These "defenders" methodically encircle the enemy positions and "patrol" until they meet a tumour cell, which they have previously learnt to recognise. They then halt to eliminate it, before resuming their rounds. The rapidity of the advance achieved by T lymphocytes is indicative of either the absence of an adversary, or defeat of the immune system in the battlefield.
This scenario was published in The Journal of Experimental Medicine.
How is a tumour destroyed by T lymphocytes? This scenario has recently been visualised by researchers at the Institut Curie. The original images obtained and assembled in twelve video sequences are the result of close collaboration between a specialist in two-photon microscopy, Luc Fetler, an INSERM scientist in the CNRS/Institut Curie "Physical Chemistry Curie" Unit1, and immunologists, notably Alexandre Boissonnas, in the INSERM "Immunity and Cancer" Unit at Institut Curie.
Our body's defences against an infection or tumour are based on a string of actors, some of them generalists, the others highly specialised. Cytotoxic T lymphocytes belong to the second category. To achieve their task, their cell surface carries a membrane receptor which is complementary to the antigen in the pathological cells to be eliminated. Alerted by the presence of this antigen, the T lymphocytes are activated. Having identified an infectious or tumour cell, they bind to it and target it with a fatal load of enzymes.
When T lymphocytes infiltrate a tumour?