E-Poster with pre-recorded video presentation Lorne Infection and Immunity 2021

Intrapulmonary vaccination with delta-inulin adjuvant stimulates non-polarised chemotactic signalling and diverse cellular interaction (#306)

Kia C Ferrell 1 2 , Erica L Stewart 1 2 3 4 , Claudio Counoupas 1 2 , Thomas M Ashhurst 5 6 , Warwick J Britton 1 2 7 , Nikolai Petrovsky 3 4 , James A Triccas 2
  1. Tuberculosis Research Program , Centenary Institute, The University of Sydney, Camperdown, NSW, Australia
  2. Discipline of Infectious Diseases and Immunology, University of Sydney, Camperdown, NSW, Australia
  3. Vaxine Pty Ltd, Warradale, SA, Australia
  4. Flinders University, Adelaide, SA, Australia
  5. Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Camperdown, NSW, Australia
  6. Sydney Cytometry Core Research Facility, Charles Perkins Centre, Centenary Institute and The University of Sydney, Camperdown, NSW, Australia
  7. Department of Clinical Immunology, Royal Prince Alfred Hospital, Camperdown, NSW, Australia

There is an urgent need for novel vaccination strategies to combat respiratory pathogens. Mucosal vaccine delivery is an attractive option as it directly targets the site of infection; however, preclinical development has been hindered by a lack of suitable mucosal adjuvants and a limited understanding of their immune effects in the lung environment. Herein, we define the early immune events following the intrapulmonary delivery of a vaccine incorporating the adjuvant delta-inulin. Analysis of the early inflammatory response showed vaccine-induced innate cell recruitment to lungs and local lymph nodes (LN) was transient and non-polarised, correlating with an increase in pulmonary chemotactic factors. Use of fluorescently labelled adjuvant revealed widespread tissue dissemination of adjuvant particles, coupled with broad cellular uptake and transit to the lung draining LN by a range of innate immune cells. Mass cytometric analysis revealed extensive phenotypic changes in innate and adaptive cell subsets induced by vaccination; this included identification of unconventional lymphocytes such as gd-T cells and MAIT cells that increased following vaccination and displayed an activated phenotype. This study details a comprehensive view of the immune response to intrapulmonary adjuvant administration and provide pre-clinical evidence to support delta-inulin as a suitable adjuvant for pulmonary vaccines.