Nonspecific Immune Defenses: Definition & Explanations

Unspezifische Immunabwehr: Definition & Erklärungen

Would you like to learn more about your health and your immune system? Or have you heard of the term and don't know what to do with it? This is understandable, because the human body and its immune system are complex and are often described using many technical terms.

In this article on non-specific immune defence you will receive all the important information about the topic so that your questions can be answered clearly. We will show you what exactly the non-specific immune defense is, how it works and what advantages it offers. This article will give you compact knowledge on the subject. After reading the article, your knowledge on the subject will have increased.

the essentials in brief

  • The non-specific immune defense is a part of the human immune system that is crucially responsible for protecting the body from the negative effects of the environment.
  • The non-specific immune defense is divided into humoral and cellular defence. It differs in the components involved in the immune response process. The cellular response is directed against intracellular microorganisms, the humoral against extracellular organisms.
  • The advantages of the non-specific immune system are that it is innate and therefore helps from childhood. In addition, it can recognize antigens as a whole and attack them in a timely manner. This is how the non-specific immune defense takes place within a few minutes

Glossary entry: The term non-specific immune defense explained in detail

To ensure that you have all the information you need after reading this article, we have addressed the most important questions about the non-specific immune system in the following sections. So you know what it means and what functions it has.

What is a non-specific immune system?

The non-specific immune defense belongs to the large complex of the human body's immune system, which is decisively responsible for existing in the environment determined by viruses and bacteria. Parasites, viruses and bacteria can cause significant damage to the body through infection. The immune system has the function of preventing such infections and protecting the body from harm.(1)

Woman doing yoga by the lake

In addition to the specific immune system, the unspecific ensures a healthy and powerful body. This is innate and works against any kind of foreign body. (Image source: Kike Vega/ unsplash)

The immune defense is differentiated between specific and non-specific immune defense. The non-specific immune response is the first line of defense against foreign bodies and antigens trying to enter the body. Attempts are made to eliminate the pathogens. This protective barrier includes the protective acid mantle found on the skin found on every human being, the stomach acid and various secretions found on the surfaces of mucous membranes. What they all have in common is that they try to keep pathogens away from the inside of the body.

How does the non-specific immune system work?

In order to understand how the non-specific immune response works, the most important elements and characteristics of it should be pointed out. The unspecific immune response does not fight specific pathogens, but tries to stop all invaders. Furthermore, it is innate, which means that almost all people possess it from an early age.

Should it now happen that antigens try to overcome the immune barrier, the non-specific immune defense becomes active first. The non-specific immune defense can fall back on two different functions. On the one hand, the cellular immune system uses white blood cells, leukocytes and other cells to identify and fight the antigens. On the other hand, the humoral immune defense is activated, which is carried out by the body's own messenger substances. B cells are stimulated to activate themselves and convert into cells that produce antibodies.

How does a non-specific immune defense work?

The course of the non-specific immune defense can best be illustrated with a concrete example. In the event of inflammation, cells set off and produce new ones to take care of the foreign body. The cells release chemical messengers that dilate the blood vessels, causing the site of infection to swell to create more immune cells to fight the inflammation. To do this, enzymes are called, which also help in the elimination of the invader. The enzymes mark the pathogens as invaders in order to identify them for the scavenger cells.

If bacteria or viruses have penetrated the inflammation, scavenger cells try to remove them by encircling the pathogen and eating according to its name. In addition, there are a number of other defense cells that can destroy bacteria. During this process, the defense cells also die off, which becomes visible through pus. Finally, the last step is taken over by the so-called killer cells, whose characteristic is to recognize modified cells that could carry a virus or a tumor. The killer cells can then eliminate them using various cell toxins.

What is the difference between a humoral and a cellular non-specific immune system?

After we have introduced you to the non-specific immune defence, we want to bring you closer to another subdivision, namely that between the humoral and cellular non-specific immune defence. The main difference between these two types lies in the components involved in the immune response process.

Humoral immune defense

Antibodies are involved in the humoral immune defense to fight a foreign body. In order to recognize these foreign bodies, so-called B-cells are necessary. These sense the invaders and at the same time are stimulated to activate themselves and transform themselves into cells that produce antibodies. During this transformation, they released different types of immunoglobulin. These immunoglobulins are antibodies that can attach themselves to the surface of the foreign body, turning it off.

In addition, the former B cell emits signals that indicate to cytokines and to the so-called scavenger cells that they are also needed to deactivate the antigens. (2.3">As their name suggests, the scavenger cells help to eliminate the antigens. Once the foreign body has been eliminated, memory B cells are formed, which know the appropriate immune reaction for future cases of the same foreign body and can execute it more quickly.

Cellular immune defense

In contrast to the humoral immune response, the cellular response is directed against intracellular microorganisms. Certain cells take up antigens, transform them and place the modified antigen on their surface. This leads to T helper cells being mobilized, which also attract other T cells. These T cells can then recognize the cells that present the altered antigen on the surface and then eliminate them.

However, it should be noted that the two different types of immune defenses cannot be viewed completely separately. Thus, the tasks of cells and antibodies are inferior to interactions, since cells play a crucial role in starting the defense reaction with antibodies. The antibodies, on the other hand, are crucial in various reactions of cells.

What is the complement system within the non-specific immune system?

The non-specific immune system also includes the so-called complete system. The system is made by the liver and can cause foreign, invading cells to be destroyed. The complement system consists of a variety of plasma proteins that attack foreign microorganisms by occupying their surface. In a multi-stage process, further functions of the immune system are activated, which improves the strength of the non-specific immune defence.

The non-specific immune defense can be activated in two ways.

Either the activation occurs indirectly, with the cell wall of the antigen being crucial. With direct activation, antigen-antibody complexes are required to fight the foreign body. The process of direct activation is the point of contact with the specific immune system, since antibodies are required here.

What are the advantages of non-specific immune defense?

The non-specific immune defense offers the body various advantages. The task of this immune defense is to form the first protective barrier for pathogens that occur. This makes it possible for the non-specific immune response to respond to and stop a large number of pathogens. It reacts to all pathogens in the same way, so that the destruction process can start immediately. As a result, the body does not have to wait long for cells or the like to form, but can start tracking down and eliminating the pathogen right away.

The human skin also belongs to the non-specific immune system. This barrier is the first layer of protection that keeps pathogens out. In addition, chemical substances such as enzymes and acids block the establishment of bacteria and viruses. The mucous membranes, which are located in the throat area, for example, also protect against foreign bodies. In addition, tears, sweat or urine are also part of the non-specific immune system, which protects the human body.

What is the difference to the specific immune system?

In contrast to the non-specific immune defense, which acts as the first protective barrier for a large number of pathogens, the specific immune defense is precisely tailored to individual pathogens. If the non-specific immune defense was not able to push back the pathogen, the specific defense takes over. The white blood cells form a large number of antibodies that fit individually on the surface of the intruder according to the key-lock principle.(4,5)

However, it can take days and weeks before coupling occurs, since the formation of the precisely fitting antibodies takes a long time. Once the antibody has attached itself to the surface of the pathogen, dismantling and destruction of the invader begins as the antibodies break down the mass.

kind Non-specific defenses Specific Defense
cellular killer cells, mast cells, monocytes B lymphocytes, T lymphocytes
humorous Cytokines, enzymes, defensins antibodies, immunoglobulins

During this process, cells are formed at the same time, which remember the structure and shape of the pathogen. These cells are called memory cells. If a person is infected again with the same pathogen in their lifetime, the memory cell can remember the pathogen and the body can immediately start producing the appropriate antibodies. Reinfection can be fought in less time and with less effort.


The non-specific immune defense is thus the part of the immune system that forms the first barrier to stop invading pathogens. The non-specific immune response can respond to and stop a variety of pathogens. It reacts to all pathogens in the same way and offers advantages in terms of time, since it can be initiated quickly and starts working immediately after the detection of the foreign body.

Since the non-specific immune system is innate, it helps both small children and adults. It is equipped with the most important means to suppress diseases. A large number of body elements such as cells and enzymes are at work. The first line of defense is therefore not to be underestimated and plays a large part in keeping your body healthy.


  1. General information about the immune system and in particular the non-specific immune system
  2. Effect of microbitotics on elements of the immune response
  3. Influence of the intestinal microbiota on cytokines
  4. Description of the effect of B lymphocytes in response to antigens, i.e. pathogens and other exogenous substances
  5. Description of the differences between specific and non-specific immune responses in relation to the humoral or cellular pathway.
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