Tracking the repertoire of human adult and neonatal T cells during ex vivo amplification

[Extract] In times of limited material, expansion of T cells in vitro has become a standard practice across many clinical and basic immunological procedures; such as haematopoietic stem cell transplantation, the study of biopsy specimens, immunomonitoring of clinical trial patients and the study of samples from neonates and children. Classically, mitogenic lectins, such as phytohaemagglutinin (PHA-P) or the phorbol esterphorbol 12-myristate 13-acetate, have been used for initiating T cell expansion. However, a more physiologically relevant method of T cell stimulation mimics the interaction with antigen-presenting cells through the use of anti-CD3 and anti-CD28 monoclonal antibodies (mAb) (Martin et al, 1986). This procedure has been improved in recent years, by fusing anti-CD3 and anti-CD28 mAb to microbead structures (Pene et al, 2003). Here, the initial signal is provided by CD3 molecule activation and the co-stimulatory signal is provided by CD28 molecule activation. In this study, we assessed whether human T-activator CD3/CD28 Dynabeads or PHA-P could amplify T cells from human umbilical cord blood (UCB) or adult peripheral blood mononuclear cells (PBMC) without distorting the baseline ex vivo T cell repertoire