quiz monday, immune system

• Immune system


  A complex network of different cellular actions and signals, allowing an organism to defend itself against a pathogen
• Immune system


  • It is based on an exchange of input and output
  • It recognizes and protects the organism against pathogens, whereby foreign structures and molecules get recognized and an appropriate immune response is produced
• Immune system dysfunction


  Condition arising from an abnormal immune response to a functioning body part
• Immunodeficiency


  When the immune system is less active than normal, resulting in recurring and life-threatening infections
• Immunology


  A branch of biology that covers the study of immune systems in all organisms
• Types of immunity

  • Innate immunity
  • Acquired immunity

  
• Innate immunity


  The resistance to infections which an individual possesses by virtue of his genetic and constitutional make up. It is not affected by prior contact with microorganisms or immunization

  
• Acquired immunity


  The immunity that develops during lifetime

  
• Types of acquired immunity


  • Active immunity
  • Passive immunity

  
• Active immunity


  Develops in response to an infection or vaccination
• Passive immunity


  Develops after an individual receive antibodies from someone or somewhere else
• Types of acquired immunity responses


  • Humoral immunity or B cell immunity
  • Cell mediated immunity or T cell immunity

  
• Humoral immunity


  The humoral immune system defends mostly against bacteria and viruses that enter the body fluids. It is antibody mediated
• Cell mediated immunity


  The cell mediated immune system is carried out by highly specialized cells, which work against pathogens, including fungi and protista that have invaded host cells. It also reacts against transplants and is thought to be important in protecting the body from its own cells if they become cancerous
• Plant immune system


  Plants are protected from infection by a "skin", a waxy cuticular layer atop the cell wall. Would-be pathogens breaching this barrier encounter an active plant immune system that specifically recognizes pathogen and altered-self molecules generated during infection
• Proteins & factors involved in plant-pathogen interaction pathway

  • PRR (Pattern Recognition Receptor)
  • PAMP/MAMP (Pathogen Associated Molecular Pattern or Microbe Associated Molecular Pattern)
  • R-Gene (Resistance protein)
  • NB-LRR (Nucleotide Binding Leucine-Rich Repeat)
• Types of plant immune responses

  • PAMP-Triggered Immunity (PTI)
  • Effector-Triggered Immunity (ETI)

  
• PAMP-Triggered Immunity (PTI)


  Plants recognize Pathogen-Associated Molecular Patterns (PAMPs) present in pathogens, which activate a general defense response

  
• Effector-Triggered Immunity (ETI)


  Plants also possess receptors that can detect specific pathogen effectors, leading to a more targeted and robust defense response
• Mechanisms of plant defense

  • Physical Barriers
  • Chemical Defenses
  • Systemic Acquired Resistance (SAR)
• Examples of plant immune responses

  • Hypersensitive Response (HR)
  • Phytoalexins Production
• Hypersensitive Response (HR)


  This rapid and localized cell death at the site of infection helps restrict the spread of pathogens
• Phytoalexins


  Secondary metabolites synthesized in response to pathogen attack and have antimicrobial properties
• Plants face evolutionary pressure from pathogens, leading to an ongoing arms race. Additionally, environmental stresses like drought, temperature extremes, and nutrient deficiencies can compromise plant immunity
• Common immune system diseases in plants

  • Blight
  • Leaf spot
• Blight


  Any of various plant diseases whose symptoms include sudden and severe yellowing, browning, spotting, withering, or dying of leaves, flowers, fruit, stems, or the entire plant. Most blights are caused by bacterial or fungal infestations, which usually attack the shoots and other young, rapidly growing tissues of a plant

  
• Leaf spot


  A limited, discolored, diseased area of a leaf that is caused by fungal, bacterial or viral plant diseases, or by injuries from nematodes, insects, environmental factors, toxicity or herbicides. These discolored spots or lesions often have a center of necrosis (cell death)

  
• Lines of defense in animal immune system


  • First Line Defense
  • Second Line Defense
  • Third Line Defense
• First Line Defense


  The innate immune system, consisting of physical barriers like skin and mucosal lining, and quick responses like tears, sweat, saliva and mucous that can eliminate some pathogens before they reach tissue or blood
• Second Line Defense


  The innate immune system consisting of cells and proteins that attack invaders in a non-specific way, including phagocytosis
• Third Line Defense


  The adaptive immune response involving specialized white blood cells like B cells and T cells
• Types of T cells

  • Memory T cells
  • Cytotoxic ("cell-killing") T cells
  • T helper cells
  • T regulatory cells
• Immunological memory


  The primary immune response is mounted upon first encountering a pathogen, while subsequent exposures trigger a faster and stronger secondary response due to the presence of memory cells
• Vaccination


  Stimulates the immune system to generate memory cells, providing long-term protection against specific pathogens
• Autoimmune diseases


  Conditions where the immune system mistakenly attacks the body's own tissues
• Immunodeficiency disorders


  Conditions where the immune system is compromised, leading to increased susceptibility to infections
• Immune system diseases in animals

  • Avian influenza (bird flu)
  • Classical Swine Fever
• Avian influenza (bird flu)


  A disease of birds caused by infection with avian influenza A viruses. Infected birds shed bird flu virus in their saliva, mucous, and feces
• Classical Swine Fever


  A highly contagious viral disease of pigs. In its acute form the disease generally results in high mortality. It is a different disease to swine flu and does not affect people or have any impact on human health
• Similarities between plant and animal immune systems

  • Innate immunity
  • Chemical warfare