CD62L as target receptor for specific gene delivery into less
differentiated human T lymphocytes
Chimeric antigen receptor (CAR) expressing T cells are a complex and
heterogeneous gene therapy product with variable phenotype composition.
A higher proportion of less differentiated CAR T cells is usually
associated with improved antitumoral function and persistence. We
describe here a novel receptor-targeted lentiviral vector (LV), named
62L-LV, that preferentially transduces less differentiated T cells
marked by the L-selectin receptor CD62L, with transduction rates of up
to 70% of CD4 + and 50% of CD8 +
primary T cells. Remarkably, higher amounts of less differentiated T
cells are transduced and preserved upon long-term cultivation using
62L-LV compared to VSV-LV. Interestingly, shed CD62L neither altered
binding of 62L-LV particles to T cells nor impacted their transduction.
Incubation of two days activated T lymphocytes with 62L-LV or VSV-LV for
only 24 hours was sufficient to generate CAR T cells that controlled
tumor growth in an NSG mouse model. The data prove that potent CAR T
cells can be generated by short-term ex vivo exposure of primary
cells to LVs. As a first vector type that preferentially transduces less
differentiated T lymphocytes, 62L-LV has the potential to circumvent
cumbersome selection of T cell subtypes and offers substantial
shortening of the CAR T cell manufacturing process.