[Graeme]

Size matters – to the immune system, at least

$this->bbcode_second_pass_quote('', ' ')July 28, 2005
A theory about the way in which the immune system identifies and responds to invasion has been confirmed by Oxford researchers in a paper published in Nature today. The paper shows that a highly sensitive and specific immune response hinges on something as straightforward as large and small molecules jostling into size order.
T-cells are a crucial part of our immune system: they patrol the body surveying cells and triggering the immune system to attack those that are infected. The surface of every cell, including T-cells and infected cells, is covered in a variety of molecules. When a T-cell comes into contact with an infected cell, a receptor molecule on the T-cell’s surface will bind with a telltale molecule on the surface of the infected cell which flags up the infection (called a peptide MHC). This binding triggers the immune response.
The answer is now shown to be the kinetic segregation model, conceived at Oxford 10 years ago by Professors Anton van der Merwe and Simon Davies, and shown to be correct in today’s Nature paper, on which Professor van der Merwe is an author along with three other members of Oxford’s Sir William Dunn School of Pathology and a scientist at Imperial College London. The model proposes that, because both T-cell receptors and the telltale peptide MHCs are relatively small molecules, they can only come into contact and bind when the bulkier CD45s are out of the way – in which case the immune response can be activated without impediment.

[Bas]

I wonder if you can compare posters on this forum as a sort of T-cells

[Graeme]

Very good point Bas. Hopefully some of our posters can also be regarded as Gaia's Immune Response!