Viruses T cells Cancer

Scientists from the University Of Geneva (UNIGE) and the University of Basel have created artificial viruses that can be used to target cancer. This virus is fashioned to act as an alarm for the immune system and instigate killer T cells to fight the tumour.

The immune system reacts more aggressively toward viral infections than it does to cancer. It can distinguish cells that have gone haywire based on the proteins they exhibit on the surface, but is much better at picking up viruses, bacteria, and other foreign cells due to their distinct molecular pattern profiles (or PAMPs). Turns out that introducing a designer virus equipped with cancer proteins can provide the immune system with that extra edge it needs to eradicate cancer cells more effectively.

The researchers in Switzerland built artificial viruses based on lymphocytic choriomeningitis virus (LCMV), which they then integrated with certain proteins found only in cancer cells. Although the viruses were self-limiting and not harmful for the infected mice in the study, they did release the alarm signals typical of viral infections.

The infection in itself is benign, however, it launches the immune system to attack the cancer cells in full gear. The unique combination of alarm signals and cancer cell proteins stimulated the immune system to create a powerful army of “killer cells”, a specialized type of effector T cells that were much better at detecting cancerous tissue and destroying it.

“We have designed a virus that has shown itself to be a potent driver of immune response,” said Doron Merkler, a professor of pathology and immunology at the University of Geneva and one of the leaders on the study. “When we compare it to other vectors, they weren’t able to trigger this kind of alarm in dependent immune response.”

According to their study published in Nature Communications , similar classical tumour vaccination regimens such as peptides-in-adjuvant showed only marginal clinical benefits so far. Major hurdles of the approach that scientists have been trying to overcome include inefficient tumour infiltration and efficacy of specific T cell response. Based on their report, the modified LCMV elicited a stronger T cell response in combination with potentially life-long immunity.

Oncologists have struggled to improve the immune response toward cancer detection for decades. This method could help in preparing the system to discern the cancer clearly.

 “We hope that our new findings and technologies will soon be used in cancer treatments and so help to further increase their success rates,” Professor Daniel Pinschewer of the University of Basel said in a statement.

Although it looks promising for now, the possibility that alternative mechanisms of interference such as T cell immunity to viral backbone epitopes may challenge and thus diminish booster responses to LCMV-vectorized transgenes.

Learn more about cancer vaccines in the video below:

By Luka Zupančič, MSc, University of Applied Sciences Technikum Vienna &

Padmashree Ghangale.