The etiology of sarcoidosis remains unknown. Recently, by mass spectrometric sequencing of peptides eluted from HLA-DR molecules of bronchoalveolar lavage (BAL) cells from DRB1⁎0301 pos patients, we identified potential self-antigens in sarcoidosis. The aim of the present study was to investigate the capacity of selected peptides to stimulate lung and blood T cells of sarcoidosis patients using an interferon-γ ELISPOT assay. In peripheral blood, there were strong T cell responses to a peptide derived from the cytoskeletal protein vimentin in 6 out of 11 DRB1⁎0301 pos patients with active disease but not in patients with other HLA types. BAL T cell responses against peptides derived from ATP synthase or from lysyl-tRNA synthetase were detected in DRB1⁎0301 pos as well as DRB1⁎0301 neg patients. By using antigenic peptides presented in vivo in the lungs of sarcoidosis patients, we have identified blood and lung T cell autoimmune responses that may help sustain the inflammation in this disease.