memory cell

Examples of memory cell in the following topics:

• Making Memory B Cells

  • Memory B cells are a B cell sub-type that are formed following primary infection.
  • Memory B cells are a B cell sub-type that are formed following a primary infection .
  • The rest persist as the memory cells that can survive for years, or even a lifetime.
  • The fact that all the cells of a single clone elaborate one (and only one) paratope, and that the memory cells survive for long periods, is what imparts a memory to the immune response.
  • They form memory cells that remember the same pathogen for faster antibody production in future infections.

• Classes of T Cells

  • T cells play a central role in cell-mediated immune response through the use of the surface T cell receptor to recognize peptide antigens.
  • This activation results in the expansion of the antigen-specific lymphocyte pool and the differentiation of these cells into effector and memory cells.
  • Effector cells include helper T cells, and cytolytic or cytotoxic T cells.
  • Memory T cells are an expanded population of T cells specific for antigens that can respond rapidly to subsequent encounter with that antigen and differentiate into effector cell to eliminate the antigen.
  • Distinguish between: naive, effector (helper and cytotoxic), memory and regulatory T cells

• Serology

  • A primary immune response occurs when a B cell sees an antigen for the first time.
  • Antigen binding to the surface of the B cell stimulates the production of antibodies that are capable of binding directly to the antigen.
  • Meanwhile, the B cells are producing highly specific Immunoglobulin G (IgG) more slowly.
  • When B and T cells begin to replicate, some of the offspring that they produce will end up becoming long-lived memory cells.
  • These memory cells will remember all specific pathogens encountered during the animal's lifetime and can thus call forth a strong response if the pathogen ever invades the body again.

• Development of the Dual Lymphocyte System

  • B cells and T cells are the major types of lymphocytes.
  • Mammalian stem cells differentiate into several kinds of blood cell within the bone marrow.
  • B and T cells) differentiate further after exposure to an antigen; they form effector and memory lymphocytes.
  • Memory cells remain in the peripheral tissues and circulation for an extended time ready to respond to the same antigen upon future exposure.
  • Mammalian stem cells differentiate into several kinds of blood cell within the bone marrow.

• Clonal Selection of Antibody-Producing Cells

  • B cells exist as clones.
  • Such clonality has important consequences, as immunogenic memory relies on it .
  • Upon encountering its specific antigen, a single B cell, or a clone of cells with shared specificity, divides to produce many B cells.
  • A small minority survives as memory cells that can recognize only the same epitope.
  • However, with each cycle, the number of surviving memory cells increases.

• Primary and Secondary Antibody Responses

  • Adaptive (or acquired) immunity creates immunological memory after an initial response to a specific pathogen, leading to an enhanced response to subsequent encounters with that same pathogen.
  • When B cells and T cells are first activated by a pathogen, memory B-cells and T- cells develop.
  • Throughout the lifetime of an animal these memory cells will "remember" each specific pathogen encountered, and are able to mount a strong response if the pathogen is detected again.
  • Following clearance of the infection, antibody level and effector T cell activity gradually declines.
  • Because immunological memory has developed, reinfection at later times leads to a rapid increase in antibody production and effector T cell activity.

• Immunization, Antiseptics, and Antibiotics

  • It will also develop the ability to respond quickly to subsequent encounters with the same substance, a phenomenon known as immunological memory.
  • The most important elements of the immune system that are improved by immunization are the T cells, the B cells, and the antibodies B cells produce.
  • Memory B cells and memory T cells are responsible for the swift response to a second encounter with a foreign molecule.
  • This method of immunization starts to work very quickly; however, it is short-lasting because the antibodies are naturally broken down and will disappear altogether if there are no B cells to produce more of them.
  • Thus, humanized antibodies produced in vitro by cell culture are used instead if available.

• Antibody Proteins and Antigen Binding

  • An antibody (Ab), also known as an immunoglobulin (Ig), is a large Y-shaped protein produced by B-cells that is used by the immune system to identify and neutralize foreign objects, such as bacteria and viruses.
  • Using this binding mechanism, an antibody can tag a microbe, or an infected cell, for attack by other parts of the immune system, or can neutralize its target directly; for example, by blocking a part of a microbe that is essential for its invasion and survival.
  • Antibodies can occur in two physical forms, a soluble form that is secreted from the cell, 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).
  • The BCR is only found on the surface of B cells and facilitates the activation of these cells and their subsequent differentiation into either antibody factories called plasma cells, or memory B cells that will survive in the body and remember that same antigen so the B cells can respond faster upon future exposure.
  • In most cases, interaction of the B cell with a T helper cell is necessary to produce full activation of the B cell and, therefore, antibody generation following antigen binding.

• Natural Killer Cells

  • Natural killer cells (or NK cells) are a type of cytotoxic lymphocyte critical to the innate immune system.
  • Natural killer cells (or NK cells) are a type of cytotoxic lymphocyte critical to the innate immune system.
  • Often NKT cell activity promotes NK cell activity by secreting IFNγ.
  • Numerous experiments have demonstrated their ability to adjust to the immediate environment and formulate antigen-specific immunological memory, which is fundamental for responding to secondary infections with the same antigen.
  • Functions of NK cells include: Cytolytic Granule Mediated Cell Apoptosis; Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC); Cytokine induced NK and CTL activation; Missing 'self' hypothesis; Tumor cell surveillance; NK cell function in adaptive response; NK cell function in pregnancy; and NK cell evasion by tumor cells .

• Overview of the Immune System

  • Adaptive (acquired) immunity creates immunological memory after an initial response to a specific pathogen, leading to an enhanced response to subsequent encounters with that same pathogen.
  • Similarly, cell-mediated immunity is active when the organism's own T cells are stimulated and passive when T cells come from another organism.
  • The cell starts rounding up and loses its spikes.
  • As the macrophage cell becomes smooth.
  • Because immunological memory has developed, reinfection at later times leads to a rapid increase in antibody production and effector T cell activity.