Related Experiment Video
Updated: Aug 25, 2026
Legionella pneumophila Outer Membrane Vesicles: Isolation and Analysis of Their Pro-inflammatory Potential on Macrophages
Published on: February 22, 2017
Effect of listeriolysin O-loaded erythrocytes on Mycobacterium avium replication within macrophages
L Rossi1, G Brandi, M Malatesta
1Institute of Biochemistry G. Fornaini, University of Urbino, Via Saffi, 2, 61029 Urbino (PU), Italy.
Objective:
To evaluate the efficacy of erythrocytes loaded with the haemolytic toxin listeriolysin O against Mycobacterium avium replication within human macrophages.
Methods:
Recombinant listeriolysin O was loaded in human erythrocytes by a procedure of hypotonic dialysis and isotonic resealing. Loaded erythrocytes were modified to allow them to be recognized and taken up by human macrophages infected with M. avium. The antimycobacterial activity of the erythrocytes loaded with listeriolysin O was evaluated by supernatant and intracellular cfu counts on days 4 and 7 post-erythrocyte administration.
Results:
Recombinant listeriolysin O was encapsulated in human erythrocytes to reach final concentrations ranging from 1 to 4 ng/mL of erythrocytes. Erythrocytes loaded with increasing quantities of recombinant protein were able to reduce (at most by 50%) M. avium replication in a dose-dependent fashion when administered to infected macrophages.
Conclusions:
Erythrocytes loaded with listeriolysin O are effective against M. avium replication within macrophages. We are confident that the strategy presented could be useful against mycobacteria other than M. avium (such as Mycobacterium tuberculosis and Mycobacterium leprae) by itself or as part of an antimycobacterial treatment.
