Antibodies - class-IX

The immune system, which is made up of special cells, proteins, tissues, and organs, defends people against germs and microorganisms every day. In most cases, the immune system does a great job of keeping people healthy and preventing infections. But sometimes problems with the immune system can lead to illness and infection. The immune system is the body's defense against infectious organisms and other invaders. Through a series of steps called the immune response, the immune system attacks organisms and substances that invade body systems and cause disease.  antibodies can activate a group of proteins called complement that are also part of the immune system. Complement assists in killing bacteria, viruses, or infected cells. All of these specialized cells and parts of the immune system offer the body protection against disease. This protection is called immunity.

An antibody, also known as an immunoglobulin is a large, Y-shaped protein which is produced mainly by plasma cells and it is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. Antibodies are secreted by B lymphocytes of the adaptive immune system, mostly by differentiated B cells called plasma cells. Hence, chemically, an antibody is a protein.

Antibody are produced by B-lymphocytes. The plasma cell /plasma B cells/effector B cell are white blood cells that secrete large volumes of antibodies. Plasma cell originates in the bone marrow.B cell differentiate into a plasma cell that produces antibody molecules. These are transported by the blood plasma and the lymphatic system. Once these are released into the blood and lymph, these antibody molecules bind to the target antigen and initiate its neutralization or destruction.

Immunoglobulin also known as antibodies are glycoprotein molecules produced by plasma cells (white blood cells). They act as a critical part of the immune response by specifically recognizing and binding to particular antigens, such as bacteria or viruses and help in their destruction.The antibody immune response is highly complex and exceedingly specific. Hence, antibodies are complex glycoproteins.

An antibody which belongs to the class of immunoglobulin is a large, Y-shaped protein which is produced mainly by plasma cells and it is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. Antibodies are secreted by B lymphocytes of the adaptive immune system, mostly by differentiated B cells called plasma cells. 

Immunoglobulins, also known as antibodies, are glycoprotein molecules produced by plasma cells (white blood cells). They act as a critical part of the immune response by specifically recognising and binding to particular antigens, such as bacteria or viruses, and aiding in their destruction.
So, the correct option is 'Glycoproteins'

Antibodies (also called immunoglobulins) are large proteins. They are found in the blood or other body fluids of vertebrates. Antibodies are the key element in the adaptive immune system. The antibody recognizes a unique part of the foreign target called an antigen. It is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. Antibody is produced by plasma cells. Antibodies can occur in two physical forms, a soluble form that is secreted from the cell to be free in the blood plasma, and a membrane-bound form that is attached to the surface of a B cell and is referred to as the B-cell receptor (BCR). 

• Body's defence system produces antibodies.
  
• Antibodies are produced when an allergen or a foreign substance enters the human body by the immune system.
• It protects the body from unwanted foreign particles which enter the body.
• So, the correct answer is 'False'.

Mast cells are coated with IgE, which is produced by plasma cells (the antibody-producing cells of the immune system). IgE antibodies are typically specific to one particular antigen. In allergic reactions, mast cells remain inactive until an allergen binds to IgE already coated upon the cell.

Antibodies are the immunoglobulins which are produced in response to the antigen. The immunoglobulin E antibodies or IgE binds to an allergen and trigger the release of inflammatory chemicals such as histamine.
Therefore, the correct answer is option A.

Antibodies are specialized proteins produced by plasma cells (a type of white blood cell) in response to antigens. They are classified as immunoglobulins.

Clone of B-cells is called as plasma cells which produce antibodies. Helper T-cells secrete IL-2 (interleukin-2) which stimulate B cells to produce antibodies. For example iInjection of snake antivenom against snake bite that provides artificially acquired passive immunity. Thus, the correct answer is option A.

An antibody is a type of proteinaceous substance produced by the body's immune system when it detects harmful substances called antigens. Examples of antigens include microorganisms (bacteria, fungi, parasites and viruses) and chemicals. Each type of antibody is unique and defends the body against one specific type of antigen.

An antibody or immunoglobulin is a  proteinaceous compound produced mainly by differentiated plasma cells i.e., B lymphocytes. It is used by the immune system to identify and neutralize pathogens such as bacteria and viruses. Thus, the correct answer is option B.

• Antibodies are the Y-shaped proteinaceous compound. Each is made up of 2 heavy chains and 2 light chains. 
• An antibody is made up of a variable region and a constant region, and the region that changes to various structures depending on differences in antigens is called the variable region, and the region that has a constant structure is called the constant region.
  
  Hence, option A is correct.

The encounter of B cell with a specific antigen activates its clonal expansion which in turn gives rise to plasma cell and memory cells.  Memory cells are the B cells (antibodies) responsible for long-term immunity and confirm the previous encounter of a person with the specific virus. Antigens are foreign substances that induce the immune system to produce antibodies. Disease-causing organisms are called as pathogens. Natural killer cells and macrophages are components of immune system. So, the correct answer is option D.

An antibody is a protein which is produced in response to the antigen by the plasma cells. Antibodies are $\gamma$-globulin proteins that have sugar groups attached to amino acid chains. They can be classified as glycoproteins. These are y-shaped. So, the correct answer is option B.

Plasma cells, also known as plasma B cells or plasmocytes are white blood cells that secrete large volumes of antibodies. They are transported by the blood plasma and the lymphatic system. Plasma cells are originated in the bone marrow, B cells differentiate into plasma cells that produce antibody molecules. Once released into the blood and lymph, these antibody molecules bind to the target antigen (foreign substance) and initiate its neutralization or destruction.

• Immunoglobulin M (IgM) is one of several forms of the antibody that are produced by vertebrates. 
• IgM is the largest antibody, and it is the first antibody to appear in the response to initial exposure to an antigen. 
• IgM can bind to complement component and activate the classical pathway, leading to opsonization of antigens and cytolysis (lysis of foreign cells).
  
• IgG is the most common type of antibody found in blood circulation. IgG molecules are created and released by plasma B cells. 
• Coating of IgG on pathogen surfaces (known as opsonization) allows their recognition and ingestion by phagocytic immune cells leading to the lysis of foreign cells.
  

B cells, also known as B lymphocytes are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system by secreting antibodies. B-cells bind to an antigen, receive help from a cognate helper T cell and differentiate into a plasma cell that secretes large amounts of antibodies.

During an active immune response, the body can produce a massive number of antibodies to combat pathogens. The estimate of 20 trillion is generally cited in immunological literature regarding the total number of antibody molecules produced daily.

An antibody is produced by plasma cell. This plasma cell /plasma B cells/effector B cell are white blood cells that secrete large volumes of antibodies. Plasma cell originates in the bone marrow. B cell differentiate into a plasma cell that produces antibody molecules. These are transported by the blood plasma and the lymphatic system. Once these are released into the blood and lymph, these antibody molecules bind to the target antigen and initiate its neutralization or destruction.

Immunoglobulin E (IgE) is a type of antibody that has been found only in mammals. IgE is synthesised by plasma cells. IgE has an essential role in type I hypersensitivity (allergy) which includes allergic diseases, such as allergic asthma, sinusitis, allergic rhinitis, food allergies, and specific types of chronic urticaria and atopic dermatitis.

An antibody, also known as an immunoglobulin is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. Antibodies are secreted by B lymphocytes of the adaptive immune system, mostly by differentiated B cells called plasma cells. Lymphocyte is a type of WBC. Hence, Antibody is formed by WBC.

Globulins are immune molecules that are produced by the immune system in response to the invasion of the body of agents that are perceived by the system as being foreign. Gamma globulins belong to the class of globulins. Most significant globulins are immunoglobulins. Gamma globulins are synthesized in cells of the immune system known as lymphocytes, lymph nodes, lymph and plasma cells. 

Immunoglobulin G (IgG) is a type of antibody., representing approximately 75% of serum antibodies in humans, IgG is the most common type of antibody found in blood circulation. The primary immunoglobulin of the newborn is the maternal IgG as this is the only immunoglobulin to cross the placental barrier. Hence, IgG is the immunoglobulin which is found in the serum of newborn babies.

Antibodies bind antigens through weak chemical interactions, and bonding is essentially non-covalent. Electrostatic interactions, hydrogen bonds, van der Waals forces, and hydrophobic interactions are all known to be involved depending on the interaction sites.

An antibody, also known as an immunoglobulin (Ig) is a large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. Antibodies or immunoglobulins provides resistance against disease by neutralising antigens which are responsible for the disease. Antibodies are secreted by B-lymphocytes, mostly by differentiated B cells called plasma cells.

Immunoglobulin M (IgM) is one of several forms of the antibody that are produced by vertebrates. IgM is the largest antibody, and it is the first antibody to appear in the response to initial exposure to an antigen. Spleen and plasma cells are the major sites of specific IgM production. IgM antibodies do not pass across the human placenta.

An antibody, also known as an immunoglobulin is a large, Y-shaped protein which is produced mainly by plasma cells and it is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses. Antibodies are secreted by B lymphocytes of the adaptive immune system, mostly by differentiated B cells called plasma cells. 

Antibodies are produced by specialized white blood cells called B lymphocytes/ B-cells. When an antigen binds to the B-cell surface, it stimulates the B cell to divide and mature into a group of identical cells called a clone. The mature B cells,called plasma cells, secrete millions of antibodies into the bloodstream and lymphatic system. Hence antibodies are secreted from lymphocytes.

Immunoglobulin A is an antibody that plays a crucial role in the immune function of mucous membranes. The amount of IgA produced in association with mucosal membranes is greater than all other types of antibody combined. It is the main immunoglobulin found in mucous secretions, including tears, saliva, sweat, colostrum and secretions from the genitourinary tract, gastrointestinal tract, prostate and respiratory epithelium. It is also found in small amounts in the blood. Hence it provides immunity to the digestive tract as it is made up of a mucous membrane.

Immunoglobulin E (IgE) is a type of antibody that has only been found in mammals. IgE is synthesised by plasma cells. It plays an essential role in type I hypersensitivity, which manifests in various allergic diseases, such as allergic asthma, rhinitis etc. It also plays a pivotal role in responses to allergens, such as anaphylactic drugs, bee stings, and antigen preparations used in desensitization immunotherapy.

An antibody is produced by plasma cell. The B-Lymphocytes are white blood cells that secrete large volumes of antibodies. Plasma cell originates in the bone marrow. B cell differentiate into a plasma cell that produces antibody molecules. These are transported by the blood plasma and the lymphatic system. Once these are released into the blood and lymph, these antibody molecules bind to the target antigen and initiate its neutralization or destruction.

Immunoglobulin M (IgM) is one of several forms of the antibody that are produced by vertebrates. IgM is the largest antibody and it is the first antibody to appear in the response to initial exposure to an antigen. On the basis of its sedimentation velocity and appearance in electron micrographs, it was inferred that IgM is mostly a pentamer i.e., a polymer composed of five monomers.

• In response to an allergy, IgE is secreted and circulates in the blood and binds to an IgE-specific receptor on the surface of other kinds of immune cells called mast cells and basophils, which are both involved in the acute inflammatory response.
•  The IgE-coated cells, at this stage, are sensitized to the allergen. 
• Hence, IgG and mast cells are involved in an allergic reaction.
• So, the correct answer is 'IgG and mast cells'.

• Immunoglobulin A (IgA) is an antibody that plays a crucial role in the immune function of mucous membranes.
• Colostrum is a milky fluid that comes from the breasts of humans, cows, and other mammals the first few days after giving birth before true milk appears.
• Immunoglobulin abundant in colostrum is IgA in the form of secretory IgA or sIgA. Much of these are produced by plasma cells in the mammary tissue.
• So, the correct answer is 'IgA'.

Immunoglobulin M (IgM) is one of several forms of the antibody that are produced by vertebrates. IgM is the largest antibody and it is the first antibody to appear in the response to initial exposure to an antigen in the blood. IgM antibodies appear early in the course of an infection and usually reappear to a lesser extent after further exposure to the same antigen. IgM antibodies do not pass across the human placenta.

The thymus gland, despite containing glandular tissue and producing several hormones, is much more closely associated with the immune system than with the endocrine system. The thymus serves a vital role in the training and development of T-lymphocytes or T cells, an extremely important type of white blood cell. T cells defend the body from potentially deadly pathogens such as bacteria, viruses, and fungi. The function of the thymus is to receive immature T cells that are produced in the red bone marrow and train them into functional, mature T cells that attack only foreign cells. T cells first reside within the cortex of the thymus where they come in contact with epithelial cells presenting various antigens. The immature T cells that respond to the antigens corresponding to foreign cells are selected to survive, mature, and migrate to the medulla while the rest die via apoptosis and are cleaned up by macrophages.

The classical pathway of the complement system is triggered specifically by the binding of C1q to antigen-antibody complexes (specifically IgG or IgM).

Antibodies are secreted by cells of the adaptive immune system; B cells, which are formed by the differentiation of the plasma cells. B lymphocytes have antibodies attached to them. Once they detect an antigen, they transform into plasma cells and secrete antibodies until the immune response is over. 

If the identical antibodies are produced by the single clone of cells such antibodies are called as monoclonal antibodies. They are clones or single type but they are target specific. Each monoclonal antibody recognizes one particular protein (antigen). They work in different ways depending on the protein they are targeting. Thus, the correct answer is option B.

In the blood, the antigens are specifically and with high affinity bound by antibodies to form an antigen-antibody complex. The antigenic determinant or epitope is recognized by the paratope of an antibody, situated at the variable region of the polypeptide chain.

A. Anti-snake venom is made by collecting venom from the snake and injecting small amounts of it usually into a horse. The antibodies that form in the horse blood are then collected and used to treat a snake bite case by injecting directly to the affected person.
B. Antibodies against smallpox are produced by B-lymphocytes.
C. Antibodies contain 2 light chains and 2 heavy chains.
D. Rejection of a kidney graft is a function of T-lymphocytes.

Monoclonal antibodies are produced by a single clone of B-cells (single parent type) and are specific to a single epitope on an antigen.