When Your Body Attacks Itself – Autoimmune

Summary

The immune system is a powerful defense mechanism made of billions of cells designed to protect the body from invaders. However, in autoimmune diseases like Type 1 diabetes, multiple sclerosis, and lupus, the system mistakenly attacks the body’s own healthy cells. This destructive process is triggered by a combination of genetic risk, bad luck, and environmental factors like infections. The result is an endless cycle of immune responses that can lead to debilitating and life-altering symptoms. While these diseases may have historically helped humanity survive pandemics, modern medicine has left us vulnerable to autoimmune conditions in a world free of such threats.

Takeaways

• 😀 The immune system is a highly complex defense mechanism, constantly patrolling and protecting the body against invaders like viruses and bacteria.
• 😀 Autoimmunity occurs when the immune system mistakenly targets the body's own healthy tissues, leading to diseases like Type 1 diabetes, multiple sclerosis, and lupus.
• 😀 Autoimmune diseases can range from manageable to deadly, with the commonality that the immune system attacks the body as if it were an enemy.
• 😀 Autoimmunity can be triggered by genetic factors, environmental factors, and a random stroke of bad luck, such as viral infections or bacteria mimicking the body’s proteins.
• 😀 Proteins are the building blocks of life, and the immune system is trained to recognize foreign proteins while protecting the body’s own proteins.
• 😀 The immune system’s defense mechanism includes a rigorous 'training' process where cells that recognize self-proteins are eliminated. However, sometimes a rogue cell survives and triggers autoimmunity.
• 😀 A trigger event, like a cold or infection, can activate the immune system and cause a misguided attack on the body’s own tissues if certain conditions align.
• 😀 Once the immune system targets its own tissues, it starts a self-reinforcing cycle of damage, cloning more cells and intensifying the attack.
• 😀 The severity of autoimmunity varies, affecting different tissues, organs, and systems, such as nerves (in MS), joints (in rheumatoid arthritis), and the pancreas (in Type 1 diabetes).
• 😀 Autoimmune diseases are thought to have evolved as a result of genetic traits that helped protect against past infectious diseases, but today, these traits can lead to harmful autoimmune reactions due to modern changes in our environment.
• 😀 The concept of 'evolutionary trade-offs' helps explain why autoimmune disease-related genes have persisted despite their potential harm in modern society, offering protection against ancient pandemics but contributing to current autoimmune risks.

Q & A

What is autoimmunity, and how does it affect the body?

Autoimmunity occurs when the immune system mistakenly attacks healthy cells and tissues in the body. This happens because the immune system misidentifies certain proteins in the body as foreign invaders, triggering an immune response that damages the body's own tissues.

What are some common autoimmune diseases mentioned in the script?

Common autoimmune diseases mentioned include Type 1 diabetes, multiple sclerosis, celiac disease, lupus, and Crohn's disease.

How does the immune system normally identify and attack invaders?

The immune system identifies invaders by checking the shapes of proteins in the body. If the proteins don’t match the body’s own, they are recognized as foreign, and the immune system attacks them. This process is critical for survival as it helps the body fight off infections.

What role does the 'murder university' play in preventing autoimmunity?

The 'murder university' refers to the training process of immune cells to ensure that they do not attack the body’s own proteins. Cells that recognize self-proteins are destroyed to prevent autoimmunity. However, sometimes a mistake happens, and a rogue immune cell survives and starts attacking the body.

What is the role of bacteria and viruses in triggering autoimmune diseases?

Bacteria and viruses can trigger autoimmune diseases by evolving proteins that resemble the body’s own proteins. This mimicry confuses the immune system, making it more likely to attack healthy cells, leading to an autoimmune response.

What is a 'trigger event,' and how does it contribute to the development of autoimmunity?

A 'trigger event' is an external factor, such as an infection or injury, that activates the immune system. These events flood the body with cytokines, signaling molecules that alert the immune system to engage. If the immune system then mistakenly targets the body’s own cells, autoimmunity may develop.

How does the immune system mistakenly target the body’s own cells in autoimmunity?

After a trigger event, immune cells may encounter proteins from the body that are similar to foreign invaders. If a rogue T cell that recognizes these proteins survives the immune training process, it can lead to an immune response where the body attacks its own tissues, mistaking them for invaders.

Why is fatigue a common symptom in autoimmune diseases?

Fatigue is common because when the immune system is in attack mode, it signals the body to rest and shut down, even if the immune system itself is the aggressor. This results in a feeling similar to having the flu, despite the real enemy being the body’s own immune system.

Why do autoimmune diseases seem to be more prevalent today than in the past?

Autoimmune diseases are more common today due to genetic variations that make the immune system more aggressive. In the past, these traits may have been advantageous for survival during infectious disease outbreaks, but now, with improved hygiene and modern medicine, they can lead to autoimmune conditions in the absence of infections.

What is the evolutionary explanation for the persistence of autoimmune disease-related genes?

Evolutionarily, genes that increase the immune system's aggressiveness might have been beneficial in the past by providing protection against deadly infectious diseases. Even though these same genes can lead to autoimmune diseases today, they were advantageous during times of pandemics, which helped these traits persist in the population.