immune cells

Examples of immune cells in the following topics:

• 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.
  • Cellular immunity is mediated by T lymphocytes, also called T cells.
  • This type of immunity promotes the destruction of microbes residing in phagocytes, or the killing of infected cells to eliminate reservoirs of infection.
  • Another class of T cells called regulatory T cells function to inhibit immune response and resolve inflammation.
  • Their major role is to shut down T cell-mediated immunity toward the end of an immune reaction.

• Immunotherapy for Cancer

  • The main idea is stimulating the patient's immune system to attack the malignant tumor cells that are responsible for the disease.
  • This involves immune cells such as the natural killer cells (NK cells), lymphokine-activated killer cells (LAK cells), cytotoxic T lymphocytes (CTLs), and dendritic cells (DC).
  • Adoptive cell-based immunotherapy involves isolating either allogenic or autologous immune cells, enriching them outside the body, and transfusing them back to the patient.
  • The injected immune cells are highly cytotoxic to the cancer cells and so help to fight them.
  • Topical immunotherapy utilizes an immune enhancement cream (imiquimod), which is an interferon producer, causing the patient's own killer T cells to destroy warts, actinic keratoses, basal cell carcinoma, squamous cell carcinoma, cutaneous T cell lymphoma, and superficial spreading melanoma.

• Dendritic Cells

  • Dendritic cells are immune cells that function to process antigens and present them to T cells.
  • Mature dendritic cells reside in the T cell zones of the lymph nodes, and in this location they display antigens to T cells.
  • Dendritic cells are constantly in communication with other cells in the body.
  • This communication can take the form of direct cell-to-cell contact based on the interaction of cell-surface proteins.
  • The ultimate consequence is priming and activation of the immune system for attack against the antigens which the dendritic cell presents on its surface.

• Type IV (Delayed Cell-Mediated) Reactions

  • Cell-mediated immunity is an immune response that does not involve antibodies, but rather involves the activation of phagocytes, natural killer cells (NK), antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
  • Historically, the immune system was separated into two branches: humoral immunity, for which the protective function of immunization could be found in the humor (cell-free bodily fluid or serum) and cellular immunity, for which the protective function of immunization was associated with cells.
  • Therefore in cell mediated immunity cytokines are not always present.
  • 3. stimulating cells to secrete a variety of cytokines that influence the function of other cells involved in adaptive immune responses and innate immune responses
  • Cell-mediated immunity is directed primarily at microbes that survive in phagocytes and microbes that infect non-phagocytic cells.

• Cells and Organs of the Immune System

  • The immune system includes primary lymphoid organs, secondary lymphatic tissues and various cells in the innate and adaptive immune systems.
  • Lymph nodes are garrisons of B, T and other immune cells.
  • Langerhans cells in the skin are part of the adaptive immune system.
  • These cells serve as a link between the bodily tissues and the innate and adaptive immune systems, as they present antigen to T-cells, one of the key cell types of the adaptive immune system.
  • Recognize the cells and organs of the immune system and their functions

• Adaptive Immunity and the Immunoglobulin Superfamily

  • There are two types of adaptive immune responses: humoral immunity and cell-mediated immunity.
  • The interaction of antigens with membrane antibodies on naive B cells initiates B cell activation .
  • Members of the IgSF include cell surface antigen receptors, co-receptors, and co-stimulatory molecules of the immune system, molecules involved in antigen presentation to lymphocytes, cell adhesion molecules, certain cytokine receptors, and intracellular muscle proteins.
  • When a B cell encounters its triggering antigen, it gives rise to many large cells known as plasma cells.
  • Describe the role of immunoglobulins in the adaptive immune response, specifically in humoral immunity

• Regulatory T Cells

  • Regulatory T cells are a subset of T cells which modulate the immune system and keep immune reactions in check.
  • Regulatory T cells are a component of the immune system that suppress immune responses of other cells.
  • This is an important "self-check" built into the immune system to prevent excessive reactions and chronic inflammation.
  • These cells are involved in shutting down immune responses after they have successfully eliminated invading organisms, and also in preventing autoimmunity.
  • The contribution of these populations to self-tolerance and immune homeostasis is less well defined.

• Overview of the Immune System

  • Passive immunity is acquired through transfer of antibodies or activated T cells from an immune host, and is short lived—usually lasting only a few months.
  • A further subdivision of adaptive immunity is characterized by the cells involved; humoral immunity is the aspect of immunity that is mediated by secreted antibodies, whereas the protection provided by cell-mediated immunity involves T lymphocytes alone.
  • 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.

• Natural Active Immunity

  • Naturally acquired active immunity occurs when a person is exposed to a live pathogen, develops the disease, and then develops 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.
  • Naturally acquired active immunity occurs when the person is exposed to a live pathogen, develops the disease, and becomes immune as a result of the primary immune response.
  • B-cells in the body produce antibodies that help to fight against the invading microbes.
  • The principle behind immunization is to introduce an antigen, derived from a disease-causing organism, that stimulates the immune system to develop protective immunity against that organism, but which does not itself cause the pathogenic effects of that organism.

• Primary and Secondary Antibody Responses

  • The immune system protects organisms from infection first with the innate immune system, then with adaptive immunity.
  • When B cells and T cells are first activated by a pathogen, memory B-cells and T- cells develop.
  • Active immunity often involves both the cell-mediated and humoral aspects of immunity as well as input from the innate immune system .
  • 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.