You’re probably aware of the immune system, but do you know how it defends your skin against harmful invaders? Enter innate immunity – the standout player in protecting your nutritional asset from harm.
How Your Innate Immune System Protects Your Skin from Harmful Invaders
Innate immunity is your physiological first line of defense, providing an immediate response to microbial intrusions.
It works hard behind the scenes with physical barriers, chemical mediators, and a variety of complex functional systems like complement activation and phagocytosis. Not to mention dendritic cells and natural killer cells that are primed to tackle pathogens before they take hold.
It’s no surprise then why understanding what strengthens or weakens our innate immunity is critical for preserving our skin’s wellbeing.
| Innate Immune Cell | Location | Function | Role in Skin Health |
| Macrophage | Tissues | Ingest and destroy pathogens or debris; secrete cytokines; present antigens to adaptive immune cells | Act as sentinels for infection or injury; promote wound healing; regulate inflammation |
| Neutrophil | Blood | Ingest and destroy pathogens or debris; release granules and extracellular traps | Migrate to sites of inflammation; kill bacteria and fungi; contribute to pus formation |
| Natural Killer Cell | Blood | Recognize and kill infected cells or tumor cells by inducing apoptosis (cell death) | Eliminate virus-infected cells or malignant melanocytes; secrete interferons or tumor necrosis factor |
| Dendritic Cell | Tissues | Capture antigens from pathogens or tissues and present them to adaptive immune cells | Migrate from skin to lymph nodes; shape adaptive immune response by influencing T cell differentiation |
Innate Immunity Is Our Body’s Natural Shield
Our innate immunity shields us from harmful microorganisms such as bacteria, fungi, and viruses; however its work doesn’t stop there. In conjunction with inflammation processes occurring inside our bodies, which play a vital role in maintaining proper homeostasis by limiting the spread of infection and stimulating healing.
Overall, our innate immune system serves an essential purpose in supporting healthy looking skin on both surfaces and below the surface—a benefit we can all appreciate!
But ever-changing external circumstances can threaten skin integrity constantly—some of which even come from activities we do every day.
Things like using harsh skincare products loaded with irritants can disrupt protective barriers while weakening effective responses that protect against environmental stressors like UV exposure. That’s why knowing which lifestyle habits are best for skin health is key to supporting and strengthening normal defenses.
How Physical Barriers Keep Pathogens Out
Your body is equipped with the first line of defense against pathogens. Skin is a physical barrier that prevents bacteria, viruses, fungi, and other microbes from entering and causing disease. Let’s look at how it works so we can better appreciate its amazing protective capabilities.
Epithelial Cells Keep Pathogens Out
The surface of your skin is made up of epithelial cells that form a tight junction to stop invaders from penetrating. These cells release antimicrobial peptides which kill or inhibit bacteria from entering the body.
Skin Sheds to Prevent Infection
On top of acting as a wall against bugs, skin also provides mechanical defense in the form of sweat and continual shedding to prevent bacteria and fungal growth on the skin’s surface. When you sweat or come into contact with water, these natural secretions rinse off many pathogenic organisms that attempt to take hold in your body’s outer layers.
Wound Healing Restores Skin Integrity When Injured
Even if pathogens manage to breach your epidermis through a wound or cut, your body will respond with another layer of defense – wound healing restores the protective function of your skin! When wounded, specialized proteins are released which work together to close any openings left behind by injuries by mobilizing cells from nearby areas towards the affected spot for rebuilding and protection.
Does Anything Compromise Skin Barrier Function?
There are several factors that can compromise the barrier function of your skin, such as aging which makes epidermal cell turnover slower and disrupts homeostasis within your skin’s environment; stressors in the environment, such as extreme weather conditions; and various types of skin diseases which soften cellular junctions leading to an easier penetration for pathogens into your body system.
Chemical Mediators: Alarm Signals for Optimal Skin Well-Being
Living organisms are equipped with an immune system that is activated when antigens such as bacteria, viruses or other pathogens enter the body. The innate immune system, also known as non-specific immunity, is part of this first line of defense and relies on physical barrier mechanisms such as skin (or mucosa) together with chemical mediators to trigger a defensive response. These chemical mediators are produced mostly by damaged tissues and innate immune cells to alert other immune cells to initiate an inflammatory response in order to fight potential threats.
How Cytokines Work: Modulating Different Types of Immune Cell Activity
Among these chemical mediators, cytokines stand out as one of the most important components. On one hand they regulate local and systemic adaptive immune responses, but they can also modulate disease activity through effects such as promoting wound healing and collagen synthesis while inducing angiogenesis when necessary.
Cytokines like interferon and interleukin have been reported to partially block ‘the alarm signals’ from external irritants and allergens thus helping maintain overall skin health in conditions like psoriasis or atopic dermatitis.
Exploit Your Body’s Natural Pathways To Prevent Skin Damage During Aging Processes
By understanding how our bodies collaborate between its different subsystems (immune system), processes (inflammation) and molecules (cytokines), we learn more about our natural mechanisms for protecting against threatening agents and avoiding –or at least maintaining– skin damage during aging processes using anti aging topical products that allows us reclaim youthful vibrant skin, naturally leveraging powerful skins challenges.
These and all the benefits associated with their mobilization should not be underestimated when it comes to achieving desired results through safe treatments offered by holistic approaches like natural therapeutic options in cosmetic products.
Phagocytes – The Eating Machines of Your Innate Immune System
Your body protects you from harmful invaders like bacteria, viruses, fungi, and parasites with your innate immune system.
It’s made up of cells and molecules that can recognize and eliminate foreign substances, giving you a first line of defense.
One of the most important types of innate immune cells are phagocytes.
There are different kinds of phagocytes that perform different functions in your body.
There are two major types: macrophages and neutrophils.
Macrophages – The Sentinels of Your Tissues
They can patrol your skin, lungs, liver, spleen, brain, and other organs for signs of trouble.
When they encounter a pathogen or a damaged cell, they engulf it and digest it with their lysosomes.
They also secrete cytokines – chemical messengers that alert other immune cells to join the fight.
But macrophages are not just killers.
They also play a crucial role in activating your adaptive immune system – the part of your immunity that can remember specific antigens and produce antibodies against them.
Macrophages can present antigens – pieces of pathogens or debris – on their surface to T cells and B cells, which then mount a more specific and effective response against the invaders.
Macrophages are essential for keeping you healthy and preventing infections from spreading.
However, they can also contribute to inflammation and tissue damage if they become overactive or dysfunctional.
For example, macrophages have been implicated in chronic inflammatory diseases such as rheumatoid arthritis, atherosclerosis, obesity, diabetes, Alzheimer’s disease, and cancer.
Neutrophils – The Rapid Responders to Inflammation
Neutrophils are the phagocytes that patrol your blood and rush when there’s inflammation.
At 55 to 70 percent of your body’s white blood cells, these important cells are the most plentiful in your system.
They are also one of the fastest-acting immune cells – they can reach an infected area within minutes after an injury or infection occurs.
Like macrophages, neutrophils can engulf and destroy pathogens or debris with their lysosomes.
But they also have other weapons at their disposal.
They can release granules containing antimicrobial agents such as defensins, proteases, and lysozyme that can kill microbes directly or disrupt their membranes.
They can also form extracellular traps (NETs) – webs of DNA and proteins that trap pathogens and prevent them from spreading further.
Neutrophils are vital for controlling acute infections and clearing out dead cells and debris from wounds or tissues.
However, they can also cause collateral damage to healthy cells and tissues if they release too many granules or NETs, or if they persist too long at an inflamed site.
For example, neutrophils have been associated with tissue injury and organ failure in sepsis, a life-threatening condition where infection triggers a systemic inflammatory response.
Factors That Affect Phagocyte Function or Number in Skin Diseases
Your skin is one of your main barriers against external threats, and it contains many phagocytes that help defend it from infection or injury. However, some factors can affect phagocyte function or number in skin diseases such as acne vulgaris or leprosy.
Acne vulgaris is a common skin condition that affects millions of people worldwide. It is caused by several factors, including excess sebum production, clogged pores, bacterial overgrowth (especially Propionibacterium acnes), and inflammation,
They can also contribute to inflammation and scarring by releasing cytokines, reactive oxygen species, and matrix metalloproteinases. Some factors that can affect phagocyte function or number in acne vulgaris include:
- Hormonal changes: Androgens such as testosterone can stimulate sebum production and increase P. acnes colonization. They can also modulate macrophage function by enhancing their phagocytic activity but suppressing their antigen presentation ability
- Diet: Some dietary factors such as high glycemic load, dairy products, chocolate, and omega-6 fatty acids may worsen acne by increasing insulin levels, inflammation, sebum production, or P. acnes growth . Conversely, some nutrients such as zinc, vitamin A, vitamin E, selenium, and omega-3 fatty acids may improve acne by enhancing phagocyte function, reducing inflammation, or inhibiting P. acnes
- Stress: Psychological stress can impair phagocyte function by altering cortisol levels, catecholamines, and neuropeptides . Stress can also increase sebum production and inflammation by activating the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system
Leprosy is a chronic infectious disease caused by Mycobacterium leprae, a bacterium that mainly affects skin and peripheral nerves. Phagocytes play a key role in leprosy pathogenesis: on one hand, they help control M. leprae infection by ingesting and killing them with lysosomal enzymes; but on the other hand, they can also harbor M. leprae inside their cytoplasm for long periods of time without destroying them. Some factors that can affect phagocyte function or number in leprosy include:
- Genetic susceptibility: Some genes involved in innate immunity such as TLR2, NOD2, PARK2, LTA4H, and TNF-alpha have been associated with increased risk or protection from leprosy. These genes may influence how phagocytes recognize and respond to M . leprae antigens.
- Immune polarization: The type of immune response elicited by M. leprae infection determines the clinical spectrum of leprosy. A Th1-type response characterized by macrophage activation, cytokine production (IFN-gamma), and granuloma formation leads to tuberculoid leprosy – a mild form of disease with few lesions and low bacterial load. A Th2-type response characterized by antibody production (IgG), eosinophilia, and humoral immunity leads to lepromatous leprosy – a severe form of disease with numerous lesions and high bacterial load. Phagocytes are influenced by these immune polarizations: Th1-type cytokines enhance their microbicidal activity while Th2-type cytokines inhibit it.
- Drug resistance: Some strains of M. leprae have developed resistance to commonly used antibiotics such as dapsone, rifampicin, or clofazimine [25]. This reduces the efficacy of treatment and increases the chances of relapse or transmission. Drug resistance may affect phagocyte function by altering M. leprae metabolism or virulence factors.
Phagocytes are amazing cells that help you fight off infections or injuries by eating up pathogens or debris.
However, they can also cause problems if they become dysregulated or overwhelmed by certain factors. That’s why it’s important to take care of your skin health and consult your doctor if you have any skin issues.
Natural Killer Cells: The Killing Machines
Do you know that your body has a powerful army of killing machines that can fight off infections and cancers?
These are called natural killer (NK) cells, and they are a type of innate lymphoid cell that can recognize and kill infected cells or tumor cells by using perforins and granzymes to induce apoptosis (cell death).
But how do NK cells know which cells to kill and which ones to spare?
They use receptors on their surface to distinguish between normal cells (which express MHC class I molecules) and abnormal cells (which lack MHC class I molecules or express stress-induced ligands).
MHC class I molecules are like ID cards that tell NK cells that a cell is healthy and belongs to your body.
Stress-induced ligands are like distress signals that tell NK cells that a cell is under attack by viruses or tumors.
NK cells also secrete cytokines such as interferons or tumor necrosis factor to activate other immune cells or inhibit viral replication.
Cytokines are like chemical messengers that coordinate the immune response.Interferons help prevent viruses from spreading to other cells. Tumor necrosis factor helps destroy tumor blood vessels and induce inflammation.
But not all NK cells are created equal.
Some factors can modulate NK cell activity or number in skin diseases such as melanoma or viral warts.
For example, some cytokines can enhance or suppress NK cell function.
Some drugs can increase or decrease NK cell numbers.
Some genetic variations can affect NK cell receptor expression.
Why does this matter?
Because understanding how NK cells work can help us develop better treatments for skin diseases and other conditions that involve NK cells.
For example, we could use drugs that boost NK cell activity to fight off infections or cancers.
We could use drugs that block NK cell activity to prevent autoimmune reactions or transplant rejection.
But how do we know if these treatments work?
Further evidence will be needed from scientific studies that test them on human subjects.
From melanoma to atopic dermatitis, psoriasis to vitiligo, alopecia areata to pemphigus vulgaris – researchers are actively exploring the role of NK cells in a wide range of skin diseases.
Dendritic Cells: The Bridge Builders
Dendritic cells (DCs) are specialized cells that can sense and capture antigens from pathogens or tissues and present them to adaptive immune cells. They act as messengers between the innate and adaptive immune systems.
DCs are present in tissues that are in contact with the external environment, such as skin, nose, lungs, stomach and intestines. When they encounter an antigen, they migrate from these peripheral tissues to lymph nodes where they interact with T cells, a type of adaptive lymphocyte.
DCs shape adaptive immune responses by influencing T cell differentiation into various subsets based on the nature of antigen and cytokine environment. These subsets include Th1,Th2,Th17,Treg,Tfh, each with different functions and roles in immunity.
FAQ:
What is the difference between innate and adaptive immunity?
Your body has two ways to protect you from germs and injuries. One is fast and general. The other is slow and specific.
The fast way is called innate immunity. It works against any foreign substance or injury. It includes your skin, mucus, inflammation, and white blood cells.
The slow way is called adaptive immunity. It works against recognized antigens. Antigens are molecules that trigger an immune response. Adaptive immunity includes antibodies and memory cells.
Antibodies are proteins that stick to antigens and mark them for destruction. Memory cells are white blood cells that remember antigens and respond faster if they encounter them again.
Adaptive immunity gives you long-term protection from diseases you have been exposed to before.
How does skin protect itself from infection?
Your skin is your first line of defense against germs and injuries. It does three things to protect you.
First, it forms a physical barrier that blocks pathogens from entering your body.
Second, it produces chemical mediators that warn other immune cells and start inflammation. Inflammation is a process that helps heal wounds and fight infections.
Third, it has immune cells that can attack or remove pathogens or infected cells. These include phagocytes, natural killer cells, and dendritic cells.
Phagocytes are white blood cells that swallow and digest pathogens. Natural killer cells are white blood cells that kill infected cells by making holes in them. Dendritic cells are white blood cells that present antigens to adaptive immune cells. Your skin works hard to keep you healthy and safe.
What are some common skin diseases that involve innate immunity?
Your skin is more than just a cover. It’s a shield that protects you from infections and diseases.
But sometimes, skin diseases can still occur.
Here are five common skin problems and how they happen.
- Acne: This happens when bacteria infect and inflame your hair follicles. You get pimples and blackheads that can hurt and scar.
- Psoriasis: This happens when your skin cells grow too fast and pile up. You get red, scaly patches that can itch and bleed.
- Atopic dermatitis: This happens when your skin barrier is weak and lets allergens in. You get dry, itchy skin and rashes.
- Lupus erythematosus: This happens when your immune system attacks your own cells and tissues. You get a butterfly-shaped rash on your face, among other problems.
- Melanoma: This happens when a mutation occurs in melanocytes, the cells that make pigment in your skin and hair. They grow out of control and escape natural killer cells, which are immune cells that destroy abnormal cells. This can lead to a deadly form of skin cancer.
What is the role of antigen presenting cells (APCs) in the innate immune system?
Antigen presenting cells (APCs) are a type of white blood cell that can capture and process foreign molecules, such as those from infectious diseases, and present them on their cell surface to activate other immune cells. APCs include macrophages, dendritic cells, and B cells.
How do mast cells contribute to inflammation and allergic reactions?
Mast cells are tissue-resident cells that contain granules rich in histamine and heparin.They are located at the boundaries between tissues and the external environment, such as the skin and mucosal surfaces.
When mast cells encounter an allergen or a pathogen, they release their granules and other molecules that cause inflammation, vasodilation, smooth muscle contraction, mucus secretion, and recruitment of other immune cells.
How do infected cells alert the innate immune system to viral invasion?
Infected cells can produce interferons, which are proteins that interfere with viral replication and spread. Interferons also signal to neighboring cells to increase their antiviral defenses and to natural killer (NK) cells to eliminate infected cells.
Infected cells can also display viral antigens on their cell surface using major histocompatibility complex (MHC) class I molecules, which can be recognized by NK cells or cytotoxic T lymphocytes.
Tips to Help Strengthen Your Skin’s Innate Immunity
Your skin is your shield. It protects you from germs, toxins, and stress.
And it has an innate immunity. It fights off threats before they harm you.
But your skin is not bulletproof. It needs a strong skin barrier.
The skin barrier keeps water in and irritants out. A weak skin barrier causes dryness, itching, inflammation, acne, or infections.
How do you strengthen your skin barrier and immunity?
Here are some tips:
- Use gentle cleansers.
- Don’t strip away your natural oils or disrupt your skin pH
- Apply moisturizers with ceramides.
- Ceramides are lipids that hold your skin barrier together6
- Wear sunscreens with UVA and UVB protection.
- Sun rays damage your DNA and immune system
- Use antioxidants.
- They reduce free radicals and oxidative stress that impair your immunity
- Take probiotics.
- They balance your gut and skin microbes that influence your immunity
These steps improve your skin health and appearance.
But if you want more, you may want to try some aesthetic treatments that revitalize your skin from within.
At SeeBeyond Beauty, we offer treatments that enhance your natural beauty and restore your youthful glow.
You can smooth out wrinkles, lift sagging skin, tighten pores, or contour your face or body.
Book a consultation with us today by calling 914-533-1802 or filling out our online form.
Don’t wait any longer. Your best self is waiting for you at SeeBeyond Beauty.
