Obesity is a major risk factor for cancer as it both feeds tumors and weakens the immune system. It also increases toxicities of immunotherapy treatments. It is hard to imagine that anything good could ever come from obesity. Yet a new research published on Nature Medicine suggests that obese patients respond better than others to immunotherapy. What is behind this paradoxical effect?

CAR-T therapy has been a major innovation in cancer treatment, revolutionizing the care of patients with various forms of leukaemia. Nonetheless, 7-25% of patients with B-cell acute lymphoblastic leukaemia relapse after a period of therapy. Researchers described the mechanisms through which the tumour escapes the treatment and returns stronger than before.

Not all bacteria come to harm: some can even be used to fight cancer. Then, it might be helpful to monitor their activity in the organism: where are they? what are they doing? That is what we need to “ask” them. In a study published in Nature, scientists from California Institute of Technology realized bacteria equipped with miniaturized “sonar”. The genetically modified microorganisms look like “submarines”: yet they do not travel underwater, but in our body.

Immunotherapic agents are of many kinds: antibodies, vaccines, cytokines and even…bacteria. The immune system has more difficulty in recognizing cancer cells than any foreign invaders. A tumour is made of the host’s own cells, only more selfish, rebellious and disobedient. On the contrary, bacteria are completely different due to their peculiar cellular structures and metabolic functions: the body’s own defences are much more prepared to identify and attack them. Can we turn bacteria into cancer fighters that help the immune system to destroy cancer cells?

Pregnancy is a complex and fascinating process. There is an organism growing inside your womb and, as if it were not enough, it only shares half of your genetic heritage. The immune system is programmed to reject anything that is non-self, yet it tolerates the foetus. Mammalian placenta is a sophisticated organ that not only nourish the foetus, but it also makes feto-maternal immune tolerance possible. Cancer cells share many similarities with placental cells and maybe use the same mechanisms to escape the immune system.

Immunotherapy works amazingly well on some tumours, less on others. Brain cancers are among the hardest, because the blood-brain barrier physically prevents circulating immune cells from reaching the tumour. What is the point in boosting the immune response against cancer, if our soldiers cannot arrive on the spot? Finding a way into the brain is the biggest challenge. In a paper published on Nature, researchers engineered T cells, triggering their infiltration in a brain cancer called glioblastoma.

In the fight against cancer, not all immune cells play on our side. Tumour Associated Macrophages are definitely on the tumour side, by not only supporting its growth, but also generating an immune suppressive environment. The good news is that there are strategies to welcome the traitors back to our team. One recently published used very small particles and a technique called “photogeneration”.

If you ever feel lonely, think about the billions of bacteria populating your warm and comfortable gut: the dream house! More than 500 different species of microorganisms hanging around in our gut are a lot and do not go unnoticed: they modulate inflammatory processes and homeostasis in all host organs through metabolic and immune regulatory functions…and all this, while they are “trapped” in the gut! Their metabolites can in fact reach distant organs…and the host antibodies can control their absorption and distribution!