice, Inbred BALB C; Pulmonary Disease, Chronic Obstructive/chemically induced; Pulmonary Disease, Chronic Obstructive/genetics*; Pulmonary Disease, Chronic Obstructive/immunology; Pulmonary Emphysema/chemically induced; Pulmonary Emphysema/genetics*; Pulmonary Emphysema/immunology; Smoking/adverse effects*; Tobacco Smoke Pollution/adverse effects*