How to educate your immune cells 101

When we hear the word ‘education’, we might think about going to school, learning new stuffs and skills, maybe science, or any subjects we like or don’t like.

When immune cells are educated, they also learn new skills: ability to combat cancer cells!

 

The immune system we possess

Before I talk further about the immune cells education, let me explain how our immune system works briefly.

We, as human, are blessed with two types of immune system, innate and adaptive.

Innate immunity is the first barrier that virus, bacteria and other evil cells have to face when they first enter our body. The defence force includes physical defence, such as mucous secretion when we catch a cold.

Some immune cells are also involved in this group, such as macrophages and dendritic cells. These immune cells can attack foreign cells by devouring them. Om nom nom nom!

 

Footage of dendritic cells munching on disease-causing yeast. Video by PLoS Pathogen via Wikimedia Commons

 

The second type is called adaptive immunity. The specialty of this immunity is its memory to remember foreign cells. Yes, it’s the one that plays role in vaccination. So, when the virus or bacteria re-invade our body, this adaptive immunity can trigger stronger immune reaction. The immune cells involve in this immunity is T-cells and B-cells.

The key thing here is adaptive immunity has to be activated first by innate immune cells. Macrophages and dendritic cells have the ability to munch on foreign cells, process, and present parts of those cells, called antigen, through surface molecules called MHC (see figure below). These presented molecules are then recognised by T- and B-cells, so they can memorise the identity of the foreign cells and further kill them when there is future invasion.

Dendritic cell introduce antigen to cytotoxic T-cell, so the T-cell can recognise foreign cells and further kill them! Image by Author

Immune cells education vs cancer

Now I’m going to talk about cancer (again).

Researchers have been trying to exploit the antigen-presenting capacity of dendritic cells to activate T-cells to recognise cancer.

Recall my previous blog, the one that are capable of combating cancer cells are a type of T-cells called cytotoxic T-cells (Tc cells).

Researchers came up with an idea of isolating dendritic cells from cancer patient’s body and introducing them with parts of the cancer cells in the lab. The aim is to ‘educate’ dendritic cells, so they can present the antigen from cancer cells, called neoantigen or tumour-associated antigen.

The educated dendritic cells are then injected back as a vaccine to patients. And this is how Tc cells can be activated to recognise cancer cells and further kill them!

This whole educating process is the main principles of dendritic cells vaccine.

Dendritic cells vaccine: patient’s dendritic cells are educated to recognise cancer cells, so they can activate Tc cells when injected back to the patient’s body. Image by Author

The good news is this dendritic cells vaccine can be used to treat many types of cancer.

Moreover, it’s personalised! It means every patient will have their own dendritic cells educated as vaccine. This will reduce the probability of unwanted reaction.

One example to this is Sipuleucel-T, which was approved in 2010 under the trade name PROVENGE. The vaccine is used to treat prostate cancer and has improved lives of many since its first use.

Amazing, right?

It’s so fascinating knowing that the cancer cure is actually in our body. We just need to find a way to outsmart the disease, in this case by educating our dendritic cells.


7 Responses to “How to educate your immune cells 101”

  1. Kimberly Chhen says:

    Great post Sam! Who would think that a cure for cancer lies in our bodies? Is there a maximum amount that the scientists can isolate dendritic cells from our body?

  2. Sam Widodo says:

    Hi Kirthana, thanks for the excellent question. Yes, you are correct. One of the challenges in DC vaccine is to find the right tumour-associated antigen (TAA). We know that cancer cells carry lots of mutation, and that’s what distinguishes them from normal cells. The mutated protein, or antigen, can be exploited here. TAA should be different than normal antigen presented by normal cells, and specific enough to induce immune reaction only to cancer cells. You can read this paper for further information. https://cvi.asm.org/content/18/1/23
    It is quite specific to cancer vaccine but because you mentioned you study DC, I assume you have a strong background in immunology. Enjoy!

  3. Sam Widodo says:

    Hi Xiaohan, thanks for reading my blog and the feedback. The drawbacks of this vaccine is the difficulties to monitor dendritic cells activities after injection. Scientists have been trying to overcome this problem by engineering DCs prior to vaccination. There are also some side effects, as reported by PROVENGE, like chills, fatigue, fever, back pain, nausea, joint ache, and headache.

  4. Sam Widodo says:

    Hi Zoe, yes this is such a groundbreaking discovery. Thanks for reading my blog!

  5. Kirthana Senthil says:

    Hey! I study dendritic cells, myself. So it’s nice to see them get some love on this blog!

    Just wondering, though, isn’t one of the challenges with cancer-targetted immunology the fact that cancer cells often express self-antigen? Would you know how this is addressed in this dendritic cell vaccine? …Or am i completely wrong?

  6. Xiaohan Hu says:

    Interesting post! The concept of immune cells education is fascinating and you have explained it in a simple and understandable way. I’m just curious are there any drawbacks of this dendritic cells vaccine?

  7. Zoe Canestra says:

    Personalised treatment, very exciting stuff! Great blog post 🙂