Tag: cytotoxic

T-cells: First responders

~ Simon ~ 5 Comments

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The cause of the cell loss and pathology associated with Parkinson’s is still unknown. While the later stages of the condition have been well investigated based on various pathological marker (ie Braak staging), the early manifestations of the condition are still a mystery.

Cells of the immune system are early responders to any signs of trouble in our bodies, and recently researchers have been looking at a specific class of immune cells (called T cells) in postmortem sections of brains from people who passed away with Parkinson’s.

Curiously, in their analysis the researchers found that the bulk of activity of T cells occurs before any cell loss or pathology appears.

In today’s post, we will discuss what T cells are, review the new research, and explore what this could mean for potential therapies for Parkinson’s.

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Your hematopoietic system. Source: Wikipedia

The process of hematopoiesis (or blood formation) is absolutely fascinating.

Seriously.

You start off with a single, multi-potential hematopoietic stem cell. This is called a hemocytoblast (it’s the big cell in middle of the image below):

A hemocytoblast. Source: Pinterest

Given enough time, this single cell will give rise to an entire blood system, made up of many of different types of cells with very specific functions that are required for us to live normal lives.

It is a remarkable achievement of biology.

Understand that at any moment in time your blood system will contain 20-30 trillion cells (in the average human body). And as the image near the top of the post suggests, there are quite a few branches of potential cell types that these blood stem cells can generate.

Very interesting, but what does this have to do with Parkinson’s?

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Keep your sights on lymphocytes

~ Simon ~ 4 Comments

Recently new research has been published that raises the question (again) as to whether there is something wrong with the immune system in Parkinson’s 

Researchers from Germany and San Diego (USA) have published data suggesting that a particular type of blood cell may be acting up in Parkinson’s, getting involved with the neurodegenerative process that characterises the condition.

In their report they also found a clinically available treatment – called Secukinumab – that could reduce the effect.

In today’s post, we will look at what lymphocytes are, how they may be playing a role in Parkinson’s, and explain how secukinumab could potentially aid us in the treatment of PD.

Ouch! Source: CT

My 5 year old recently cut her leg, and there was a bit of blood. We patched her up with a plaster, but also took advantage of the moment to learn a little something about how the body works.

Me: Do you know what that red stuff is?

Little monster: It is blood?

Me: That’s right.

Little monster: Papa, where does blood come from?

That was when I got all excited, and pulled out my black board.

This was the answer I gave her:

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The autoimmunity of Parkinson’s disease?

~ Simon ~ 12 Comments

Auto

In this post we discuss several recently published research reports suggesting that Parkinson’s disease may be an autoimmune condition. “Autoimmunity” occurs when the defence system of the body starts attacks the body itself.

This new research does not explain what causes of Parkinson’s disease, but it could explain why certain brain cells are being lost in some people with Parkinson’s disease. And such information could point us towards novel therapeutic strategies.

Nature_cover,_November_4,_1869

The first issue of Nature. Source: SimpleWikipedia

The journal Nature was first published on 4th November 1869, by Alexander MacMillan. It hoped to “provide cultivated readers with an accessible forum for reading about advances in scientific knowledge.” It has subsequently become one of the most prestigious scientific journals in the world, with an online readership of approximately 3 million unique readers per month (almost as much as we have here at the SoPD).

Each Wednesday afternoon, researchers around the world await the weekly outpouring of new research from Nature. And this week a research report was published in Nature that could be big for the world of Parkinson’s disease. Really big!

On the 21st June, this report was published:

Nature
Title: T cells from patients with Parkinson’s disease recognize α-synuclein peptides
Authors: Sulzer D, Alcalay RN, Garretti F, Cote L, Kanter E, Agin-Liebes J, Liong C, McMurtrey C, Hildebrand WH, Mao X, Dawson VL, Dawson TM, Oseroff C, Pham J, Sidney J, Dillon MB, Carpenter C, Weiskopf D, Phillips E, Mallal S, Peters B, Frazier A, Lindestam Arlehamn CS, Sette A
Journal: Nature. 2017 Jun 21. doi: 10.1038/nature22815.
PMID: 28636593

In their study, the investigators collected blood samples from 67 people with Parkinson’s disease and from 36 healthy patients (which were used as control samples). They then exposed the blood samples to fragments of proteins found in brain cells, including fragments of alpha synuclein – this is the protein that is so closely associated with Parkinson’s disease (it makes regular appearances on this blog).

What happened next was rather startling: the blood from the Parkinson’s patients had a strong reaction to two specific fragments of alpha synuclein, while the blood from the control subjects hardly reacted at all to these fragments.

In the image below, you will see the fragments listed along the bottom of the graph (protein fragments are labelled with combinations of alphabetical letters). The grey band on the plot indicates the two fragments that elicited a strong reaction from the blood cells – note the number of black dots (indicating PD samples) within the band, compared to the number of white dots (control samples). The numbers on the left side of the graph indicate the number of reacting cells per 100,000 blood cells.

Table1

Source: Nature

The investigators concluded from this experiment that these alpha synuclein fragments may be acting as antigenic epitopes, which would drive immune responses in people with Parkinson’s disease and they decided to investigate this further.

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