Strong Immune System: Women 1 Men 0?
The organs and mechanism of the body that provides resistance to infections, toxins and foreign organisms entering our body are collectively known as the Immune system.
The Department of Health and Human Services Office of Women Health reports that the autoimmune disease and disorders are considered 1st in the top ten list of most popular health disease. Autoimmune disease is a medical term used to define the condition in which your immune system starts to damage your own body.
Considering only 24 autoimmune diseases, the National Institute of Health (NIH) estimated that 23.5 million Americans experience autoimmune disease and is still expected to rise. The American Autoimmune Related Diseases Association (AARDA) reports, 50 million Americans are affected by autoimmune disease.
The Institute of Medicine declared that the U.S is lagging behind from other countries in researching the autoimmune disease and immune system. After going through the above-mentioned statistics, it is important to know about the immune system and the diseases associated with it.
Immune System Definition
The immune system is a complex network of cells and protein comprising of many biological structures in order to defend the human body from foreign infectious organisms.
It is a defensive mechanism that keeps a record of every foreign material it has ever defeated in the types of white blood cells- B (also known as memory cells) and T lymphocytes. The reason for such a database is to detect and destroy the foreign material if entered again in the body before it can multiply and harm you.
An immune system must detect a wide variety of agents, known as pathogens, viruses to parasitic worms, and distinguish them from the body’s own healthy bacteria.
Our immune system consists of various main parts of the immune system which are as follows:-
- White blood cells
- Complement system
- Lymphatic system
- Bone marrow
Immune System Parts
1. White blood cells: These are key cells, a part of the lymphatic system that is made in your bone marrow. It constantly looks for any foreign materials for an immune attack to protect your body before it starts to harm you. It is further subdivided into lymphocytes(B cells, T cells, and natural killer cells), and many other types of immune cells.
2. Antibodies: Antibodies are the proteins produced by the immune system that deals with the organisms entering from outside and the chemicals produced by them. They recognize the antigen by detecting a chemical compound attached on the surface of the antigen.
3. Complement system: It is a system made up of protein which compliments the antibodies for taking actions against foreign material.
4. Lymphatic system: It is a network of delicate tubes consisting of lymph nodes, lymph vessels, and WBC to perform the following functions:-
- To maintain the fluid level in the body
- Inflammation against bacteria
- Rect to cancer cells
- To absorb some fats from the intestine
- Deal with the chemicals released by the foreign materials
5. Spleen: It is the largest organ in the lymphatic system used to filter blood and helps in maintaining fluid in the body. It is the storage for WBCs and platelets.
6. Bone marrow: It is a spongy tissue present inside the bones to produce components of blood- red blood cells (RBC), white blood cells (WBC), and platelets.
7. Thymus: Thymus is a small, irregular-shaped gland located in the top portion of the chest which is used to filter and monitor blood content. It is also involved in the preparation of a type of white blood cells called T-lymphocytes.
What is Immune System Disorder?
Immune system disorder is a type of disorder that is caused due to inflammation in the immune system; it can be overactive or underactive.
When the immune system overreacts, the body attacks and starts to damage its own cells and tissues causing harm to itself. While in the case of underactive/immunodeficiency, the body’s immune system becomes less efficient.
Immune system disorders are as follows:-
1. In the case of the immune system overactive:
- Rheumatoid arthritis
- System lupus erythematosus
- Inflammatory bowel disease(IBD)
- Multiple sclerosis(MS)
- Type 1 diabetes mellitus
- Guillain-Barre syndrome
- Chronic inflammatory demyelinating polyneuropathy(CIDP)
- Grave’s disease
- Hashimoto’s thyroiditis
- Myasthenia gravis
2. In the case of immunodeficiency disorders:-
- X-linked agammaglobulinemia(XLA)
- Common variable immunodeficiency(CVID)
- Severe combined immunodeficiency(SCID), also known as alymphocytosis/boy in a bubble disease
Who has strong immunity, men or women?
In general, females have a stronger, innate and adaptive immune response in comparison to males. The factors responsible for strong immune response in females are due to biological factors such as gender differences, genetic and epigenetic factors, sex hormones and psychosocial factors-gender differences.
In the case of immunity, females have the upper hand because their immunity responds very effectively, showing no mercy to the invaders. It means they are less prone to bacterial, viral, fungal and other types of infections as compared to males.
Females have two X chromosomes, while males have two, X and Y. However, in females, one X chromosome of each cell in the body is randomly shut off or inactivated, while the embryo is developing.
The inactivation is not a perfect process, and sometimes genes from the X chromosome escape inactivation. In this case, a female ends up with two active copies of a particular gene. Here is where the researchers think the microRNAs come in.
The X chromosome contains 10 percent of all microRNAs in the human genome. The Y Chromosome has none. Some of the microRNAs on the X chromosome are said to be involved in immune system functions and cancer development. Having two copies of that microRNA might provide females with extra protection against cancer.
Whereas males contain one X and one Y chromosome causing an immunological disadvantage as they have only one X-chromosome. The Y-Chromosome contains fewer genes so if the genes involved in immunity are silenced maternally the male is left with no compensating genetic information and no extra protection against cancer.
But the bitter truth is that women’s immune systems are more likely to overreact due to the presence of two X chromosomes(extra protection). When the female immune system is overstimulated, it can attack healthy tissues which can cause autoimmune diseases.
It can also cause potentially fatal post-infection complications, such as a cytokine storm after getting the flu, in which an overproduction of immune cells overwhelms the body’s normal functions.
In fact, we found that more than 4000 genes were extra active in female mast cells compared with those in males. Further, many of the highly active genes in females produce proteins that are involved in manufacturing and storing inflammatory substances-histamine and proteases.
This unique difference in the ability of females to store and release more histamine and proteases may explain why female mast cells can trigger a more potent immune reaction. It may also suggest why women may be more vulnerable to certain diseases and disorders and men are more resistant.
The study from Lund University hypothesized that sex differences in the strength of immune response might be associated with levels of MHC(Major Histocompatibility Complex) diversity.
By sequencing immune system genes of the MHC in the warblers, they were able to compare the variation of these genes in males and females as well as their offspring. The results showed that a variation in MHC genes in females is too high, but males are too low.
For males, having a higher MHC variation was advantageous, they gained better territories and their offspring had higher survival rates but for females, having a higher MHC was disadvantageous, leading to a decreased survival in the offspring. Males with higher MHC variation and females with lower MHC variation were also more successful in engaging offspring.
Women are known to have a lower incidence of cancer while men have a two-five fold greater risk of developing the disease. Women are also better able to survive trauma.
In a new paper, researchers from Ghent University, Belgium argue these sex-specific health disparities may be due to tiny pieces of genetic material called microRNAs.
The main function of microRNAs in cells is to turn off, or "silence" specific genes. Researchers say microRNAs located on the female X chromosome may give women an advantageous immune system over males.
Females and males differ in the energy consumption and nutritional requirements which are based on the interactions between environmental factors and sex hormones. The studies in the early 1940s ascertained that females have an enhanced capability of producing antibodies.
This enhanced immune reactivity in females helps mount an effective resistance to infections and therefore females are less susceptible to viral infections but can develop immune-pathogenic effects and predisposition to autoimmunity due to hyperimmune responses.
Due to the overestimation of the immune system, females have to face certain autoimmune diseases such as lupus, predisposition to autoimmunity due to hyperimmune responses and pathogenic effects.
However, the study also notes that the advantages of having two X chromosomes are slightly offset by the fact that it increases their susceptibility to developing autoimmune disorders later in life.
Women might have evolved a particularly fast and strong immune response to protect the developing fetus and newborn babies, says Marcus Altfeld, an immunologist at the Heinrich Pette Institute in Hamburg, Germany.
But everything costs- the immune system can overreact and attack the body. This might explain why women tend to develop more autoimmune diseases such as multiple sclerosis and lupus than men.