A groundbreaking study published in the journal Immunity has shed light on how cancer cells manipulate the immune system to evade detection and treatment. The research, led by Dr. Ian Parish from Peter Mac, uncovered two mechanisms, known as exhaustion and tolerance, that cancer cells use to suppress the immune response against them.
The immune system has a natural mechanism called exhaustion, which acts as a safeguard to prevent excessive immune responses. Cancer cells exploit this process by hijacking the immune system at the exhaustion phase, effectively silencing key immune cells called CD8+ T-cells, and dampening down the immune attack on cancer cells.
However, this study revealed an additional mechanism, tolerance, where cancer cells prevent the immune system from initiating an immune response against them in the first place. Dr. Parish explained that current cancer immunotherapies focus on reviving pre-existing anti-cancer immunity during the exhaustion phase. Unfortunately, these therapies are ineffective in most cancers because the immune system fails to initiate an immune response against the cancer cells.
The findings of this study have significant implications for the development of new cancer treatments. Dr. Parish and his team are now exploring ways to disrupt the tolerance mechanism and engage the immune system to restart and attack cancer cells resistant to treatment.
Professor Chris Goodnow, Head of the Immunogenomics Laboratory at Garvan Institute of Medical Research, added that this study has far-reaching implications, as tolerance is a separate mechanism used by tumors to block anti-cancer immune responses at an early stage in the immune response.
Exhaustion has long been known to be exploited by tumors, but this study provides new insights into the role of tolerance as an additional mechanism used by cancer cells to evade the immune system. The team’s next step is to understand how they can target these mechanisms to develop effective cancer treatments.