How cancer blocks attacking T-cells

How cancer blocks attacking T-cells

An immune blocking system involving a compound IDO1, which inhibits T-Cells, is being explored by the Max Plank Institute.

The first immunotherapy drugs were PD-1 drugs (such as Nivolumab and Pembrolizumab) and set out to unblock the T-cells in your Innate immune system so that they could better attack the cancer cells (or, indeed, any rogue cell). Targeting the ‘checkpoints’ aimed to release this tumour-induced brake.

However, it seems it’s not as simple as that and cancer cells have other ways to escape the immune response.

One is the production of the enzyme indoleamine-2,3-dioxygenase (IDO1), which converts tryptophan into kynurenine damaging the immune response in two ways:

First, the depletion of tryptophan in the body restricts the growth of T-cells. Secondly, the produced kynurenin inhibits T-cells when they get close and personal with cancer cells.

Chris Woollams, former Oxford University Biochemist added, “Tryptophan is an essential amino acid – you cannot make it, you must eat it. It plays a role in the production of serotonin (a mood enhancer), melatonin (the antioxidant, anti-inflammatory, anti-cancer, sleep aid), and in the production of vitamins B3 (niacin) and B6 (nicotinamide) both known to possess anti-cancer properties.

Top sources of tryptophan include chicken, turkey, red meat, pork, tofu, fish, beans, milk, nuts, seeds, oatmeal, and eggs”.

Meanwhile, scientists at the Max Plank Institute of Molecular Physiology have identified 150,000 possible compounds that might block IDO1 and are wading through them!

Go to: Vitamin D activates T-cells


  1. Herbert Waldmann, Elisabeth Hennes, Philipp Lampe, Lara Dötsch, Nora Bruning, Lisa-Marie Pulvermacher, Sonja Sievers, Slava Ziegler. CellBased Identification of New IDO1 Modulator Chemotypes.  Angewandte Chemie International Edition, 2021; DOI: 10.1002/anie.202016004


  Approved by the Medical Board. Click Here 


2021 Research
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