Part 1: How your immune system functions

The first part of our series explains how your immune system functions to keep you healthy, and also gives you some information about viruses.

The Human Immune System

The immune system is the defence and surveillance system of the body that protects us from infections with many types of micro-organisms (germs) and toxins as well as cancer. Your immune system is your greatest health asset – if it’s not healthy you will be unable to withstand many types of infections, including liver infections. Antibiotic drugs are useless against viral infections such as hepatitis – antibiotics only work against bacteria, which are a different type of micro-organism (germ). Anti-viral drugs and flu vaccines are not always effective, as the virus can develop resistance to these things. For these reasons you must first rely on your own immune system to fight a virus. The human immune system consists of various parts – let’s take a look!
  1. The spleen which filters out micro-organisms from the blood stream and destroys them.
  2. The bone marrow which is the soft centre inside the hard bones – in the marrow the stem cells are manufactured and these turn into specialised immune cells which fight viruses.
  3. The lymph nodes – also known as lymph glands; these small roundish lumps of tissue are found all over the body and receive lymph fluid from the lymph vessels. The lymph glands are a meeting point for the cells of the immune system especially the cells known as lymphocytes.
  4. Lymph tissue in the tonsils and intestines which contains immune cells.
  5. The lymphatic vessels which carry lymph fluid to the glands to be filtered and cleansed.
  6. The thymus gland situated behind the breast bone (sternum) which makes immune cells like T lymphocytes.
  7. Immune cells which fight and kill micro-organisms. These include leukocytes, neutrophils, macrophages, killer cells, helper cells, lymphocytes (B & T types of lymphocytes exist). Some types of T cells are very clever and can target the body cells that are infected by viruses – they then release chemicals to tell the virus infected cells to die (commit suicide); this kills the infected cell and any viruses hiding or duplicating inside the cell.
  8. Immune chemicals such as interferon & interleukin etc; interferon prevents cell death caused by viruses and reduces viral replication. Administered interferon is the major treatment for hepatitis C.
  9. Immune proteins (known as antibodies) which attach to viruses and neutralise and kill them. They are produced by immune cells; the cells that produce antibodies are known as B lymphocytes. Antibodies are also known as immunoglobulins.
  10. The liver which is not only a part of the immune system but is also the protector of the immune system.

Immune Function

There are two main types of immune function: 1. Innate Immunity This consists of the physical barriers and secretions in the body that prevent micro-organisms from invading your body – the skin, mucous membranes in the respiratory tract and intestines, mucus secretions, tears, saliva and stomach acid. 2. Adaptive Immunity This develops in the body after it has been invaded (infected) with a particular type of micro-organism and the body forms substances that allow it to remember or recognise this particular micro-organism. If the body is attacked by this micro-organism again the body can quickly recognise it and mount an attack against it which quickly destroys it. Adaptive immunity is acquired throughout life, as a result of successfully fighting off an infection or after vaccination. The flu virus is a master at continually changing itself or disguising itself so that the body’s adaptive immunity is not able to work.

What is a virus?

A virus is a microscopic (extremely tiny) parasite that infects cells in humans, animals and plants etc. A virus has a centre made of genetic material (either DNA or RNA, but not both) and this centre is surrounded by a protective coat (envelope) made of proteins, fats or sugar-protein combinations. Viruses use the reproductive system of the cells they invade. Viruses can only reproduce (replicate) themselves inside the cells of the human or animal they have infected. After the virus gets inside the cell, it immediately begins its destructive process of making the cell produce new viruses just like itself.

Viruses – the great survivors

Viruses are very hard to kill; otherwise scientists would have discovered a cure for them long ago. Over the last 30 years new viruses have evolved which are causing a growing global public health problem. Whilst we consider important causal factors to be modern agricultural practises, an increase in the earth’s population, rainforest clearing, climate changes and rapid international jet travel, the importance of the nutritional status of the person has not been given its deserved importance. Generally any one compound or drug that is powerful enough to kill viruses inside cells would have to be relatively toxic---and that’s the problem. However, as you will see later in this series, some single natural remedies, such as ginseng, can reduce the likelihood of you getting the flu or reduce the severity and duration of the illness. It is true that herbs and foods have a relatively weak antiviral effect otherwise, for instance, anyone who drank herbal teas, ate oranges and used garlic, would never contract a viral infection. You will get a much better protective effect against viruses if you combine several different natural therapies – eg. take a few medicinal herbs, plus a selection of culinary herbs, in addition to a generous use of antiviral foods and specific supplementation.