Efficient adenovirus-mediated gene transfer into primary T cells and thymocytes in a new coxsackie/adenovirus receptor transgenic model

To render T cells susceptible to adenoviral gene transfer, we have developed three new murine transgenic lines in which expression of the human coxsackie/adenovirus receptor (hCAR) with a truncated cytoplasmic domain (hCARΔcyt) is limited to thymocytes and lymphocytes under direction of a human CD2 mini-gene. hCARΔcyt.CD2 transgenic mice were crossed with DO11.10 T cell receptor transgenic mice (DO11.hCARΔcyt) to allow developmental studies in a defined, clonal T cell population. Expression of hCARΔcyt enabled adenoviral transduction of resting primary CD4+ T cells, differentiated effector T cells and thymocytes from DO11.hCARΔcyt with high efficiency. Expression of hCARΔcyt transgene did not perturb T cell development in these mice and adenoviral transduction of DO11.hCARΔcyt T cells did not alter their activation status, functional responses or differentiative potential. Adoptive transfer of the transduced T cells into normal recipients did not modify their physiologic localization.The DO11.hCARΔcyt transgenic model thus allows efficient gene transfer in primary T cell populations and will be valuable for novel studies of T cell activation and differentiation.Gene transfer into developing and mature primary T cells has been limited by the lack of efficient techniques for ex vivo or in vivo transfection or transduction. The adaptation of retroviral vectors for gene delivery into lymphocytes has gained favor recently [1,2], but has several features that limit its use. First, retroviral gene transduction requires cell cycle progression of the cellular host to permit viral genome integration, limiting studies of regulatory genes that are operative early in T cell activation or differentiation. Second, because the integration site of the viral genome is variable, there can be local, host chromatin effects on exogenous gene expression and unpredictable silencing of viral integrants. Third, efficiencies of transduction with retroviral vectors are often limiting. Finally,