A new therapy which strengthens the power of a patient’s immune system to attack tumours is curing people of cancer. It is an exciting and ingenious technique which links many areas of Biology which IB students study. Called the “fifth pillar” of cancer treatment it builds on the first four pillars; surgery, chemotherapy, radiotherapy, targetted therapies like Herceptin.

Drugs that target cancer cells through their attachment to monoclonal antibodies have been used for twenty years. They can bind to specific molecular changes seen in cancer cells.  IB biology students study this mechanism in topic 11 Antibody production and vaccination.

The weakness ot these antigen-seeking drugs relates to a strength of some types of cancer cells. Tumour cells often reduce the expression of genes for surface antigens effectively hiding themselves from the immune system. This exciting "fifth pillar" is able to target these sneaky cancer cells while simultaneously activating the immune response. It has a fierce bite, and a sharp sting in its tail.  This new therapy is a living drug and a type of Chimera.  In mythology a Chimera is a fire-breathing monster with a lions head a goats body and a serpent's tail. 

CAR T-cells make up the living part of this immunological method which has become the fifth pillar of cancer treatment. The Chimeric antigen receptors (CAR) are built from different immune system components so that they not only bind to tumour cells, but they also activate the T-cell which carries them.

Revision idea

Rather than having students reviewing their notes, reading and re-reading the same things, why not give students an article to read.There are usually several questions in the IB exam which relate IB Biology to a research paper and this activity will be a good practice in making these links.

This article makes good links to the topics; defence against disease, genetic modification and cell division.

CAR T Cells: Engineering Patients’ Immune Cells to Treat Their Cancers originally published by the National Cancer Institute, free of copyright.

Ask students to find links in the article to IB Biology which they have studied. This will also help them to use their IB knowledge to understand the article.
Some educators call this a "Trash or Treasure" activity, finding the useful parts of an article, and leaving our the "trash".
To help structure the activity, this table gives a few hints.

An alternative, more detailed and more complicated article, with excellent diagrams can be found here.