The in vivo distribution of autologous human and murine lymphoid cells grown in T cell growth factor (TCGF): Implications for the adoptive immunotherapy of tumors

The in vivo distribution of lymphoid cells grown in T cell growth factor (TCGF) has been studied after i.v. injection in both the mouse and human. Lymphoid cells were cultured in TCGF for 3 to 4 wk and increased in cell number 10³- to 10⁴-fold. Murine cells were labeled with ⁵¹Cr, and the in vivo distributions of normal and TCGF-cultured cells were compared by performing whole body and individual organ counts at varying intervals after i.v. injection. Cells cultured in TCGF were localized to the image in the first 4 hr after injection and redistributed to the liver and spleen over the next 24 hr; 72% and 57% of the injected counts remained in the mouse at 4 and 28 hr, respectively. Human lymphoid cells grown in TCGF were labeled with ⁶⁷Ga or ¹³¹In, and the organ distribution of injected cells was noninvasively measured by rectilinear scanning using a whole body imager, point counting over individual organs with a collimated whole body scanner, and using a computer-interfaced gamma camera to assess total organ distribution of measured radioactivity. In addition, blood and urine samples were collected at varying intervals after cell injection and analyzed for radioactivity. The in vivo distribution of cells grown in TCGF in the human was very similar to that in the mouse. Cells at 4 hr appeared in high numbers in the lungs (30%), and subsequently at 24 and 48 hr they were found almost exclusively in the liver (48%) and spleen (25%). No toxicity of any kind was seen after the infusion of up to 5 x 10⁸ cells i.v. in the human. These studies represent the first attempts to study in vivo in the human the effects of lymphoid cells grown in TCGF and demonstrate the safety of i.v. injection of these cells. The implications for the role of these cells in the immunotherapy of human and experimental tumors is discussed.