Immunity

Humoral Immunity

by Pduran 15 June 2023

How your body fights off germs with a special type of immunity

Imagine you are exposed to a germ that lives outside your cells, such as a bacterium or a parasite. How does your body detect and destroy this germ before it causes an infection or a disease? The answer lies in a special type of immunity that your body develops over time, called humoral immunity.

Humoral immunity is a part of your immune system, which is your body’s defense system against harmful substances and organisms, such as bacteria, viruses, fungi, parasites, and even cancer cells. Your immune system has two main types: innate immunity and humoral immunity. Innate immunity is the immunity that you are born with. It consists of physical barriers, such as your skin and mucous membranes, and general immune cells, such as phagocytes and natural killer cells, that can recognize and destroy common types of germs. Innate immunity is fast and effective, but it is not very specific or long-lasting.

Humoral immunity is the immunity that you acquire during your lifetime. It consists of specialized immune cells and molecules that can recognize and eliminate specific types of germs and tumor cells. Humoral immunity is slower and more complex than innate immunity, but it is more specific and long-lasting. Humoral immunity works by using antibodies, which are proteins produced by B cells that can stick to specific antigens on the surface of germs or their toxins. Antigens are any substances that trigger an immune response. Antibodies can neutralize the germs or mark them for destruction by other immune cells. Humoral immunity is especially good at fighting off germs that live outside your cells, such as bacteria and parasites.

Humoral immunity requires the activation of naive B cells by antigen-presenting cells (APCs), such as dendritic cells, macrophages, and B cells. APCs capture and process antigens from germs or their products and present them to naive B cells in the lymph nodes or other organs. Naive B cells are B cells that have not encountered their specific antigen yet. When a naive B cell binds to its specific antigen on an APC, it becomes activated and multiplies into many copies of itself. Some of these copies become plasma cells that produce large amounts of antibodies against the antigen, while others become memory B cells that can remember and respond faster and stronger to the same antigen in the future.

Humoral immunity is important because it provides us with a lasting defense system that can be used against new and varying germs. The diversity of antibodies is generated by a process called somatic recombination, which randomly shuffles and rearranges segments of genes that encode these molecules in developing B cells. This process creates millions of different combinations of antibody specificities that can recognize virtually any antigen. Moreover, some B cells undergo somatic hypermutation, which introduces small changes in the antibody genes at a high rate, resulting in antibodies with higher affinity for the antigen.

Humoral immunity is also regulated by various mechanisms to prevent excessive or inappropriate responses that could harm us. For example, some antibodies act as feedback inhibitors that bind to receptors on B cells and inhibit their activation or growth. Additionally, some cytokines act as anti-inflammatory agents that modulate the intensity and duration of the immune response.

In summary, humoral immunity is a sophisticated and dynamic system that protects us from a variety of germs and tumors. It involves specialized immune cells and molecules that recognize and eliminate foreign antigens with high specificity and memory. It also involves genetic mechanisms that generate diversity and regulation of the immune response.

Reference Links

Humoral immunity – Wikipedia – This article provides an overview of humoral immunity, its history, components, functions, and mechanisms. It also explains how humoral immunity differs from cell-mediated immunity and innate immunity.
Humoral Immunity – The Definitive Guide | Biology Dictionary – This article gives a detailed explanation of humoral immunity, its role in fighting off germs that live outside the cells, and its various immune cells and molecules. It also provides examples and illustrations to help understand the concepts.
The Humoral Immune Response – Immunobiology – NCBI Bookshelf – This article describes the humoral immune response in depth, including the activation of B cells by antigens and antigen-presenting cells, the production and secretion of antibodies by plasma cells, the diversity and regulation of antibodies, and the effector functions of antibodies.

Cell-mediated Immunity Immunity

Cell-mediated Immunity

by Pduran 9 June 2023

How your body kills infected cells with a special type of immunity

Imagine you are infected with a virus that invades your cells and uses them to make more copies of itself. How does your body detect and destroy these infected cells before they spread the virus to other cells? The answer lies in a special type of immunity that your body develops over time, called cell-mediated immunity.

Cell-mediated immunity is a part of your immune system, which is your body’s defense system against harmful substances and organisms, such as bacteria, viruses, fungi, parasites, and even cancer cells. Your immune system has two main types: innate immunity and cell-mediated immunity.

Innate immunity is the immunity that you are born with. It consists of physical barriers, such as your skin and mucous membranes, and general immune cells, such as phagocytes and natural killer cells, that can recognize and destroy common types of germs. Innate immunity is fast and effective, but it is not very specific or long-lasting.

Cell-mediated immunity is the immunity that you acquire during your lifetime. It consists of specialized immune cells and molecules that can recognize and eliminate specific types of germs and tumor cells. Cell-mediated immunity is slower and more complex than innate immunity, but it is more specific and long-lasting.

Cell-mediated immunity works by using T cells, which are a type of immune cells that can recognize and kill infected or abnormal cells. T cells have receptors on their surface that can bind to antigens presented by other cells. Antigens are any substances that trigger an immune response. T cells can either help other immune cells by secreting chemicals called cytokines, or directly kill infected or abnormal cells by releasing substances that create holes and trigger cell death. Cell-mediated immunity is especially good at fighting off germs that live inside your cells, such as viruses and some bacteria.

Cell-mediated immunity requires the activation of naive T cells by antigen-presenting cells (APCs), such as dendritic cells, macrophages, and B cells. APCs capture and process antigens from germs or their products and present them to naive T cells in the lymph nodes or other organs. Naive T cells are T cells that have not encountered their specific antigen yet. When a naive T cell binds to its specific antigen on an APC, it becomes activated and multiplies into many copies of itself. Some of these copies become effector T cells that carry out the immune response against the germ, while others become memory T cells that can remember and respond faster and stronger to the same antigen in the future.

Cell-mediated immunity is important because it provides us with a lasting defense system that can be used against new and varying germs. The diversity of T cell receptors is generated by a process called somatic recombination, which randomly shuffles and rearranges segments of genes that encode these molecules in developing T cells. This process creates millions of different combinations of T cell receptor specificities that can recognize virtually any antigen. Moreover, some T cells undergo somatic hypermutation, which introduces small changes in the T cell receptor genes at a high rate, resulting in T cells with higher affinity for the antigen.

Cell-mediated immunity is also regulated by various mechanisms to prevent excessive or inappropriate responses that could harm us. For example, some T cells act as regulatory T cells that suppress the activity of other immune cells to maintain tolerance to our own antigens and prevent autoimmune diseases. Additionally, some cytokines act as anti-inflammatory agents that modulate the intensity and duration of the immune response.

In summary, cell-mediated immunity is a sophisticated and dynamic system that protects us from a variety of germs and tumors. It involves specialized immune cells and molecules that recognize and eliminate foreign antigens with high specificity and memory. It also involves genetic mechanisms that generate diversity and regulation of the immune response.

Reference Links

• Cell-mediated immunity – Wikipedia – This article provides an overview of cell-mediated immunity, its history, components, functions, and mechanisms. It also explains how cell-mediated immunity differs from humoral immunity and innate immunity.

• 14.1: Cell-Mediated Immunity – An Overview – Biology LibreTexts – This article gives a detailed explanation of cell-mediated immunity, its role in fighting off germs that live inside the cells, and its various immune cells and molecules. It also provides examples and illustrations to help understand the concepts.

• Cell-mediated Immunity | Pathway Medicine – This article describes the cell-mediated immunity in depth, including the activation of T cells by antigens and antigen-presenting cells, the production and secretion of cytokines by helper T cells, and the killing of infected or abnormal cells by cytotoxic T cells.

Immunity Innate Immunity

Innate Immunity – How your body defends itself

by Pduran 3 June 2023

How your body defends itself with a special type of immunity

Imagine you are walking in the park and you get a cut on your finger. How does your body prevent the wound from getting infected by germs that are everywhere in the environment? The answer lies in a special type of immunity that you are born with, called innate immunity.

Innate immunity is a part of your immune system, which is your body’s defense system against harmful substances and organisms, such as bacteria, viruses, fungi, parasites, and even cancer cells. Your immune system consists of various cells and molecules that work together to protect you from infections and diseases. Your immune system has two main types: innate immunity and adaptive immunity.

Innate immunity is the immunity that you are born with. It consists of physical barriers, such as your skin and mucous membranes, and general immune cells and molecules, such as phagocytes, natural killer cells, complement proteins, cytokines, and interferons, that can recognize and destroy common types of germs. Innate immunity is fast and effective, but it is not very specific or long-lasting.

Innate immunity works by using different mechanisms to prevent or limit the entry of germs into your body, or to eliminate them if they manage to get in. These mechanisms include:

• Physical barriers, such as your skin and mucous membranes, that act as the first line of defense against germs. They prevent most germs from entering your body or reaching your internal organs. They also produce substances that can kill or inhibit germs, such as sweat, saliva, tears, mucus, stomach acid, and enzymes.

• Inflammation, which is a process that occurs when your tissues are damaged or infected by germs. It involves the dilation of blood vessels, the increase of blood flow, the leakage of fluid and immune cells into the affected area, and the production of chemical signals that attract more immune cells and molecules. Inflammation helps to isolate and destroy germs, remove dead cells and debris, and promote healing.

• Phagocytosis, which is a process that involves certain immune cells called phagocytes that can engulf and digest germs and other foreign particles. Phagocytes include neutrophils, monocytes, macrophages, dendritic cells, and mast cells. Phagocytes can also present parts of the germs to other immune cells to trigger an adaptive immune response.

• Natural killer cells, which are a type of immune cells that can recognize and kill infected or abnormal cells. Natural killer cells have receptors on their surface that can bind to molecules on the surface of other cells. If these molecules indicate that the cell is infected by a virus or transformed by cancer, natural killer cells release substances that create holes and trigger cell death.

• Complement system, which is a group of proteins that circulate in your blood and can be activated by germs or antibodies. The complement system can enhance the activity of phagocytes and natural killer cells by coating or marking germs for destruction. It can also form pores on the surface of germs and cause them to burst.

• Cytokines and interferons, which are chemical signals that help the immune system communicate and coordinate its actions. Cytokines can stimulate or inhibit the growth and activity of various immune cells and molecules. Interferons are a type of cytokines that can interfere with viral replication and activate other immune cells.

Innate immunity is important because it provides us with a quick and general defense against germs that we encounter every day. It also helps to activate the adaptive immune system, which is a more specific and long-lasting type of immunity that we acquire during our lifetime.

In summary, innate immunity is a basic and essential system that protects us from a variety of germs and tumors. It involves physical barriers and general immune cells and molecules that recognize and eliminate foreign substances with low specificity and memory. It also involves inflammatory processes that help to control infections and promote healing.

• Innate immune system – Wikipedia – This article provides an overview of the innate immune system, its components, functions, and mechanisms. It also explains how the innate immune system interacts with the adaptive immune system and how it differs from other types of immunity.

• Innate immunity (article) | Immune system | Khan Academy – This article gives a detailed explanation of the innate immune system, its role in defending the body from germs, and its various physical barriers and general immune cells and molecules. It also provides examples and illustrations to help understand the concepts.

• The innate and adaptive immune systems – InformedHealth.org – NCBI Bookshelf – This article compares and contrasts the innate and adaptive immune systems, their advantages and disadvantages, and their cooperation and regulation. It also describes some common diseases and disorders that affect the immune system.

Immunity Immunotherapy

Immunotherapy: How your body can fight cancer with a special type of treatment

by Pduran 28 May 2023

How your body can fight cancer with a special type of treatment

Imagine you have cancer, a disease that occurs when abnormal cells grow out of control and invade other parts of your body. How can you treat this disease and stop it from spreading? One of the options you may have is immunotherapy, a special type of treatment that uses your body’s own immune system to fight cancer.

Your immune system is your body’s defense system against harmful substances and organisms, such as bacteria, viruses, fungi, parasites, and even cancer cells. Your immune system consists of various cells and molecules that work together to protect you from infections and diseases. However, sometimes your immune system fails to recognize or destroy cancer cells, or it is weakened by the cancer itself or by other treatments.

Immunotherapy is a type of treatment that helps your immune system to better act against cancer. It can either boost your immune system’s natural ability to fight cancer, or it can give your immune system new tools to find and attack cancer cells.

There are several types of immunotherapy that are used to treat different kinds of cancer. These include:

• Immune checkpoint inhibitors, which are drugs that block certain proteins on the surface of immune cells or cancer cells. These proteins normally act as brakes or checkpoints that prevent the immune system from attacking normal cells. By blocking them, these drugs allow the immune system to unleash a stronger response against cancer cells. For example, some drugs block a protein called PD-1 on immune cells called T cells, or a protein called PD-L1 on cancer cells. These drugs are used to treat cancers such as melanoma, lung cancer, kidney cancer, bladder cancer, and head and neck cancer.

• T-cell transfer therapy, which is a treatment that boosts the natural ability of your T cells to fight cancer. In this treatment, T cells are taken from your tumor or blood. Those that are most active against your cancer are selected or changed in the lab to better attack your cancer cells. They are then grown in large numbers and put back into your body through a vein. This treatment may also be called adoptive cell therapy or CAR T-cell therapy. It is used to treat cancers such as leukemia and lymphoma.

• Monoclonal antibodies, which are immune system proteins made in the lab that are designed to bind to specific targets on cancer cells. Some monoclonal antibodies mark cancer cells so that they will be better seen and destroyed by the immune system. Others block signals that help cancer cells grow and survive. Others carry drugs or radioactive substances that kill cancer cells directly. Monoclonal antibodies are used to treat cancers such as breast cancer, colorectal cancer, lymphoma, and leukemia.

• Cancer vaccines, which are substances that stimulate the immune system to recognize and attack specific antigens on cancer cells. Antigens are any substances that trigger an immune response. Some vaccines are made from killed or weakened cancer cells or parts of them. Others are made from proteins or peptides that mimic antigens on cancer cells. Cancer vaccines can be used to prevent cancers caused by certain viruses, such as cervical cancer caused by human papillomavirus (HPV), or to treat cancers that have already developed, such as prostate cancer.

• Cytokines, which are chemicals that help the immune system communicate and coordinate its actions. Some cytokines boost the activity and growth of immune cells, while others slow them down or change their function. Cytokines can be given as drugs or produced by genetically modified immune cells or tumors. Cytokines are used to treat cancers such as kidney cancer, melanoma, and lymphoma.

Immunotherapy can be given alone or in combination with other treatments, such as surgery, chemotherapy, radiation therapy, or targeted therapy. It can be given through different ways, such as injections under the skin or into a muscle, infusions into a vein, pills or capsules taken by mouth, creams applied on the skin, or implants placed under the skin.

Immunotherapy can have different effects on different people and different cancers. Some people may have a complete response, meaning that their cancer disappears completely. Others may have a partial response, meaning that their cancer shrinks but does not go away completely. Others may have stable disease, meaning that their cancer does not grow or shrink but stays the same. Others may have progressive disease, meaning that their cancer grows or spreads despite the treatment.

Immunotherapy can also cause side effects that vary depending on the type of immunotherapy and the person receiving it. Some common side effects include fatigue, fever, chills, nausea, vomiting, diarrhea, skin rash, itching, pain, swelling, inflammation, infection, and allergic reactions.
Some rare but serious side effects include autoimmune reactions, where the immune system attacks normal organs and tissues, such as the lungs, liver, kidneys, thyroid, heart, brain, or nerves.
These side effects can be mild or severe, and may occur soon after starting the treatment or months later.
They may require additional drugs to suppress the immune system or stop the immunotherapy.

Immunotherapy is an exciting and promising field of research and treatment for many types of cancer. It offers new hope for people who have cancers that do not respond well to other treatments or who have cancers that come back after other treatments. It also offers new insights into how the immune system works and how it can be harnessed to fight diseases. However. immunotherapy is not a cure for all cancersand it does not work for everyone. More research is needed to understand how immunotherapy works and how it can be improved and combined with other treatments to achieve better outcomes for more people with cancer.

Load More Posts