Abstract: Long term culture of resting T lymphocytes. The present invention provides methods and compositions for maintaining resting, mature T lymphocytes (cells) for long term in the absence of mitogens, antigens, or stimulatory cytokines, in which the T cells maintaining their ability to respond to nitrogens and allogenic cells. T cells cultured under such conditions can be used as target cells for retroviral vector-mediated gene transfer and implemented in certain gene therapy applications. The culturing conditions described herein allow for the continuous availability of T lymphocytes for various pharmacological, diagnostic, gene therapy, and experimental purposes, and can be utilized for any application requiring non-stimulated T lymphocytes.