42.1 Innate Immune Response

42.1 Innate Immune Response

  • The immune system has both innate and adaptive responses.
    • The immune response is innate and adaptive.
  • Early in animal evolution, the innate immune system developed as an essential response to infections.
    • Innate immunity has a limited number of specific targets that can be identified by a consistent sequence of events.
    • Microbicidal factors can be found in tears and mucus.
  • The skin is an impermeable barrier to potentially infectious pathogens before immune factors are triggered.
    • Pathogens can be killed on the skin by desiccation and by the skin's acidity.
    • In addition, beneficial microorganisms that coexist on the skin compete with invading pathogens.
    • The eyes, nose, and respiratory tract are regions of the body that are not protected by skin and have alternative methods of defense.
    • The low pH of the stomach is one of the body's other defenses.
  • The body can be entered by pathogens through punctures or skin abrasions, or by collecting in large numbers on mucosal surfaces.
    • Some pathogens can overcome physical and chemical barriers.
    • When a pathogen enters the body, the innate immune system responds with inflammation.
  • Depending on the pathogen, an infection can be either intracellular or extracellular.
    • All viruses replicate within cells, whereasbacteria and other parasites do not.
    • The innate immune system must respond by identifying the host cells that have already been attacked.
    • PAMPs are different from what is found on host cells in that they are expressed by viruses,bacteria, and parasites.
    • PRRs aremolecules on cells that are in contact with the outside environment.
    • Dendritic cells promote the destruction of pathogens.
    • A type of PRR that recognizes molecules that are shared by pathogens but distinguishable from host molecule is called Toll-like receptors.
  • The nervous system of the mammal has been identified as having Tollygunges.
  • The innate immune system's characteristics and location are described.
  • The cells of the blood include monocytes, lymphocytes, neutrophils, red blood cells, and platelets.
    • The morphologies of the leukocytes are very similar.
  • The binding of PRRs with PAMPs causes the release of cytokines, which signals that a pathogen is present and needs to be destroyed.
    • There are at least 40 different types of cytokines in humans that are different in terms of the cell type that produces them, the cell type that responds to them, and the changes they produce.
  • TheIL is one of the subclasses of cytokines and it is named because of the interactions between white blood cells.
    • Interleukins help bridge the innate and adaptive immune responses.
    • In addition to being released from cells after PAMP recognition, cytokines are released by the cells which bind to nearby cells and induce them to release cytokines, which results in a cytokine burst.
  • Interferons are a second class of early-acting cytokines and are released by cells that have been bitten.
    • They have other important functions.
    • Interferons work by signaling neighboring cells to destroy and kill each other, as well as signaling neighboring cells to die.
  • Uninfected cells alter their genes to increase their resistance to infections.
    • There is a reduction in the production of cellular proteins.
    • The cells that produce the viruses are infectious.
    • A cell becomes resistant to viral infections if it is reduced in size.
  • Interferons are released by a cell if it has a virus.
    • The response of neighboring cells helps stem the infections.
  • Depending on the nature of the infecting pathogen, the population of leukocytes that arrives at an infection site depends.
    • Neutrophils have a nucleus with two to five lobes, and they contain lysosomes that digest pathogens.
  • Neutrophils and eosinophils are important for the defense of large pathogens.
  • Specific types of inflammatory responses are caused by basophils.
  • Additional inflammatory mediators are produced by eosinophils and basophils.
    • The release of histamine by basophils and mast cells is what causes a hypersensitive immune response.
  • Mast cells cause nearby capillaries to dilate when they respond to a cut.
    • Neutrophils and monocytes leave the capillaries.
    • Monocytes mature into macrophages.
    • The inflammatory response is stimulated by Neutrophils, dendritic cells, and macrophages.
    • Neutrophils and macrophages consume invadingbacteria.
  • The symptoms encourage the individual to rest and prevent the spread of the infection to others.
    • The core body temperature can be increased by cytokines, which can cause a fever and iron deficiency in the body.
    • Some pathogens can't replicate without iron, which is called nutrition immunity.
  • There is a stop- motion video that shows a neutrophil that searches for and kills fungus during an elapsed time of about 81 minutes.
  • T cells and B cells are part of the adaptive immune system.
    • Red blood cells and non-nucleated platelets are not covered by MHC I molecule because they are nucleated.
    • The function of MHC I molecule is to display fragments of proteins from the infectious agents within the cell to T cells, while healthy cells will be ignored.
  • The majority of II molecule are found on cells with non-self proteins.
  • Lymphocytes are characterized by their large nuclei that actively absorb Wright stain and therefore appear dark colored under a microscope.
  • An infectious cell is usually incapable of displaying MHC I molecule appropriately.
    • The MHC I processing and/or trafficking of the cell surface can be interfered with by the metabolic resources of the cells.
    • The reduced MHC I on host cells varies from virus to virus.
    • The process depletes host MHC I molecule on the cell surface, which can cause the cells to be abnormal.
  • The killing sequence on a healthy cell is disabled by an interaction with normal, intact MHC I molecule.
    • The perforin is released in the immunological synapse.
    • phagocytic cells 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- 888-609- Control of potential infections and preventing cancer progression can be achieved with the help of NK cells.
  • The cells of the immune system are capable of responding immediately to infections and are abundant in the blood.
    • The complement system is related to the adaptive immune system.
    • Complement proteins are attracted to pathogens that have already been bound by an immune system.
    • In a highly regulated sequence, each successiveProtein is activated by the precedingProtein and Structural changes are caused by the binding of the precedingProtein.
    • A cascade of binding events begins after the first few complement proteins bind.
  • There are several functions performed by complement proteins.
    • Attack complexes can be formed by certain complement proteins.