@article{7ef8b9a08da0424b88a2e5efe5423c46,
title = "Characterization of a live-attenuated HCMV-based vaccine platform",
abstract = "Vaccines based on cytomegalovirus (CMV) demonstrate protection in animal models of infectious disease and cancer. Vaccine efficacy is associated with the ability of CMV to elicit and indefinitely maintain high frequencies of circulating effector memory T cells (TEM) providing continuous, life-long anti-pathogen immune activity. To allow for the clinical testing of human CMV (HCMV)-based vaccines we constructed and characterized as a vector backbone the recombinant molecular clone TR3 representing a wildtype genome. We demonstrate that TR3 can be stably propagated in vitro and that, despite species incompatibility, recombinant TR3 vectors elicit high frequencies of TEM to inserted antigens in rhesus macaques (RM). Live-attenuated versions of TR3 were generated by deleting viral genes required to counteract intrinsic and innate immune responses. In addition, we eliminated subunits of a viral pentameric glycoprotein complex thus limiting cell tropism. We show in a humanized mouse model that such modified vectors were able to establish persistent infection but lost their ability to reactivate from latency. Nevertheless, attenuated TR3 vectors preserved the ability to elicit and maintain TEM to inserted antigens in RM. We further demonstrate that attenuated TR3 can be grown in approved cell lines upon elimination of an anti-viral host factor using small interfering RNA, thus obviating the need for a complementing cell line. In sum, we have established a versatile platform for the clinical development of live attenuated HCMV-vectored vaccines and immunotherapies.",
author = "Patrizia Caposio and {van den Worm}, Sjoerd and Lindsey Crawford and Wilma Perez and Craig Kreklywich and Gilbride, {Roxanne M.} and Hughes, {Colette M.} and Ventura, {Abigail B.} and Robert Ratts and Marshall, {Emily E.} and Daniel Malouli and Axthelm, {Michael K.} and Daniel Streblow and Nelson, {Jay A.} and Picker, {Louis J.} and Hansen, {Scott G.} and Klaus Fr{\"u}h",
note = "Funding Information: We thank the International AIDS Vaccine Initiative (IAVI) for providing low passage MRC-5 cells and the GRIN plasmid. We thank Dr. Thomas Shenk, Princeton University, for recombinant AD169 and for anti-pp71 antibody. The following reagent was obtained through the NIH AIDS Reagent Program, Division of AIDS, NIAID, NIH: Anti-HIV-1 SF2 p24 Polyclonal. We also thank Dr. David Johnson, OHSU for anti-UL130 and Dr. Dong Yu, Washington University for TR-GFP. We are grateful to Jennie Womack for generating figures and graphics and to Dave Stein for help with the siRNA design. We acknowledge the generation of libraries for NextGen Illumina sequencing by the OHSU Massively Parallel Sequencing Shared Resource and NextGen sequencing on the Illumina MiSeq platform by the ONPRC Molecular Technologies Core. This work was supported by the Bill and Melinda Gates Foundation grants OPP1107409 and OPP1033121 to L.J.P. and K.F.; by National Institute of Allergy and Infectious Diseases grants R01 AI095113, P01 AI094417 and R37 AI054292 to L.J.P.; and by the National Institutes of Health Office of the director grant P51OD011092. Publisher Copyright: {\textcopyright} 2019, The Author(s).",
year = "2019",
month = dec,
day = "1",
doi = "10.1038/s41598-019-55508-w",
language = "English (US)",
volume = "9",
journal = "Scientific Reports",
issn = "2045-2322",
publisher = "Nature Publishing Group",
number = "1",
}