Creating a Powerful Cancer Fighter: IFNγ and Fas Join Forces

Trying to fight a bad guy (like cancer) but not having enough soldiers (immune cells) to help. That’s where interferon gamma (IFNγ) comes in. This tiny protein wakes up immune cells so they can fight invaders or even cancer cells. Scientists wanted to make a super vaccine for colon cancer, so they played with some cellular genetics. They took CT26 colon cancer cells and made them express IFNγ in two ways: either as a secreted form (sIFNγ) or as a membrane-bound form (mbIFNγ/Fas). This second form was like a dual-sided sword, with IFNγ attached to Fas, which has intricate parts called extracellular cysteine-rich domains, a transmembrane domain, and a cytoplasmic domain.Guess what? The tumor cells expressing both sIFNγ and mbIFNγ/Fas grew slower than the normal cells. But the cells with the dual-sword (mbIFNγ/Fas) were way less likely to become tumors again. In fact, 85% of mice injected with these cells stayed tumor-free for more than two months! The mice that beat the tumors also developed a strong immunity against CT26 cells. Their bodies had more CD4+ and CD8+ T cells, and natural killer (NK) cells. When scientists looked at the splenocytes (cells from the spleen) they saw that those activated by the mbIFNγ/Fas cells could kill more cancer cells than the others. So, this magical combination of mbIFNγ/Fas could be a big deal for creating vaccines or gene therapies that use the whole tumor cell to fight cancer.