The fastest and oldest cells and responses to microbes is known as innate immunity.

The name is due to the fact that it involves recognition and response mechanisms, which are inherited and ready to function rapidly.

Read on to learn what innate immunity is and how it works as the first line of defenses.

RELATED: How to Strengthen the Immune System?

What is innate immunity and what is its role?

Innate immunity (also called natural or native immunity) is the set of molecules and cells that respond almost immediately to the presence of damaged microbes and cells.

This system has a defined and limited recognition pattern, selected throughout the evolution of the species and that is not modified by repeated contact with the pathogen (virus or bacteria).

The main function of innate immunity is to defend against germs in the first hours or days after an infection.

Other functions of innate immunity cells are: to act as sentinels, to block the entry of microbes and to activate adaptive immunity .

Components of the innate immune system

The components of innate immunity reflect its specificity. They can recognize molecules shared by groups of microbes and molecules produced by damaged host cells.

The main components of innate immunity are:

1. Physical and chemical barriers

This category includes skin, mucosal epithelia, and antimicrobial molecules. Its main function is to block microbes and prevent them from entering the body.

2. Phagocytic cells

These types of cells are capable of ingesting microbes or foreign molecules and then destroying them. Some examples of phagocytic cells are: macrophages, dendritic cells, NK cells, and neutrophils . (The latter are the star effectors of innate immunity).

3. Blood proteins

The main component proteins of innate immunity are the members of the complement system, the pentraxins and the ficolins. These are important both to neutralize, and to signal and mark microbes in order to optimize and amplify the immune response.

How does the innate immune system work?

When a pathogen enters the body, it generates danger signals capable of activating innate immunity. These are the so-called PAMPS and DAMPS.

So the innate immune response can fight microbes through two main reactions:

1. By inflammation

After the entry of an infectious agent into the tissues, changes can develop in the blood vessels that increase their permeability. This is an innate response known as inflammation.

This enables large numbers of innate cells to be recruited at the site of infection to engulf microbes. Inflammation is a fundamental tool to amplify the immune response.

2. Inhibiting virus replication

The innate immune system can block viral infections by expressing type 1 interferons .

As the word suggests, interferons are a family of cytokines capable of interfering in the viral cycle. These molecules can activate genes capable of generating rapid changes to block viral transcription and replication.

Note: All innate immune responses are regulated by negative feedback mechanisms that limit possible damage to self tissues.

Why is innate immunity so important in fighting an infection?

Innate immunity is important to fight an infection because it is not only responsible for acting quickly and first, but it also plays a fundamental role as an activator of adaptive immunity.

In most cases, innate immunity is sufficient to fight infection. However, these mechanisms also lead to the production of molecules that stimulate adaptive immunity.

Without innate immunity, our body would not be able to produce inflammation and orchestrate the rest of the molecules that exist to combat and prevent possible damage from infectious agents.

ABSTRACT

Innate immunity is the set of molecules, cells and mechanisms whose function is to give a rapid response to an infection.

The innate immune system is the oldest evolutionarily, but that does not stop being specific. Its activation signals are the PAMPS and DAMPS.

The components of innate immunity are: chemical barriers, phagocytic cells and proteins that circulate in the blood.

The two main mechanisms of the innate immune system are the induction of inflammation and the inhibition of virus replication by type 1 interferons.

As the word suggests, adaptive immunity is one that arises in response to and adapts to infection.

The adaptive immune system is a vigorous and sophisticated defense system that enables an organism to fight off invading pathogens.

Through specific identification, the adaptive immune system amplifies the innate response, and generates immune memory.

These mechanisms serve to strengthen defenses after repeated exposure to the same aggression.

Read on to learn how adaptive immunity works and what are the components and mechanisms of this response system.

RELATED: How to Strengthen the Immune System?

What is the adaptive immune system?

By definition, adaptive immunity (also known as acquired or specific) is all the mechanisms, cells and molecules involved in the late response of the immune system .

To fight an infection, the adaptive immune system can take days, even weeks. And it is their answer, the one in charge of generating defense memory cells.

Unlike the innate immune system, the adaptive one is slower, but responds to a greater number of molecules.

That is, the adaptive immune system recognizes a larger number of microbial and non-microbial substances called antigens. And therefore their responses are more specialized and also stronger.

That is why although many microorganisms have evolved to avoid the innate immune response, they have not been able to do so towards adaptive immunity. In fact, this is the basis of vaccines.

Components of adaptive immunity

Most of the components of the adaptive immune system appeared later in evolution (approximately 360 million years ago in jawed vertebrates).

In terms of types, the components of adaptive immunity are less diverse than those of innate immunity but work together to reinforce protective mechanisms.

The main components of adaptive immunity are:

1. Cells – Lymphocytes

The key component cells of the adaptive immune system are lymphocytes . Generally speaking, there are two types of lymphocytes, also known as T and B cells.

Each lymphocyte has a unique specificity, so they are capable of recognizing a number of antigens equal to the number of lymphocytes that exist. (This is up to 1 trillion molecules)

Both B cells and T cells are derived from specific types of stem cells, called multipotent hematopoietic stem cells, in the bone marrow.

Once they are produced, the lymphocytes need to mature and activate. Each type of cell follows different paths to its final mature forms and serves a specific function.

2. Proteins – antibodies and cytokines

The main component proteins of adaptive immunity are antibodies and cytokines.

Antibodies act as specific probes directing the effector action of different types of cells that act on the pathogen. These appear as membrane receptors for B lymphocytes or are secreted by them once they have been transformed into plasma cells.

In particular, antibodies and the T lymphocyte receptor are the molecules that confer on the adaptive immune system the ability to specifically recognize any chemical structure that may enter the body, and on this basis mount an immune response adapted to the pathogen in question.

Cytokines are a large family of proteins with similar (homologous) structures that stimulate the movement of leukocytes and regulate their migration.

How does it work? – Response mechanism

To activate, adaptive immunity requires communication with innate immunity. For example, once the pathogen enters, the dendritic cells recognize it and travel to the ganglion.

Here the adaptive immune system initiates its response mediated by lymphocytes and their products.

When activated, lymphocytes with specificity for non-self or altered components (such as those of tumor cells) are stimulated to proliferate (increase in number) and differentiate (phenotypic changes).

The phenotypic changes give rise to the appearance of cells that will contribute to the destruction of the aggression. For example, capable of secreting antibodies.

Other lymphocytes turn into memory cells, which ensure a quicker and better response in case the infection reoccurs.

Why is the adaptive immune system specific?

One of the mechanisms that the adaptive immune system has to be able to respond is to function on the basis of a clonal distribution of receptors linked to specific recognition.

What does this mean? That in the process of generating lymphocytes, a membrane receptor with a certain specificity is produced randomly. That is, with the ability to react with a single chemical structure.

Note that this process has the risk of reacting against its own components. It is for this reason that tolerance mechanisms exist to eliminate self-reactive clones.

Then, once the repertoire of lymphocytes has been generated, a clonal selection mechanism operates by which clones with specificity for their own components are eliminated.

The role of the adaptive immune system in immune memory

Immune memory is defined as the ability of the immune system to respond more quickly and effectively to a previously encountered pathogen.

Memory cells are activated due to the body’s ability to recognize pathogens that the body has previously been in contact with.

Once the body creates the necessary antibodies to quell a pathogen, it can do so more quickly when it encounters it again in the future.

This occurs whether you are infected with a pathogen or inoculated with a weakened or dead form of it. It is thanks to immune memory that we can get vaccinated against infectious diseases.

ABSTRACT

The adaptive immune system is only present in vertebrates and, unlike the innate immune system, its responses are slower and specific to the particular invading pathogen.

The molecules that elicit an adaptive immune response are known as antigens.

The most important cells in the adaptive immune response are B lymphocytes and T lymphocytes. Together with antibodies and cytokines, they constitute the main components of the system.

The mechanisms of the adaptive immune system are diverse, but all require the work of lymphocytes in close communication with the innate immune system.

The immune system offers this protection through two main responses: innate and adaptive immunity.

Innate immunity is that rapid response with which an organism is born, and adaptive immunity is acquired after exposure to certain aggression.

This article briefly describes what each one consists of and what their main differences are.

What is innate immunity?

Innate immunity, also known as genetic or natural immunity cells includes molecules and mechanisms capable of responding almost immediately to the presence of microbes and damaged cells.

Innate immunity is what one is born with, it is written in the genes and offers protection for life. It is fast acting and always responds the same way – of course, depending on the specific virus or bacteria it detects.

The innate immune system encompasses physical barriers, chemical, and cellular defenses. For example the skin, eyelashes, ears, and mucous membranes. These defenses identify cellular pathogens and substances that are potentially dangerous and take the necessary steps to neutralize or destroy them.

The mechanisms of innate immunity provide an effective initial defense against a large number of infections. However, many pathogenic microbes have evolved to resist innate immunity and their elimination requires the most powerful mechanisms of adaptive immunity.

What is adaptive immunity?

Adaptive immunity is the acquired immunity of an organism to a specific pathogen.

Adaptive immunity is not immediate, and although it can last a lifetime, this does not always happen.

The adaptive immune response is mediated by the clonal expansion of T and B lymphocytes. These cells are released in many copies and are capable of generating responses to neutralize or destroy their antigen.

For example, B lymphocytes can differentiate to generate antibodies or generate memory cells. T lymphocytes can transform into specific cytotoxic cells to destroy viruses and bacteria.

Adaptive immune responses often work by enhancing the protective mechanisms of innate immunity, making them better able to effectively fight pathogenic microbes.

Differences between innate and adaptive immunity

There are numerous connections between the innate and adaptive immune systems. The innate immune response to microbes stimulates the adaptive immune response and influences the nature of adaptive responses. However, they have several differences in the level of action and detection of pathogens.

The following table summarizes the main differences between innate and adaptive immunity systems.

Table of main differences between innate and adaptive immunity

What cells are involved in innate and adaptive immunity?

There are many types of cells involved in immunity. In the innate immune response, these include macrophages, neutrophils, eosinophils, basophils, mast cells, dendritic cells, and NK cells.

Cells involved in the adaptive immune response include B cells (or B lymphocytes) and a variety of T cells (or T lymphocytes), including helper T cells and suppressor T cells.

Natural killer T cells and gamma-delta T cells are part of the innate and adaptive immune response.

Neutrophils are produced in the bone marrow, have a short half-life and are one of the effector cells of the immune system par excellence.

When a microbe (pathogen) enters our body, the immune system recognizes it and sends a large number of neutrophils to the site of infection to destroy it.

Read on to find out how neutrophils work, what their function is, and what it means to have high and low normal values.

RELATED: How to Strengthen the Immune System?

What are Neutrophils?

By definition, neutrophils are cells of myeloid lineage characterized by the presence of granules that contain enzymes and other toxic agents involved in the defense of the body. (1)

Neutrophils are the most abundant type of white blood cell in the blood. White blood cells, also called leukocytes, are a key part of your immune system .

In fact, most of the white blood cells that lead the rapid response of the immune system are neutrophils. These cells make up 55 to 70 percent of the total circulating leukocytes in the blood.

Humans produce approximately 1 x ^10-11 neutrophils per day, each circulating in the blood for hours to days and then dying.

Its shape is almost spherical, with a diameter of approximately 12-15 μm with numerous membrane projections. Due to the shape of their nucleus, neutrophils are also known as polymorph nuclear leukocytes.

Neutrophils work in acute inflammation and provide an essential defense against acute bacterial infections. Neutrophil function abnormalities are rare and affect the ability to respond to life-threatening infections.

What are they for? – Function

When a microbe enters your body or has a minor injury, substances that your body sees as foreign trigger your immune system to kick in.

Neutrophils are important because they can engulf, produce, and release chemicals capable of killing microorganisms.

In particular, neutrophils are the main cells involved in the inflammation reaction. That is why these are the main effector cells of innate immunity to infection.

Unlike other white blood cells, neutrophils are not confined to a specific area of ​​the circulation. They can move freely through vein walls and into body tissues to immediately attack microbes.

In addition, neutrophils can release their content to the extracellular environment: what is known as NET traps. This mechanism has the function of trapping and destroying bacteria, but it also plays a role in promoting inflammation and thrombosis.

The role of neutrophils in the immune system is:

• Phagocytosis (especially opsonized microbes)
• Produce antimicrobial substances – reactive O2 species, defensins
• Promote inflammation – Chemotaxis
• Trapping microbes – by NET traps
• Other antimicrobial functions: activation of proteases

Normal, high and low values

To find out your neutrophil values, your doctor may ask you for an absolute neutrophil count (ANC).

This test can give your doctor important clues about your health. For example, help diagnose a disease, monitor an existing condition, or how your treatment is going if you are receiving chemotherapy.

An ANC is usually ordered as part of a complete blood count that measures the cells in your blood. It is important for your doctor to explain your test results to you. Results may vary depending on the person’s age, gender, heredity, or other factors.

Here is a table with high and low normal neutrophil values.

What Causes High Neutrophil Levels?

Having a high percentage of neutrophils in the blood is called neutrophilia. This is a sign that your body has an infection. Neutrophilia can indicate a number of conditions and factors, including:

• most likely bacterial infection
• non-infectious inflammation
• injury
• surgery
• Smoking cigarettes
• high stress level
• excessive exercise
• steroid use
• heart attacks
• chronic myeloid leukemia

What Causes Low Neutrophil Levels?

Neutropenia is the term for low levels of neutrophils. Neutropenia can last a few weeks or it can be chronic. It can also be a symptom of other conditions and diseases, and it increases your risk for more serious infections.

More often, low neutrophil counts are associated with the use of certain medications. But they can also be a sign of other factors or diseases, including:

• Chemotherapy treatment
• suppressed immune system
• bone marrow failure
• aplastic anemia
• congenital disorders, such as Kostmann syndrome and cyclic neutropenia
• hepatitis A, B, or C
• VIH / PAGE
• autoimmune diseases, including rheumatoid arthritis
• leukemia
• myelodysplastic syndromes

ABSTRACT

Neutrophils are cells of myeloid lineage characterized by the presence of granules containing enzymes and other potentially toxic agents involved in host defense.

The key functions of neutrophils include phagocytosis and the degradation of foreign organisms, such as bacteria, through the activation of proteases and other molecules, as well as the generation of toxic oxygen radicals.

Neutrophils play a major role as the major inflammatory cells in many conditions and can be attracted to tissues by non-infectious stimuli such as activated complement components and inflammatory mediators.

Having high (neutrophilia) or low (neutropenia) levels of neutrophils can be an indicator of your health. That is why your doctor may send you a count test to help your diagnosis.

It must respond quickly and locate and destroy microbes that can enter any body part.

It has several protective cells of variable nature and functions.

Read on to find out what these immune system cells are and what each one does.

Cells of the immune system

Almost all immune system cells are derived from hematopoietic cells in the bone marrow. Then they differentiate and generate different populations.

A summary of the different types of immune system cells with their respective function is described below.

1. Monocytes and macrophages

Monocytes are cells that makeup 5 to 10 percent of white blood cells. They are found lining the walls of blood vessels in organs such as the liver and spleen. Here they capture microorganisms in the blood as they circulate.

When monocytes leave the bloodstream and enter tissues, they change shape and size and become macrophages.

Macrophages are cells whose primary function is to ingest microbes through the process of phagocytosis and then kill them.

To kill, macrophages can form cytoplasmic organelle and fuse them with lysosomes. Lysosomes contain reactive nitrogen and oxygen species that are toxic to microbes.

Together with the activity of proteolytic enzymes, they constitute a fundamental mechanism for eliminating pathogens.

The macrophages are activated by microbial substances and recruit other immune cells to the site of infection. In this way, they amplify the immune response. For example, they serve as antigen-presenting cells to activate T lymphocytes.

In addition, macrophages can ingest necrotic cells of their own and other cells of the immune system, just like neutrophils. This is part of the cleaning process that occurs after an infection.

1. Neutrophils

The neutrophils are a type of cell found in the bloodstream that can quickly ingest and kill microorganisms.

Neutrophils are the most abundant circulatory immune cell population and play a significant role in innate inflammatory reactions.

Once inflammation occurs, neutrophils rapidly travel to the site of infection. This is where they perform their primary function – phagocytosis, particularly those microbes that have undergone the opsonization process.

In addition to phagocytosis, neutrophils can attack pathogens in other ways. For example, they can release granules filled with enzymes and aggressive substances, such as defensins, just as they can export traps in the form of networks (NET) to the extracellular medium.

1. Dendritic cells

Dendritic cells (DC) are immune cells that fulfill a unique role of communication between the response of the innate and adaptive immune systems.

On the one hand, their main functions are to act as sentinels, detecting the presence of microbes and initiating innate defense reactions.

On the other, activate adaptive responses by capturing and presenting microbial peptides to T lymphocytes.

Dendritic cells can fulfill these dual functions because they have several types of receptors.

For example, TLRs respond to microbial molecules. When these receptors bind, cytokines are released, and other cells of the immune system are rapidly recruited to the site of infection.

Furthermore, all dendritic cells express MHC molecules of the I and II classes, which explains their ability to mediate with the adaptive immune system through binding to T lymphocytes.

1. Lymphocytes

The lymphocytes are the primary immune cells of the adaptive response. All lymphocytes are similar in shape, and their appearance does not reflect their variety of functions.

It is these cells that are responsible for generating antibodies and ensuring memory function, which is why they play a unique role in the transfer of immunity.

A fascinating feature of lymphocytes is their diversity of receptors with different specificities. In other words, there are millions of lymphocyte clones in the body and each one is specific against a certain antigen.

This diversity of recognition is achieved through a process known as clonal expansion.

There are two main classes of lymphocytes, B and T cells.

Type B lymphocytes recognize many different antigens and evolve into antibody-secreting cells. Its function is essential to neutralize the microbe, activate the complement, and engulf it.

T lymphocytes can have various functions and subtypes. For example, they can act as helpers, recognizing antigens on presenting cells and marking them to stimulate other immune system responses.

They can also evolve into cytotoxic T lymphocytes that recognize antigens on infected cells and kill microbes directly, as well as they can fulfill the regulatory function and avoid an immune response to their cells.

1. NK cells

Natural killer (NK) cells are a subtype of lymphocytes that play fundamental roles in the innate immune system.

They are so named because they readily kill virus-infected cells and do not require the same thymic education that T cells require.

NK cells are cytotoxic; they contain small granules in their cytoplasm with particular proteins like perforin and proteases known as granzymes.

NK cells are derived from the bone marrow and are present in relatively low amounts in the bloodstream and tissues. They are essential to defend against viruses and prevent cancer.

1. Eosinophils, basophils, and mast cells

Basophilic eosinophils and mast cells are three additional cell types of the immune system that share the property of having cytoplasmic granules filled with inflammatory and antimicrobial molecules.

These immune cells play essential roles in fighting parasites and allergic diseases.

Mast cells are derived from the bone marrow and are found in the skin and mucous epithelia. They have granules filled with histamine, and when activated, they promote inflammation.

Basophils are rare cells and are generally found circulating in the blood (they represent 1% of circulating immune cells). Although their function is not entirely clear, they are known to have mast cell-like granules and become activated upon binding of the IgE antigen.

Eosinophils are granulocytes that contain enzymes capable of damaging the cell walls of parasites. They are found in the blood and mucous membranes, where they perform essential defense functions in the digestive and respiratory systems.

ABSTRACT

Cells of the immune system can be classified as lymphocytes (T cells, B cells, and NK cells), granulocytes (neutrophils, basophils, etc.), and monocytes/macrophages. These are all types of white blood cells.

Each type of cell has different functions, and they work in conjunction with other elements such as signaling proteins (cytokines), antibodies, and complement proteins.

The cells of the immune system act in a coordinated way to elicit rapid immune responses (innate and adaptive)

The immune system is made up of many elements; whose operation depends on several factors.

However, some fundamental processes of the immune system are well known and can be simplified. This material will briefly review these mechanisms and how the immune system ensures its function – immunity.

RELATED: How to Strengthen the Immune System?

What is the immune system?

The immune system is all the molecules, cells, and mechanisms responsible for ensuring immunity.

The immune system includes all the strategies to defend against tissue damage and infection. And therefore, it is responsible for maintaining the integrity of the tissues.

The most classic example of these elements is white blood cells. However, the immune system is diverse and forms an interactive network that includes organs and proteins.

The word immunity comes from the word immunity, which refers to the protection against legal processes enjoyed by Roman senators. (1)

Today the term immunity refers to protection against disease, particularly against infectious diseases.

Although relatively recently, there has been a branch of science that studies this system – (immunology); Since the 1960s, our understanding of the immune system has been dramatically transformed.

What is the immune system for? – Function

The primary function of the immune system is a defense against infectious microorganisms – viruses and bacteria. However, the immune system can also trigger its response against other foreign substances.

Another essential function of the immune system is fighting against the body’s cells where dangerous changes are detected. This mechanism is necessary to ensure homeostasis and prevent tumor cells from developing.

The immune system works every day to fulfill its function. And, most of the time, we don’t even notice it. But when immunity fails is when we face a disease.

How does the immune system work?

Defense against microbes is regulated by coordinated responses known as innate and adaptive immunity.

The innate immune system (natural or native) responds quickly to microbes and damaged cells. This response is the first line of defense, and it hardly changes over time.

The main components of innate immunity are:

• Physical and chemical barriers (skin, mucous membranes)
• Phagocytic cells (macrophages, neutrophils )
• Dendritic cells
• Mast cells
• NK lymphocytes
• Blood proteins (complement system)

Innate immunity fights microbes in 2 ways; recruiting cells that destroy pathogens and blocking the replication of viruses or infected cells.

On the other hand, there is adaptive immunity. This response is mediated by cells called lymphocytes and their products. Their defense mechanisms are more specialized and are found only in jawed vertebrates.

The main components of adaptive immunity are:

• T lymphocytes
• B lymphocytes
• Antibodies

Lymphocytes can recognize several signals as varied as the number in the body. This is up to a trillion possible threats to immunity.

The adaptive immune system response is exquisite and can generate memory. It increases when it detects the repeated attack of the same microbe.

These two systems – immune and adaptive – work in tandem. They communicate with each other to combat all possible dangers to our bodies.

What affects immunity?

The factors that affect immunity are various.

Our immunity is affected by an infection itself and by stress, hygiene, and the lack of nutrients in the diet. In addition, the quality and hours of sleep also play an essential role.

Genetics, age, use of medications and supplements can also affect immunity.

Factors that affect immunity are:

• Age
• Nutrition
• Hygiene
• Medications and supplements
• Levels of cortisol

ABSTRACT

The immune system is a complex system that includes organs, cells, and proteins.

The primary function of the immune system is to protect the body against infections (by viruses and bacteria). However, it can also fight against other threats and even kill defective cells of its own.

How does the immune system work? Protective immunity is controlled by early reactions – (innate immunity) and later responses (adaptive immunity). These two responses work in a coordinated and specific way to act in the face of each danger.

The mechanisms of the immune system are wide and varied; these range from neutralizing microbes so that they cannot infect, opening pores to break their membranes to generating antibodies to ensure defense in the future.

Understanding what lymphocytes do is essential to knowing how the immune system fights against bacteria viruses and how it adapts to generate memory for these attacks.

This article describes what lymphocytes are, what main types exist, and what primary role they play in immunity.

RELATED:

How to strengthen the immune system?

What are lymphocytes?

Lymphocytes are a type of white blood cell of fundamental importance for the immune system.

Lymphocytes are the cells that determine the specificity of the immune response to infectious microorganisms and other foreign substances.

In human adults, lymphocytes make up about 20 to 40 percent of the total number of white blood cells. (2)

These are found in the circulation and concentrated in central lymphoid organs and tissues, such as the spleen, tonsils, and lymph nodes.

Characteristics

A fascinating feature of lymphocytes is their diversity of receptors with different specificities. In other words, there are millions of lymphocyte clones in the body, and each one is specific against a particular antigen.

Most lymphocytes are short-lived, with an average lifespan of a week to a few months, but some live for years.

These cells are responsible for immune “memory,” which means a faster and more efficient response to a second encounter with the same antigen.

Lymphocyte types

The two main types of lymphocytes are B and T lymphocytes, also known as B cells and T cells.

Both types originate from stem cells in the bone marrow, and although they are similar in appearance and all lymphocytes help the immune system, their functions are very different.

Here are the main types of lymphocytes present in the body.

1. B lymphocytes

B cells are specialized cells of the immune system whose primary function is to produce antibodies.

B cells develop in the bone marrow from hematopoietic stem cells. B cells are trained not to produce antibodies against healthy tissues as part of their maturation.

When B cells encounter foreign material (antigens), they can evolve into other cells—for example, the so-called plasma cells, which are responsible for producing large amounts of antibodies.

Antibodies serve to neutralize the microbe, activate complement, and engulf.

Thus, B lymphocytes mediate humoral immunity and serve as a defense against extracellular microbes.

1. T lymphocytes

T lymphocytes (also known as T cells or thymocytes) are cells that can attack infected cells and also act as regulators of the immune system.

T cells develop from hematopoietic stem cells in the bone marrow but complete their development in the thymus (this is where the letter T comes from).

Within the thymus, immature lymphocytes become mature and travel to other immune system organs, such as the spleen, lymph nodes, bone marrow, and blood.

T cells have different abilities to recognize antigens, and each has another function. The T cell subtypes are:

• Killer or cytotoxic (also known as CD8 T cells)
• Helper or accessory T cells (also known as CD4 T)
• ​​ Regulatory T cells

Killer T cells carry out the actual destruction of infected cells, binding directly to their target to ensure their destruction.

Helper T cells help B cells to produce antibodies and killer T cells in their attack.

Regulatory T cells suppress or turn off other T cells. Without them, the immune system would continue to function even after curing an infection. They are like the thermostat of the immune system, and they serve to keep it on long enough, not too little or too much.

T lymphocytes mediate cellular immunity, and their products, such as cytokines, are essential for defense against intracellular microbes.

1. NK cells

Natural killer (NK) cells are a subtype of lymphocytes that play a critical role in defending against viruses and preventing cancer.

NK cells are also derived from the bone marrow and are present in relatively low amounts in the blood and tissues. Its main action lies in the rapid response of the innate immune system.

They are so named because they readily kill virus-infected cells and do not require the same thymic education that T lymphocytes need.

Role of lymphocytes in the immune system

Lymphocytes are the primary immune cells of the adaptive response.

These cells are responsible for orchestrating the late response and ensuring memory function.

On the one hand, B lymphocytes recognize antigens, proliferate, and differentiate into cells that secrete different classes of antibodies with other functions.

On the other hand, T lymphocytes recognize self-cell-associated microbe antigens and differentiate into different lymphocytes.

Together, the antibodies and activated T lymphocytes work with phagocytes to destroy infected microbes and cells.

In addition, some lymphocytes differentiate into memory cells, which protects the body against possible future and repeated attacks by the same microorganism. This is what most vaccines are based on.

ABSTRACT

Lymphocytes are the only immune cells capable of explicitly recognizing antigens. They are considered the most important white blood cells of adaptive immunity.

The two main types of lymphocytes are B and T. The response mechanisms between each type are quite different.

Generally, B’s play an essential defense function against extracellular microorganisms and T’s against intracellular ones.

Without the presence of this type of white blood cell, the immune system cannot generate a memory of exposure to bacterial or viral infections, as well as playing a fundamental role in recognizing what it’s own is and what is foreign.

Although it cannot be considered a cure, this drug could be a preventive solution and an effective treatment for the early stages of coronavirus infection.

If this is the first time you’ve heard the word interferon, read on to find out what it is and what its possible effects are against COVID-19.

What is Interferon Alpha 2B?

Interferons are a group of proteins produced naturally by cells of the immune system. They occur in response to infection by pathogenic viruses or bacteria.

Interferons are named for their ability to “interfere” with viral replication. (8)

Interferons do not directly kill viral cells but instead stimulate the immune system response and reduce the growth of damaged cells. Adding an extra amount of interferons can help the body fight infections from viruses, cancer, and other diseases.

Interferon Alfa2-2B is a drug with a high concentration of interferons; it can be administered in injectable form or through a nebulizer.

The antiviral effects of interferon-alpha 2B have been scientifically proven. Its products are to prevent viruses from replicating and to improve the immune response at the beginning of the infection. (3)

Types and functions of interferons

The interferons produced by human cells have been divided into three groups: alpha, beta, and gamma.

Alpha and beta-type interferons have broad-spectrum antiviral activity, demonstrating clinical efficacy against HBV, HCV, influenza A, and SARS-CoV viruses. (6).

The production of interferon-beta occurs as the first nonspecific response to viral infection. (7)

The combination of alpha and beta interferons is also used to treat different types of cancer such as skin, bladder, kidney, and blood. As well as it is used as a treatment for multiple sclerosis, hepatitis B, C, and HIV. (5)

Interferons have as main functions:

• Prevent viruses from replicating (since they activate the production of molecules that inhibit viral replication)
• Activate the action of other immune cells to kill virus-infected cells, bacteria cells, or tumor cells.

Interferon alpha-2B and coronavirus

Little is known about the effects of interferon alfa-2B against the new coronavirus.

However, its mechanism of action is known as a treatment against other viral infections; in particular, it has been used when no specific therapies are available.

According to previous studies with SARS, interferon alfa-2b can directly affect the adaptive immune response. This is associated with positive results in an acute viral infection. (6)

Interferon is known to stimulate genes that produce enzymes responsible for destroying the RNA of some viruses. SARS-CoV-2 is an RNA virus. Therefore, supplying interferon alfa-2B seems logical to combat this virus.

However, the antibody response and the complete mechanism of action of interferon-alpha 2b are still unclear.

Viruses may use IFN-β for their purposes. (4) This is one of the reasons why scientists are careful before using it as a treatment on a large scale.

Also, some clinical studies have confirmed that it can cause mild to severe side effects in some patients. (5)

Interferon Alpha 2B is not the coronavirus cure. But it could be an effective treatment of the disease in its early stages, especially as a prevention method.

Cuban Interferon Alpha 2B was used in China to treat COVID-19.

Interferon-alpha 2B has been produced in Cuba since 1896. In 2020, it was made using Cuban technology at the Chang Heber plant. It was used by Chinese doctors as a treatment for the coronavirus, with positive recovery results in more than 1500 patients. (8)

The Cuban drug Interferon Alpha 2B has been described by specialists in China as the most effective medicine against the new coronavirus.

On his Twitter account, the president of Cuba wrote: “Interferon alpha 2B: The Cuban drug used in China against the coronavirus. We support the Chinese Government and people in their efforts to combat the coronavirus. “

According to concubines, interferon 2-beta may be effective as a treatment for SARS-CoV infections. (1)

It has been used in China “because it is a rapid means of reaching the lungs and acts in the early stage of infection.” Said Dr. Eduardo Martínez Díaz, president of BioCubaFarm.

Now, is there something special about Cuban interferon-alpha 2b?

Not really; various international pharmaceutical laboratories produce this drug. It has likely been used in China because its production in Cuba makes it less expensive than other parts of the world.

The cure or vaccine for the coronavirus is not yet ready. The WHO has stated that: At the moment, no specific medicine is recommended to prevent or treat infection by the new coronavirus (2019-nCoV).

The results of interferon-alpha 2b against the coronavirus are promising but preliminary.

ABSTRACT

• Interferon Alpha 2B is an antiviral, not a vaccine.
• This drug was used against COVID-19 in China as a treatment.
• Everything seems to indicate that if it is administered at the beginning of the infection or as a prevention drug, it has positive results. The results of its use in people with advanced diseases are not conclusive.
• More studies still need to be done to propose interferon-alpha 2b as a mass preventive treatment.

Hairdryer, colored baths, children’s urine…. Some people have tried everything to protect themselves from COVID-19.

This article will tell you ten myths and truths about the coronavirus with proven evidence and support from official sources.

1. MYTH – children cannot get coronavirus

The children have less chance of developing severe illnesses from the coronavirus but may become infected and get sick. They are more likely to be affected the younger they are (12 months and younger). (1)

The risk of contracting coronavirus is lower for children at home who are not exposed to other children in school, daycare, or public spaces. If you have children in charge, teach them to practice preventive habits such as good hand hygiene and avoid kissing the lips or sharing drinks.

1. MYTH – masks protect you from coronavirus

Masks can give a false sense of security. For this reason, the WHO does not recommend its use for the majority of the population. (2) Wearing a mask probably won’t hurt you, but it’s not always necessary. The masks should be used in hospitals as a reminder not to touch the face and reduce the probability of contagion to patients.

For the general public, masks could make you touch your face more and increase the chances of contagion. You should wear a mask if advised by medical professionals or when you have any of the symptoms of COVID-19, such as coughing or sneezing.

1. MYTH – The COVID-19 virus cannot be transmitted in areas with hot and humid climates

Another misconception is that the COVID-19 virus cannot be transmitted in areas with hot and humid climates. According to the WHO, the new coronavirus is sent in hot and cold temperatures. (3)

Regarding this myth, the journal Nature has published an article that reports: – It is not clear if COVID-19 transmissions will be affected by the variation in seasonal temperatures. (8)

According to the Nature article: due to the high number of cases in many countries,  continuous transmission of the virus can occur during the summer, overcoming any seasonal variation found in more minor epidemics.

While the proximity of warmer climates may reduce viral transmission in the Northern Hemisphere, it is doubtful that the environment itself could end the COVID-19 epidemic.

1. MYTH – Mosquitoes can transmit the new coronavirus

The possibility of catching Covid-19 through mosquito bites worries many. According to the WHO: “To date, there is no information or evidence indicating that 2019-to

can be transmitted by mosquitoes.” (3)

The new coronavirus is transmitted from person to person, mainly from symptomatic individuals, although there is evidence of transmission from asymptomatic people. The main transmission route is by respiratory droplets (coughing, sneezing) and by contact.

In addition, the virus can remain in the environment on various materials for varying periods. The possibility of transmission through fecal matter has been raised, but it is a mechanism that is still under study. The virus can remain in the environment on various materials for varying periods of time.

1. MYTH – Pets can transmit the new coronavirus

Pets have not been identified as sources of transmission of the virus. The animal members of your family should not be a concern during the pandemic.

The WHO declares – that there is no evidence that the coronavirus that causes COVID-19 can infect companion animals and neither that they can transmit it to people or other animals “. In any case, animals “can function as passive carriers of viral particles.”

Animal health specialists explained that the feline coronavirus and the one that affects dogs are genetically different from the coronavirus (SARS-CoV-2) that causes COVID-19. (4)

Don’t abandon your pets; If you need support, turn to a friend or family member. If you need to ration your food, do so. If you are going to change your diet for something cheaper, find out well. If you do not have a patio, you can take them out on a leash, but avoid being in the street and public places if it is not necessary.

1. MYTH – Coronavirus can be cured by bathing the body with alcohol or chlorine.

Some recommend spraying the body with alcohol or chlorine to kill the coronavirus—the WHO explains that this does not work to kill the viruses that have once entered our body. It warns that spraying these substances on the body can damage our skin, mucous membranes, and clothing.

The most recommended measure to prevent infection by the new coronavirus continues to be washing your hands frequently with soap and water, or failing that, cleaning with an alcohol-based disinfectant.

1. TRUTH – encouraging your children to practice good hand hygiene can make a difference

Good hand hygiene is always one of the best ways to prevent the spread of the virus. If children can learn early, they can improve their hand hygiene skills.

If school-age children use disinfectant at least four times a day, it can reduce illnesses by 25 percent. (9)

In addition, studies have made it clear that most children do not wash their hands properly, so it should be of great importance that parents teach good hygiene practices during the pandemic. (5)

WHO continues to reaffirm that the best way to prevent Coronavirus infection is to “avoid close contact with anyone with a fever and cough, and practice good hand and respiratory hygiene.”

1. MYTH – The new coronavirus can be killed with a hand dryer

Due to the pitiful statements (Okeechobee County Commissioner in the US), the myth has spread that the new coronavirus can be killed with a hand dryer.

Culpeper said that because the nasal passages and nasal membranes are “the coldest part of the body,” the virus settles there before going to the lungs. “Heating those nasal passages will kill the COVID-19 coronavirus.” And to do that, you can take a hairdryer, hold it to your face and inhale. (6)

After this rumor, the WHO has published explicitly on its page that hand dryers do not kill the coronavirus. (3) To protect against the new coronavirus (2019-nCoV), wash your hands

frequently with a hydroalcoholic gel or soap and water. Once clean, dry them well with paper towels or a hot air dryer.

1. MYTH – Eating garlic or ginger prevents or cures new coronavirus infection

Despite its antimicrobial properties, there is no scientific evidence that affirms that garlic or ginger can ensure the prevention of the new coronavirus.

However, studies have confirmed the benefits of ginger for the common flu. Fresh ginger could stimulate mucosal cells to secrete ( interferon beta IFN-β) and possibly helps to counteract viral infection. (7) It is not a safe method of prevention.

1. Neither Cocaine nor infant urine can help you against the coronavirus.

In addition to the fact that Cocaine is an addictive drug that is very harmful to health, the consumption of Cocaine does not kill the coronavirus.

On the other hand, information has circulated that washing hands with infant urine could prevent infection by the new coronavirus. This is a myth.

Both are unsafe and unhealthy behaviors so prohibiting these two behaviors have been added to the advice on coronavirus rumors on the WHO site. (3)

SARS-CoV-2 is a new type of coronavirus discovered in late 2019. COVID -19 disease can be asymptomatic for the first 14 days, after which it is characterized by mild symptoms such as a dry cough and fever. In approximately 5-10% of cases of coronavirus infection, complications requiring mechanical ventilation are observed. Debunking the myths about this disease is of utmost importance to minimize the consequences of the pandemic.

Identifying the symptoms of coronavirus is essential to differentiate it from other diseases caused by viruses, such as the common flu.

This article publishes updated information on the symptoms of the coronavirus, its prevention methods, and possible treatments.

What is coronavirus?

Coronaviruses are a family of viruses that include more than 40 different virus species. The name is associated with its structure; the word crown refers to the spikes on its surface.

Coronaviruses can penetrate the membranes of a healthy cell by imitation. After the transmembrane receptor captures the cells, it is introduced, and the RNA of the virus arrives there.

The new coronavirus is a new strain SARS-CoV-2, detected in late 2019, that causes a contagious infectious disease.

What are the symptoms of the COVID-19 coronavirus?

The most common symptoms of COVID-19 are fever, tiredness, and a dry cough. Some patients may have pain, nasal congestion, runny nose, sore throat, or diarrhea. These symptoms are usually mild and appear gradually. 

Older people with other diseases such as high blood pressure, heart problems, or diabetes, are more likely to develop severe illnesses.

According to the WHO, about 80% of coronavirus patients can easily tolerate the disease with mild or no symptoms. COVID-19 requires hospitalization in 15% of cases, and only 5% need extreme medical attention; in approximately 2-4%, it is fatal. (1)

Among the complications of the coronavirus are lower respiratory tract injuries and viral pneumonia. Deterioration in vulnerable patients occurs rapidly: many patients develop respiratory failure in as little as 24 hours. In this case, they require respiratory support using a mechanical ventilation device. (2)

// Symptoms of coronavirus:

• Fever
• Fatigue
• Nasal congestion
• Dry cough
• Difficulty breathing
• Throat pain

What to do with the symptoms of COVID-19?

If you are not feeling well, call the appropriate lines within your medical area. If you have mild symptoms of the disease, such as a headache or a runny nose, do not contact others.

By limiting contact and not visiting medical institutions immediately, you are helping these institutions to work more efficiently and protect yourself and others from possible SARS-CoV-2 coronavirus infection.

If you have symptoms of coronavirus, you don’t need to panic; this is not going to help you or those around you. If you have a fever, cough, or shortness of breath, call your healthcare provider and report any travel or people contact you’ve had.

Calling for medical care by phone will allow specialists to refer you to an appropriate medical institution quickly. Additionally, this will help prevent the possible spread of the coronavirus.

Coronavirus – treatments

There is no cure for the disease that causes the new coronavirus, COVID-19. Possible vaccines and different specific drug treatments are being investigated.

WHO coordinates efforts to develop vaccines and drugs to prevent and treat COVID-19.

The most effective drugs so far have been interferon alfa-2b and chloroquine. These drugs have previously been used to treat other diseases caused by viruses, such as malaria and the SARS outbreak in 2003 (4).

The WHO estimates that the time to launch an efficient and specific drug on the market is at least 4 to 6 months.

Since one of the main symptoms of the coronavirus is fever, it is allowed to use painkillers to reduce it. WHO recommends taking paracetamol (at a dose of 500 mg 2-3 times a day).

On the other hand, the French Minister of Health, Olivier Veran, said that taking anti-inflammatory drugs such as cortisone or ibuprofen can worsen the condition of a patient with coronavirus.

It is not advisable to take supplements or medications without the preliminary evaluation of a specialist doctor.

How to prevent coronavirus?

Viruses (including coronavirus) are most often transmitted by airborne droplets, such as by sneezing or coughing.

To avoid getting infected, the best way is to stay at least 1-2 meters from a person. Wearing a mask is not an effective method of protecting yourself from infection, but it does help protect others – wear a mask if you have symptoms of the disease.

Avoid touching your eyes, nose, or mouth when you are away from home. Remember that coronavirus can be infected by transferring from the surface of objects to the face. The virus can be active in the air for up to 3 hours, on cardboard for up to 24 hours, on metal surfaces for up to 48 hours, and plastic for up to 72 hours (5).

Frequent hand washing with a 70% alcohol solution or soap and water is recommended. Washing your hands kills viruses that may be on your hands. How to prevent coronavirus:

• Wash your hands frequently
• Adopt respiratory hygiene measures
• Maintain social distancing
• Avoid touching your eyes, nose, and mouth
• Stay informed and follow the recommendations of healthcare professionals

Differences between COVID-19, SARS, MERS, and the common flu

The new coronavirus, sars, and the common flu all fall under the category of viruses. But they have differences both at the genome level and in the consequences and symptoms of the disease.

COVID-19 is more contagious, and its symptoms are often more severe than the common flu. The fatality is significantly lower concerning SARS and MERS, but the incubation time is longer.

The virologist Akiko Iwasaki, currently actively investigating the coronavirus, has made it clear in the following image:

Children and coronavirus Why do they get sick less?

Children and young people get less sick from the coronavirus. A logical explanation would be that children are better resistant to infection, but that does not seem to be the case. A recent study found that children are just as likely to be infected as adults. (2)

“No one has a sure answer to that question yet,” says Akiko Iwasaki. She and other expert virologists suspect it may be due to the unique way that children’s immune systems respond to these viruses.

A common complication of COVID-19, SARS, and MERS in adults is acute respiratory distress syndrome. This occurs when the immune response against the coronavirus becomes too aggressive and causes damage to the lungs. (5)

When the immune system is trying to help by attacking the virus, they can end up blocking the absorption of oxygen in the lungs. This phenomenon is called a cytokine storm.

Because children’s immune systems are still developing, one possibility is that they are protected from this type of excessive immune response, caused by the coronavirus.

Immune system and coronavirus

People with impaired immune systems are at higher risk of infections from viruses and bacteria.

A lack of vitamins, minerals, and other essential nutrients can weaken the immune system and increase the risk of virus and bacterial infections.

Making changes in habits and including certain foods and supplements can help strengthen your natural defenses.

During the pandemic, watch your diet and check your habits. While strengthening the immune system does not prevent coronavirus prevention, it can be an advantage against COVID-19.

Do ginger tea, garlic, and vitamin C help prevent or cure coronavirus?

Neither ginger tea, garlic, nor vitamin C is an effective cure or treatment to prevent or cure coronavirus.

Hot beverages help cough up and relieve symptoms of other respiratory tract infections, but they are not a proven coronavirus alternative.

If you observe signs of coronavirus, it is recommended that you call the hotline to the institutions in your country.

COVID-19 is a new type of coronavirus discovered in late 2019. The disease can be asymptomatic for the first 14 days, after which it is characterized by mild symptoms such as a dry cough and fever. In approximately 5-10% of cases of coronavirus infection, complications requiring mechanical ventilation are observed.