| abstract |
The present invention provides compositions and methods for stimulating, enriching, expanding, and / or activating genetically engineered cells that express a recombinant receptor, for example, a chimeric antigen receptor. In some embodiments, the methods of the invention include ex vivo or in vitro stimulation, enrichment, expansion, and / or activation of cells by incubation with a particle, e.g. ball, attached to a binding molecule, such as a polypeptide antigen or an anti-idiotypic antibody, which recognizes or binds to the recombinant receptor. The present invention also relates to methods of transfection or transduction of cells that have not previously been incubated with an activating or stimulating agent, such as cells not incubated with anti-CD3 / anti-CD3 antibodies. CD28 and / or one or more recombinant cytokines, by transduction or transfection of cells in the presence of particles having fixed binding molecules. In some embodiments, the compositions provided may be used in methods for preparing cells, for example, genetically engineered T cells for adoptive immunotherapy. |