An Attenuated Strain of Human Cytomegalovirus for the Establishment of a Subviral Particle Vaccine
Steffi Krauter,
Nicole Büscher,
Eric Bräuchle,
Samira Ortega Iannazzo,
Inessa Penner,
Nadine Krämer,
Patricia Gogesch,
Simone Thomas,
Marina Kreutz,
Mario Dejung,
Anja Freiwald,
Falk Butter,
Zoe Waibler,
Bodo Plachter
Affiliations
Steffi Krauter
Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
Nicole Büscher
Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
Eric Bräuchle
Division of Immunology, Section 3/1 “Product Testing of Immunological Biomedicines”, Paul-Ehrlich-Institut, D-63225 Langen, Germany
Samira Ortega Iannazzo
Division of Immunology, Section 3/1 “Product Testing of Immunological Biomedicines”, Paul-Ehrlich-Institut, D-63225 Langen, Germany
Inessa Penner
Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
Nadine Krämer
Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
Patricia Gogesch
Division of Immunology, Section 3/1 “Product Testing of Immunological Biomedicines”, Paul-Ehrlich-Institut, D-63225 Langen, Germany
Simone Thomas
Leibniz Institute for Immunotherapy, Regensburg and Klinik und Poliklinik für Innere Medizin III, Hämatologie und Internistische Onkologie, University Hospital Regensburg, D-93053 Regensburg, Germany
Marina Kreutz
Leibniz Institute for Immunotherapy, Regensburg and Klinik und Poliklinik für Innere Medizin III, Hämatologie und Internistische Onkologie, University Hospital Regensburg, D-93053 Regensburg, Germany
Mario Dejung
Proteomics Core Facility, Institute of Molecular Biology, D-55128 Mainz, Germany
Anja Freiwald
Proteomics Core Facility, Institute of Molecular Biology, D-55128 Mainz, Germany
Falk Butter
Proteomics Core Facility, Institute of Molecular Biology, D-55128 Mainz, Germany
Zoe Waibler
Division of Immunology, Section 3/1 “Product Testing of Immunological Biomedicines”, Paul-Ehrlich-Institut, D-63225 Langen, Germany
Bodo Plachter
Institute for Virology, University Medical Center of the Johannes Gutenberg-University Mainz, D-55131 Mainz, Germany
Human cytomegalovirus (HCMV) infection is associated with severe disease conditions either following congenital transmission of the virus or viral reactivation in immunosuppressed individuals. Consequently, the establishment of a protective vaccine is of high medical need. Several candidates have been tested in preclinical and clinical studies, yet no vaccine has been licensed. Subviral dense bodies (DB) are a promising vaccine candidate. We have recently provided a GMP-compliant protocol for the production of DB, based on a genetically modified version of the HCMV laboratory strain Towne, expressing the pentameric complex of envelope protein gH-gL-pUL128-131 (Towne-UL130rep). In this work, we genetically attenuated Towne-UL130rep by abrogating the expression of the tegument protein pUL25 and by fusing the destabilizing domain ddFKBP to the N-terminus of the IE1- and IE2-proteins of HCMV. The resulting strain, termed TR-VAC, produced high amounts of DB under IE1/IE2 repressive conditions and concomitant supplementation of the viral terminase inhibitor letermovir to the producer cell culture. TR-VAC DB retained the capacity to induce neutralizing antibodies. A complex pattern of host protein induction was observed by mass spectrometry following exposure of primary human monocytes with TR-VAC DB. Human monocyte-derived dendritic cells (DC) moderately increased the expression of activation markers and MHC molecules upon stimulation with TR-VAC DB. In a co-culture with autologous T cells, the TR-VAC DB-stimulated DC induced a robust HCMV-specific T cell-activation and –proliferation. Exposure of donor-derived monocytic cells to DB led to the activation of a rapid innate immune response. This comprehensive data set thus shows that TR-VAC is an optimal attenuated seed virus strain for the production of a DB vaccine to be tested in clinical studies.
