Directions in gene therapy.

Retroviral mediated gene transfer has proven to be an effective method of transferring genetic material into many different mammalian cells. Presented in this short review is a history of retroviral-mediated gene transfer as it relates to hematopoietic- and blood-derived cells. Gene transfer into mouse, primate, and fetal sheep and primate hematopoietic stem cells is discussed. Gene transfer into lymphocytes, in particular tumor-infiltrating lymphocytes, is also addressed. The use of such lymphocytes in ongoing and submitted clinical protocols utilizing retroviral-mediated gene transfer are presented.