A method for extracting tissue proteins for use in lymphocyte function assays

Currently human T-cell responses to unpurified tissue extracts cannot be easily measured because current cell lysis methods yield a lysate that is toxic. Here we describe the optimization of a protocol for extracting proteins from human tissues in a format that is compatible with the functional analysis of human T cells. The tissue was homogenized in a mixture of butan-1-ol, acetonitrile and water and then lyophilized. Lyophilized protein extracts were dissolved in 8 M urea because urea did not affect T-cell function when present at 0.08 M or less. Using this method cytokine production and proliferation responses were detected from islet, acinar and spleen extracts. Hence, our method allows the rapid preparation of human tissue lysates in a format that is compatible with the analysis T-cell responses. We suggest that this method will facilitate the analysis of adaptive immune responses to tissues in transplantation, cancer and autoimmunity.