Dendritic cell-targeted lentiviral vector immunization uses pseudotransduction and DNA-mediated STING and cGAS activation

Jocelyn T Kim; Yarong Liu; Rajan P Kulkarni; Kevin K Lee; Bingbing Dai; Geoffrey Lovely; Yong Ouyang; Pin Wang; Lili Yang; David Baltimore

doi:10.1126/sciimmunol.aal1329

Dendritic cell-targeted lentiviral vector immunization uses pseudotransduction and DNA-mediated STING and cGAS activation

Sci Immunol. 2017 Jul 21;2(13):eaal1329. doi: 10.1126/sciimmunol.aal1329.

Authors

Jocelyn T Kim^{1

2}, Yarong Liu³, Rajan P Kulkarni^{1

4}, Kevin K Lee¹, Bingbing Dai³, Geoffrey Lovely¹, Yong Ouyang¹, Pin Wang³, Lili Yang^{1

5}, David Baltimore⁶

Affiliations

¹ Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
² Division of Infectious Diseases, Department of Medicine at University of California, Los Angeles, Los Angeles, CA 90095, USA.
³ Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA.
⁴ Division of Dermatology, Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, Los Angeles, CA 90095, USA.
⁵ Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA.
⁶ Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA. baltimo@caltech.edu.

Abstract

Dendritic cell (DC) activation and antigen presentation are critical for efficient priming of T cell responses. Here, we study how lentiviral vectors (LVs) deliver antigen and activate DCs to generate T cell immunization in vivo. We report that antigenic proteins delivered in vector particles via pseudotransduction were sufficient to stimulate an antigen-specific immune response. The delivery of the viral genome encoding the antigen increased the magnitude of this response in vivo but was irrelevant in vitro. Activation of DCs by LVs was independent of MyD88, TRIF, and MAVS, ruling out an involvement of Toll-like receptor or RIG-I-like receptor signaling. Cellular DNA packaged in LV preparations induced DC activation by the host STING (stimulator of interferon genes) and cGAS (cyclic guanosine monophosphate-adenosine monophosphate synthase) pathway. Envelope-mediated viral fusion also activated DCs in a phosphoinositide 3-kinase-dependent but STING-independent process. Pseudotransduction, transduction, viral fusion, and delivery of cellular DNA collaborate to make the DC-targeted LV preparation an effective immunogen.

Abstract

Grants and funding