Oral Presentation Australian Society for Microbiology Annual Scientific Meeting 2023

Establishing preclinical safety profiles of phages targeting P. aeruginosa (93695)

Renee Ng 1 2 , Barbara Chang 3 , Stephen Stick 2 4 5 , Anthony Kicic 2 5 6 , WAERP - 1 2 4 7 , AREST CF 2 4 8 9
  1. School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
  2. Wal-Yan Respiratory Research Centre, Wal-Yan Respiratory Research Centre, Telethon Kids Institute, Perth, Western Australia, Australia
  3. The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, The University of Western Australia, Perth, WA, Australia
  4. Department of Respiratory Medicine, Perth Children’s Hospital, Perth, WA, Australia
  5. Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, The University of Western Australia and Harry Perkins Institute of Medical Research, Perth, WA, Australia
  6. Occupation and the Environment, School of Population Health, Curtin University, Australia, Perth, WA, Australia
  7. St John of God Hospital, Subiaco, Perth, WA, Australia
  8. Murdoch Children's Research Institute, Melbourne, VIC, Australia
  9. Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia

Acute respiratory infections are one of the commonly presented conditions treated with antimicrobials. Despite this, they are extremely challenging to treat since bacteria have the potential to readily become antibiotic resistant. With a lack in new antimicrobials, alternative treatments including bacteriophage (phage) therapy is currently being explored. In this project, we aimed to investigate the safety profile of Kara-mokiny 3, an isolated phage, on a fully differentiated primary airway in vitro cell model. Kara-mokiny 3 was propagated and endotoxins removed using tangential flow filtration and anion exchange. Residual levels quantification using the limulus amebocyte lysate assay. Primary airway epithelial cells (pAEC, n=7; 5 males; mean; 4.2±2.4 years) were established and cultured at air-liquid interface (ALI). Primary cultures were exposed to Kara-mokiny 3 and PAO1 at 1:1 ratio for 24 h. Inserts were stained with hemotoxylin and eosin and alcian blue stain to assess for macroscopic structural modifications post exposure and collected basolateral supernatants and apical washes were measured for inflammatory cytokine production (IL-6 and IL-8) and cytotoxicity (LDH). There was no disruption to the pseudostratified layers observed. Exposure of primary airway cells to Kara-mokiny 3 did not induce cell death (LDH fold change (FC); -0.6±0.3) when compared to PAO1 infected controls (FC: 1.3±0.6).  Although elevated, IL-6 production in apical washes (representative of luminal inflammation) was not significant (FC; 7.3±15.8) compared to controls. A similar observation was seen in the basolateral supernatant (representative of systemic inflammation, FC; -0.5±0.7) measured.  Similarly, IL-8 was not induced when pAEC were exposed to Kara-mokiny 3 (apical FC; -0.1±0.3; basolateral FC; -0.2±0.2). However, there was significant reduction of IL-8 of Kara-mokiny 3 in the basolateral supernatant when compared to the controls (FC; -0.2±0.2; p<0.05). In conclusion, results demonstrated preclinical safety data on phage use, namely that they did not cause any major disruption to the airway cellular architecture, nor induce airway cell death, or localised airway and systemic inflammation.