A team of scientists from Institut Pasteur and Inserm has filmed how the French Vaccine Research Institute and ANRS’ AIDS vaccine candidate activates the immune system against infected cells. The footage reveals its mechanism and the inner workings of immune system function, according to a study published in Nature Medicine.

Inserm lead research director Philippe Bousso, PhD, and colleagues at the Dynamics of Immune responses unit at Institut Pasteur observed the immune system’s response to the candidate vaccine, known as MVA-HIV, which was administered to healthy mice. 

The vaccine triggered formation of an inflammasome – a specifically structured multiprotein that occurs in microphages, which are the first immune cells the vaccine targets, according to a prepared statement about the video. Interleukin-1 is matured by the inflammasome, which also induces the death of the microphage and sets loose a signal causing a series of events that activates key aspects of the immune system in the lymph node. This includes killer cells, which are essential for immune response to the vaccine.

Scientists now have a clear picture of exactly how MVA-HIV works and have also observed how the immune system effectively mobilizes its response.

“This is the first time that the formation of this original structure, the inflammasome, has been observed in vivo and in real time,” Dr  Bousso said in the statement. “Our research demonstrates the potential of the vaccine candidate MVA-HIV to trigger a significant, diverse immune response.” 

Reference

1. Sagoo P, Garcia Z, Breart B et al. In vivo imaging of inflammasome activation reveals a subcapsular macrophage burst response that mobilizes innate and adaptive immunity. Nat Med. 2016;22(1):64-71.