R.J. Reynolds Tobacco Company 1 article published in JoVE Immunology and Infection Methods to Evaluate Cytotoxicity and Immunosuppression of Combustible Tobacco Product Preparations Subhashini Arimilli1, Brad E. Damratoski1, Prasad G.L.2 1Department of Microbiology and Immunology, Wake Forest University Health Sciences, 2R&D Department, R.J. Reynolds Tobacco Company Using optimized human peripheral blood mononuclear cell (PBMC) ex vivo assays, we showed that a combustible tobacco product preparation markedly suppresses receptor-mediated intracellularly secreted cytokines and cytolytic ability of effector PBMCs. These rapid assays may be useful in product evaluation and understanding the potential long-term effects of tobacco exposure.