Adaptive, Specific Immunity And Immunization

Lymphocyte specificity refers to the ability of lymphocytes to recognize and respond to specific antigens. This specificity is determined by the genetic makeup of lymphocytes before any antigen enters the system. Each genetically different lymphocyte expresses a single specificity. When a new antigen is introduced into the immune system, it selects a genetically distinct lymphocyte that can recognize and react to that antigen. This selected lymphocyte then expands into a clone of cells that can specifically respond to the antigen. This process occurs in both B cells, which stay in the bone marrow, and T cells, which migrate to the thymus and then to secondary lymphoid tissue.

Lymphocytes, specifically T and B cells, are cells of the immune system that produce antibodies in response to antigens. These antibodies are specific to the antigen that triggered their production. This means that they are programmed to "recall" their first encounter with the antigen and respond rapidly to subsequent encounters. This memory response allows the immune system to mount a faster and more effective defense against the same antigen if it is encountered again in the future.

The Clonal Selection Theory states that lymphocytes, a type of white blood cell, use 500 genes to produce a wide variety of specific receptors. These receptors allow lymphocytes to recognize and bind to antigens. Undifferentiated lymphocytes undergo a continuous series of divisions and genetic changes, resulting in the generation of millions of different cell types, each with a unique receptor specificity. This diversity allows the immune system to effectively recognize and respond to a wide range of antigens.

Artificial immunity is acquired through a medical procedure such as a vaccine. This means that a person is deliberately exposed to a weakened or killed form of a pathogen, which stimulates the immune system to produce an immune response. The vaccine introduces antigens to the body, triggering the production of antibodies that provide protection against future infections. This type of immunity does not create memory, acts immediately, and is short-term. It is different from natural immunity, which is acquired through normal life experiences such as getting an infection and recovering from it.

The correct answer is "regulatory receptors found on macrophages, dendritic cells, and B cells." This answer is supported by the information provided in the passage, which states that Class II markers are required for T lymphocytes and are involved in presenting antigen to T-cells. The passage also mentions that Class II markers display unique characteristics of self molecules and regulate immune reactions. Therefore, it can be inferred that these markers are found on macrophages, dendritic cells, and B cells, as these cells are involved in presenting antigens to T-cells and regulating immune reactions.

Lymphocytic stem cells in the bone marrow have the ability to differentiate into either T or B cells. B cells remain in the bone marrow, while T cells migrate to the thymus. Both T and B cells then migrate to secondary lymphoid tissue. This process is important for the development of lymphocyte specificity, as each genetically different type of lymphocyte expresses a single specificity. The first introduction of an antigen into the immune system selects a genetically distinct lymphocyte, causing it to expand into a clone of cells that can react to that specific antigen.

Natural immunity refers to the immunity that is acquired through normal life experiences. This means that the individual has been exposed to various pathogens and has developed antibodies against them, providing protection against future infections. Unlike immunity acquired through medical procedures such as vaccines, natural immunity does not involve the donation of preformed antibodies. It is also important to note that natural immunity does not create memory, acts immediately, and is short term.

Artificial passive immunity refers to the transfer of specific antibodies from one individual to another. In this case, the correct answer states that it is acquired through the administration of a preparation containing specific antibodies. This means that the antibodies are obtained from an external source, such as through injection or infusion of a serum or immunoglobulin containing the desired antibodies. This method provides immediate protection against the targeted antigen, but the immunity is temporary as the transferred antibodies eventually degrade and are eliminated from the body.

Natural passive immunity is acquired when an individual receives antibodies from another source, rather than producing them themselves. In the case of a child, they can acquire passive immunity through the transfer of antibodies from their mother through the placenta during pregnancy and through breast milk after birth. This provides the child with temporary protection against certain diseases until their own immune system develops fully.

The explanation provided describes the development of receptors in B cells. It states that immunoglobulin genes are located on three different chromosomes and that undifferentiated lymphocytes have multiple genes for the variable regions of light and heavy chains. During development, recombination occurs to activate only the selected V and D genes in mature cells. Once synthesized, immunoglobulins are transported to the cell membrane and inserted as receptors.

Passive immunity is the transfer of preformed antibodies to an individual. This process does not stimulate the production of antibodies or create memory in the recipient. Instead, the preformed antibodies immediately act to provide temporary protection against the antigen. This type of immunity is short-term and is typically acquired through external sources, such as receiving antibodies from another person or through medical interventions like immunoglobulin therapy.

Cell receptors or markers play a crucial role in conferring specificity and identity to a cell. These receptors are responsible for recognizing and binding to specific molecules or antigens, which then trigger a response from the immune system. By interacting with these receptors, cells can differentiate between self and non-self molecules, allowing the immune system to target and eliminate foreign invaders while sparing healthy cells. Therefore, the presence of cell receptors or markers is essential for the development and functioning of the immune response system.

Antibodies are proteins produced by B cells in response to a specific antigen. These antibodies are highly specific and are designed to bind only to the antigen that triggered their production. This specificity allows antibodies to target and neutralize the specific antigen, preventing it from causing harm in the body. Therefore, antibodies function only against the antigen that they were produced in response to.

The correct answer includes the major functions of receptors in the immune system, which are to perceive and attach to nonself or foreign molecules, promote the recognition of self molecules, receive and transmit chemical messages among other cells, and aid in cellular development. This answer also mentions the development and differentiation of the immune system, lymphocytes and antigen processing, the cooperation between lymphocytes during antigen presentation, and the production and actions of antibodies by B lymphocytes and T lymphocyte responses. These topics are all related to specific immune responses and are important for understanding how the immune system functions.

B-cell receptors are large glycoproteins that serve as specific receptors of B cells. They are composed of 4 polypeptide chains, 2 identical heavy chains (H) and 2 identical light chains (L). The arrangement of these chains forms a Y shape, with the ends of the forks containing a wide range of variable antigen binding sites. These variable regions allow the B-cell receptor to recognize and bind to specific antigens. The constant regions of the receptor provide stability and structural support. The genes responsible for the synthesis of these receptors are located on different chromosomes and undergo recombination during B-cell development to generate a diverse repertoire of receptors. Once synthesized, the immunoglobulin is transported to the cell membrane and inserted there to act as a receptor.

Antigens are molecules that stimulate a response by T and B cells. They are recognized by these cells as foreign substances and trigger an immune response. T cells and B cells are programmed to "recall" their first encounter with an antigen and respond rapidly to subsequent encounters. This response includes the production of antibodies, which function only against the specific antigen that they were produced in response to. Therefore, antigens play a crucial role in activating the immune system and initiating an immune response.

Lymphocytes play a crucial role in the immune system's surveillance and recognition of foreign substances. This is possible due to the specific receptors found on the surface of lymphocytes. B-cell receptors are responsible for binding free antigens, while T-cell receptors bind processed antigens along with major histocompatibility complex (MHC) molecules on antigen-presenting cells. These receptors allow lymphocytes to identify and respond to different types of antigens, contributing to the body's defense against pathogens and foreign substances.

The major histocompatibility complex (MHC) is a group of genes that encode for receptors found on all cells except red blood cells (RBCs). These receptors, also known as human leukocyte antigen (HLA), play a crucial role in the recognition of self by the immune system and in the rejection of foreign tissue. The MHC genes are clustered together in a multigene complex.

Active immunity is the result of a person being exposed to an antigen, which then stimulates the production of antibodies. This process takes time and creates a memory response, meaning that the immune system will remember how to fight off that specific antigen in the future. Active immunity is acquired through normal life experiences, such as getting sick or receiving vaccines. This type of immunity is long-lasting and provides protection against future infections.

The correct answer is "markers that display unique characteristics of self molecules and regulation of immune reactions. Required for T lymphocytes." This answer accurately describes the function of the markers in question. These markers play a crucial role in the immune system by identifying self molecules and regulating immune reactions. They are specifically required for T lymphocytes, which are a type of white blood cell involved in the immune response.

Receptors have multiple functions in the body. They are responsible for perceiving and attaching to nonself or foreign molecules, promoting the recognition of self molecules, receiving and transmitting chemical messages among other cells of the system, and aiding in cellular development. These functions allow receptors to play a crucial role in the immune system's recognition of foreign substances and in the communication between cells.

Artificial active immunity is acquired through inoculation with a selected antigen (Ag). This means that a person is deliberately exposed to a specific antigen, usually through vaccination, in order to stimulate their immune system to produce a response and develop immunity against that particular antigen. This type of immunity is different from the administration of a preparation containing specific antibodies, as it relies on the body's own immune response to generate long-term protection. It is also distinct from immunity acquired by a child through placenta and breast milk, which is a form of passive immunity.

Natural active immunity is acquired upon infection and recovery. When a person is infected with a pathogen, their immune system responds by producing antibodies and memory cells that provide long-term protection against future infections from the same pathogen. This type of immunity is considered natural because it occurs as a result of natural exposure to the pathogen. In contrast, artificial active immunity is acquired through inoculation with a selected antigen, such as a vaccine.

The correct answer is that genes for MHC are clustered in a multigene complex. MHC (Major Histocompatibility Complex) is a group of genes that play a crucial role in the immune system's recognition of self and rejection of foreign tissue. These genes are closely located together in a specific region of the genome known as a multigene complex. This clustering allows for coordinated regulation and expression of the MHC genes, which is important for their proper functioning in immune responses.