Unit 37

Acquired Immune System – Specific for distinct pathogens and the ability to create immunological memory; requires presentation of foreign antigens by antigen presenting cells(Rodriguez, 2014, p. 86).

Adaptive immunity (p.446): The body’s ability to recognize and defend itself against distinct invaders and their products.

Active immunizing agents stimulate the body to make its own antibodies and to continue on making them, the

Human beings are born with immunity as well as they acquire it from the environment they grow in. Human innate immunity is assigned the task to hinder the harmful substances from entering the body. These immunity barriers develop a defense line. The innate immunity includes cough, tear enzymes, mucus, skin and the stomach acid. Hence, the role of innate immune system is to stop harmful materials from entering our body. In case the innate immunity is insufficient to fight, there is acquired immunity that fights harmful substances by getting exposed to various antigens. The acquired immunity is developed against specific antigen. Its role is to fight

IgG antibodies are monomers that provide long-term protection against viruses, bacteria, and toxins by triggering immune protein production cascades and binding to antigens to increase the effectiveness of phagocytosis. The second subclass is the immunoglobulin A (IgA) which are monomers joined together that primarily bind to antigens on microbes before they can invade the tissues. IgA antibodies are found most commonly in mucous membranes (like those lining the gastrointestinal and respiratory tracts) and body secretions like breast milk and tears. Immunoglobulin M (IgM) is the third subclass that are large and found mainly in the lymph fluid and blood. Additionally, IgM are involved in the ABO blood group antigens on the outer surface of red blood cells. The fourth subclass is immunoglobulin D (IgD), which are monomers that exist in small amounts. Their function is not entirely known, but they are found in the lymph fluid, the blood, and on the surface of B cells. The last subclass is immunoglobulin E (IgE) which are associated with allergic reactions and are found in the lungs, skin, and mucous membranes. When an antigen binds to this kind of antibody, the mast cell or basophil releases

The vaccine given to the children contained live but sufficiently weakened or attenuated viruses to stimulate immune response. The capacity to stimulate immune response was from the ability of human immune system to distinguish non-self cells that carry epitopes. First, the immune B cells with antibody would bind and engulf to process the attenuated virus. Then, helper T cells would bind to the processed virus and form plasma cell. The plasma cells then stimulate the production of more antibodies to mark virus for destruction. After destruction, some of the B cells and helper T cells left form memory cells to produce immediate response to 2nd attack of the same viruses.

The immune system utilizes vaccination as a method of triggering the immune system. Small doses of an antigen, such as either a dead or a weakened live virus, are then given to activate immune system “memory” (activated B cells and sensitized T cells), Memory allows the human body to react quickly and efficiently to future exposures with the pathogen. Through the use of the specific immune system, the immune system will develop a defence against the invading virus.

I understand how create representations and models to describe immune responses. There are two main types of immune responses; primary and secondary. Primary is the first time a response occurs in the presence of an antigen while secondary refers to a response after the initial. Both may be modeled by showing examples of an antigen and the respective secondary/primary response. (Campbell 719-720)

The ebook, Focus on Pharmacology, explains on page 114 that the active immunity is acquired immunity. And Google dictionary states that this acquired immunity is from either the development of antibodies as a response to antigen exposure (1) from vaccination or (2) an attack of an infectious disease. Whereas passive immunity is the result of the introduction of antibodies from another person or animal. The example given in the ebook is of a mother exposing the fetus or when the mother breastfeeds her infant. One major difference between them is that passive immunity is much quicker but the duration is a lot shorter than the active immunity.

The immune system is a complex bodily system involving multiple organs, tissues and cells. What exactly is immunity? Immunity is the state of protection against infectious disease conferred either through an immune response generated by immunization or previous infection or by other non-immunological factors (Baxter, 2007, p. 552). Immunity can be broken into two major categories, innate and adaptive immunity. The innate and adaptive immunity both play a vital role when it comes to the immune systems function and health.

Adaptive, or acquired, immunity refers to antigen-specific defence mechanisms that take several days to become protective and are designed to react with and remove a specific antigen. This is immunity develops throughout life.

Innate immunity refers to the defence mechanisms that are already available prior to the exposure of a pathogen. Therefore, once the body is exposed to a pathogen, the innate immune system can respond swiftly and attack the microorganism, preventing damage to the body. Innate immunity includes: the skin, stomach acid and mucus membranes. If the pathogen still manages to enter the body, then leukocytes within the blood can attack the pathogen. Phagocytes are the main

Autoimmunity is an immune response directed against an antigen within the body of the host. The definition does not distinguish whether the response is innate or acquired and, if acquired, whether it is induced by a foreign or autochthonous antigen. It usually involves both T-cell and B-cell responses. It only requires that the immune response be directed to a

The immune system is comprised of two responses: the adaptive immune response and the innate immune response. The first line of defence against invading organisms is classified as the innate immune response and the second line of defence and protection against re- exposure to the same pathogen is known as the adaptive immune response.

Whilst this is occurring, memory B cells figure out the shape of the antigen and remember it. This allows the B cells to produce antibodies much faster if the pathogen reinfects the person. The problem with the human immune system is that it takes approximately three weeks to reach peak antibody concentration and remove all of the pathogens in the body. Many pathogenic diseases (tetanus, polio, meningococcal etc) will kill the individual before the 3rd line of defence has the chance to destroy them. Vaccination involves injecting antigens (in the form of attenuated pathogens or pathogen parts) into the body. This causes the same immune response that would occur if the individual was infected with the actual disease; however, because the pathogens have been weakened (or killed) and had their reproductive ability inhibited, they cannot kill. This means that If the individual is infected by the pathogen in the future, he/she is extremely unlikely to get the disease (RNA based viruses such as Influenza are exempt from this due to their antigenic shift/drift ability). The use of repeated vaccination (eg. vaccination for a particular disease at two, four and six years of age) enhances the immune system even more.