Alexander I Makarkov1, Sabrina Chierzi2, Stéphane Pillet3, Keith K Murai4, Nathalie Landry5, Brian J Ward6. 1. Division of Experimental Medicine, Department of Medicine, McGill University, 1001 Décarie Boul., Montréal, Québec H4A 3J1, Canada; Research Institute of McGill University Health Centre, Glen Site, 1001 Décarie Boul., Montréal, Québec H4A 3J1, Canada. 2. Research Institute of McGill University Health Centre, Glen Site, 1001 Décarie Boul., Montréal, Québec H4A 3J1, Canada; Research Institute of McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Montréal, Québec H3G 1A4, Canada. 3. Research Institute of McGill University Health Centre, Glen Site, 1001 Décarie Boul., Montréal, Québec H4A 3J1, Canada; Medicago Inc., 1020 Route de l'Église, Bureau 600, Québec, Québec G1V 3V9, Canada. 4. Research Institute of McGill University Health Centre, Montreal General Hospital, 1650 Cedar Avenue, Montréal, Québec H3G 1A4, Canada. 5. Medicago Inc., 1020 Route de l'Église, Bureau 600, Québec, Québec G1V 3V9, Canada. 6. Research Institute of McGill University Health Centre, Glen Site, 1001 Décarie Boul., Montréal, Québec H4A 3J1, Canada. Electronic address: brian.ward@mcgill.ca.
Abstract
INTRODUCTION: Plant-made virus-like particles (VLP) bearing influenza virus hemagglutinins (HA) are novel vaccine candidates that induce cross-reactive humoral and poly-functional T cell responses. To better understand the mechanisms that underlie this broad immunogenicity we studied early interactions of VLPs bearing either H1 (A/California/07/2009 (H1N1)) or H5 (A/Indonesia/05/2005 (H5N1)) with a human monocytoid cell line (U-937 cells) and human monocyte-derived macrophages (MDMs) as model antigen-presenting cells (APC). METHODS AND RESULTS: Using Vibrio cholerae sialidase and lectins that target α2,6- (Sambucus nigra lectin) or α2,3-linked sialic acids (Maackia amurensis lectin I), we demonstrated that VLPs bind to these APCs in a sialic acid-dependent manner. Using lysosomal markers and DiD-labelled VLPs, we found that attachment to the cell surface leads to internalization, trafficking to acidic cell compartments and fusion of the VLP lipid envelope with endosomal membranes. Incubation of MDMs with H1- but not H5-VLPs induced proliferation of autologous peripheral blood mononuclear cells suggesting antigen processing and stimulation of a memory T cell response. CONCLUSIONS: Plant-made VLPs bearing influenza HA not only mimic the structure of influenza virions to some degree but also recapitulate key features of the initial virus-APC interaction. These observations may help to explain the balanced humoral and cellular responses to plant-made VLP vaccines.
INTRODUCTION: Plant-made virus-like particles (VLP) bearing influenza virus hemagglutinins (HA) are novel vaccine candidates that induce cross-reactive humoral and poly-functional T cell responses. To better understand the mechanisms that underlie this broad immunogenicity we studied early interactions of VLPs bearing either H1 (A/California/07/2009 (H1N1)) or H5 (A/Indonesia/05/2005 (H5N1)) with a human monocytoid cell line (U-937 cells) and human monocyte-derived macrophages (MDMs) as model antigen-presenting cells (APC). METHODS AND RESULTS: Using Vibrio cholerae sialidase and lectins that target α2,6- (Sambucus nigra lectin) or α2,3-linked sialic acids (Maackia amurensis lectin I), we demonstrated that VLPs bind to these APCs in a sialic acid-dependent manner. Using lysosomal markers and DiD-labelled VLPs, we found that attachment to the cell surface leads to internalization, trafficking to acidic cell compartments and fusion of the VLP lipid envelope with endosomal membranes. Incubation of MDMs with H1- but not H5-VLPs induced proliferation of autologous peripheral blood mononuclear cells suggesting antigen processing and stimulation of a memory T cell response. CONCLUSIONS: Plant-made VLPs bearing influenza HA not only mimic the structure of influenza virions to some degree but also recapitulate key features of the initial virus-APC interaction. These observations may help to explain the balanced humoral and cellular responses to plant-made VLP vaccines.
Authors: Maria Lobato Gómez; Xin Huang; Derry Alvarez; Wenshu He; Can Baysal; Changfu Zhu; Victoria Armario-Najera; Amaya Blanco Perera; Pedro Cerda Bennasser; Andera Saba-Mayoral; Guillermo Sobrino-Mengual; Ashwin Vargheese; Rita Abranches; Isabel Alexandra Abreu; Shanmugaraj Balamurugan; Ralph Bock; Johannes F Buyel; Nicolau B da Cunha; Henry Daniell; Roland Faller; André Folgado; Iyappan Gowtham; Suvi T Häkkinen; Shashi Kumar; Sathish Kumar Ramalingam; Cristiano Lacorte; George P Lomonossoff; Ines M Luís; Julian K-C Ma; Karen A McDonald; Andre Murad; Somen Nandi; Barry O'Keefe; Kirsi-Marja Oksman-Caldentey; Subramanian Parthiban; Mathew J Paul; Daniel Ponndorf; Elibio Rech; Julio C M Rodrigues; Stephanie Ruf; Stefan Schillberg; Jennifer Schwestka; Priya S Shah; Rahul Singh; Eva Stoger; Richard M Twyman; Inchakalody P Varghese; Giovanni R Vianna; Gina Webster; Ruud H P Wilbers; Teresa Capell; Paul Christou Journal: Plant Biotechnol J Date: 2021-07-19 Impact factor: 13.263