Multivalent 4-1BB binding aptamers costimulate CD8+ T cells and inhibit tumor growth in mice
James O. McNamara II, … , Bruce Sullenger, Eli Gilboa
James O. McNamara II, … , Bruce Sullenger, Eli Gilboa
Published December 3, 2007
Citation Information: J Clin Invest. 2008;118(1):376-386. https://doi.org/10.1172/JCI33365.
View: Text | PDF
Research Article Technical Advance Oncology

Multivalent 4-1BB binding aptamers costimulate CD8+ T cells and inhibit tumor growth in mice

Abstract

4-1BB is a major costimulatory receptor that promotes the survival and expansion of activated T cells. Administration of agonistic anti–4-1BB Abs has been previously shown to enhance tumor immunity in mice. Abs are cell-based products posing significant cost, manufacturing, and regulatory challenges. Aptamers are oligonucleotide-based ligands that exhibit specificity and avidity comparable to, or exceeding, that of Abs. To date, various aptamers have been shown to inhibit the function of their cognate target. Here, we have described the development of an aptamer that binds 4-1BB expressed on the surface of activated mouse T cells and shown that multivalent configurations of the aptamer costimulated T cell activation in vitro and mediated tumor rejection in mice. Because aptamers can be chemically synthesized, manufacturing and the regulatory approval process should be substantially simpler and less costly than for Abs. Agonistic aptamers could therefore represent a superior alternative to Abs for the therapeutic manipulation of the immune system.

Authors

James O. McNamara II, Despina Kolonias, Fernando Pastor, Robert S. Mittler, Lieping Chen, Paloma H. Giangrande, Bruce Sullenger, Eli Gilboa

×

Figure 4

Binding of M12-23 aptamers to 4-1BB expressed on the cell surface.

Options: View larger image (or click on image) Download as PowerPoint
Binding of M12-23 aptamers to 4-1BB expressed on the cell surface. Forma...
Formaldehyde-fixed cells were incubated with a 4-1BB Ab or an isotype-matched control Ab and an AF488-conjugated anti-rat IgG secondary Ab, or with FAM-labeled aptamers, and analyzed by flow cytometry. (A) Binding of 4-1BB Ab and M12-23 aptamer dimers to 4-1BB–transfected HEK293 cells (top panels) or empty vector–transfected control HEK293 cells (bottom panels). Background fluorescence of the 4-1BB–expressing and control HEK293 cells (shown in black) was assessed independently with a rat IgG2a primary Ab and an AF488 anti-rat IgG secondary Ab. (B) 4-1BB–transfected HEK293 cells were incubated with increasing concentrations of M12-23 monomers (top panels) and M12-23 dimers (bottom panels). Percentages within each panel indicate the fraction of cells that underwent proliferation. (C) Binding of 4-1BB Ab and M12-23 dimers to anti-CD3 Ab–stimulated and unstimulated CD8+ T cells. Background fluorescence of the stimulated and unstimulated cells (shown in black) was assessed independently with a rat IgG2a primary Ab and an AF488 anti-rat IgG secondary Ab. Also, anti-CD3 Ab–stimulated CD8+ T cells were preincubated with an isotype-matched control Ab or 4-1BB Ab and then incubated with FAM-conjugated M12-23 aptamer dimers; binding of the M12-23 aptamer dimer was competed by the 4-1BB Ab.