The disclosed bead vectors direct entry into a cell of monocytic origin and cause the expression of an extracellular domain of PD-1, an anti-CTLA4 antibody, or an antibody that is specific for a checkpoint protein. The bead vectors can comprise a nucleic acid component, a lysosome evading component and a bead particle that can be phagocytized. The disclosed vectors are useful in various methods of cancer therapy, treatment, and prevention. Due to the ability of monocytic cells to target tumors, the disclosed vectors are particularly well suited for use in anti-tumor applications and directing expression of target genes in tumor-associated macrophages.
