Theme 1 (W 1-2)

• What types of cells are involved in immunity?

  All white blood cells and some others
• From where are immune cells derived?

  From self-renewing stem cells in bone marrow
• What do stem cells differentiate into under growth factors?

  Pluripotent stem cells and then progenitor cells
• What are the two lineages for leukocytes?

  Myeloid and lymphoid
• How do leukocytes contribute to immunity?

  They contribute to innate and adaptive immune responses
• What markers identify T cells?

  CD3
• What markers identify B cells?

  CD19 and CD20
• What is the significance of the CD system established in 1982?

  It provides a strict nomenclature for cell identification
• What do myeloid progenitor cells give rise to?

  Polymorphonuclear cells, monocytes, and more
• What are polymorphs also known as?

  Granulocytes
• What percentage of white blood cells are polymorphs?

  60-70%
• What do monocytes become in tissues?

  Macrophages
• How long do neutrophils typically live?

  ~2-3 days
• What is the primary function of neutrophils?

  To kill bacteria through phagocytosis
• What do eosinophils primarily target?

  Parasites, especially helminths
• What color do eosinophil granules stain?

  Bright red with eosin

  
• What role do basophils play in the immune system?

  They promote inflammation and are important in allergies
• What is the function of mast cells?

  Release mediators important in allergy
• How do monocytes and macrophages recognize foreign material?

  Using a variety of surface receptors
• What are the two major sub-groups of macrophages?

  M1 and M2
• What are Kupffer cells?

  Macrophages located in the liver
• What are dendritic cells known for?

  Presenting antigens to T cells
• What do immature dendritic cells do?

  Capture antigens and migrate to lymphoid tissues
• What do megakaryocytes give rise to?

  Platelets
• What is the role of platelets?

  Play important roles in blood coagulation
• What percentage of peripheral blood white cells are lymphocytes?

  20-30%
• What happens to lymphocytes upon stimulation by antigen?

  They become effector or memory cells
• What do B cells express as part of their receptor?

  Membrane-bound immunoglobulin (mIg)
• What do activated B cells differentiate into?

  Plasma cells or memory cells
• What is the role of T lymphocytes?

  To recognize and bind to foreign material
• What is the structure of the T cell receptor (TCR)?

  Formed of an α and a β chain
• What are the two main sub-groups of T cells?

  Helper T cells and cytotoxic T cells
• What do helper T cells express?

  CD4 and CD3
• What is the function of cytotoxic T cells?

  To kill infected targets

  
• What do regulatory T cells primarily express?

  CD4+ and some CD8+
• What is the role of γ/δ T cells?

  Recognize lipid antigens in mucosal tissues
• What percentage of white blood cells are innate lymphoid cells?

  4%

  
• What is the role of Natural Killer (NK) cells?

  Kill tumor and virally infected cells

  
• How do Natural Killer T cells (NKT) function?

  Kill target cells like cytotoxic T cells
• What receptors do Natural Killer cells use?

  Surface receptors for self and non-self