Fifty years ago, we knew little about the immune system. Back then, only a handful of illnesses were classified as autoimmune conditions where the immune system doesn’t recognize proteins normally present in the body and attacks its own cells. Today, researchers have found that autoimmune responses explain about at least 10 percent of the diseases that affect the planet’s population; among them, diabetes (type I), lupus, multiple sclerosis and rheumatoid arthritis, to name only the most common ones. But other conditions such as ulcerative colitis and even schizophrenia are possibly linked to autoimmune responses. Furthermore, coronary disease has been related to the efficiency of the immune system in clearing up plaque deposits in the arteries of the heart.
By the end of the 19th century, when vaccines were invented, Louis Pasteur discovered germs as the cause of many illnesses and later bodily reactions to specific microorganisms, like the tuberculosis Koch’s bacillus, were identified, confirming the existence within the body of the immune system. Initially, immunity was conceptualized as a defense army in charge of destroying an enemy, concept that reflects a predominantly martial mentality in society. Mainstream western medicine still holds this concept. However, a holistic approach will more accurately reflect the amazing immune system.
Researchers Koch and Pasteur inaugurated a craze where most illnesses started to be explained as caused by germs. In the early 1940s, viruses were found capable of generating illness, and the sixties and seventies saw a great boom in virology, when researchers tried to establish a causal relationship between viral infections and cancer. This causal relationship has however not been confirmed. In some cases, like the infection by papilloma virus (HPV) there seems to exist a strong correlation to cervical cancer in women. However, scientific evidence points to chronic inflammation (not the viral infection) as the precursor of cancer. Take into account that inflammation is modulated by the immune system and that our inflammatory response depends on our lifestyle.
Science has advanced a great deal. Studies have established that human bodies continuously produce cancer cells but thanks to an immune system capable of recognizing misbehaving cells, cancer can be prevented. By isolating, reeducating and/or destroying those crazy cells, the immune system can keep us cancer free. A clear relationship between cancer and the immune system has thus been established. When the immune system is not working optimally, cancerous cell growth might go out of control.
Since the beginning of the AIDS epidemic, investigators have plunged into studying what exhausts the immune system, contributing very interesting insights into its multiple functions.
Beyond this concept of the immune system as an army that chases, confronts and destroys invaders, the immune system is a self-governing network that participates in the body’s learning process, and is responsible for both its molecular identity and the biochemical communication between organs. That’s why author Fritjov Capra deems it our second brain.
Different from other bodily systems, which are confined to a precise anatomic location, the immune network penetrates each tissue of the body. It is made of a number of tissues and organs (lymphatic organs) and specialized cells (lymphocytes and macrophages or white blood cells) that swim back and forth along the circulatory system during surveillance missions, gathering data to ensure the organism’s accurate functioning.
This extraordinary system learns and evolves with experience! From the moment we are born, the immune system learns how to react to unfamiliar agents. It learns to discriminate which molecular features typify bacteria that are usually not present in mammals. It also recognizes the body’s idiosyncratic proteins. Vaccines are developed based on the immune system’s capacity to memorize how to react to alien proteins.
There is also a kind of natural selection taking place in the thymus, where only T-cells (a specific kind of immune cells) that have learned to unite harmoniously with other cells in the organism can survive.
The thymus is one of the most important organs of the immune system. It is a small gland situated behind the breastbone (sternum) and is fundamental in shaping the way in which the body responds to infections. Half of the white blood cells, which originate in the bone marrow, go directly to the blood stream and interstitial fluids. But the rest of them have to go through the thymus where they become T-cells. These have three main roles: to stimulate the production of antibodies and other lymphocytes, to stimulate the growth and function of phagocytes that ingest and digest viruses and bacteria, and to identify foreign or abnormal proteins.
Many immune system organs function as gatekeepers. This is the case of the lymph nodes (in the neck, armpit and groin), the tonsils and the Peyer’s patches in the intestine. The lymphatic fluid, or lymph, goes through these customs checkpoints where lymphocytes capture particulate matter and microorganisms and decide if they should be granted admission to the system or not. Another lymphatic organ, the spleen, is in charge of recycling old and dysfunctional cells.
This amazing system only uses its defensive resources when facing a massive invasion of foreign agents.
Recent research shows that the brain, the endocrine glands and the immune system cooperate and share functions. Moreover, the borders that science had delineated between these systems start to blur, bringing opportunities for new understandings of the body’s functioning. Candace Pert used the term net to describe these systems, because their function encompasses a constant exchange, processing and storage of information. Most substances in charge of transmitting information in the body are peptides, and recent research has shown they are multifunctional; they accomplish different functions for different systems.
For example, the brain produces neuropeptides that are antibacterial precursors; the immune system has perceptual functions, and the endocrine system produces substances that work as neurotransmitters. Initially deemed exclusive to the nervous system, the neurotransmitters have also been found in the bone marrow, where the immune system cells are produced.
The three systems are thus, multifunctional. They form a network that exchanges, stores and passes on information, using peptide molecules as messengers. But, also, our physiology is modulated by emotions. Popular wisdom, which results from observations transmitted from generation to generation, has always correlated emotional stress with vulnerability to illness, and science has proven that our thoughts, mood and emotions influence the functioning of the nervous, endocrine and immune systems.
In a nutshell, science is telling us that we can regulate the production and efficiency of our inner messengers (peptides) by adopting healthy lifestyles. It’s telling us to eat healthy, have fun (to reduce stress) and exercise.