Intro to immunology

• What is immunity?

  Protection from disease, not all immune responses protect from disease -allergens.

  consist Of cells, molecules, proteins and soluble Factors
• Why do not all immune responses protect from disease?

  Some responses target allergens instead
• What are the components of immunity?


  Cells, molecules, proteins, soluble factors
• What are the routes of transmission for pathogens?

  Aerosol, cuts, ingestion, placenta
• What are markers of non-self cells?


  Distinctive markers on foreign molecules
• What is an antigen?


  Any substance triggering an immune response

  • bacterium
  • virus
  • or portion of product - toxin of one of these organisms
• Why are tissues from another individual considered antigens?

  They have different markers and are rejected
• What is self-tolerance?


  Body's defenses do not attack self markers - each body cell carries distinctive markers that distinguish it as self- varieS between people
• What can cause autoimmune diseases?

  Destruction of self tissue by immune response
• What is the first part of the innate immune system?


  The skin also consists of sweat glands
• What role do sweat glands play in immunity?


  They have antibacterial properties
• What is the function of tears in immunity?


  Contain antibacterial and antiviral properties
• What is the role of phagocytic cells?


  To ingestion and destruction of microorganisms and pathogens by individual cells such as - macrophages, neutrophils and dendritic cells.

  Microorganisms releases substances or during. Inflammation that attract phagcytic cells - allow opsonisation
• What do pattern recognition receptors (PRRs) do?


  Detect microbial components that are foreign

  • pathogen associated molecular patterns (PAMPs)
  • mannose (bacterial carbohydrates)
  • liposaccharide (lipids)
  • peptidoglycans
• What are pathogen-associated molecular patterns (PAMPs)?


  Microbial components recognized by PRRs
• What is complement in the immune system?


  A proenzyme activated into an enzyme once they see an organism they will start this process
• How does complement help in immunity?


  Clears pathogens and destroys cell membranes, the compliment cascade punches holes in the cell membranes of pathogens and hence destroys them
• What is inflammation?


  Body's reaction to injury or infection
• What happens during inflammation?


  Increased blood supply and capillary permeability - allows soluble mediators to influx leucocytes - neutrophils
• What is the role of lymphocytes in adaptive immunity?

  Recognize foreign agents and acquire memory
• What is specific memory in adaptive immunity?

  Life-long protection against the same antigen
• What is the primary response in adaptive immunity?


  First challenge with a specific antigen
• What occurs during the secondary response?


  More rapid and powerful response to antigen
• What are the components of the innate immune system?


  • Physical barriers: Skin, mucous
  • Physiological factors: pH, temperature, gut flora
  • Protein secretions: Complement, interferons
  • Phagocytic cells: Macrophages, leukocytes
• What is the role of macrophages in the immune system?


  • Eat up debris
  • Recognize bacteria through receptors
  • Part of early immune response
• What is the difference between innate and adaptive immunity?


  • Innate immunity: Immediate, non-specific response
  • Adaptive immunity: Specific response, memory formation
• What are the key features of the adaptive immune system?

  • Adapts to specific antigens
  • Acquires memory for long-term protection
  • Involves lymphocytes (B cells and T cells)
• What is phagocytosis?

  • Process of engulfing and digesting pathogens
  • Key function of phagocytic cells
• What is the adaptive immune system made up of?

  Antibodies

  white blood cells

  T cells

  B cells

  Both provide immunological memory
• What do antibodies have at their two ends?


  One interacts with antigens- the variable region , the other with immunoglobulin receptors on a variety of immune cells - constant region
• What is the role of macrophages in the immune system?

  They ingest and destroy microorganisms
• How do microorganisms attract phagocytes?

  By releasing substances that cause inflammation
• What is the process called when cells ingest and destroy microorganisms?

  Phagocytosis
• What do cytokines do in the immune response?

  They activate and recruit immune cells
• What is neutralization in the context of antibodies?

  Blocking the biological activity of target molecules
• What is opsonization?

  Antibodies mark pathogens for phagocytosis
• What does the complement system do?

  Causes direct lysis of cells
• How do macrophages alert other white blood cells?

  By undergoing phagocytosis
• What are the two major ways T cells contribute to immune defense?

  By helping and killing infected cells
• What type of T cells help activate the immune system?


  Helper T cells (CD4)