Specific immuno-imaging of pulmonary-resident memory lymphocytes in human lungs.

INTRODUCTION

Pulmonary-resident memory T cells (T) and B cells (B) orchestrate protective immunity to reinfection with respiratory pathogens. Developing methods for the detection of these populations would benefit both research and clinical settings.

METHODS

To address this need, we developed a novel immunolabelling approach combined with clinic-ready fibre-based optical endomicroscopy (OEM) to detect canonical markers of lymphocyte tissue residency in human lungs undergoing lung ventilation (EVLV).

RESULTS

Initially, cells from human lung digests (confirmed to contain T/B populations using flow cytometry) were stained with CD69 and CD103/CD20 fluorescent antibodies and imaged using KronoScan, demonstrating it's ability to detect antibody labelled cells. We next instilled these pre-labelled cells into human lungs undergoing EVLV and confirmed they could still be visualised using both fluorescence intensity and lifetime imaging against background lung architecture. Finally, we instilled fluorescent CD69 and CD103/CD20 antibodies directly into the lung and were able to detect T/B following labelling within seconds of direct delivery of microdoses of fluorescently labelled antibodies.

DISCUSSION

, no wash, immunolabelling with OEM imaging is a novel methodology with the potential to expand the experimental utility of EVLV and pre-clinical models.